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Massive galaxies in massive datasets M. Bernardi, J. Hyde and E. Tundo
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Transcript of Massive galaxies in massive datasets M. Bernardi, J. Hyde and E. Tundo
Massive galaxies in massive datasetsMassive galaxies in massive datasets M. Bernardi, J. Hyde and E. TundoM. Bernardi, J. Hyde and E. Tundo
University of Pennsylvania
Importance of Early-Type Galaxies Importance of Early-Type Galaxies – Stellar masses & Black HolesStellar masses & Black Holes
The Hierarchical formation pictureThe Hierarchical formation picture– Down-sizing and Dry mergersDown-sizing and Dry mergers
Testing Dry mergers using scaling relationsTesting Dry mergers using scaling relations– Luminosities, Sizes, Velocity dispersions, Luminosities, Sizes, Velocity dispersions,
ColorsColors
Selection bias in the MSelection bias in the Mbhbh – L – – L – relations relations
OUTLINE
Early-types don’t dominate number, but they do dominate stellar mass
57%
17%
43% 83%
Renzini 2006
The most massive galaxies are red and dead
Super Massive Black HolesSuper Massive Black Holes
Gebhardt et al. 2000
Connection with “AGN feedback”!!
Ferrarese & Merritt 2000
We need to find out when ….We need to find out when ….
stars were formedstars were formed
the galaxy was assembledthe galaxy was assembled
DownsizingDownsizing
Star formation Star formation only in only in smaller smaller systems at systems at late timeslate times
Environmental Environmental dependence dependence important, but important, but controversial controversial ((Thomas et al. Thomas et al. 2005; but see 2005; but see Bernardi et al. Bernardi et al. 2006a; Bundy et 2006a; Bundy et alal. . 20062006))
Old stellar population (OK for everybody!!)Old stellar population (OK for everybody!!)?? When were galaxies assembled ???? When were galaxies assembled ??Population of massive red galaxies seen even at Population of massive red galaxies seen even at z~1.5 z~1.5 (K20 Survey, VVDS)(K20 Survey, VVDS) Consistent with passive evolution Consistent with passive evolution (e.g. Cimatti et al. 2006, (e.g. Cimatti et al. 2006, Bundy et al. 2006, Brown et al. 2006)
ORStill assembling at low z Still assembling at low z (e.g. (e.g. Faber et al. 2006)??
In the hierarchical formation picture …..In the hierarchical formation picture ….. the problem is to the problem is to form starsform stars, and , and assemble themassemble them into into
a single massive system, in a relatively short time (in a single massive system, in a relatively short time (in this respect, LCDM is friendlier than SCDM)this respect, LCDM is friendlier than SCDM)
How to do this?How to do this?
Importance of Early-Type Galaxies Importance of Early-Type Galaxies – Stellar masses & Black HolesStellar masses & Black Holes
The Hierarchical formation pictureThe Hierarchical formation picture– Down-sizing and Dry mergersDown-sizing and Dry mergers
Testing Dry mergers using scaling relationsTesting Dry mergers using scaling relations– Luminosities, Sizes, Velocity dispersions, Luminosities, Sizes, Velocity dispersions,
ColorsColors
Selection bias in the MSelection bias in the Mbhbh – L – – L – relations relations
OUTLINE
New models New models match K-band match K-band luminosity luminosity function at z~0function at z~0
Main change is Main change is to include AGN to include AGN related effectsrelated effects
No AGN feedback
AGN feedback
Croton et al. 2006 (Munich)Bower et al. 2006 (Durham)
Massive Massive Redheads?Redheads?
Latest generation of Latest generation of semi-analytic models, semi-analytic models, calibrated to z=0, calibrated to z=0, able to match K-band able to match K-band luminosity function at luminosity function at z~1.5z~1.5Main change is to Main change is to include AGN related include AGN related effects effects BCG BCGDry mergers commonDry mergers common
Bower et al. 2006 (Durham)
Passive evolution + Dry mergers
BimodalityBimodality
Models now Models now produce produce reasonable reasonable color-color-magnitude magnitude relationsrelations
BCGs BCGs bluer?bluer? Bower et al. 2006 (Durham)
BCGs
Satellite galaxies(not BCGs)
Croton et al. 2006 (Munich)
BCGs
Importance of Early-Type Galaxies Importance of Early-Type Galaxies – Stellar masses & Black HolesStellar masses & Black Holes
The Hierarchical formation pictureThe Hierarchical formation picture– Down-sizing and Dry mergersDown-sizing and Dry mergers
Testing Dry mergers using scaling relationsTesting Dry mergers using scaling relations– Luminosities, Sizes, Velocity dispersions, Luminosities, Sizes, Velocity dispersions,
ColorsColors
OUTLINE
Selection bias in the Mbh – L – Selection bias in the Mbh – L – relations relations
Brightest Brightest Cluster Cluster
GalaxiesGalaxies
C4 cluster C4 cluster catalogcatalog
Uses both Uses both position and position and color infocolor info
Miller et al. 2005
Properties of early-type galaxiesProperties of early-type galaxies
Pairwise scaling relationsPairwise scaling relations– Faber-Jackson: L-Faber-Jackson: L-– Kormendy: IKormendy: Iee-R-Ree
– L-RL-Ree
– Color - LColor - L
Inclusion of third parameterInclusion of third parameter– The Fundamental Plane: IThe Fundamental Plane: Iee-R-Ree--
Are they the same for BCGs????
BCGs show deviation from Kormendy relation
Oegerle & Hoessel 1991
BCGs
ETGs
Luminosity-Size relationLuminosity-Size relation
Upturn to Upturn to larger sizes larger sizes at large at large luminositiesluminosities
Why?Why? ● BCGs ● High-
Oegerle & Hoessel 1991
R ~ L0.8
R ~ L0.6
Dry merging?
Bernardi et al. 2007a
L-R relation expected to depend on mass ratio and impact parameter of merging spheroids
(Robertson et al. 2006)
Flattening?
Scatter correlates with size: consistent with Virial theorem:
2 ~ M/R
Luminosity- relation
● 2 comp ● deV
The Fundamental Plane
BimodalityBimodality
Models now Models now produce produce reasonable reasonable color-color-magnitude magnitude relationsrelations
BCGs BCGs bluer?bluer? Bower et al. 2006 (Durham)
BCGs
Satellite galaxies(not BCGs)
Bower et al. 2006 (Durham)
BCGs
Color-MagnitudeColor-Magnitude
Croton et al. 2006 (Munich)
SDSS measurements OUR measurements
B03-EtypesC4-BCGsPL-BCGs
Color-MagnitudeColor-Magnitude
Models
Hyde & Bernardi 2007
OUR-SDSS
B03-EtypesC4-BCGsPL-BCGs
Another class of massive galaxies?Another class of massive galaxies?
BCGs are most luminous galaxiesBCGs are most luminous galaxies
What about galaxies with largest What about galaxies with largest ::– these host the most massive BHs these host the most massive BHs – constraints on formation mechanism constraints on formation mechanism
(cooling cutoff)(cooling cutoff)
Once again, to select a clean sample must Once again, to select a clean sample must worry about systematics! worry about systematics!
Expect 1/300 objects to be a superposition
Galaxies with the largest velocity dispersion
● Single/Massive Double ◊ BCG
Sheth et al. 2003
Bernardi et al. 2006b
‘Double’ from spectrum and image
‘Double’ from spectrum, not image
‘Single?’
HST images: with ACS-HRCHST images: with ACS-HRC
SDSS
= 412 ± 27 km/s
SDSS J151741.7-004217.6
3”
1’
HST
SDSS J204712.0-054336.7
= 404 ± 32 km/sHST
SDSS
1’
3’
HST: ACS-HRC
28 single 15 multiple
= 369 ± 22 = 383 ± 27 = 385 ± 34 = 385 ± 24
= 395 ± 27 = 402 ± 35 = 404 ± 32 = 407 ± 27
= 408 ± 39 = 413 ± 35
Large not likely due to projection
Luminosity-Size relationLuminosity-Size relation
● High- ● BCGs
Oegerle & Hoessel 1991
L ~ R0.8
L ~ R0.6
Compared to BCGs, large sample has smaller sizes
Large from extreme dissipation?
Bernardi et al. 2006b
Importance of Early-Type Galaxies Importance of Early-Type Galaxies – Stellar masses & Black HolesStellar masses & Black Holes
The Hierarchical formation pictureThe Hierarchical formation picture– Down-sizing and Dry mergersDown-sizing and Dry mergers
Testing Dry mergers using scaling relationsTesting Dry mergers using scaling relations– Luminosities, Sizes, Velocity dispersions, Luminosities, Sizes, Velocity dispersions,
ColorsColors
OUTLINE
Selection bias in the MSelection bias in the Mbhbh – L – – L – relations relations
Selection bias in the MSelection bias in the Mbhbh - L - - L - ! !
From L
From
Discrepancy between Mbh function from L and
Tundo et al. 2007
What is the cause for this discrepancy?What is the cause for this discrepancy?Selection bias in the -L relation!!
Bernardi et al. 2007b
ConclusionsConclusions
Hierarchical models getting closer to Hierarchical models getting closer to observations … but not there yetobservations … but not there yet
BCGs should be good testing groundBCGs should be good testing ground
BCGs appear to be consistent with dry BCGs appear to be consistent with dry merger formationmerger formation
Large Large objects consistent with more objects consistent with more dissipationdissipation
Selection bias in the MSelection bias in the Mbhbh – L - – L -