THCA

Tsinghua University

• Physics Department,

• Engineering Physics Department,

• IHEP

• NAOC,

• CPPM (France)

+ Other Universities

+…

Charling TAO, Xiamen 2012

• Computer Science Department

• Department of Precision Instruments and Mechanics

• Institute of advanced studies

• Geology department

since 2001 Prof. Li Ti Pei

THCA students

• 3-5 undergraduate students every year Excellent ones: go for PhD in the US 2012 Hubble Fellows: 3 from Tsinghua

• Best undergraduate take advanced graduate classes: high energy astrophysics , cosmology, galaxy dynamics,,…

• 3-5 Master and 3-5 PhD students from Tsinghua and other Chinese U.

1 Irish PhD student.

人才培养、学术奖励和学术交流

清华－高能所研究生学术讨论会

+ Charling TAO

. Understanding the Dark Universe

. Multiprobe determination of cosmological parameters

HXMT +… Prof. Li Tipei +

Shang Rencheng + Zhang YouHong, Feng Hua, Zhou Jianfeng (Zhang SN)observations and analysis of X-ray binaries, ultraluminous X-ray sources and intermediate mass black holes, space instrumentation.

SN observation and data analysis, cosmology Wang Xiaofeng +…

LIGO Gravitational Wave Cao Jun Wei

THCA Research ProgramsBroad range of data analysis efforts

Sources of data: Chandra, XMM-Newton, XTE, ASCA, BATSE, EGRET, WMAP, SDSS, 2dF, NVSS, etc…Astrophysical objects: The Sun, X-ray binaries, gamma-ray bursts, galaxies, AGNs/QSOs, clusters of galaxies, large scale structures, CMB, SN, etc…

80 cm optical telescope in XingLong. - Gamma-ray bursts, supernovae, stellar oscillation

DM direct detection (Yue Qian +…)

Doug Lin exoplanets + environments +…Tian FengHan Tao Theoretical particle cosmology

Spectrographs ( Yang Huaidong+…)

A mysterious Universe !

Graph source: Wikipedia Definition: c (c=10-29 g/cm3)

What we know is only 4%

of the energy density of the Universe

The Accelerating Universe Nobel Prize for Physics in

2011!

Riess et al., 1998

Perlmutter et al., 1999

What is this Dark Energy?

Cosmological Constant???

New form of « field/matter? » Quintessence?

Unified Dark Matter?

Modified Gravity/GR ?

- Non minimal Couplings?

- Extra-Dimensions?

- Anisotropy/ inhomogeneity effects?

- Negative energy?

- ….

How to distinguish them?- equation of state w(z) = p/- structures growth factor- ???

w =-1

DE cosmology Future

• SNIa less powerful than BAO or WL for dw/dz ? (pending systematics)

• SNIa still purest geometrical probe. Other probes have structure growth factor effects

• Need to control systematics in all probes to reach 1% precision on dw/dz

• Power of combination multiprobe analysis

• LSST, Euclid, + KDUST?

Supernovae type Ia Best known «  standardisable »

candles

SNIa : 2 stars accretion (a white dwarf +…)

Chandrasekhar mass 1.4 MO

Red giant

White dwarf

Chandrasekhar mass 1.4 MO

magnitude

SN Ia are not exact standard candles!

The light of SNIa explosions can be followed up for several weeks with telescopes

SNIa Light curves

A mysterious Universe

CMB 宇宙微波背景 (WMAP)

SNe Ia

LSS 大尺度结构

Universe is mainly dark

~72% DE

and

~23% DM

>10 >10 effect effect

nownowDefinition: c (c=10-29

g/cm3)

Cluster counts

Supernovae

Baryon Wiggles

Cosmic Shear Angular diameter distanceGrowth rate of structure

Evolution of dark matter perturbations

Standard ruler

Angular diameter distance

Standard candleLuminosity distance

Evolution of dark matter perturbationsAngular diameter distanceGrowth rate of structure

The concordance model stands quite strong!

CMBSnapshot at ~400,000 yr, viewed from z=0

Angular diameter distance to z~1000

Growth rate of structure (from ISW)

SN + other probes

Power of Combinations

astro-ph 0609591

DE Task force

Caveat: Beware in case of different central values!

use other probes, especially necessary for equation of state

not constrained by CMB

Combined constraints

equation of state parameter w around 5% statistical and systematic accuracy.

The statistical uncertainty on w from SNe Ia is now reduced to the level where systematic effects are comparable.

Today systematics are dominated by calibrations, dust corrections, and SNIa diversity

Best studied with nearby SN spectroscopy

Latest results SNLS3 years + WMAP +BAO

Current State of SN Systematics

PhotometricCalibration Uncertainties Dominate !

From Sullivan et al. 2011

The near future: 2012-2020 ?

- SN: Improve systematics control to improve SN performance

- BAO: Baryonic oscillations provide angular diameter distances: BOSS, eboss, Bigboss, PFS,… HSHS in China (Chen Xuelei) 21CMA version (Wu Xiangping) No systematics?

- Weak lensing : DES, Subaru, … Understanding systematics, needs SPACE ?

- Clusters- ….- ….

The future (>2020): multiprobe DE projects

KDUST

South Pole Dome A Kunlun Telescope will answer fundamental questions about

the structure of the Universe.

Wang Lifan

Advantage: great seeing!

Expect: 0.3 arc sec, eg space

Towards a large South Pole Dome A Kunlun Dark Universe Survey Telescope

(KDUST) Multiprobe measurements (SNIa, Weak Lensing, BAO,

Clusters) for cosmology and ancillary science

First stage 2011-2014: 3 x 60 cms telescopes (AST3) - 1 AST3 installed in Dome A, 1st datataking in 2012. THCA contribute to one AST3 and coordinates SN search

2.5 m KPATH (Kunlun Pathfinder): 2013-2016? - Collaboration with Australia, US and France

Larger (> 4m) KDUST: Timescale too early to define!

Opportunity in Jinping, Sichuanfor direct detection DM detectors

Yue Qian

• After Mentougou > 20 years ago…• Great mountain coverage

Tsinghua engineering physics department Leadership

Many Underground Lab physics: Proton Decay, neutrinos physics, DM, …

Possible size of cavity ?

What is this DM ?

Modified

Gravity

Neutrino

.WIMPsWeakly interactingmassive particles 10-1000GeV

Light Axions

SIMPs

Exotica

MACHOs

Black holes

dust Cold Molecular Hydrogen

Warm Dark Matter?

My mission for Tsinghua

Understanding the Dark Universe: astroparticle, Cosmology and gravity physics

– CMB analysis, SNIa,BAO, WL: . SNfactory, SouthPole, Euclid, . eboss/BigBoss, LSST, TMT, other?

– DM : JinPing + phenomenology + future projects…

International collaborations (sino-french, Berkeley, USC, Lausanne, Sweden, EU,…)

Develop internal Tsinghua engineering collaboration with astrophysics

More people (students, postdocs, faculty, visitors)?Analyse how to develop THCA

Develop collaboration with NAOC, IHEP Develop collaborations with other astrophysics departments

Need for an astrophysics department in Tsinghua?

Your experience is precious !

Our THCA experience• Difficult to develop in a strong physics or

engineering physics department where astrophysics < 10% .

• Promotion for your professors and staff is difficultDemocracy in the department: 2/3 positive votes! • Window of opportunity: - Developing Chinese astrophysics context,- Support of NSFC and CAS- Tsinghua can now offer good salaries for tenure track positions - Tsinghua can offer housing (for a few years)

- Critical size ~ 10-20 people !- Proposal to Tsinghua University in 2013 ?

A personal view on Chinese astrophysics community

• Experience limited to astroparticle and cosmology• Theory and data analysis has now reached

international level• Need more “creativity” and self-confidence

• Need more people in observation, instruments • Better understanding and consideration for

systematics studies and control• This takes time, give less papers (? more technical

ones), need collective team spirit – contradiction with high visibility first author competitive spirit ?

• Need different types of promotion and visibility

Scientific revolution: concepts + technology

Long Live the Xiamen University Astrophysics Department !

+ Nanjing U, PKU, Beijing Normal U, USTC, Jiaotong, Hebei, +…

Thank you all for your hospitality and advices.We are looking towards closer collaboration

Many thanks to Prof Lu for this invitation and opportunity to know better the Chinese astrophysics academic

community

Not yet 20, Prof Chen, but soon !