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J/MNRAS/382/109    Massive galaxies in Extended Groth Strip    (Trujillo+, 2007)
Strong size evolution of the most massive galaxies since z∼2.
    Trujillo I., Conselice C.J., Bundy K., Cooper M.C., Eisenhardt P.,
    Ellis R.S.
   <Mon. Not. R. Astron. Soc., 382, 109-120 (2007)>
   =2007MNRAS.382..109T
ADC_Keywords: Galaxies, photometry ; Morphology ; Redshifts

Keywords: galaxies: elliptical and lenticular, cD - galaxies: evolution -
          galaxies: formation - galaxies: fundamental parameters -
          galaxies: high-redshift - galaxies: structure

Abstract:
    Using the combined capabilities of the large near-infrared
    Palomar/DEEP-2 survey, and the superb resolution of the Advanced
    Camera for Surveys HST camera, we explore the size evolution of 831
    very massive galaxies (M*≥1011h-270M☉) since z∼2. We
    split our sample according to their light concentration using the
    Sersic index n. At a given stellar mass, both low (n<2.5) and high
    (n>2.5) concentrated objects were much smaller in the past than
    their local massive counterparts. This evolution is particularly
    strong for the highly concentrated (spheroid like) objects. At z∼1.5,
    massive spheroid-like objects were a factor of 4(±0.4) smaller (i.e.
    almost two orders of magnitudes denser) than those we see today. These
    small sized, high-mass galaxies do not exist in the nearby Universe,
    suggesting that this population merged with other galaxies over
    several billion years to form the largest galaxies we see today.

Description:
    We use the Palomar Observatory Wide-field Infrared (POWIR)/DEEP-2
    survey (Davis et al., 2003, SPIE, Vol. 4834, p. 161; Bundy et al.,
    2006ApJ...651..120B ; Conselice et al., 2007ApJ...660L..55C,
    2007MNRAS.381..962C) to define a sample of 831 galaxies with masses
    larger than 1011h70-2M☉ located over ∼710arcmin2 in the
    Extended Groth Strip (EGS). This field (63 Hubble Space Telescope
    tiles) was imaged with the Advanced Camera for Surveys (ACS) in the V
    band (F606W, 2660s) and I band (F814W, 2100s). Each tile was observed
    in four exposures that were combined to produce a pixel scale of
    0.03arcsec, with a point spread function (PSF) of 0.12arcsec full
    width half-maximum (FWHM). In addition to the HST data, optical
    imaging from the CanadaFranceHawaii Telescope 3.6-m telescope in the
    B, R and I bands taken with the CFH12K camera was used. Integration
    times for these observations were 1h in B and R, and 2h in I. Limiting
    magnitudes reached are B=24.5 (AB, 8σ), R=24.2 (AB, 8σ)
    and I=23.5 (AB, 8σ). The details of the data reduction for this
    data are provided in Coil et al. (2004ApJ...617..765C).

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
tablea1.dat       63      796   Properties of the Palomar/DEEP2 sample galaxies


Byte-by-byte Description of file: tablea1.dat

   Bytes Format Units       Label     Explanations

   1-  8  I8    ---        [TCB2007]  Galaxy identification number
  10- 14  F5.2  mag         Ks        Ks magnitude (in Vega system)
  16- 19  F4.2  arcsec      ae        Effectif radius along semi-major axis
  21- 24  F4.2  ---         n         Sersic index (f(r)∝r1/n)
  26- 29  F4.2  ---         eps       Ellipticity of the source
  31- 35  F5.2 10+10solMass Mstar     Stellar mass of the galaxy
                                       (in 1010(h70)-2M☉
  37- 40  F4.2  ---         z         Measured redshift (see 'n_z' column)
  42- 51  F10.6 deg         RAdeg     Right ascension in decimal degrees (J2000)
  53- 61  F9.6  deg         DEdeg     Declination in decimal degrees (J2000)
      63  I1    ---         n_z       [0/1] spectroscopic (0) or photometric (1)
                                            redshift


History:
    From electronic version of the journal
(End)                                      Patricia Vannier [CDS]    31-Mar-2008