be very afraid. cosmologia en la playa 2010 supernovae and the accelerating universe nicholas b....
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BE VERY AFRAID
Cosmologia en la Playa 2010
Supernovae and the Accelerating Universe
Nicholas B. SuntzeffMitchell Institute for Fundamental Physics & Astronomy
Department of Physics & AstronomyTexas A&M University
University of Texas/Austin
14 January 2010
How cosmology used to be done: Historical Visit of Einstein to Mt. Wilson
Al Einstein
George Ellery Hale
Ed Hubble
Milt Humason
Chuck St. JamesWalt Adams
lots of books
The sad reality of cosmology today:Unhistorical Visit of Suntzeff to Mt. Wilson
Suntzeff
Gaston
Folatteli
Mark Phillips
George Ellery Hale
Same books =>
can’t get no respect…
SN1994D
Supernovae!
P. Challis
CfA & NASA
SN spectra
Type Ia
Core
Collapse
Type Ib/c &
Type II
SN SEDs
Ia
Ib/c
II
General light curves56Ni 56Co 56Fe
Leibundgut & Suntzeff
98
delta m15
Suntzeff (1996)
Phillips (1993)
Calan/Tololo survey
1990-1996One parameter
family
Color
Rate of decline
Peak brightness
Secondary max due to Fe++
Fe+
mystery - where is Fe+ Fe0 ??
Absolute magnitudes of Type
Ia SNe
H, K probable standard candles,
Krisciunas etal 2003.
brighter
Effects of correction
to m15
brighter
fainter0.2 magPeak effect for
L is at about z~0.8.
We are looking for
about a 0.25m effect.
Distance Modulus II
Equation-of-State Signal
Difference in apparent SN brightness vs. zΩΛ=0.70, flat cosmology
Assume P = wc2
The ESSENCE SurveyDetermine w to 10% or w!=-1
6-year project on CTIO/NOAO 4m telescope in Chile; 12 sq. deg.
Wide-field images in 2 bands
Same-night detection of SNe
Spectroscopy
Keck, VLT, Gemini, Magellan
Goal is 200 SNeIa, 0.2<z<0.8
Data and SNeIa public real-time
ESSENCE Survey Team
Claudio Aguilera CTIO/NOAO Bruno Leibundgut ESO
Andy Becker Univ. of Washington Weidong Li UC Berkeley
Stéphane Blondin Harvard/CfA Thomas Matheson NOAO
Peter Challis Harvard/CfA Gajus Miknaitis Fermilab
Ryan Chornock UC Berkeley Jose Prieto OSU
Alejandro Clocchiatti Univ. Católica de Chile Armin Rest NOAO/CTIO
Ricardo Covarrubias Univ. of Washington Adam Riess STScI/JHU
Tamara Davis Dark Cosmology Center Brian Schmidt ANU/Stromo/SSO
Alex Filippenko UC Berkeley Chris Smith CTIO/NOAO
Arti Garg Harvard University Jesper Sollerman Stockholm Obs.
Peter Garnavich Notre Dame University Jason Spyromilio ESO
Malcolm Hicken Harvard University Christopher Stubbs Harvard University
Saurabh Jha SLAC/KIPAC Nicholas Suntzeff Texas A&M
Robert Kirshner Harvard/CfA John Tonry Univ. of Hawaii
Kevin Krisciunas Texas A&M Michael Wood-Vasey Harvard/CfA
ESSENCE Summary
200 SNeIa from 2002-2007
200 good light curves (Wood-Vasey, et al 2009)
Data from Keck, Gemini, VLT, CTIO, HST
GoldUnionConstitutionwhat the **** set
SDSS SN plot
Lesson in plotting
Being from Texas, I suggest
the Confederate Set is next
Carnegie Supernova Project
• Phillips, Freedman, Hamuy, Madore, Burns, Follatelli, Cadenas, Suntzeff
High-z project
I-band measurements
Cosmology fits
Carnegie Low-z Sample• 5-year project, 270n per year on 1m Swope + nights
on Magellan, du Pont, VLT
• Ending 2009 (around now)
• ugriBVYJH(Ks). Ks with WIRC on duPont
• Spectra where we can [more hot spectrographs on 2m telescopes are needed]
• Follow all types with z≤0.08 (if caught early)
• 200 Sne with 100 Type Ia
What we are trying to do
• So many data samples with so many methods of analysis have confused us
• We want to “rewrite” history, that is, start with a clean data set and redo our analyses to find the weaknesses of our techniques.
• Purely phenomenological guided by simple physics
• Basic parameter - m15, measured from the light curves, NOT from a black box program
• Measure photometry in the natural system with measured precise transmission functions
• Ultimately the goal is an accuracy of <1% in distance for cosmology with no systematics.
Summary of Sample
First ReleaseContreras, C. et al 2009 arXiv:0910.3330V1
35 Type Ia, 5559 ugriBV optical , 1043 NIR YJHKs
Natural System
Definition of photometric
zero-points
Second Parameter
Same
m15
The secondary maximum is not tightly correlated with the peak luminosity.
Bolometric light curves
Reddening
RV = 1.7 or 3.1??Wang, Goobar
suggestion
Distances to 3%
Hubble Diagram
z=0.001
m=0.12
Hicken et al 2009
A difficult diagram to understand
2 separation between blue
and orange points??
Flux calibrationsFlux calibrations
Bias in distance determination codesBias in distance determination codes
ExtinctionExtinction
Host galaxy
Our Galaxy
Atmosphere
Extinction law
Passband errorsPassband errors
K corrections
Photometry normalization
Nonlinearity in flux measurementsNonlinearity in flux measurements
Potential sources of systematic errorPotential sources of systematic error
More Potential More Potential Systematics Systematics
• “ “Hubble bubble” troubleHubble bubble” trouble
• Gravitational lensingGravitational lensing
• Evolutionary effects in SNeEvolutionary effects in SNe
• Biases in low redshift sampleBiases in low redshift sample
• Search efficiency/selectionSearch efficiency/selection
(Wood-Vasey et al., 2007, ApJ)
SNe and GRB’sWright (2007)
Higher-Z SN Team
Riess, et al
(2007)
Summary
The accelerating Universe poses a significant challenge to theory, experiment and observation.
Current goal: w to 10%
The SNIa data are consistent with a flat Universe with a cosmological constant.
Closing thoughts
• The scale of dark matter
• DETF and future measures of dark energy
• The Hubble constant
• Why are we wasting our time with w’???
• Why are there only 4 techniques?
• We need people to create realistic error models.
Okay, no questions
Come up to the front, leave your computers behind, and let’s talk what it means to be a successful researcher.
(ESA)
(JAXA)(ESA)
46
Astrophysics Division Missions
Astrophysics FY2010 President's Budget andEstimates for 2011 - 2023
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800.0
1,000.0
1,200.0
1,400.0
1,600.0
FY07
FY 08
FY 09
FY 10
FY 11
FY 12
FY 13
FY 14
FY 15
FY 16
FY 17
FY 18
FY 19
FY 20
FY 21
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FY 23
Fiscal Year
$M
Future Missions
Form, Dev & OpMissions
Mission Enabling
Program Mgmt &Other
• Assumed operating missions beyond 2016 include JWST, SOFIA
• HST De-orbit mission development ramps up ~2020
• “Future Missions” wedge would be used for new mission initiatives, R&A/technology augmentations, extended missions, etc.
• The amount of “Future Missions” funding available between 2013 – 2020 is ~$4B
Budget Guidance for Decadal Survey
• Assumed operating missions beyond 2016 include JWST, SOFIA; plus HST, Chandra, Fermi, etc. (e.g., Astro-H)
• HST De-orbit mission development ramps up ~2020
• “Future Missions” wedge is for strategic missions recommended by the Astro2010 decadal survey
• The amount of “Future Missions” funding available between 2013 – 2020 in such a scenario would be ~$2.3B
Budget Guidance for Decadal Survey – Notional
scenario
• 160 PhD’s per year, 35 permanent positions per year• NASA science sees declining budgets• NSF at best is flat• DOE may step in?• Job register has ~100 postdocs and ~16 faculty positions• US budget is now heavily encumbered with future payments• Obama loves science, but don’t assume that will go to basic science except in green and health science• you probably will not live where you want to live
The bad news
The good news• everyone loves astronomy• it ain’t a lot worse than in 1980• in the past, most people who stuck it out got good jobs
So what to do?• don’t keep on doing your thesis over and over again• establish prominent collaborators and mentors, but appear independent• publish, publish, publish. Include useful tables of summary and colorful figures that can be easily captured.• apply for external funding• luck verus hard work• become the leader in your field• think carefully about joining large projects with time scales of > 5 years.• Spergel’s law• don’t be afraid to go out on a limb and say something weird. • The Aaronson effect in obsevations• When you apply for jobs, make sure you know all about the department – and brown nose a bit. Write your application as if there is no other job out there. Know your audience.•