Galaxy Clusters as Cosmic Probes Subha Majumdar Cluster
Galaxy Clusters as Cosmic Probes Subha Majumdar Cluster Cosmology - A flavour of decades old results Pre WMAP - 1999 Science article Bahcall, Ostriker, Steinhardt DTP Colloquium, TIFR, 29 June 2010 2
DTP Colloquium, TIFR, 29 June 2010 3 In this era of CMB, SNe, etc Why do we need clusters? LSST forecast: Strengths of different approaches within one single survey DTP Colloquium, TIFR, 29 June 2010 4 Cluster surveys / observational programs (incomplete list) Red Sequence Cluster Survey (RCS) Spitzer Adaptation of the RCS (SpARCS)
Spitzer Legacy Extremeley Wide Survey (SLEWS) Gemini Cluster Astrophysics Spectroscopic Survey (GCLASS) South Pole Telescope (SPT) APEX-SZ Atacama Cosmology Telescope (ACT) Blanco Cosmology Survey Sunyaev-Zeldovich Array (SZA) ROSAT XMM-LSS Serendipitous Survey XMM-Cluster Survey Pan-Starrs Dark Energy Survey (DES) Hyper SuprimeCam (HSC) Large Synoptic Survey Telescope (LSST) eROSITA,
Wide Field Xray Telescope AMIBA, SuZIE, Cluster Imaging Experiment, Cluster Cosmology Atacama Telescope DTP Colloquium, TIFR, 29 June 2010 5 South Pole Telescope papers are rolling in 6+1 paper since June 2009 Results are full of
surprises!! DTP Colloquium, TIFR, 29 June 2010 6 Atacama Cosmology Telescope papers are not behind DTP Colloquium, TIFR, 29 June 2010 7 What are clusters? How do they form? What do they contain?
AND How are they distributed? DTP Colloquium, TIFR, 29 June 2010 8 The WMAP Sky DTP Colloquium, TIFR, 29 June 2010 9 QuickTime and a decompressor
are needed to see this picture. DTP Colloquium, TIFR, 29 June 2010 10 Counting clusters: mass function, growth fn & 8: Universality when written in terms M Seth-Tormen: ellipsoidal collapse & Nbody Jenkins etal, bestfit to simulations Also Warren etal, Lukic etal latest. [8 for R=8h-1 Mpc]]
Cosmology with Cluster Number Counts (with apologies to) 1. with Xray luminosity function 2. Xray temperature function 3. Xray gas mass fraction 4. Optical/Xray cluster 3D corr fn 5. Optical/Xray 2D angular correlations 6. SZ+XR method of Hubble Const DTP Colloquium, TIFR, 29 June 2010 12 Cosmology affects cluster counts -
DTP Colloquium, TIFR, 29 June 2010 13 Almost 10 years back Weller, Battye & Kneissi 2002 Fixed Mlim --> so NO uncertainty in cluster physics --> unrealistic , good as first attempt. Ncl = 13600 SNAP Ncl = 5200
Ncl = 1972 Ncl =90 Problem is we have to deal with real clusters! Large peak in matter density Dark matter clump (~80% of mass) Many luminous galaxies (~2%: 10% of baryons) Chandra Image of Zw38 BCG and red sequence
Additional galaxies Diffuse light Hot gas (~18%: 90% of baryons) Emits X-rays Causes SZ decrement in microwave background DTP Colloquium, TIFR, 29 June 2010 15 Cluster Physic]s Interplay Example SZ scaling: 2
L 2 f x ( z) 4d = AM E (z)(1+ z) DTP Colloquium, TIFR, 29 June 2010 16
Example - Lets talk about scatter Sc]atter c]an boost signal, ex: Cls or n(z) Reason : shape of the mass func]tion. Widens the range of possible masses for fixed value of the observable Inc]lude it by c]onvolving the mass fn with distribution of the sc]atter sc]aling mass fn Distribution of observable Probability of assigning obs mass-true mass Standard assumption: gaussian sc]atter in loglog plane
DTP Colloquium, TIFR, 29 June 2010 17 Scatter and cosmology : Sc]atter 8 degenerac]y in dn/dz Pdf of 8 with priors on sc]atter DTP Colloquium, TIFR, 29 June 2010 18 Self-Calibration - A paradigm shift in cluster cosmology Use complimentary information from the survey itself
e.g. the mass dependence of bias / spatial distribution 1. 2. 3. Using the cluster power spectrum and P(k) oscillations Adding information from counts-in-cell Shape of mass-function in redshift slices (Majumdar & Mohr, Lima & Hu) Unbiased parameter estimation with small error bars in the presence of systematics. This idea has now propagated to other fields in cosmology Weak Lensing Galaxy Bias BAO
Photo-z Non-gaussianity from LSS etc DTP Colloquium, TIFR, 29 June 2010 19 Self Calibration using Cluster Power Spectrum Power spectrum of dark matter density fluctuations P(k) Clusters are biased: 20,000 clusters comparable to ~5x105 galaxies Turnover on large scales- standard rod calibrated by primary CMB fluctuations From redshift surveys, we will get P(k) for free ! DUET P(k)
Unfortunately, only P(k) gives almost no constraints on `w. Combined with CMB priors, one can constraint w ~ 25-30% Things become interesting when dn/dz and P(k) are Combined. SM & J.Mohr 2003 DTP Colloquium, TIFR, 29 June 2010 20
Prospects for Self-Calibrating Cluster Survey SM & J Mohr, 2003 DTP Colloquium, TIFR, 29 June 2010 21 Some ideas on what to expect on DE Xray - < 5-10% for eROSITA ~ 1% like from WFXT Similar constraints from optical with similar cluster numbers Ignore SZE for now! DTP Colloquium, TIFR, 29 June 2010
22 `The Proof of the Pudding is in Eating or Real Results from Real Survey (RCS1 and RCS2) DTP Colloquium, TIFR, 29 June 2010 23 DTP Colloquium, TIFR, 29 June 2010 24
We are in a little spot with recent SZE results Pre 2009 SPT/ACT surveys forecasted to yield 4-7clusters/deg (Planck ~ 1000 to few 1000) Post 2009 SPT/ACT finds 0.05-0.12 clusters/degsq
Also finds less SZ power in SZ Cls mplication - Cosmological constraints are washed out ! o, will doing cosmology with clusters become secondary cience for these SZ surveys ? eed to do something More with these surveys Our Options 1. Come up with new ideas for cluster surveys 2a) Make progress with understanding of cluster physics (for cases wherecluster modeling cannot be avoided) 2b) Make atleast a useful working model of cluster 3) Fall back on some old ideas of combining diff SZE outputs
DTP Colloquium, TIFR, 29 June 2010 26 Quick Thinking 1 - Change Survey Design tobs 2000 deg2 Example ACT - 2000 deg2 survey with tobs~107 s ftime = fractional time spent on the smaller patch. 1800
deg2 200 deg2 tS = ftimetobs tL = (1-ftime)tobs Magic of a tiered survey (in numbers) (from Satejs talk) Single area survey (2000)
deg2. Wedding Cake survey (200+180 0) deg2. A, , unkown unkown with follow-up m
0.676 0.019 0.032 w 1.343 0.400 0.147 8
2.849 0.121 0.028 factor of 4 BIG improvement improvement! ! better than mass followup m
0.105 0.009 0.030 w 0.115 0.095 0.088
8 0.116 0.019 0.028 Bottomline - A simple change of survey plan can do wonders Overlapping areas for SZE+Xray surveysAn ensemble of dual detected clusters for free XRay clusters Temp
Sizes Common SZ clusters mock catalog of 430 clusters created from ACT/SPT+eROSITA for Nbeam=2 with minimum 20% errors in dA(z). dA from clusters CAN BE LIKE dL from Sne !! 100 mass followup: 30-100 %
error ACT/SPT dN/dz + dA(430) ACT/SPT dN/dz only ACT/SPT dN/dz + SNe(307) Use flux counts with SZ Cl to remove cluster uncertainties Diego & SM DTP Colloquium, TIFR, 29 June 2010
31 Higher - z and Larger Surveys 1. Completed Optical 2. Proposed (and failed) Optical 3. Upcoming and funded Xray 4. Proposed XRay DTP Colloquium, TIFR, 29 June 2010 32 PI - G Wilson (USA) DTP Colloquium, TIFR, 29 June 2010
33 more DTP Colloquium, TIFR, 29 June 2010 34 What about masses? - For the c]luster in SpARCS SOUTH Vdisp = 1050 +/- 230 km/s M = 9.4 +/- 6.2 x 1014 Msun 5.7 x 1014 Msun (from sc]aling)
z = 1.34 This cluster just should not exist !! Or maybe a sign of non-gaussianity We are working on it now. DTP Colloquium, TIFR, 29 June 2010 35 DTP Colloquium, TIFR, 29 June 2010 36 A comparison of survey volumes
SDSS: 10000 deg, z<0.5, Vol ~ 7 Gpc3 SPT/ACT : 2000- 4000deg, z=0.1 -1, Vol ~ 7-14 Gpc3 RCS2: 900 deg, z=0.2-0.9, Vol ~ 2.4 Gpc3 & SpARCS ~ 0.5 Gpc3 350 deg, z=1-2 Vol ~ 3.6 Gpc3 high-z survey having smaller area has same leverage due to Its higher volume! DTP Colloquium, TIFR, 29 June 2010 37
Becoming more ambitious - More with Spitzer Proposed, for ~3000 hours (i. e., 4 months of Spitzer time) making it a legac]y c]lass survey: The Spitzer Legacy Extremely Wide Survey (SLEWS) PI: Jonathan Gardner (NASA) & Gillian Wilson (UCRiverside) (Multi c]ountry, multi supportive PI from other surveys, huge team Total members : 84 (with different bac]kgrounds and expertise) Roughly 59 (USA), 24 (Europe + Japan), 1 (India) Basic coverage: 350 deg2 , 1< z < 2 Basic aim: a) To do c]lusters at high z b) To do quasars at z>6.5 when reionization is about to oc]c]ur and there are probable stromgen spheres
Passed initial stages but finally lost to a ExoPlanet Survey :-( DTP Colloquium, TIFR, 29 June 2010 38 Into the not too distant future - Wide Field Xray Telescope (Mission pushed ahead by R. Giacconi , 2010 Decadal Survey) If funded, this will be the mother of all cluster surveys DTP Colloquium, TIFR, 29 June 2010 39 Forecast for WFXT - using N(z) + P(k)
DTP Colloquium, TIFR, 29 June 2010 40 Cluster constraints on generalised modified gravity models with = 0.55 for standard model (GR+CDM) DTP Colloquium, TIFR, 29 June 2010 41 Can India have a world class optical survey ??? A comparison Telescope
RCS on 4m CFHT 2m in Hanle Seeing 0.7 arc sec <1 arc sec Resolution 0.187 arc sec
I think its possible with a little effort !! Technology additions are easy and cheap. DTP Colloquium, TIFR, 29 June 2010 42 Thanks Thanks also to Ravi Subrahmanyan, Biman Nath, Joe Mohr Martin White, Dick Bond, Wayne Hu, Nabila Aghanim, Joe Silk, Christoph Pfrommer, Nick Battaglia, Jon Sievers, Sudeep Das, Jose Diego,Bhuvnesh Jain, Howard Yee, Mike Gladders, Henk Hoekstra, Gillian Wilson, Adam Muzzin, Yen Ting Lin , Alexey Vikhlinin, Salman Habib, David Gilbank
According to the Global Burden of Disease project, sponsored by the World Health Organization, World Bank, and Harvard School of Public Health, manifestations of atherothrombosis (ischemic heart disease and cerebrovascular disease) were the primary causes of death and disability in...
Atuação importante do MST e início de uma tímida Reforma Agrária. Investimentos na educação com a criação do Provão (atual ENADE) e ENEM. Crise dos Tigres Asiáticos (1997-98) desvalorizou o real e levou a uma crise financeira. Elevação dos juros...
It seemed gloomy in the little cove in which she found herself. The air was damp, the silence close and deep. ... Implemented modules during SY 13/14 and 14/15 with support and feedback from members of Project READI through planning...
English as a Second Language (ESL) formative and summative data (i.e. student samples of discourse, writing, journaling, miscue analysis, running record (survey level assessment), English proficiency assessment, common formative assessments, district benchmarks, and/or end of year assessments) Comparison of ELs...
Character Archetypes Devil Figure: The Wicked Witch of the West is the most evil and conniving character in this movie. ... Major Archetype The Wise Old Man: Professor Marvel is a traveling fortune teller and The Wizard of Oz is...
The bird faces a serial decision problem; it must decide which segments to eat and which to ignore. The decisions the bird makes are influenced by the mean rates at which both prey types are encountered, the difficulty of capturing...
Ready to download the document? Go ahead and hit continue!