Quenched and Quenching Galaxies at Low to High
RedshiftsS.M. Faber & UCSC and CANDELS collaborators
Dekel60 FestDecember 13, 2011
M31: UV GALEX
Quenching Scenarios for Central Galaxies
Halo-based Massive halo quenching: “cold flows” to hot halos + AGN (“radio mode”)
Bulge-building Major merger -> starburst + AGN Minor mergers + AGN Disk instability + AGN Disk secular evolution + AGN Morphological quenching (Toomre Q)
Hopping/rejuvenation Mergers Stochastic accretion
Correlate with galaxy properties
Correlate with halo properties
Part I:Quenching of central SDSS
galaxies at z ~ 0 with halo mass vs. stellar mass
Joanna Woo & Avishai Dekel
Joanna
Probability of quenching vs. M* and Mhalo
Woo et al. 2011
Contours run vertically.
Quenching correlates better with halo mass than with stellar mass.
Part II:HST UV images of nearby Green Valley
galaxiesJerome Fang, Samir Salim, S. M. Faber, et al.
Jerome
HST UV images of SDSS green valley galaxies
Fang, Salim et al. 2011
20 galaxies imaged with HST SBC.
Sample lies in bluer part of green valley.
HST FUV images
Fang, Salim et al. 2011
HST sample vs. general green valley
Fang, Salim et al. 2011
Many more GV galaxies with similar properties.
Colors imply underlying substrate of older stars
Fang, Salim et al. 2011
ESFETGs
Mass-matched in blue cloud
Fang, Salim et al. 2011
HST FUV images
Fang, Salim et al. 2011
GALEX: M31
Part III:Structure of AEGIS galaxies on Red Sequence vs. Blue Cloud at z ~ 0.8
Edmond Cheung, Liz McGrath, & David Koo
Edmond
Try different combinations of mass and radius
Cheung et al. 2011
DEEP2 survey: spec z’s and photoz’s. Redshift range z = 0.5-0.8.
Mass M/reff M/reff2
None work perfectly. There is always overlap region.
Cheung et al. 2011
DEEP2 survey: spec z’s and photoz’s. Redshift range z = 0.5-0.8.
Mass M/reff M/reff2
Surface density Kauffmann+06
Cheung et al. 2011
Is there a second structural variable?
Cheung et al. 2011
DEEP2 survey: spec z’s and photoz’s. Redshift range z = 0.5-0.8.
U-B
U-B
U-B
Bulge M* is higher
Bulge radius is smaller
Bulge M*/re is lower
Cheung et al. 2011
AEGIS galaxies have bulge-disk decompositions using GIM2D.
In the overlap region, the color change is accompanied by structural changes.
Stellar mass becomes more concentrated.
Sersic index: looks like a threshold, except for outliers
Cheung et al. 2011
outliers
See also Bell+08, Bell+11
Inner mass surface density increases across color divide
McGrath, Koo et al. 2011
Rejuvenation model no good; one way trip
Structure is better predictor of quenching than halo or stellar mass
Part IV:Pre- and post-quenched galaxies in
CANDELS at z ~ 2
Mark Mozena, Tao Wang, JS Huang, and CANDELS team
Mark
Color-mass diagram: CANDELS/ERS in GOODS-S
✖ Spheroid
✖ Mixed or Irr
✖ Disk
Z = 1.5-2.5
Mozena et al. 2011
Visual classes:
Note color-mass relation already
at z~2!
Massive galaxies > 1010.8 M at z~2 in Gini/M20
Quiescent
Star-forming
Wang et al. 2011
Half quenched, half star-forming.
Strong correlation with morphology.
These SFR galaxies will all be quenched by z~1.
WFC3-IR images from CANDELS and ERS in GOODS-S
Radius-mass diagram: GOODS-S
✖ Spheroid
✖ Mixed or Irr
✖ Disk
Z = 1.5-2.5
Mozena et al. 2011
Also Cirasuolo et al. 2011
Visual classes:
Radius-mass diagram: GOODS-S
✖ Spheroid
✖ Mixed or Irr
✖ Disk
Z = 1.5-2.5
Mozena et al. 2011
Also Cirasuolo et al. 2011
Visual classes:
Almost bimodal!
Radius-mass diagram: GOODS-S
✖ Spheroid
✖ Mixed or Irr
✖ Disk
Z = 1.5-2.5
Mozena et al. 2011
Also Cirasuolo et al. 2011
Visual classes:
X5
Conclusions: There exist structural parameters that are better predictors of quenching than either halo or stellar mass. An indispensible ingredient in the quenching process at all redshifts is either caused by (or leaves its imprint on) the stellar mass distribution – stars move to center. At low z, this process does not involve major mergers or a large change in radius. At high z, gross shrinkage in radius of x5 occurs.
Is the process the same or different at high z?