J/ApJ/793/39 Spectroscopic properties of BOSS compact galaxies (Damjanov+, 2014)
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The number density of quiescent compact galaxies at intermediate redshift.
    Damjanov I., Hwang H.S., Geller M.J., Chilingarian I.
   <Astrophys. J., 793, 39 (2014)>
   =2014ApJ...793...39D    (SIMBAD/NED BibCode)
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ADC_Keywords: Galaxies, optical ; Redshifts ; Velocity dispersion ; Abundances ;
              Morphology
Keywords: galaxies: evolution - galaxies: fundamental parameters -
          galaxies: stellar content - galaxies: structure

Abstract:
    Massive compact systems at 0.2<z<0.6 are the missing link between
    the predominantly compact population of massive quiescent galaxies at
    high redshift and their analogs and relics in the local volume. The
    evolution in number density of these extreme objects over cosmic time
    is the crucial constraining factor for the models of massive galaxy
    assembly. We select a large sample of ~200 intermediate-redshift
    massive compacts from the Baryon Oscillation Spectroscopic Survey
    (BOSS) spectroscopy by identifying point-like Sloan Digital Sky Survey
    photometric sources with spectroscopic signatures of evolved
    redshifted galaxies. A subset of our targets have publicly available
    high-resolution ground-based images that we use to augment the
    dynamical and stellar population properties of these systems by their
    structural parameters. We confirm that all BOSS compact candidates are
    as compact as their high-redshift massive counterparts and less than
    half the size of similarly massive systems at z~0. We use the
    completeness-corrected numbers of BOSS compacts to compute lower
    limits on their number densities in narrow redshift bins spanning the
    range of our sample. The abundance of extremely dense quiescent
    galaxies at 0.2<z<0.6 is in excellent agreement with the number
    densities of these systems at high redshift. Our lower limits support
    the models of massive galaxy assembly through a series of minor
    mergers over the redshift range 0<z<2.

Description:
    We use the BOSS DR10 data set (Ahn et al. 2014ApJS..211...17A) and
    employ the selection criteria of Damjanov et al. (2013ApJ...775L..48D)
    to select compact galaxy candidates in the redshift range 0.2<z<0.6.
    We search for stellar-like objects with spectroscopic redshifts in the
    redshift range of interest (22288 sources) and exclude all
    spectroscopically confirmed quasars (14108 sources) and actively
    star-forming galaxies (by requiring the equivalent width of the
    [OII]{lambda}{lambda}3726, 3729 emission line to be EW [OII]<5{AA};
    7299 sources excluded). In addition, we inspect every pre-selected
    spectrum to identify a 4000{AA} break and several absorption features
    including the Balmer series, Ca H+K, and G band. We also apply a cut
    to the inferred dynamical mass at M_dyn_=10^10^M_sun_ to construct a
    sample of compact quiescent systems as massive as high- and
    low-redshift comparison samples (see Sections 4 and 5.3). The final
    list of BOSS compact galaxy candidates at redshift 0.2<z<0.6 contains
    198 objects.

File Summary:
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 FileName      Lrecl  Records   Explanations
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ReadMe            80        .   This file
table1.dat        75      198   Spectroscopic Properties of Compact Galaxy
                                Candidates Selected from BOSS
table2.dat        88       14   Structural Properties of BOSS Compact Galaxies
                                at Intermediate Redshift with Existing CFHT
                                Imaging
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See also:
 II/317           : The CFHTLS Survey (T0007 release) (Hudelot+ 2012)
 V/147            : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
 J/MNRAS/418/1055 : BOSS morphology of galaxies (Masters+, 2011)

Byte-by-byte Description of file: table1.dat
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   Bytes Format Units   Label     Explanations
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   1- 19  I19   ---     SDSS      SDSS object identification number
  21- 25  F5.3  ---     z         Redshift
  27- 34  F8.4  deg     RAdeg     Right Ascension in decimal degrees (J2000)
  36- 44  F9.6  deg     DEdeg     Declination in decimal degrees (J2000)
  46- 48  I3    km/s    sigma     Velocity Dispersion
  50- 51  I2    km/s  e_sigma     Error in sigma (1)
      53  A1    ---   l_Age       [<] Limit flag on Age
  55- 59  I5    Myr     Age       Galaxy Age of best-fit SSP model
  61- 64  I4    Myr   e_Age       ? Error in Age (1)
  66- 70  F5.2  ---     [Z/H]     Metallicity of best-fit SSP model
  72- 75  F4.2  ---   e_[Z/H]     Error in [Z/H] (1)
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Note (1): The internal kinematics and stellar population errors are formally
  computed statistical errors and do not include possible systematic
  uncertainties.
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Byte-by-byte Description of file: table2.dat
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   Bytes Format Units   Label     Explanations
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   1- 19  I19   ---     SDSS      SDSS object identification number
  21- 24  A4    ---     ---       [SDSS]
  25- 43  A19   ---     Name      SDSS designation (JHHMMSS.ss+DDMMSS.s)
  45- 49  F5.3  ---     z         Redshift
      51  A1    ---   l_Rec       [<] Limit flag on Rec
  52- 55  F4.2  kpc     Rec       Circularized half-light radius of
                                   the single-profile model (1)
  57- 60  F4.2  kpc   e_Rec       ? Error in Rec
  62- 65  F4.2  ---     n         ? Sersic index of the single-profile model
  67- 70  F4.2  ---   e_n         ? Error in n
  72- 75  F4.2  ---     b/a       ? Axial ratio of the single-profile model
  77- 80  F4.2  ---   e_b/a       ? Error in b/a
  82- 83  A2    ---     Filter    [g'r'i'z'] CFHT MegaCam filter
  85- 88  F4.2  kpc     HWFM      Half width at the half maximum of the
                                   point-spread function (2)
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Note (1): R_e,c_=R_e_.sqrt(b/a), where Re is the half-light radius along
  the major axis and b/a is the axial ratio.
Note (2): In units of kiloparsecs at the target's redshift, constructed by
  combining a set of stars in the CFHT MegaCam image.
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History:
    From electronic version of the journal

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(End)                Prepared by Tiphaine Pouvreau [CDS]             18-Apr-2017