J/ApJ/655/51        HDFS IRAC observations of 2<z<3.5 galaxies    (Wuyts+, 2007)
What do we learn from IRAC observations of galaxies at 2 < z < 3.5?.
    Wuyts S., Labbe I., Franx M., Rudnick G., Van Dokkum P.G., Fazio G.G.,
    Forster Schreiber N.M., Huang J., Moorwood A.F.M., Rix H.-W.,
    Rottgering H., Van Der Werf P.
   <Astrophys. J., 655, 51-65 (2007)>
   =2007ApJ...655...51W 2007ApJ...655...51W
ADC_Keywords: Galaxies, IR ; Photometry, infrared ; Redshifts
Keywords: galaxies: evolution - galaxies: high-redshift - infrared: galaxies
Abstract:
    We analyze very deep HST, VLT, and Spitzer photometry of galaxies at
    2<z<3.5 in the Hubble Deep Field-South. The sample is selected from
    the deepest public K-band imaging currently available. We show that
    the rest-frame U-V versus V-J color-color diagram is a powerful
    diagnostic of the stellar populations of distant galaxies. Galaxies
    with red rest-frame U-V colors are generally red in rest-frame V-J as
    well. However, at a given U-V color a range in V-J colors exists, and
    we show that this allows us to distinguish young, dusty galaxies from
    old, passively evolving galaxies. We quantify the effects of IRAC
    photometry on estimates of masses, ages, and the dust content of z>2
    galaxies.
Description:
    Observations of the HDF-S WFPC2 field were obtained with IRAC on the
    Spitzer Space Telescope in 2004 June and 2005 June (GTO program 214).
    A field of view was covered by the four broadband filters at 3.6, 4.5,
    5.8, and 8um.
File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
table3.dat     69       75   K+IRAC photometry of HDFS galaxies at 2<z<3.5
table4.dat     73       75   Modeling results for HDFS galaxies at 2<z<3.5
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See also:
   J/AJ/119/486  : HDF-S: STIS imaging (Gardner+, 2000)
   J/AJ/125/1107 : Ultra-deep near-IR observations in HDF-S (Labbe+, 2003)
   J/A+A/452/119 : EIS: infrared observations of CDF-S and HDF-S (Olsen+, 2006)
   J/AJ/131/2383 : Photometry and spectroscopy in the HDF-S (Glazebrook+, 2006)
Byte-by-byte Description of file: table3.dat
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   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1-  3  I3    ---     [LFR2003] Object identification number (1)
   5-  9  F5.2  ---     FKtot     Total aperture K band flux (2)
  11- 14  F4.2  ---   e_FKtot     Uncertainty in FKtot
  16- 20  F5.2  ---     FK        Color aperture K band flux (2)
  22- 25  F4.2  ---   e_FK        Uncertainty in FK
  27- 31  F5.2  ---     F3.6      Color aperture 3.6 micron flux (2)
  33- 36  F4.2  ---   e_F3.6      Uncertainty in f3.6
  38- 42  F5.2  ---     F4.5      Color aperture 4.8 micron flux (2)
  44- 47  F4.2  ---   e_F4.5      Uncertainty in f4.5
  49- 53  F5.2  ---     F5.8      Color aperture 5.8 micron flux (2)
  55- 58  F4.2  ---   e_F5.8      Uncertainty in f5.8
  60- 64  F5.2  ---     F8.0      Color aperture 8.0 micron flux (2)
  66- 69  F4.2  ---   e_F8.0      Uncertainty in f8.0
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Note (1): Object identification number corresponds to that of the U-to-K
     catalog by Labbe et al. (2003, Cat. J/AJ/125/1107).
Note (2): Scaled to an AB zeropoint of 25, i.e. magAB=25-2.5log(f).
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
   Bytes Format Units      Label     Explanations
--------------------------------------------------------------------------------
   1-  3  I3    ---        [LFR2003] Object identification number (1)
   5-  8  F4.2  ---        z         Redshift
  10- 13  F4.2  ---      E_z         Upper limit uncertainty on z
  15- 18  F4.2  ---      e_z         Lower limit uncertainty on z
  20- 29  A10   ---        SFH       Star-formation history (2)
  31- 35  F5.2 [solMass]   logM      Log of the modeled mass
  37- 40  F4.2 [solMass] E_logM      Upper limit uncertainty on logM
  42- 45  F4.2 [solMass] e_logM      Lower limit uncertainty on logM
  47- 49  F3.1  mag        AV        Model V band extinction
  51- 53  F3.1  mag      E_AV        Upper limit uncertainty on AV
  55- 57  F3.1  mag      e_AV        Lower limit uncertainty on AV
  59- 63  F5.2  [Gyr]      logA      Log of the model mass-weighted age
  65- 68  F4.2  [Gyr]    E_logA      Upper limit uncertainty on logA
  70- 73  F4.2  [Gyr]    e_logA      Lower limit uncertainty on logA
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Note (1): Object identification number corresponds to that of the U-to-K
     catalog by Labbe et al. (2003, Cat. J/AJ/125/1107).
Note (2): Star-formation history is:
    CSF = constant star-formation;
    SSP = single stellar population;
    τ300 = an exponentially declining star-formation history
                 with an e-folding timescale of 300Myr
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History:
    From electronic version of the journal
(End)                  Greg Schwarz [AAS], Patricia Vannier [CDS]    08-Dec-2008