Professor David Carter (PI) Liverpool John Moores University UK Dr Habib G. Khosroshahi Liverpool John Moores University UK Mr Mustapha Mouhcine Liverpool John Moores University UK Ms Susan M. Percival Liverpool John Moores University UK Dr Harry C. Ferguson (USA PI) Space Telescope Science Institute USA/MD Dr Paul Goudfrooij Space Telescope Science Institute USA/MD Dr Terry Bridges Queen's University Canada Dr Thomas H. Puzia Dominion Astrophysical Observatory Canada Dr Carlos del Burgo Dublin Institute For Advanced Studies Ireland Dr Bryan Miller Gemini Observatory, Southern Operations Chile Dr Bianca Poggianti INAF - Osservatorio Astronomico di Padova Italy Dr Alfonso Aguerri Instituto de Astrofisica de Canarias Spain Dr Marc Balcells Instituto de Astrofisica de Canarias Spain Mr Derek Hammer Johns Hopkins University USA/MD Dr Reynier F. Peletier Kapteyn Astronomical Institute Netherlands Prof. Edwin Valentijn Kapteyn Astronomical Institute Netherlands Dr Gijs Verdoes Kleijn Kapteyn Astronomical Institute Netherlands Dr Peter Erwin Max-Planck-Insitute for Extraterrestrial Physics Germany Dr Ann Hornschemeier NASA Goddard Space Flight Center USA/MD Dr Yutaka Komiyama National Astronomical Observatory of Japan Japan Dr Masafumi Yagi National Astronomical Observatory of Japan Japan Dr Jennifer Lotz National Optical Astronomy Observatories, AURA USA/AZ National Radio Astronomy Observatory, Dr Neal A. Miller USA/VA and Johns Hopkins University Dr Eric W. Peng Peking University China Dr Dan Batcheldor Rochester Institute of Technology USA/NY Prof. David Merritt Rochester Institute of Technology USA/NY Dr Ronald O. Marzke San Francisco State University USA/CA Dr Alister W. Graham Swinburne University of Technology Australia Dr Helmut Jerjen The Australian National University Australia Dr Avon P. Huxor University of Bristol UK Prof. Steve Phillipps University of Bristol UK Mr James Price University of Bristol UK Prof. Bahram Mobasher University of California - Riverside USA/CA Dr Neil Trentham University of Cambridge UK Dr John Lucey University of Durham UK Prof. Ray M. Sharples University of Durham UK Dr Russell Smith University of Durham UK Dr Rafael Guzman University of Florida USA/FL Dr Carlos Hoyos University of Florida USA/FL Dr Kristin Chiboucas University of Hawaii USA/HI Dr R. Brent Tully University of Hawaii USA/HI Prof. Shardha Jogee University of Texas at Austin USA/TX Prof. Sadanori Okamura University of Tokyo, Department of Astronomy Japan Dr Jonathan Davies University of Wales, College of Cardiff UK Dr Michael J. Hudson University of Waterloo Canada HST/ACS Coma Cluster Treasury Survey
Supporting Observations
MMT Hectospec KPNO 4m Mosaic Keck DEIMOS/LRIS CFHT Megacam CFHT WIRCam UKIRT Subaru SuprimeCam Subaru MOIRCS XMM/EPIC GALEX Spitzer/IRAC VLA Why the Coma Cluster? Why the Coma Cluster?
The ACS Fornax Cluster Survey Why the Coma Cluster?
Local Coma Group y e v r u S r e t s u l C x a n r o F S C A e h T
12 13 14 15 Log Halo Mass (solar masses) Why the Coma Cluster?
Local Coma Group y e v r u S r e t s u l C x a n r o F S C A e h T
12 13 14 15 Log Halo Mass (solar masses) Luminosity Functions: The Theoretical Problem
Rees & Ostriker 1977 Schechter 1976 White & Rees 1978 Felten 1977 Davis et al. 1985 Huchra et al. 1982 White & Frenk 1991 Efstathiou, Ellis & Peterson 1988
CDM Halo Mass SpectrumSNe Mergers
Photoionization
tcool > t0 AGN Luminosity Functions: The Observational Problem
Imaging
Too much background contamination Luminosity Functions: The Observational Problem
Imaging
Too much background contamination
105
104 -2
3
deg 10 -1
102 N(r) mag 101
100 12 14 16 18 20 22 24 r Luminosity Functions: The Observational Problem
Imaging
Too much background contamination
Popesso et al. 2006 Luminosity Functions: The Observational Problem
Imaging
Too much background contamination
100 ) r 10 N(M Coma (Secker et al. 1996) Virgo (Trentham & Hodgkin 2002)
1
-24 -22 -20 -18 -16 -14 -12 Mr Luminosity Functions: The Observational Problem
Imaging
Too much background contamination
100 Coma Jenkins et al. 2007 ) r 10 N(M Coma (Secker et al. 1996) Virgo (Trentham & Hodgkin 2002)
1
-24 -22 -20 -18 -16 -14 -12 Mr Luminosity Functions: The Observational Problem
Imaging Spectroscopy
Too much background contamination Not enough photons
100 Coma Jenkins et al. 2007 ) r 10 N(M Coma (Secker et al. 1996) Virgo (Trentham & Hodgkin 2002)
1
-24 -22 -20 -18 -16 -14 -12 Mr Luminosity Functions: The Observational Problem
Imaging Spectroscopy
Too much background contamination Not enough photons
Christlein & 100 Coma Zabludoff 2003 JenkinsPopesso et al. et2007 al. 2006 ) r 10 N(M Coma (Secker et al. 1996) Virgo (Trentham & Hodgkin 2002)
1
-24 -22 -20 -18 -16 -14 -12 Mr An intermediate approach
Surface brightness selection Tully et al. 2002
5 Dwarf/giant ratio increases with host 4 Coma halo mass
3 Virgo gal N 10 2 Log Ursa Major 1 Interpreted as evidence that global reionization 0 suppresses dwarf formation Local Goup in low-mass group halos -1 -24 -22 -20 -18 -16 -14 -12 Mr Surface Brightness Selection
dE, dSph surface brightness -0.2 profiles from the literature -0.4 placed at Ursa Major and observed in 0.9” seeing -0.6 Better completeness Text intermediate surface-brightness -0.8 fail the criterion but are -1.0 straightforward to identify in other ways -1.2 the lowest surface-brightness -1.4
Inner Concentration Parameter galaxies are nearly always More efficient -1.6 members -20 -18 -16 -14 -12 -10 -8 Mr A Spectroscopic Survey of the Coma Cluster: From the Core to the Virial Radius
6259 spectra with MMT Hectospec 1392 members (524 newly detected)
300 1.5” fibers 5 minute configuration time Fabricant et al. 2005
RM, Ann Hornschemeier, Russell Smith Terry Bridges, Mike Hudson, Neal Miller, John Lucey 10 nights awarded through NOAO/TSIP N Hectospec Survey 2007-9
Faint end of the luminosity function to M* + 6.5 from the core to the E infall region
Line index analysis of stellar populations to M* + 4.5
Detection and characterization of ultracompact dwarfs 3○
Coma Cluster Kinematics MMT 6000 Hectospec
4000
2000 new cluster members 0
-2000
-4000 cz - 6917 km/s (Colless & Dunn 1996)
-6000 0 1 2 3 Projected distance from Coma X-ray center (Mpc) Coma Cluster Kinematics 6000 MMT Hectospec 4000
2000
0 new cluster members r > 18 -2000
-4000 cz - 6917 km/s (Colless & Dunn 1996)
-6000 0 1 2 3 Projected distance from Coma X-ray center (Mpc) Coma Cluster Kinematics MMT 6000 Hectospec
4000
2000 new cluster members 0 r > 19.5
-2000
-4000 cz - 6917 km/s (Colless & Dunn 1996)
-6000 0 1 2 3 Projected distance from Coma X-ray center (Mpc) Radial Distribution of Cluster Members
Differential Cumulative
120 1500
100
80 1000
60
40 500 Number of galaxies Number of galaxies
20
0 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Projected distance from cluster center (Mpc) Projected distance from cluster center (Mpc) Spectroscopically Confirmed Members: Core + Infall Regions 50
40
30
20 Number of galaxies per 0.15 mag
10
0 -22 -20 -18 -16 -14 Absolute Magnitude (r) Number of clean sources in Megacam i-band image 105 Photometric 104 Completeness 103
2
Number 10
101 selected by SDSS r-band
100 Petrosian magnitude 12 14 16 18 20 22 Petrosian magnitude (r) r < 20.5 Fraction of Megacam sources detected by SDSS
1.0 0.8 and SDSS r-band 0.6
0.4 3” fiber magnitude Completeness 0.2 r < 22.5
0.0 12 14 16 18 20 22 Petrosian magnitude (r) no color cut in 2007A
24 g-r < 1.2 in 2008A, 2009A
22 20 completeness determined using 18 deeper CFHT/Megacam imaging 16 3 arcsec aperture magnitude (r) 12 14 16 18 20 22 over 3x3 degree field obtained in Petrosian magnitude (r) 2008A Simulated SDSS photometry of local dEs/dSphs translated to 100Mpc
Local Group Sculptor Group 26 M81 Group Cen A Virgo 24
22 Published Sersic fits
3" aperture magnitude (r) 20 Binggeli & Jerjen 1998
18 Jerjen, Freeman & Binggeli 2000 16 18 20 22 24 26 Caldwell et al. 1998 Total magnitude (r) Spectroscopic completeness
Hectospec Core Hectospec NE fiber assignment in dense 1.0 1.0 regions dominates overall 0.8 0.8 completeness 0.6 0.6
0.4 0.4 Completeness Completeness 0.2 0.2
0.0 0.0 15 16 17 18 19 20 21 15 16 17 18 19 20 21 spectroscopic redshifts r-band Petrosian magnitude r-band Petrosian magnitude Hectospec W XMM Footprint (SW) obtained in all populated 1.0 1.0 magnitude/surface-
0.8 0.8 brightness bins to r=20.5
0.6 0.6
0.4 0.4
Completeness Completeness In fully observed regions, 0.2 0.2 80% complete at r=20 0.0 0.0 15 16 17 18 19 20 21 15 16 17 18 19 20 21 50% complete at r=20.5 r-band Petrosian magnitude r-band Petrosian magnitude Overall Luminosity Functions
Hectospec Core Hectospec NE
100.0 100.0 Corrected for photometric and
10.0 10.0 spectroscopic incompleteness in 1.0 1.0 0.4 magnitude bins in
Number per 0.4 mag bin Number per 0.4 mag bin Petrosian magnitude 0.1 0.1 12 14 16 18 20 12 14 16 18 20 and fiber magnitude r-band Petrosian magnitude r-band Petrosian magnitude Hectospec W XMM Footprint (SW)
100.0 100.0
10.0 10.0
1.0 1.0 Posterior probability Number per 0.4 mag bin Number per 0.4 mag bin
0.1 0.1 12 14 16 18 20 12 14 16 18 20 r-band Petrosian magnitude r-band Petrosian magnitude The faint-end upturn in Coma
The Coma LF turns up at Mr ~ -16.5 Popesso et al. 2006
100
The upturn is much less pronounced than the upturns Hectospec claimed by Jenkins et al. 2007 10 and Popesso et al. 2006
If the steep upturn
Number of galaxies per 0.4 magnitude 1 in the Popesso et al. LF is real, then Coma must have an -24 -22 -20 -18 -16 -14 Absolute magnitude (r) unusually low dwarf/giant ratio Coma vs. Virgo
100
10
Number of galaxies per 0.4 magnitude Coma Hectospec
-22 -20 -18 -16 -14 Absolute magnitude (r) Rines & Geller 2008 Coma vs. Virgo
100 Does the shape of the conditional LF depend strongly on host halo mass?
10
Number of galaxies per 0.4 magnitude Coma Hectospec
-22 -20 -18 -16 -14 Absolute magnitude (r) Rines & Geller 2008 Coma vs. Virgo
100 Does the shape of the 100 conditional LF depend strongly on host halo mass?
10 10
Number of galaxies per 0.4 magnitude Coma Hectospec Number of galaxies per 0.4 magnitude -22 -20 -18 -16 -14 -22 Absolute-20 magnitude-18 -16 (r) -14 Absolute magnitude (r) Rines & Geller 2008 The Field Galaxy Luminosity Function
1
0 !
10 -1 log
-2
CfA2 North -3 RM, Huchra & Geller 1994 -22 -20 -18 -16 -14 -12 MB The Field Galaxy Luminosity Function
1
0 !
10 -1 log
-2
CfA2 North -3 RM, Huchra & Geller 1994 -22 -20 -18 -16 -14 -12 MB The Field Galaxy Luminosity Function
SDSS The faint end of the faint end
-1
) -2 r (M !
10 -3 Log
-4
-5 Blanton et al. 2005 -22 -20 -18 -16 -14 Mr Luminosity function: clusters vs. field
D/G ratio is largest in the field
Virgo (Rines & Geller 2008)
100 Coma (Hectospec)
10 SDSS (Blanton et al. 2005) Number of galaxies per 0.4 magnitude
-22 -20 -18 -16 -14 Absolute magnitude (r) Luminosity function: clusters vs. field
D/G ratio is largest in the field
How does this conclusion square Virgo (Rines & Geller 2008) with well-measured LFs of poor systems?
100 Coma (Hectospec) 5
4 Coma
3 Virgo gal N 10 2
10 Log Ursa Major SDSS (Blanton et al. 2005) 1
0
Number of galaxies per 0.4 magnitude Local Goup -1 -22 -20 -18 -16 -14 -24 -22 -20 -18 -16 -14 -12 Absolute magnitude (r) Mr Luminosity function: clusters vs. field
Can the field LF be expressed as an appropriately weighted sum of group and cluster LFs?
5
4 Coma
3 Virgo gal N 10 2 Log Ursa Major 1
0 Local Goup -1 -24 -22 -20 -18 -16 -14 -12 Mr The Conditional Luminosity Function
Loose groups of L* -1 Blanton et al. 2005 (Corrected) galaxies are Blanton et al. 2005 (Raw) particularly inhospitable to dwarf galaxies -2
) LG Fornax r (M
! 13 14 3 10 M < M < 5 10 M Most dwarfs are not 10 × ! × ! -3 Fornax Virgo satellites of L* galaxies Log
M > 5 1014M Virgo × Coma!
-4 Physics behind the Tinker et al. 2008 n(m) missing satellite WMAP5 -5 problem is likely to be -22 -20 -18 -16 -14 local, not global Mr The Stellar Mass Function in the Field
Baldry, Glazebrook & Driver 2008 Li & White 2009
both SDSS Stellar Masses in Coma
-22 -20 -18 -16 -14 1012
1011 from KCORRECT Blanton & Roweis 2007 1010
109
Stellar Mass (solar masses) 108
107 12 14 16 18 20 Petrosian magnitude (r) Stellar mass function: Coma vs. the field
1000 Baldry, Glazebrook & Driver 2008
100 Li & White 2009
Coma
10 Number of Galaxies
1
107 108 109 1010 1011 1012 Stellar mass (solar masses) The stellar mass function in Coma is not steeper than the stellar mass function in the field
Baldry, Glazebrook & Driver 2008 Conclusions
The faint end of the Coma luminosity function turns up at Mr=-16.5, but much less steeply than the composite LF of Popesso et al. 2006 and the Coma LF derived at 3.5 microns by Jenkins et al. 2007
The luminosity functions of Virgo and Coma, the two clusters with the best-measured LFs, are similar
The D/G ratio in the field is, if anything, larger than it is in Coma and Virgo
The stellar mass function in Coma is similar to the stellar mass function in the field