J/MNRAS/454/1332 SFR in galaxies at redshift z∼0.8 (Shetty+, 2015)
Observed trend in the star formation history and the dark matter fraction of
galaxies at redshift z ∼ 0.8.
Shetty S., Cappellari M.
<Mon. Not. R. Astron. Soc., 454, 1332-1357 (2015)>
=2015MNRAS.454.1332S 2015MNRAS.454.1332S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs
Keywords: galaxies: evolution - galaxies: formation - galaxies: haloes -
galaxies: high redshift - galaxies: star formation -
galaxies: stellar content
Abstract:
We study the star formation history for a sample of 154 galaxies with
stellar mass 1010≲M*≲1012M☉ in the redshift range
0.7<z<0.9. We do this using stellar population models combined with
full-spectrum fitting of good quality spectra and high-resolution
photometry. For a subset of 68 galaxies (M*≳1011M☉) we
additionally construct dynamical models. These use an axisymmetric
solution to the Jeans equations, which allows for velocity anisotropy,
and adopts results from abundance matching techniques to account for
the dark matter content. We find that (i) the trends in star formation
history observed in the local Universe are already in place by z∼1:
the most massive galaxies are already passive, while lower mass ones
have a more extended star formation histories, and the lowest mass
galaxies are actively forming stars; (ii) we place an upper limit of a
factor 1.5 to the size growth of the massive galaxy population; (iii)
we present strong evidence for low dark matter fractions within 1Re
(median of 9 per cent and 90th percentile of 21 per cent) for galaxies
with M*≳1011M☉ at these redshifts; and (iv) we confirm that
these galaxies have, on average, a Salpeter normalization of the
stellar initial mass function.
Description:
The spectral data used in this study was taken from the DEEP2 survey.
The observations for the survey were done using the DEIMOS
spectrograph on the Keck-2 telescope, covering an observed wavelength
range of 6100-9100Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 52 154 Results of Stellar Population Modelling
table3.dat 37 68 Results of our Dynamical Modelling
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See also:
II/301 : The DEEP2-DR1 Photometric Catalog (Coil+ 2004)
III/268 : DEEP2 Redshift Survey, Data Release 4 (Matthews+ 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- DEEP2 DEEP2 galaxy identifier
10- 14 F5.3 --- z DEEP2 estimated redshift
16- 19 F4.1 kpc Re Effective radius of the galaxy derived
analytically from the circularized MGE
model (1)
21- 24 F4.1 kpc ReMaj Major axis of the isophote containing half of
the observed light of the galaxy (2)
26- 31 F6.2 mag BMAG Absolute B-(Vega) band magnitude of the
galaxies derived analytically through MGE
models of the F814W photometry
33- 35 F3.1 Msun/Lsun M*/LSalB Mass-weighted M*/LB derived through the
regularized full-spectrum fit using the
entire template grid (3)
37- 40 F4.2 Gyr AgeM Mass-weighted age of the galaxies calculated
from the regularized full-spectra fit using
the entire template grid
42- 45 F4.2 Gyr AgeL Luminosity-weighted age of the galaxies
calculated from a regularized full-spectra
fit using the entire template grid
47- 52 F6.3 [Msun] logM*Sal log of the stellar mass (4)
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Note (1): This Re has been corrected for the underestimation that was shown in
Shetty & Cappellari (2014ApJ...786L..10S 2014ApJ...786L..10S).
Note (2): Similar to the Re, this value has also been corrected for the
underestimation.
Note (3): In this study, we adopt the intrinsic scatter between the (M*/L)
derived through the different methods and template grids as their error,
i.e. 0.08dex.
Note (4): derived using the values in Column AgeM and Column BMAG.
Adopting the intrinsic scatter between our value and that of
Bundy et al. (2006ApJ...651..120B 2006ApJ...651..120B), 0.16dex is a good approximation
to the error in this value.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- DEEP2 DEEP2 galaxy identifier
10- 14 F5.1 km/s sigma Velocity dispersion as measured by
full-spectrum fitting of the galaxy spectra
16- 19 F4.1 km/s e_sigma Error on the derived velocity disperion of
the galaxy through a bootstrapping technique
21- 24 F4.2 Msun/Lsun M*/LJAM B-band stellar (M*/L) derived through
dynamical modelling (1)
26- 31 F6.3 [Msun] logM*JAM log of the stellar mass of the galaxy derived
using the absolute luminosity and
the M/L of M*/LJAM
33- 37 F5.3 --- fDM Fraction of dark matter within 1Re of the
galaxy (2)
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Note (1): where the dark matter halo was assigned using the SHMR of
Leauthaud et al. (2012ApJ...744..159L 2012ApJ...744..159L).
Note (2): This was derived bu using the SHMR of
Leauthaud et al. (2012ApJ...744..159L 2012ApJ...744..159L).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 28-Jun-2016