workshop program - ritridl.cfd.rit.edu/products/glcw12_program.pdf · 5. intensity mapping, which...

Workshop Program

Rochester, New York ⦁ August 6 - 8, 2019

12th Great Lakes Cosmology Workshop Large Scale Structure from Surveys

Table of Contents

General workshop information 2......................................................

Workshop scheduleDaily schedule includes presentation titles and abstracts

Day 1 4 ........................................................................................

Day 2 11 .....................................................................................

Day 3 17 .....................................................................................

Poster 23....................................................................................

Things to do in Rochester 26...............................................................

Attendee directory 28..............................................................................

Support provided by:

& RIT Astrophysical Sciences and Technology Graduate Program

Cover photo credit: Illustris Collaboration Side photo credit: ESA/Planck Collaboration

WORKSHOP INFORMATION

ABOUT THE WORKSHOPOur program will run roughly from 9am to 5pm each of the three days. We will have provision for contributed talk and poster presentations, and will include a variety of invited speakers. The GLCW12 meeting is organized around six major subtopics in modern cosmology, including:1. Studies of the cosmic microwave background (CMB), whose polarization and small scale

structure are still yielding insights central to the field;2. Cosmology as traced by the large scale structure of galaxies and matter, which over the next

two decades are likely to yield the tightest constraints on the origins and evolution of the universe possible;

3. Galaxy structure and formation, which are crucial components of our physical models of the universe;

4. Advances in theory pointing the way to the new, paradigm-shattering physics of the future;5. Intensity mapping, which when coupled with an understanding of the physics of galaxies will

allow us to map out the history of matter in the universe; and6. Direct probes of dark matter and particle astrophysics, which offer some of the clearest paths to

physics beyond the standard model.Our program of invited and contributed speakers will center on these topics, their interactions, and future collaborations that could result from new data, new techniques, and cross-pollination between these topics.

Scientific Organizing Committee Michael Zemcov (Chair, Rochester Institute of Technology) Segev BenZvi (University of Rochester) Renee Hlozek (University of Toronto) Jeyhan Kartaltepe (Rochester Institute of Technology) Anthony Pullen (New York University) Erik Shirokoff (University of Chicago)

Local Organizing Committee Robyn Rosechandler (Rochester Institute of Technology) Chi Nguyen (Rochester Institute of Technology) Satya Gontcho A Gontcho (University of Rochester) Kelly Douglass (University of Rochester) Ektaben Shah (Rochester Institute of Technology)

LOCATION Unless otherwise noted, all conference events, including registration, will be held on the campus of the Rochester Institute of Technology. The workshop sessions will be held in Louise Slaughter Hall rooms 2210-2240, with convenient parking in T lot. Please see our interactive campus map at https://maps.rit.edu.

TRAVEL ARRANGEMENTS Note: Please make your own travel and lodging arrangements. Our conference committee WILL NOT contact you to arrange or change accommodations or other travel details. Please contact us at [email protected] if you have any questions we can assist you with.

Airport The nearest airport is the Rochester International Airport (ROC): https://www2.monroecounty.gov/airport-information.php

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https://maps.rit.edu

https://maps.rit.edu

mailto:[email protected]

https://www2.monroecounty.gov/airport-information.php

WORKSHOP INFORMATION

Hotel/Accommodations There are many hotels near RIT’s campus. There is no “conference rate” or blocks of rooms as availability is generally good and prices are always competitive in Rochester. A helpful guide to hotels near RIT can be found at: https://www.rit.edu/emcs/admissions/visit/info/area-hotels.We have created a GLCW Room Share Google sheet for those who are interested in room share. The spreadsheet does require requesting access, which is given within 24hrs:https://docs.google.com/spreadsheets/d/1MWsJQf30_kOyTeunfm4FXu6teO1czhGdwu_MedLZN2M/edit?usp=sharing

GETTING AROUND ROCHESTER Cabs, Lyft, and Uber are available in Rochester. The workshop will provide shuttles for the off campus events on Aug 6 and 7. See daily schedule for shuttle pickup and return time.

FOOD The workshop will provide a small breakfast, coffee break, and lunches during each day of the workshop. The Conference dinner will be on Aug 7.

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https://www.rit.edu/emcs/admissions/visit/info/area-hotels

https://docs.google.com/spreadsheets/d/1MWsJQf30_kOyTeunfm4FXu6teO1czhGdwu_MedLZN2M/edit?usp=sharing

https://docs.google.com/spreadsheets/d/1MWsJQf30_kOyTeunfm4FXu6teO1czhGdwu_MedLZN2M/edit?usp=sharing

Day 1 August 6, 2019Time Event

8:00 am Continental Breakfast, Registration, and Poster Setup

8:45 am Welcome and Introduction

MORNING SESSION I 9:00 am - 10:30 am

9:00 am Latest News from the Dragonfly Telephoto Array Invited Talk Roberto Abraham University of Toronto The Dragonfly Telephoto Array is a novel telescope designed to image large and extremely faint structures in the nearby Universe. In this talk, I'll sketch out how Dragonfly works and describe some of its scientific highlights. We are now upgrading Dragonfly to allow it to undertake measurements of ridiculously low surface brightness line emission. I’ll describe our progress in getting this done, and outline a plan to use Dragonfly to explore the circumgalactic medium and the disk-halo interface of nearby galaxies.

9:30 am Cosmic Expansion From Spinning Black Holes Chi Tian Case Western Reserve University

We examine how cosmological expansion arises in a universe containing a lattice of spinning black holes. We study averaged expansion properties as a function of fundamental properties of the black holes, including the bare mass of the black holes and black hole spin. We then explore how closely the expansion properties correspond to properties of a corresponding matter-dominated FLRW universe. As residual radiation present in the initial data decays, we find good agreement with a matter-dominated FLRW solution, and the effective density in the volume is well-described by the horizon mass of the black hole.

9:45 am Comparing Systematic-Error Mitigation Methods for Galaxy Clustering Noah Weaverdyck University of Michigan

The increasing size and precision of large scale structure surveys demand unprecedented control of systematic errors to avoid biasing cosmological results. Several methods have been employed to account for systematic effects in galaxy clustering data, such as those caused by variable observing conditions, but these have often been developed in an ad hoc manner. We compare several of these methods on simulated data and find that the choice of method can significantly impact the estimated density map, angular power spectrum and cosmological constraints. Understanding the the properties of these methods will be important for obtaining unbiased constraints from future large scale structure surveys.

10:00 am The Influence of the Void Environment on the Ratio of Dark Matter Halo Mass to Stellar Mass in SDSS MaNGA Galaxies

Kelly Douglass University of RochesterWe study how the void environment affects the formation and evolution of galaxies in the universe by comparing the ratio of dark matter halo mass to stellar mass of galaxies in voids with galaxies in denser regions. Using spectroscopic observations from the SDSS MaNGA DR15, we estimate the dark matter halo mass of 641 void galaxies and 937 galaxies in denser regions. We use the velocity from the H-alpha emission line to measure the rotation curve of the galaxies, since the kinematics of the interstellar medium is smoother than the stellar kinematics. We observe no difference in the distribution of the ratio of dark matter halo mass to stellar mass between void galaxies and galaxies in denser regions. We also find that the stellar-halo-mass relation is not affected by the void environment.

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10:15 am The Local Perspective on the Hubble Tension: Local Structure Does Not Impact Measurement of the Hubble Constant

William Kenworthy Johns Hopkins UniversityUsing the largest sample of spectroscopically confirmed SNe Ia to date, we show that the Hubble tension cannot be resolved by a local inhomogeneity. We derive a 5σ constraint on local density contrasts on scales larger than 69 Mpc/h of |δ| < 27%. The presence of local structure does not appear to impede the possibility of measuring the Hubble constant to 1% precision.

10:30 am Break

MORNING SESSION II 11:00 am - 12:30 pm

11:00 am Updates from the Hydrogen Epoch of Reionization Array Invited Talk Adrian Liu McGill University

Despite tremendous recent progress, gaps remain in our knowledge of our cosmic history. For example, we have yet to make direct observations of Cosmic Dawn or the subsequent Epoch of Reionization. Together, these represent the important period when the first stars and galaxies were formed, dramatically altering their surroundings in the process. Radio telescopes targeting the 21cm line will open up these crucial epochs to direct observations in the next few years, filling in a missing chapter in our cosmic story. I will provide updates from the recently commenced Hydrogen Epoch of Reionization Array (HERA), a 350-element low-frequency radio interferometer in the South African desert targeting 6 < z < 25.

11:30 am A New Approach To Eliminate Thermal Sunyaev-zel'dovich Effect (SZ) Induced Systematic Uncertainty and Reduce SZ-Related Statistical Uncertainty Sanjaykumar Patil University of MelbourneGalaxy clusters being the most massive objects in the Universe provide crucial insight into the standard model of Cosmology. Cluster abundance as a function of mass and redshift provide critical information about histories of structure formation and expansion rate of the Universe. Upcoming surveys such as LSST, eROSITA, CMB-S4 etc., will provide us with hundreds of thousands of clusters and to fully utilize their potential in constraining cosmology we need to have robust cluster mass estimates.One of the promising ways to get a robust cluster mass is through cosmic microwave background (CMB) lensing, especially for clusters at high redshift. CMB-cluster lensing has the potential to achieve 1% mass calibration for future surveys. However, reaching this goal will require handling the systematic and statistical uncertainties due to the thermal Sunyaev-Zel'dovich (SZ) effect. In this talk, I will present new techniques that we have developed to eliminate the SZ systematic biases and to reduce the SZ-related statistical uncertainties.

11:45 am Constraining Fuzzy Dark Matter with Redshift Space Distortions & Galaxy Surveys

Alex Lague University of TorontoFuzzy dark matter (FDM) is a well-motivated dark matter candidate which has been proposed as a solution to the small scale problems of the LCDM. Many cosmological observables have been used to constrain such models and we aim to determine the required measurement precision needed for galaxies surveys to improve existing bounds. We consider models of mixed dark matter composed in whole or in part of FDM particles with mass varying between -23 < log(m/eV) < -22, and create mock observations by simulating the corresponding large scale structure. We find that upcoming experiments such as Euclid or DESI could potentially

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detect even small fractions of FDM while a factor of four improvement on the redshift measurements of these surveys could distinguish our largest particle mass FDM from CDM. In the process, we also derive an analytical expression linking a given survey accuracy with the particle properties it can (conservatively) probe. Finally, we consider the dynamical information given by redshift space distortions to study the velocity dispersion of satellite galaxies and their host halo's underlying dark matter distribution.

12:00 pm Small Scale CMB Lensing with Local Map-Space Statistics Victor Chan University of TorontoThe traditional quadratic estimators for gravitational lensing signatures in the cosmic microwave background become sub-optimal at very small scales (l > 3000) because the estimator is assumed to be ignorant of the background temperature gradient of the CMB. In reality, this temperature gradient is observed, and can be measured to a high degree of accuracy. I will outline the development and characterization of a map-based estimator for the lensing potential power at very small scales (l > 3000). The shape of the lensing potential power spectrum offers insight into the matter content, as well as the structure formation history of the Universe. I will also discuss the application of the estimator's principles for picking out kinetic Sunyaev-Zel'dovich signatures in the small scale CMB, which will further our understanding of large scale structure formation.

12:15 pm Probing Structure Formation with the Cosmic Infrared Background Experiment 2 (CIBER-2)

Chi Nguyen Rochester Institute of TechnologyThe integrated emission from all sources of light outside of the Milky Way, known as the Extragalactic Background Light (EBL), traces the history of star formation from the Epoch of Reionization (EOR) to the modern era and presents tight constraints on cosmological model. The EBL has been shown to fluctuate in exceed of predictions from known galaxy populations, which can be attributed to the contribution from sources at very high redshifts (EOR or earlier), or from stars that are gravitationally separated from their host galaxies during merging events at more recent epochs. To disentangle these two populations by tracing their spectral signatures, the second Cosmic Infrared Background ExpeRiment (CIBER-2) uses a 28.5-cm wide field imager with six wavebands spanning the 0.5 - 2.5 micron window, significantly improving the wavelength coverage and sensitivity compared to its predecessor CIBER-1. CIBER-2 is scheduled to fly multiple times on a recoverable NASA Black Brant IX sounding rocket. In this talk, we discuss how CIBER-2 addresses near-IR fluctuations science, present the status and performance of the payload, and outline the remaining steps to ready the experiment for flight.

LUNCH 12:30 - 1:30pm

AFTERNOON SESSION I 1:30 pm - 3:00 pm

1:30 pm Secondary Anisotropies in the Cosmic Microwave Background, a Look Ahead I Invited Talk

Nick Battaglia Cornell University A new window into the growth and evolution of large-scale structure has opened up with the recent observations of the thermal and kinetic Sunyaev-Zel’dovich (SZ) effects. I will review these recent observations and highlight their expected rapid growth over the next decade with upcoming cosmic microwave background experiments.

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I will show how we can use SZ observations to constrain the important baryonic process that govern galaxy formation and discuss the prospects of using them to mitigate the modeling uncertainties associated with “baryonic effects" in future large-scale structure surveys.

2:00 pm CMB Lensing Measurements from the SPTpol 500 deg2 survey Kimmy Wu KICP/University of ChicagoGravitational lensing of the cosmic microwave background (CMB) encodes information of the low-redshift universe. Therefore, its measurement is useful for constraining cosmological parameters that describe structure formation, e.g. ΩM, σ8, and the sum of neutrino masses. In this talk, I will present a measurement of the CMB lensing potential and its power spectrum using data from the SPTpol 500 deg2 survey. From the minimum-variance combination of the input lensing estimators, we measure the lensing amplitude AMV = 0.944 ± 0.058 (Stat.) ± 0.025 (Sys.), which constitutes the tightest lensing amplitude measurement using ground-based CMB data alone. Restricting to only polarization data, we measure the lensing amplitude APol = 0.906 ± 0.090 (Stat.) ± 0.040 (Sys.), which is more constraining then our measurement using only temperature data. As upcoming experiments like SPT-3G continue to lower the CMB map noise levels, polarization data will dominate the signal-to-noise of lensing measurements for angular multipoles below at least several hundred. Looking to the future, high signal-to-noise measurements of lensing enabled by deep polarization maps is crucial for constraining the sum of neutrino masses and the amplitude of inflationary gravitational waves through delensing.

2:15 pm Transformer-coupled TES Frequency Domain Readout Prototype Maclean Rouble McGill UniversityFrequency domain multiplexing (fMUX) is a mature readout scheme for TES detectors in the millimetre and sub-millimitre bands. It is implemented at MHz carrier frequencies for the South Pole Telescope, POLARBEAR, and Simons Array, and is planned for deployment on the LiteBIRD space polarimeter. Existing implementations couple to the detectors with low-noise, low-input impedance SQUID transimpedance amplifiers and complex arrangements are in place to handle the inherent SQUID non-linearity and their tuning requirements.We introduce a new cryogenic amplification scheme that couples the multiplexed TES devices to a traditional FET amplifier using a high turns-ratio wide-band cryogenic transformer that steps up the TES impedance to the noise match of the amplifier. We characterize the bandwidth, transimpedance, input impedance, and noise of the transformer-coupled fMUX system to demonstrate that it is a promising candidate for SQUIDless MHz frequency domain multiplexing.

2:30 pm The Probe of Inflation and Cosmic Origins (PICO): Science Objectives and Design Qi Wen University of MinnesotaThe Probe of Inflation and Cosmic Origins (PICO) is a next decade CMB space mission that will be prioritized by the Astro2020 decadal panel. It is the product of a mission study funded by NASA over the last two years. I will describe the mission's science objectives and design. The mission consists of an imaging polarimeter that will scan the sky for 5 years in 21 frequency bands spread between 21 and 799 GHz. Its noise level is equivalent to 3300 Planck missions for the baseline required specifications, and our current best estimate is that it would perform as 6400 Planck missions. With these capabilities, unmatched by any other existing or proposed platform, PICO will determine the energy scale of inflation by detecting the tensor-to-scalar ratio r at a level of r = 5 x 10-4 (5σ). This level is 100 times lower than current upper limits, and more than 10 times lower than limits forecast by funded future experiments. The mission will measure the minimal expected sum of the neutrino masses, 58 meV with 4σ

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confidence, rising to 7σ if the sum is near 0.1 eV, by combining BAO data from DESI or Euclid. PICO will also constrain light particle species with ΔNeff < 0.06 at 95% confidence level. PICO will study cosmic structure formation and evolution by (1) measuring the optical depth to reionization tau with σ (τ) = 0.002, limited only by cosmic variance; (2) tightly constraining the evolution of the amplitude of linear fluctuations σ8 with sub-percent accuracy; (3) constraining feedback process through Sunyaev-Zeldovich effect and yielding full-sky Compton-γ map. PICO will also study galactic structure and star formation by providing 21 deep full-sky polarization maps of Galactic emission at frequencies between 21 and 799 GHz, of which the highest angular resolution is 1 arcmin. PICO will be able to constrain properties of Galactic dust and determine how magnetic fields affect molecular cloud and star formation. The science that PICO will deliver will enrich many areas of astrophysics, and will form the basis for the cosmological paradigm of the 2030s and beyond. Many of these advances can only be achieved by a space-based mission. The design of PICO is informed by science breakthroughs made by Planck and sub-orbital experiments over the last decade. Further breakthroughs in CMB science require a scale-up that is most optimally achieved by PICO. There is a long heritage of space and sub-orbital measurements in these frequency bands and the PICO implementation is a conservative extension of past successes. The mission relies on today's technologies; no new fundamental developments are required. PICO is the only single-platform instrument with the combination of sensitivity, angular resolution, frequency bands, and control of systematic effects that can deliver the compelling, timely, and broad science.

2:45 pm Parameterizing the Recombination Visibility Function Nathaniel Starkman University of TorontoThe last scattering surface of the CMB is the peak of the recombination visiblity function. While the peak has been studied fruitfully and in depth by every CMB experiment since COBE, the full shape of the visibility function is very poorly constrained. The full visibility function encodes a great deal of information which cannot be probed by the peak alone. With upcoming experiments, we have the unprecedented opportunity to use the visibility function to provide constraints, the first for some, on cosmological theories. To this end, we explore parameterizations of the visibility function, extending work done on Gaussian parameterizations. We conduct MCMC analysis of these new parameters in conjunction with the standard suite of cosmological parameters to explore their correlations and better understand potential of the visibility function to serve as a model-independent test of ΛCDM and other cosmological theories.

3:00 pm Break

AFTERNOON SESSION II 3:30 pm - 5:00 pm

3:30 pm Current and Upcoming Ground-based Cosmic Microwave Background Experiments Invited Talk Tom Crawford University of ChicagoObservations of the cosmic microwave background (CMB) form the backbone of our understanding of the formation and evolution of the Universe. In this talk, I will review the state of the field of post-Planck ground-based CMB observations, discuss some of the most exciting science that can be explored with current and upcoming ground-based CMB experiments, and introduce some of the experiments being designed and fielded to pursue those scientific goals.

4:00 pm Optical Characterization of BICEP3 and the Keck Array from 2016 to 2019 Tyler St. Germaine Harvard University

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BICEP3 and the Keck Array are small-aperture polarimeters observing the Cosmic Microwave Background (CMB) from the South Pole in search of the imprint of primordial gravitational waves. This imprinted signal, parametrized by the tensor-to-scalar ratio r, peaks at degree angular scales in the B-mode polarization of the CMB and is predicted by inflationary theory. Since 2016, BICEP3 and the Keck Array have been observing the CMB in frequency bands of 95, 150, 220, and 270 GHz. Here we present the optical characterization of these receivers, including far field beam maps measured in situ every austral summer with a chopped thermal source. From these high-fidelity per-detector maps, we derive array-averaged beam profiles and differential beam parameters. Measurements of differential beam mismatch are used for estimating the level of temperature-to-polarization leakage in our CMB maps as well as providing feedback on detector and optics fabrication. Understanding and reducing the systematic uncertainty in these beam maps is therefore critical to constraining the bias on r induced by temperature-to-polarization leakage. We highlight recent efforts to reduce the beam map uncertainty with improved low-level beam map analysis techniques, including efficient removal of non-Gaussian noise as well as improved spatial masking.

4:15 pm LiteBIRD's Projected Impact on Inflationary Models Simran Nerval University of TorontoThe Lite satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection (LiteBIRD) is a proposed cosmic microwave background polarization satellite. It will be sensitive to a multipole range of 2 ≤ ell ≤ 200 and measure fifteen frequency bands from 40 - 400 GHz. This means that it will be able to probe the strong B-mode signal that is predicted by inflation to be at low multipoles ell < 10. We present a model for LiteBIRD that accounts for the 1/f component and highlight the impact on cosmological parameters through Fisher forecasts. The main parameters of interest are the tensor-to-scalar ratio (r) and the scalar-spectral index (ns). We discuss the implications of the forecasts of LiteBIRD errors on some select models of inflation and their predictions for r and ns.

4:30 pm An Excess of non-Gaussian Fluctuations in the Cosmic Infrared Background Consistent With Gravitational Lensing Chang Feng University of Illinois at Urbana - Champaign The cosmic infrared background (CIB) is gravitationally lensed. A quadratic-estimator technique that is inherited from lensing analyses of the cosmic microwave background (CMB) can be applied to detect the CIB lensing effects. However, the CIB fluctuations are intrinsically strongly non-Gaussian, making CIB lensing reconstruction highly biased. We perform numerical simulations to estimate the intrinsic non-Gaussianity and establish a cross-correlation approach to precisely extract the CIB lensing signal from raw data. We apply this technique to CIB data from the Planck satellite and cross-correlate the resulting lensing estimate with the CIB data, galaxy number counts and the CMB lensing potential. We detect an excess that is consistent with a lensing contribution.

4:45 pm Using CMB Consistency Checks to Understand Tensions Josh Kable Johns Hopkins UniversityIn recent years tensions have arisen between cosmological measurements. The most serious involves the Hubble constant, but there are other tensions as well. In light of these tensions, consistency checks provide valuable checks of the presence of underestimated or unidentified systematic errors and may provide insights into potential extensions to LCDM to resolve tensions. Toward this end, we derived a new analytic method for calculating the correlations between correlated data sub-sets that can assess the consistency of parameter constraints from various CMB power spectra. We applied this method to the most recent SPTpol data set and conclude that these correlations need to be accounted for when performing internal TT vs TE vs

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EE consistency checks in future CMB experiments. In addition, I will discuss the degeneracy between H0 and the matter density across several current CMB experiments showing that the degeneracy directions are consistent with LCDM predictions (Kable et al. 2019). Kable, J. A., Addison, G. E., & Bennett, C. L. 2019, ApJ, 871, 77

5:00 pm Wrap up

PUBLIC LECTURE 7:00 pm - 9:00 pm Room 1400 Wegmans Hall, University of Rochester

6:15 pm - Shuttle to University of Rochester leaves campus from parking lot T. 6:30 pm

6:30 pm Reception

7:30 pm - IceCube: A Neutrino Window on the Universe Public Lecture 9:00 pm Francis Halzen University of Wisconsin - Madison

The IceCube project at the South Pole melted eighty-six holes over 1.5 miles deep in the Antarctic icecap to construct an enormous astronomical observatory. The experiment recently discovered a flux of neutrinos reaching us from the cosmos, with energies more than a million times those of neutrinos produced at accelerator laboratories. These cosmic neutrinos are astronomical messengers coming from some of the most violent processes in the universe and from the biggest explosions since the Big Bang. We will discuss the IceCube telescope and highlight the recent discovery that some high-energy neutrinos—and cosmic rays—originate from sources powered by rotating supermassive black holes.

8:30 pm - Shuttle returns to RIT campus. 9:00 pm

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8:00 am Continental Breakfast and Registration


9:00 am Simulations for Cluster-Based Cosmology Invited Talk Camille Avestruz University of Chicago Observations of galaxy clusters have thus far supported the standard model of cosmology and provided constraints on non-standard models including evolving models of dark energy and modifications of gravity. The statistical power of galaxy clusters is at a golden age, where forthcoming observations will provide data for tens of thousands of galaxy clusters. However, our ability to further use clusters as probes is now limited by how well we measure cluster masses and quantify systematic effects in how we detect and measure galaxy clusters. To calibrate observations and understand underlying astrophysical processes, we need simulations that capture both those relevant astrophysical processes and the diversity within a large sample of galaxy clusters. I will discuss ongoing modeling efforts and software infrastructure development that allows us to best leverage the data in upcoming surveys.

9:30 am Downsizing of Star Formation: Weighing Dark Matter Haloes Hosting Dusty Star-Forming Galaxies

Kirsten Hall Johns Hopkins UniversityPowerful quasars can be seen out to large distances. As they reside in massive dark matter haloes, they provide a useful tracer of large-scale structure. Stacking far-infrared and sub-millimeter maps on the locations of quasars has proved a useful tool in studying quasars and their environments. We stack Herschel-SPIRE images at 250, 350, and 500 μm at the location of 11,235 quasars in 10 redshift bins spanning 0.5 ≤ z ≤ 3.5. The unresolved dust emission of the quasar and its host galaxy dominate on instrumental beam scales, while extended emission is spatially resolved on physical scales of order a megaparsec. This emission is due to dusty star-forming galaxies (DSFGs) clustered around the dark matter haloes hosting quasars. We measure radial surface brightness profiles of the stacked images to compute the angular correlation function of DSFGs correlated with quasars. We then model the profiles to determine large-scale clustering properties of quasars and DSFGs as a function of redshift. We adopt a halo model and parametrize it by the most effective halo mass at hosting star-forming galaxies, finding log(Meff/M⊙) = 13.8 ± 0.1 at z = 2.21-2.32, and, at z = 0.5-0.81, the mass is log(Meff/M⊙) = 10.7 ± 0.2. Our results indicate a downsizing of dark matter haloes hosting DSFGs between 0.5 ≤ z ≲ 2.9. The derived dark matter halo masses are consistent with other measurements of star-forming and sub-millimeter galaxies. The physical properties of DSFGs inferred from the halo model depend on details of the quasar halo occupation distribution in ways that we explore at z > 2.5, where the quasar HOD parameters are not well constrained.

9:45 am Measuring the Epoch of Reionization with TIME Abigail Crites Caltech I will discuss TIME, an instrument being developed to study the faint objects in our universe using line intensity mapping (LIM). TIME allows us to to study the epoch of reionization, illuminating how the first astronomical objects ionized the neutral hydrogen in the universe. The TIME instrument is a mm-wavelength spectrometer spanning the frequency range of 200-300 GHz with 60 spectral pixels and 16 spatial pixels. TIME will trace redshifted [CII] emission at redshift 5 to 9 to probe the evolution of our universe over that epoch of reionization. TIME will also detect low-redshift CO fluctuations and map the cosmic history of molecular gas in the epoch of peak cosmic star formation from redshift 0.5 to 2. This new instrument and emerging technique will allow us to provide complimentary measurements from typical galaxy surveys to illuminate the history of our universe.

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10:00 am Simulation Support for X-ray Follow-up Studies of DES redMaPPer Clusters William Black University of Michigan

An analysis of successes and failures of galaxy clusters as cosmology probes, investigating the failure modes of the redMaPPer cluster finding algorithm on simulated skies.

10:15 am Counts-in-cells Distribution of Dark Matter Halos Di Wen University of Illinois at Urbana - Champaign

The evolution of the large-scale structure of the universe can be different in the cold dark matter paradigm with different dark energy models. I will describe how the counts-in-cells probability distribution function of dark matter halos can be used to distinguish among a cosmological constant, quintessence and phantom dark energy models. I will discuss the counts-in-cells distribution of dark matter halos between redshifts z=0 to z=4 on both linear and non-linear scales in the Dark Energy Universe Simulations and their best-fit analytical models. The percentage differences of quintessence and phantom dark energy on the counts-in-cells distribution in comparison with the standard cold dark matter cosmology with a cosmological constant are a few percent at low redshift, but can be significantly larger at high redshift. This may provide a potential way to distinguish among dark energy models using galaxy surveys.

10:30 am Break

MORNING SESSION II11:00 am - 12:30 pm

11:00 am The Universe, Magnified: The Power of Gravitational Lensing Invited Talk Keren Sharon University of Michigan

When did the Universe form its first galaxies? What do galaxies look like at the epoch when the Universe formed most of its stars? Some of the answers to those questions (and others) await a new generation of large ground and space based telescopes. In the meanwhile, strong gravitational lensing has become a useful tool to boost the power of present day telescopes, enabling detailed studies of galaxies that are otherwise either too dim or have too small of an angular size on the sky. In this talk, I will present applications of strong gravitational lensing using galaxy clusters as cosmic telescopes. I will highlight some exciting results, and conclude with future prospects.

11:30 am Novel Approach of Predicting Exact Escape Velocity Profiles of Galaxy Clusters Vitali Halenka University of MichiganThe radial escape-velocity profile of galaxy clusters has been shown to be a competitive probe of cosmology in an accelerating universe. Projection onto the sky is a dominant systematic uncertainty for statistical inference, since line-of-sight projection of the galaxy positions and velocities can suppress the underlying 3D escape-velocity edge. In our work, we utilize Keplerian Orbital dynamics to numerically model cluster phase-spaces. We then compare the analytical escape edge to those from N-body and hydrodynamic simulations. We show that high enough sampling, the 3D escape velocity edge is in fact observable without systematic bias or suppression (to 1014 M⊙) systems over the range 0.4 < r/r200 < 1. The model incorporates observables such as richness and the line-of-sight velocity dispersion. Finally, we show that the numerically modeled suppression is independent of velocity anisotropy over the range -3 < β < 0.5. We conclude that the 3D cluster escape velocity profile can be inferred from projected phase-space data without knowledge of cosmology or the use of simulations.

11:45 am Cross-Covariances Between Cluster Number Counts and 2pt Statistics Chun-Hao To Stanford University

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The strongest cosmological constraints to date from imaging surveys including the Dark Energy Survey (DES) have come from the combination of three 2 point statistics: galaxy clustering, galaxy-galaxy lensing, and cosmic shear (3x2pt). There is significant cosmological power in combining cluster number counts with this 3x2pt measurement. Here we develop the cross-covariance between these observables, and employ this in a joint analysis of cluster number count, the three 2pt statistics from the previously published DES analysis, and the cluster-galaxy cross correlation function. We test our model and analysis pipeline on the Buzzard simulation, where we have realistic RedMaPPer cluster samples and RedMaGiC galaxy samples, and demonstrate that our model is unbiased. I will discuss the key uncertainties and future potential of this method for analyzing imaging surveys.

12:00 pm Quantifying the Performance of BAO Reconstruction Algorithms Xinyi Chen Yale UniversityThe baryon acoustic oscillation (BAO) technique is one of the most prominent probes of dark energy and will play a pivotal role in obtaining the tightest constraints on cosmology with the use of the large galaxy surveys in the next decade. Reconstructing the BAO peak reverses the effects of nonlinear evolution and redshift-space distortions, increasing the precision and accuracy of these measurements. Recently, there have been a number of alternative reconstruction algorithms proposed. We have begun a study to improve the reconstruction framework, aiming to achieve smaller uncertainties suitable for the next generation surveys. We present a comparison of these algorithms, quantifying their performances on simulated data.

12:15 pm Separate Universe Techniques from High to Low Densities Andrew Jamieson Stony Brook University

Separate universe simulations provide a method for studying mildly nonlinear aspects of large scale structure. Observables in this regime can be used to probe primordial non-gaussianity, neutrino mass, and dynamical dark energy. We present the first applications of this technique to a model with quintessence isocurvature perturbations. In this case, we obtain simulation halo biases that are scale-dependent in a characteristic way that relates to the model's quintessence Jeans scale, and the spectra of primordial curvature and isocurvature fluctuations. We also present the first separate universe measurements of voids bias, the sensitivity of void profiles to the background density, and the separate universe response of the probability density function of matter density perturbations. Applications of these observables to constrain cosmological parameters will be discussed.

LUNCH 12:30 - 1:30pm


1:30 pm IceCube: A Neutrino Window on the Universe Francis Halzen University of Wisconsin - Madison The IceCube project at the South Pole melted eighty-six holes over 1.5 miles deep in the Antarctic icecap to construct an enormous astronomical observatory. The experiment recently discovered a flux of neutrinos reaching us from the cosmos, with energies more than a million times those of neutrinos produced at accelerator laboratories. These cosmic neutrinos are astronomical messengers coming from some of the most violent processes in the universe and from the biggest explosions since the Big Bang. We will discuss the IceCube telescope and highlight the recent discovery that some high-energy neutrinos—and cosmic rays—originate from sources powered by rotating supermassive black holes.

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2:00 pm Re-Analysis of Cluster rSZ Data Utilizing Herschel-SPIRE: Eliminating Cluster Coincident Dust Emission Victoria Butler Rochester Institute of Technology

The Relativistic Sunyaev-Zeldovich Effect can be an effective tool in studying the evolution of cluster gas through cosmic time, and isolate the role of mergers in these systems. This effect is caused by the Inverse – Compton scattering (ICS) of Cosmic Microwave Background (CMB) photons off of hot electrons in the intra-cluster gas, resulting in a relativistically boosted CMB spectrum. The amplitude of this distortion is related to the integrated pressure of the gas along the line of sight, and independent of the cluster redshift. This makes it an ideal counterpart to cluster X-ray measurements, which thus far outnumber significant detections of rSZ. With increasingly accurate measurements of the thermodynamic properties of the cluster gas at high redshift, a more complete understanding of cluster evolution will emerge. Despite these advantages, the rSZ spectrum is significantly affected by cluster coincident dust emission, and impossible to extract through measurement of this effect alone. The Planck satellite has made robust detections of rSZ towards a large set of clusters, but because of its beam size, cannot easily identify the contaminating gas foreground. By combining this dataset with that of Herschel-SPIRE, which has a much smaller beam, the individual dust emission sources can be isolated and removed. The addition of Bolocam data provides a further rSZ measurement that reduces systematics from the analysis. Once foreground contaminants are removed from the SZ spectrum, the temperature and pressure profiles can be compared with those of Chandra and XMM-Newton, and reveal the precise evolution of the gas.

2:15 pm Cosmological Constraints With Self-Interacting Sterile Neutrinos Ningqiang Song Queen's UniversityWe revisit the question of whether Cosmology can be made compatible with scenarios with light sterile neutrinos, as invoked to explain the short baseline neutrino oscillation anomalies, in the presence of self-interaction among sterile neutrinos mediated by massive gauge bosons. We examine this proposal by deriving the cosmological predictions of the model in a wide range of the model parameters including the effective interaction strength, sterile neutrino mass and active-sterile mixings. With those we perform a statistical analysis of the cosmological data from BBN, CMB, and BAO data to infer the posterior probabilities of the sterile self-interaction model parameters. We conclude then that adding the self-interaction can alleviate the tension between eV sterile neutrinos and CMB data, but when including also the BAO results the self-interacting sterile neutrino model cannot lead to a satisfactory description of the data.

2:30 pm Hunting for Dark Matter Substructure in Strong Lensing With Neural Networks Joshua Yao-Yu Lin University of Illinois at Urbana - ChampaignDark Matter Substructures are interesting since they can reveal the properties of dark matter, especially the cold dark matter small-scale problems such as missing satellites problem. In recent years, it has become possible to detect individual dark matter subhalos near images of strongly lensed extended background galaxies. In this talk, I would discuss the possibility of using deep neural networks to detect dark matter subhalos, and showing some preliminary result with simulated data.

2:45 pm Macroscopic Dark Matter Detection Using Fluorescence Detectors Jagjit Sidhu Case Western Reserve UniversityMacroscopic dark matter (aka macros) constitutes a broad class of alternatives to particulate dark matter. We calculate the luminosity produced by the passage of a single macro as a function of its physical cross section. A general detection scheme is developed for measuring

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the fluorescence caused by a passing macro in the atmosphere that is applicable to any ground based or space based Fluorescence Detecting (FD) telescopes. In particular, we employ this scheme to constrain the parameter space of macros than can be probed by the Pierre Auger Observatory and by the Extreme Universe Space Observatory onboard the Japanese Experiment Module (JEM-EUSO). It is of particular significance that both detectors are sensitive to macros of approximately nuclear density, since most candidates that have been explored (excepting primordial black holes) are expected to be around that density.

3:00 pm Break


3:30 pm Making a Universe with Axions Invited Talk Chanda Prescod-Weinstein University of New Hampshire

What’s an axion and why do people keep talking about Bose-Einstein condensates in space? In this talk, I will describe the axion as a popular solution for open problems in particle physics, most notably dark matter. I will discuss the possibility that neutron stars are astrophysical axion laboratories and what we may learn in future endeavors, including proposed X-ray and Gamma-ray missions such as STROBE-X, eXTP, and AMEGO.

4:00 pm Capture of Superheavy Dark Matter by the First Stars Cosmin Ilie Colgate UniversityIn this talk, I will discuss the mechanisms and effects of capture of self-annihilating Superheavy Dark Matter by the first stars (PopIII stars), extending previous analysis on the case of WIMP Dark Matter. Pop III stars form as a consequence of hydrogen cloud collapse at the center of DM halos at redshifts of z~10-20. They are typically massive, sometimes exceeding 1000 solar masses, and shine at the Eddington luminosity limit. I find that, if the DM halo environment is sufficiently dense or conversely if the accreting star is sufficiently massive, the luminosity captured DM can exceed the luminosity output via nuclear fusion. More importantly, since the latter is the Eddington limit, this implies that capture of Superheavy DM can lead to a cutoff in the mass function of PopIII stars. With the upcoming JWST, one could potentially use this to constrain models of Dark Matter.

4:15 pm Beyond CDM: Ultralight Dark Matter in Simulation Luna Zagorac Yale UniversityThough Cold Dark Matter (CDM) does admirably well in cosmological simulations at large scales, small scales present tensions with observational data, known as the core-cusp problem. One solution to this is Ultralight Dark Matter (ULDM), an axion-like particle whose quantum nature smoothes cores of DM halos via the Heisenberg uncertainty principle. In order to test the plausibility of such a candidate, a ULDM simulator is necessary. I will present such a simulator, called PyUltraLight, and describe its development since its publication in 2018. I will also discuss the case for astrophysical realistic tests of ULDM using this software.

4:30 pm Constraining the Particle Astrophysics of the Sun in TeV Gamma rays Mehr Nisa Michigan State UniversityThe Sun is of interest to high energy astrophysics as a target for indirect searches of dark matter, and for its role in modulating the observed cosmic-ray flux on Earth. It is also a known steady emitter of very high energy gamma rays above 100 GeV. The observed spectrum in the GeV range is much brighter ( > factor of 6) and harder than anticipated by theory. The flux also shows a dependence on solar activity, with the highest energy photons occurring during the solar

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minimum and exhibiting no spectral cutoff up to at least 200 GeV. The High Altitude Water Cherenkov Observatory (HAWC) is currently the only detector capable of monitoring the Sun at energies above 1 TeV. HAWC observations placed strong constraints on steady TeV emission from the Sun during the active phase of solar cycle 24, demonstrating sensitivity to a flux near ~10-12 TeV cm-2 s-1. The Sun entered a new solar minimum beginning 2018. We present our search for gamma rays from the Sun using 4 years of data collected by HAWC and discuss the implications for models of gamma-ray emission from the Sun, including models of dark matter annihilation through long-lived mediators.

4:45 pm Tackling the Deblending Problem in Large Scale Surveys Fred Moolekamp LSSTBlending of stars and galaxies will become an increasingly difficult problem with large ground based surveys like LSST, where the majority of astrophysical sources will be blended with at least one neighboring object. I'll briefly outline issues related to blending, including its affect on weak lensing and photometric redshift measurements, and discuss scarlet, the deblender being developed for use with LSST and joint processing with space telescopes like Euclid and WFIRST.

5:00 pm Wrap up

CONFERENCE DINNER 7:00 pm - 9:00 pm “Locals Only” 311 Alexander St, Rochester

6:15 pm First shuttle to “Locals Only” restaurant leaves campus from parking lot T.

9:00 pm Last shuttle returns to RIT.

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8:00 am Continental Breakfast and Registration


9:00 am Weak Lensing: State-of-the-Art and Future Prospects Invited Talk Rachel Mandelbaum Carnegie Mellon University Weak gravitational lensing is one of the most sensitive probes of the growth of structure in the Universe, and is therefore a key part of the cosmological community's program for understanding the nature of dark energy. It is also a powerful probe of the connection between the visible components of galaxies and galaxy clusters, and their dark matter halos. The past few years have seen advances in weak lensing measurements with ongoing surveys such as the Dark Energy Survey (DES), the KIlo-Degree Survey (KIDS), and the Hyper-SuprimeCam (HSC) Survey. In this review talk I will summarize the current state of the field, including key recent results, synergies with other observations, and challenges that must be overcome in order to realize the scientific potential of even more powerful upcoming surveys (Euclid, LSST, and WFIRST).

9:30 am (talk withdrawn)

9:45 am An Offset Cooling Flow Exhibiting Formidable Stellar Formation Rate in a z=1.7 Galaxy Cluster Carter Rhea L'Université de Montréal SpARCS104922.6+564032.5 is one of the most massive and extreme galaxy clusters known to date. It stands out as harboring a still assembling brightest cluster galaxy (BCG) undergoing extreme stellar formation at z = 1.7091 (~850 M⊙/year), with evidence of a minor-merger occurring north-west of the BCG and a curved tidal tail extending south-east of the BCG. We present the first X-ray images for the cluster. Our 170 ks (~50 hour) of Chandra observations are groundbreaking not only due to the exceptional nature of the cluster but also because the object is the first of its ilk to ever be imaged so deeply in the X-rays. Using several techniques for calculating galactic substructure and proxies of cooling flows, we develop a more coherent image of the mechanism responsible for the rampant stellar formation of the BCG. Since the SpARCS cluster is positioned at a pivotal epoch in our cosmological history, these results have direct consequences for our understanding of how the most massive over densities in the Universe form and evolve with time.

10:00 am Predictably Missing Satellites: Subhalo Abundances in Milky Way-like Haloes Catherine Fielder University of Pittsburgh

On small scales there have been a number of claims of discrepancies between the standard Cold Dark Matter (CDM) model and observations. Various solutions have been proposed to deal with the missing satellites and too big to fail problems; however, these problems have not been explored within the context of a Milky Way-like halo, as opposed to a halo of the Milky Way's mass. Recent studies suggest that the MW galaxy is atypical (e.g., Licquia et al. 2015). We investigate how the properties of dark matter halos with mass comparable to our Galaxy's --- including concentration, spin, shape, and scale factor of the last major merger --- correlate with the subhalo abundance. Using zoom-in simulations of Milky Way-like halos, we build two models of subhalo abundance as functions of host halo properties. From these models we conclude that the Milky Way most likely has fewer subhalos than the average halo of the same mass. We expect up to 30% fewer subhalos with low maximum rotation velocities at the 68% confidence level and up to 52% fewer than average subhalos with high rotation velocities (comparable to the Magellanic Clouds) than would be expected for a typical halo of the Milky Way's mass. Concentration is the most informative single parameter for predicting subhalo

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abundance. Our results imply that models tuned to explain the missing satellites problem assuming typical subhalo abundances for our Galaxy may be over-correcting. If time allows, I will also discuss how the gross properties of halos, such as concentration and spin, are partly determined by their subhalo populations.

10:15 am Stellar-to-halo Mass Relation of Cluster Galaxies Anna Niemiec University of Michigan

Galaxy clusters are large structures in the Universe, composed of tens or hundreds of galaxies bound by gravity. In the hierarchical formation model, they form and grow by accretion of smaller groups or isolated galaxies. In this scenario, understanding how these accreted galaxies interact with the very dense cluster environment is an important step towards explaining the global picture of galaxy evolution and structure formation. Indeed, during infall, galaxies are subject to numerous interactions with the host cluster, both at the level of the baryonic and dark matter component, and these interactions influence their properties. In particular, both observations and numerical simulations suggest that its dark matter halo is stripped by the tidal forces of the host. In this talk I will present our measurements of the stellar-to-halo mass relation for the galaxies in the redMaPPer clusters with the galaxy-galaxy weak lensing technique, using shear data from the DES-SV, CFHTLenS and CS82 surveys. To then help interpret these results I will discuss our analysis of the evolution of subhaloes in the Illustris hydrodynamical simulation.

10:30 am Break

MORNING SESSION II11:00 am - 12:30 pm

11:00 am Mapping the Universe with Dark Energy Survey Invited Talk Dragan Huterer University of Michigan

I will give a theory-centered overview of the results from the Dark Energy Survey, an experiment mapping the large-scale structure in order to better understand the cause of the accelerated expansion of the universe. Year-1 DES analyses published in 2017/18 included the combination of galaxy clustering, cosmic shear, and their cross-correlation to impose constraints on key cosmological parameters, while the imminent Year-3 and, later, Year-6 analyses will dramatically improve those constraints. I will briefly outline the status of our general understanding of dark energy, then discuss the results some of the challenges in the DES analysis, and finally identify the most promising methodologies to better the nature of dark energy.

11:30 am The Strongest Cluster Lenses: Using Lens Models To Investigate the Properties That Influence Lensing Strength Carter Fox University of MichiganStrong gravitational lensing provides a unique opportunity to investigate the mass distribution of galaxy clusters and study high redshift galaxies. Thanks to large surveys of lensing clusters, lens models are now available for many clusters of different mass ranges. This allows for analysis of their lensing strengths, as well as comparison between theoretical predictions and models of real clusters. Using the lens models of 21 clusters from the Reionization Lensing Cluster Survey, 6 from Frontier Fields, and 36 from the SDSS Giant Arcs Survey, modeled with a parametric approach, we evaluate the lensing strength of each cluster. We search for correlations between the lensing strength of a cluster and its physical properties, such as its projected mass within different radii and the inner slope of its projected mass density profile. With a deeper understanding of how cluster properties influence lensing strength, we can more efficiently focus our observations and analyses of galaxy clusters.

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11:45 am Measuring the Growth Rate of Structure Through Optimized Tracers and Techniques

Faizan Mohammad University of WaterlooEstimates of growth rate of structure from clustering measurements have become one of the primary probe to constrain gravity on cosmological scales. However, theoretical and observational systematics make this task challenging. I will show how selecting appropriate tracers helps us improving the systematic bias on the growth rate measurements with respect to standard techniques. I will also present the application of a new technique, the Pairwise-Inverse-Probability (PIP) weighting, to data from VIPERS and eBOSS surveys in order to mitigate for missing observations when measuring the galaxy two-point correlation function.

12:00 pm Testing General Relativity Using Kinetic Sunyaev Zel'dovich Tomography James Mertens York University/CITA/PIUpcoming experiments will allow us to measure the cosmic microwave background and large scale structure with unprecedented precision and angular resolution. Such measurements will enable observations of subtle relativistic corrections to both CMB secondaries and tracers of large-scale structure, as well as constraints on cosmological parameters such as the amplitude of non-Gaussianities. I will discuss recent work forecasting our ability to measure these effects using multiple tracers, in particular galaxy number counts and the kinetic Sunyaev Zel'dovich effect. Together, these effects can significantly improve upon the constraining power of either probe independently.

12:15 pm Measuring the Mass at the Cores of Strong Gravitational Lensing Galaxy Clusters Juan Remolina Gonzalez University of Michigan

In the era of large surveys, it is becoming necessary to develop fast, robust, and well understood methods for estimating properties of astrophysical objects. In this talk, I will present two methods for automatic estimation of the mass in the cores of strong lensing galaxy clusters. First, the projected enclosed mass can be determined from the observed Einstein Radius (M(< θE)), by assuming spherical symmetry. We measure a scatter of 27% with a bias of 14% in the mass estimate, and quantify the systematic uncertainty from deviation from spherical symmetry. We identify indicators of the field specific uncertainty on M(< θE) and develop an empirical correction to de-bias and reduce the scatter on the mass estimate. Second, we compute a “basic” lens model (BLM), which requires minimal human interaction, is automatically generate once the lensed images have been identified and redshifts measured, and takes a fraction of the computing time compared to a detailed lens model. We measure a scatter on the BLMs of 12% with 5% bias. Understanding the associated statistics will enable the efficient mass estimation of large samples of strong lensing galaxy clusters. The concentration-Mass (c-M) relation can be measured when combining a mass estimate at the core and large radial scales of the galaxy cluster. The c-M relation and the total projected mass distribution at the core of clusters can inform dark matter properties and the growth of large-scale structure.

LUNCH 12:30 - 1:30pm


1:30 pm CHIME : A Status Update Laura Newburgh Yale University I will present a status update for the Canadian Hydrogen Intensity Mapping Experiment (CHIME), which will use 21cm intensity maps to place sensitive constraints on

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Dark Energy between redshifts 0.8 -- 2.5, a poorly probed era corresponding to when Dark Energy began to impact the expansion history of the Universe.

2:00 pm Intensity Mapping Tomography: Method and Application to Data Yi-Kuan Chiang Johns Hopkins University

The targets of intensity mapping do not need to be limited to strong emission lines in the extragalactic background. I will introduce a cross-correlation-based formalism to recover previously collapsed redshift information for cosmic photons in intensity maps of arbitrary bandwidths. This enables a tomography not only in line-of-sight distance (or cosmic time) but also in frequency space as the photons get redshifted by the cosmic expansion. I will demonstrate this method with data by probing the continuum, Lyα; line, and Lyman break; in the cosmic UV background up to z~2 using GALEX All Sky and Medium Imaging Surveys. This allows us to perform spectral diagnostics for the entire body of the UV background and provide insights on cosmic star formation, black hole accretion, and potential emission from the diffuse intergalactic medium. We expect this method to be generically applicable for a rich set of existing and upcoming wide-field datasets in probing the cosmic background over a wide range of wavebands up to cosmic high noon.

2:15 pm Evidence for CII Diffuse Line Emission at Redshift z~2.6 Shengqi Yang New York UniversityWe detect excess emission for in the 545 GHz Planck band by cross-correlating Planck maps with BOSS LSS tracer maps. This excess is consistent with redshifted CII emission.

2:30 pm The Deep Dish Development Array: a Test Bed for Precision Radio Astronomy Dallas Wulf McGill UniversityIn the last year, the Canadian Hydrogen Intensity Mapping Experiment (CHIME) has demonstrated the unparalleled mapping speed achievable with transiting interferometer arrays, which feature a large instantaneous field of view comprised of 1000+ beams, each with a point source sensitivity comparable to a single dish of equivalent total collecting area. However, the calibration of thousands of individual receivers is a major obstacle to harnessing the full power of this new technology. For future instruments, we plan to build-in redundancy at the level required for the science objectives (typically below 1%). This requirement runs counter to conventional wisdom, which dictates that radio receivers need only be accurate to ~1/20 of the observed wavelength. In partnership with NRC Herzberg Astronomy and Astrophysics, we are in the process of building a two-element interferometer with a targeted precision of 1/1000 of a wavelength at 300 MHz, called the Deep Dish Development Array (D3A). The D3A will serve as test bed for prototyping dish, antenna, and support components capable of being scaled to large arrays without sacrificing precision. Here we will present an overview of the technology currently being tested on the D3A, as well as the state of testing and performance. These technologies are candidates for the Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) and the Canadian Hydrogen Observatory and Radio Transient Detector (CHORD).

2:45 pm Full-sky Maps from CHIME Paula Boubel McGill University

When the Universe was around 10 billion years old, it became dominated by dark energy and began to accelerate in its expansion. This stage in the expansion history of the Universe is crucial for distinguishing dark energy models. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a radio telescope designed to measure the expansion during this period by mapping the large-scale distribution of neutral hydrogen gas. CHIME will directly detect the hydrogen 21 cm emission redshifted to frequencies between 400 and 800 MHz. Astrophysical

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foregrounds are several orders of magnitude brighter than the 21 cm cosmological signal. There is an ongoing effort to understand the instrument to the level of precision required for foreground removal.Measurements of the foregrounds are useful ancillary data products in and of themselves. To date, the best measurement of the full sky in this frequency regime is the 408 MHz map by Haslam et al. from a survey that was conducted in the 70's. As a drift scan interferometer, CHIME is uniquely capable of producing maps of the full radio sky on a daily basis. These detailed maps provide valuable astrophysical data at unexplored frequencies. In this talk I will discuss how we take advantage of the instrument's unique design to employ a non-traditional mapmaking strategy, along with its associated challenges. I will present the first CHIME maps and outline some of their potential contributions to astrophysics.

3:00 pm Break


3:30 pm Dark Matter Science in the LSST Era Invited Talk Keith Bechtol University of Wisconsin

Astrophysical observations probe the physics of dark matter through its impact on structure formation throughout cosmic history. On large scales, current observational data are well described by a simple model of stable, non-relativistic, collisionless, cold dark matter (CDM). However, many viable theoretical models of dark matter predict deviations from CDM that are testable with current and future observations. Fundamental properties of dark matter — e.g., particle mass, self-interaction cross section, coupling to the Standard Model, and time evolution — can imprint themselves on the macroscopic distribution of matter in a detectable manner. With supporting theoretical efforts and follow-up observations, LSST will be sensitive to several distinct classes of dark matter models, including particle dark matter, field dark matter, and compact objects. I will discuss several astrophysical probes of dark matter microphysics that can be pursued with LSST, as well as synergies between LSST and other astronomical, cosmological, and particle physics experiments of the 2020s.

4:00 pm A Lensed Proto-Cluster Candidate at Redshifts 4 and Its Diffuse Lyman-Alpha Emission, Finding the Progenitor of Regular Clusters Guillaume Mahler University of MichiganStudying groups of galaxies and proto-clusters at high-redshift (z > 4) is challenging. Today only a small number of them are known because they are mainly discovered from the detection of large/costly spectroscopic coverage of previously imaged field (e.g. COSMOS, SILVERRUSH). Among all spectroscopic capabilities, VLT/MUSE is nicely suited to capture those structures using their Lyman-alpha emission, from redshifts z~3 to z~6. Targeting the lensing cluster Abell 2744 with MUSE we discovered a proto-cluster candidate at redshifts z~4 made of from 7 up to 21 galaxies. The members of this structure are magnified sources (some strongly lensed) allowing us to disentangle very close separation; separating Lyα blobs distanced from ~10 kpc and HST imaging counterpart down to a couple of kpcs. The Lyman alpha flux coming from the galaxies is suggesting a low SFR but it is known that Lyman flux does not capture all the sources. Nonetheless, the dynamical mass estimate does not suggest a massive structure, supporting the idea that we are looking at a more typical group or proto-cluster than the usual beasts discovered so far. We support our interpretation of the observed Lya flux with simulated MUSE cube of Lya emitting galaxies. In addition to the detection of the group, magnified regions (μ ≳ 15) are allowing us to robustly study the material down to 5x10-19 erg/(Å cm2 s) that is between few galaxies of our system because there are stretched on such large area.

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Observations of typical structures, yet no often observed, is crucial to tailored our view of structure formation.

4:15 pm BICEP Array: a Next-Generation CMB Polarimeter for the South Pole Steven Palladino University of CincinnatiInflation theory generally predicts the existence of primordial gravitational waves. These waves would have left a unique imprint on the Cosmic Microwave Background (CMB) known as B-modes. BICEP Array will target these B-mode signals and is scheduled to start observing in 2020. The first receiver will observe at 30 and 40GHz and additional receivers observing at frequencies of 95GHz, 150GHz, and 220/270GHz will be added in future seasons. This multi-frequency observation will provide world-leading measurements on B-modes by both constraining foregrounds and deepening the map of the CMB. In this talk, I will present an overview of the design and the expected performance of BICEP Array in the coming years.

4:30 pm Patterns in Galaxy Distributions at the Largest Scales Zachery Brown University of RochesterBaryon acoustic oscillations in the primordial Universe imprint patterns in the large scale distribution of galaxies. We investigate correlations between galaxies at scales up to twice the usual acoustic peak. We present a simple method for the extraction of this feature from the galaxy two point correlation. We then discuss its application to cosmology measurements.

5:00 pm Wrap up

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POSTER August 6 - 8, 2019Poster ID Poster Information

Note: Posters can be set up in the conference area starting at 8:00 am on August 6 and are available for viewing August 6 - 8. All posters must be removed by 6:00 pm, August 8.

1 The Cosmic Web: Impacts on Galaxy Quenching in Clusters Sachin Kotecha McMaster UniversityWe present a novel perspective on galaxy quenching by examining how filaments of the cosmic web plunging into clusters affect galaxies in simulations. How and why galaxies shut off star formation remain open questions, but it has been noted that galaxies acquire cold gas through filaments of the cosmic web. This idea, along with new data with an unrivaled combination of statistics and resolution, leads us to an innovative method for learning how the large scale environment of a galaxy affects quenching. We employ the recent Three Hundred Project, which has built up a catalogue of over 300 galaxy clusters run with multiple smoothed-particle hydrodynamic (SPH) simulations. From the data, we identify and track the evolution of filamentary structure of the cosmic web, and we utilize a halo finder to locate where galaxies are at these times. Furthermore, we hope to differentiate the effect feedback with a galaxy's environment has had on its quenching from effects by smaller scale internal feedback. This research is positioned to be foundational, as the Hector instrument and the Euclid mission, which are set to be launched in 2020 and 2021 respectively, will also begin to look at quenching from an evolutionary standpoint in relation to the cosmic web.

2 Conditional Generative Adversarial Networks: An Alternative to Cosmological Emulators? Richard Feder-Staehle CaltechCosmology has transformed from a data-scarce to data-driven field of study. Observations of millions of galaxies and other emission that trace large scale structure have enriched our understanding of the universe and how it evolved at early times. Making precise predictions that relate cosmological observables to LCDM parameters often involves simulating the evolution of matter and other structure on the largest scales through N-body or hydrodynamical simulations. However, these simulations are computationally expensive and future experiments will require thousands of independent realizations to reduce sample variances. We propose the use of Generative Adversarial Networks (GANs) to learn a latent representation of the matter density field, from which new samples can be generated. We train on 64 Mpc3 sub-volumes from a suite of 32x512 Mpc3 GADGET N-body simulations and demonstrate that a deep-convolutional GAN can generate realistic 3D realizations of the matter density field. Generated samples have one-point statistics consistent with training data as determined by the Kolmogorov-Smirnov (KS) test, and the resulting distributions of power spectra are consistent to within 10% up to k ≃ 2. Furthermore, we demonstrate that conditional GANs can smoothly interpolate between samples conditioned on redshift. Lastly, we explore the tradeoffs between training set size and the fidelity of generated samples.

3 Density Ion Correlations in the 21cm Power Spectrum Michael Pagano McGill UniversityThe Epoch of Reionization (EoR) is the period in our universe's history when neutral hyrdogen is ionized by the first generation of stars and galaxies. Due to the difficulty in making measurements during this epoch there is still considerable uncertainty regarding how the process unfolds. A key prediction of most models is a correlation between the density and ionization field during reionization. This has consequences for the 21cm power spectrum. Here, we forecast the ability of upcoming HERA power spectrum measurements to constrain this correlation. Such constraints would rule out certain classes of reionization models, for instance favouring inside-out vs outside-in models.

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4 Measuring the Cosmic Optical Background with New HorizonsTeresa Symons Rochester Institute of Technology

The data collected by NASA’s New Horizons mission offer an excellent opportunity to measure diffuse astrophysical backgrounds in a way that avoids the bright local foregrounds that complicate such measurements from 1 AU. A measurement of the cosmic optical background (COB), which is the sum of all emission from sources beyond the Milky Way at optical wavelengths, allows for a comparison with the expected emission from known galaxies and potential identification of the source of any excess component of diffuse emission. We are using data from New Horizons’ Long Range Reconnaissance Imager (LORRI) to measure the COB using images pointed away from Pluto or other bright objects and looking out of the plane of the Milky Way. Here, we discuss our progress to date, including data cuts, image masking, and a study on defects from optical ghosting due to illumination of LORRI’s secondary mirror. Future analysis will include a dark reference pixel correction, image calibration, estimations of residual starlight and diffuse galactic light, and a correction for galactic extinction, resulting in a definitive measurement of the absolute photometric brightness of the COB for the first time.

5 Measuring Growth Rate of Cosmic Structure in SDSS With Corrected Fibre Collision Michael Chapman University of WaterlooWe make use of a new systematic correction, recent data sets, and advanced modeling to place improved constraints on the growth rate of cosmic structure using SDSS data. Previous attempts to constrain the growth rate through SDSS-III BOSS small scale clustering were limited by the fibre collision issue, where physical limitations prevent targeting close targets in a single pass of the instrument, producing a biased sample. However, the pairwise inverse probability (PIP) weighting scheme provides the first unbiased correction to measurements affected by fibre collision, by calculating the probability each pair in the sample could have been observed. We apply PIP weights to the recently completed SDSS-IV eBOSS luminous red galaxy (LRG) sample to measure the monopole and quadrupole of the redshift space correlation function and projected correlation function on small scales. These measurements are compared to a redshift space distortion emulator, which makes use of modern computational techniques and the halo occupation distribution (HOD) to efficiently compute the clustering of galaxies for a variety of cosmologies and HOD parameters. Fitting the measured correlation function to the prediction allows us to constrain the growth rate of cosmic structure and the underlying cosmology.

6 Comparing the Systematics of Different Void-Finding Algorithms Dylan Veyrat University of RochesterIt has become increasingly evident in recent years that voids, expansive regions of the universe containing significantly fewer galaxies than surrounding clusters and filaments, can provide us with important information about cosmology and galaxy physics. In addition to being a fundamental feature of the cosmic web, voids' two-point correlations with other tracers have been used to improve constraints on cosmological parameters such as the BAO radius, and galaxies in void environments exhibit significant differences in properties and evolution compared to galaxies in more populated regions. Several different void-finding algorithms, such as VoidFinder and ZOBOV, have been used in these analyses, and we aim to examine how these algorithms compare in terms of the voids they find and the results that can be drawn from them.

7 Preliminary Results from ACCEPT2.0 Dana Koeppe Michigan State UniversityThe Archive of Chandra Cluster Entropy Profile Tables (ACCEPT) is a public database of galaxy cluster properties (Cavagnolo et al. 2008, 2009) including radial profiles of entropy and

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temperature. In addition to containing more than twice the number of clusters, ACCEPT2.0 includes several more uniformly derived cluster properties such as global temperatures and metallicities, along with their radial profiles. Here, I will present early results pertaining to the temperature and metal distributions in spatially resolved clusters, and their relations to cool core and non-cool core clusters in ACCEPT2.0.

8 Mitigation of Systematics for Bicep3 and Keck Array at the South Pole Eric Hung-I Yang Stanford UniversityThe BICEP/Keck collaboration has deployed a series of telescopes to the South Pole in search of the B-mode signal potentially originating from the primordial gravitational waves. This imprint on CMB is parameterized by the tensor-to-scalar ratio r. With BICEP2, Keck Array, and BICEP3, we have been observing CMB at frequencies of 95, 150, 220, and 270 GHz. As we obtain deeper polarization maps, understanding and reducing possible systematics in the data becomes essential. Here I highlight the mitigation of systematics from the gain calibration procedure "elevation nod". Elevation nod fits the atmospheric response to calculate gain. Coupled to beam sidelobes and different detector band passes, it creates a varying gain effect on the CMB maps that can bias r at the level of a few times 10^−4. We present methods of mitigating the bias by developing a new model for elevation nod that incorporates high precision detector beam map and band pass measurements.

9 A Synthetic WFIRST Survey: Simulation Suite and the Impact of Wavefront Errors on Weak Lensing Heyang Long Ohio State University

The Wide-Field InfraRed Survey Telescope (WFIRST) will be a flagship space observatory launching in the mid-2020s, designed to explore dark energy, extrasolar planets, and other areas of astrophysics. Weak gravitational lensing is one of the three major pillars of the dark energy program, along with 3D galaxy clustering and Type Ia supernovae. Because the weak lensing program will attempt a precise measurement of very small distortions of galaxies, it places stringent requirements on wavefront knowledge and stability. In this work, we simulate a set of synthetic WFIRST images to test the impacts on weak lensing shape measurement and correlation functions of wave front errors, including static, low-frequency (changing over many exposures), and high-frequency (within one exposure) biases, and a variety of Zernike modes. These simulations will be used as part of the error budgeting process for the weak lensing shape measurement, and will ultimately replace the analytic mappings used in previous phases of the project.

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THINGS TO DO IN ROCHESTER, NEW YORK

Museums Strong Museum of Play1 Manhattan Sq., Rochester | www.museumofplay.orgInteractive, collection-based museum devoted to the history and exploration of having fun. Notable exhibits include the National Toy Hall of Fame, the World Video Game Hall of Fame, and the International Center for the History of Electronic Games.

George Eastman House900 East Ave., Rochester | www.eastman.orgExplore the world’s oldest photography museum on the estate of George Eastman, pioneer of popular photography and motion picture film. Current exhibitions include The Art of Warner Bros. Cartoons, and A History of Photography.

Rochester Museum & Science Center657 East Ave., Rochester | www.rmsc.orgInteractive science museum that also runs the Strasenburgh Planetarium next door.

Places to eat Genesee Brew House25 Cataract St., Rochester | www.geneseebeer.comFounded in 1878, the Genesee Brewing Company is one of the largest and oldest continually operating breweries in the United States. Enjoy some of their fresh brews at their restaurant while looking out over the Genesee River.

Three Heads Brewing186 Atlantic Ave., Rochester | http://threeheadsbrewing.comRelatively new brewery and beer garden. Live music every Thursday, Friday, and Saturday.

Mullers Cider House1344 University Ave., Rochester | www.mullersciderhouse.comCraft cider bar serving over 100 bottle varieties and fresh seasonal food.

Napa Wood Fired Pizzeria & Bistro573 S. Clinton Ave., Rochester | napawoodfired.comDelicious pizzeria with a large gluten-free menu.

Roam Café260 Park Ave., Rochester | www.roamcafe.comItalian café with full bar that includes paleo-friendly dishes.

Dinosaur BBQ99 Court St., Rochester | www.dinosaurbarbque.com/rochester/BBQ joint with live music Wednesday through Saturday.

Natural Oasis288 Monroe Ave., Rochester| www.naturaloasisny.comDelicious vegan Ethiopian BYOB restaurant.

Pittsford Farms Dairy & Bakery44 N. Main St., Pittsford | www.pittsfordfarmsdairy.comDelicious ice cream and baked goods.

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THINGS TO DO IN ROCHESTER, NEW YORK

Powers Farm Market161 Marsh Rd., Pittsford | www.powersfarmmarket.comFamily run farm market open daily.

Pittsford Village / Schoen Place| www.rocwiki.org/Schoen_PlaceQuaint collection of shops and restaurants along the Erie Canal in Pittsford.

Places to explore Mount Hope Cemetery1133 Mount Hope Ave., Rochester | www.cityofrochester.gov/visitmounthope/The first municipal cemetery in the United States. Notable individuals interred here includeFrederick Douglass and Susan B. Anthony. Guided tours are available.

Genesee Valley Park1000 E River Rd., Rochester | www2.monroecounty.gov/parks-geneseevalley.phpBeautiful park along the Genesee River and Erie Canal.

Highland Park180 Reservoir Ave., Rochester | www2.montroecounty.gov/parks-highland.phpExplore the Warner Castle and Sunken Garden in this beautiful arboretum.

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workshop program - ritridl.cfd.rit.edu/products/glcw12_program.pdf · 5. intensity mapping, which...

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