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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.
+ 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)
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- ….- ….
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
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 !