J/ApJS/234/21 hCOSMOS: Hectospec survey of galaxies in COSMOS (Damjanov+, 2018)
hCOSMOS: a dense spectroscopic survey of r≤21.3 galaxies in the COSMOS field.
Damjanov I., Zahid H.J., Geller M.J., Fabricant D.G., Hwang Ho S.
<Astrophys. J. Suppl. Ser., 234, 21 (2018)>
=2018ApJS..234...21D 2018ApJS..234...21D
ADC_Keywords: Galaxies ; Spectra, optical ; Velocity dispersion ; Stars, masses
Keywords: cosmology: observations ; galaxies: distances and redshifts ;
galaxies: evolution ; galaxies: fundamental parameters ;
galaxies: structure ; large-scale structure of universe
Abstract:
We describe the hCOSMOS redshift survey of the COSMOS field conducted
with the Hectospec spectrograph on the MMT. In the central 1deg2,
the hCOS20.6 subset of the survey is >90% complete to a limiting
magnitude r=20.6. The hCOSMOS survey includes 1701 new redshifts in
the COSMOS field. We also use the total of 4362 new and remeasured
objects to derive the age-sensitive Dn4000 index over the entire
redshift interval 0.001≲z≲0.6. For 85% of the quiescent galaxies in
hCOS20.6, we measure the central line-of-sight velocity dispersion. To
explore potential uses of this survey, we combine previously measured
galaxy sizes, profiles, and stellar masses with the spectroscopy. The
comparison reveals the known relations among structural, kinematic,
and stellar population properties. We also compare redshift and
Dn4000 distributions of hCOS20.6 galaxies with SHELS; a complete
spectroscopic survey of 4deg2 observed to the same depth. The
redshift distributions in the two fields are very different, but the
Dn4000 distribution is remarkably similar. The relation between
velocity dispersion and stellar mass for massive hCOS20.6 galaxies is
consistent with the local relation from the Sloan Digital Sky Survey.
Using measured velocity dispersions, we test a photometric proxy
calibrated to galaxies in the local universe. The systematic
differences between the measured and photometric proxy velocity
dispersions are correlated with galaxy dynamical and stellar
population properties highlighting the importance of direct
spectroscopic measurements.
Description:
We target galaxies with r-band magnitudes 17.77<r<21.3 in the
UltraVISTA photometric catalog of Muzzin+, 2013, J/ApJS/206/8 for
spectroscopy. We selected extended objects in HST images;
see section 2.1 for further details.
We observed hCOSMOS galaxies with Hectospec mounted on the 6.5m MMT.
The Hectospec spectra cover the wavelength range 3700-9100Å at a
resolution of R∼1500. We conducted observations during dark and gray
nights in 2015 February, 2015 April, 2016 February, and 2016 March.
We obtained 5492 science quality spectra (out of which 1405 are
duplicates) in varying conditions. We include additional 275 spectra
of galaxies in the COSMOS field from the Hectospec data archive. Thus,
the hCOSMOS sample includes 4362 unique galaxies. Among these objects,
2661 have a redshift in the zCOSMOS (Lilly+ 2007, J/ApJS/172/70 ;
2009, J/ApJS/184/218) catalog and 1701 redshifts are completely new.
For the galaxies that overlap with zCOSMOS, the Hectospec spectra
yield a redshift with a smaller error along with broader wavelength
coverage.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 109 4399 Photometric and spectroscopic properties of
the hCOSMOS galaxy sample
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See also:
III/250 : The VIMOS VLT deep survey (VVDS-DEEP) (Le Fevre+ 2005)
II/284 : COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
VII/203 : Las Campanas Redshift Survey (Shectman+ 1996)
VII/250 : 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003)
VII/259 : 6dF galaxy survey final redshift release (Jones+, 2009)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/MNRAS/276/1341 : Spectroscopy of E and S0 galaxies (Jorgensen+, 1995)
J/ApJS/142/1 : DEEP Groth Strip Survey. II. (Simard+, 2002)
J/A+A/407/423 : Coma cluster early-type galaxies. III. (Mehlert+, 2003)
J/ApJ/592/728 : Lyman break galaxies at redshift z∼3 (Steidel+, 2003)
J/AJ/127/2455 : Gemini Deep Deep Survey (GDDS) (Abraham+, 2004)
J/A+A/418/885 : The FORS Deep Field Spectroscopic Survey (Noll+, 2004)
J/ApJ/604/521 : Luminosities & masses of gal. out to z∼3 (Trujillo+, 2004)
J/AJ/127/3121 : TKRS catalog of GOODS-North Field (Wirth+, 2004)
J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)
J/ApJS/172/70 : zCOSMOS-bright catalog (Lilly+, 2007)
J/MNRAS/382/109 : Massive galaxies in Extended Groth Strip (Trujillo+, 2007)
J/ApJS/184/218 : The zCOSMOS 10k-bright spectroscopic sample (Lilly+, 2009)
J/ApJ/720/723 : Compact galaxies in the local universe (Taylor+, 2010)
J/AJ/139/1857 : Sample of major galaxy pairs at z=0.08-0.38 (Woods+, 2010)
J/ApJ/739/L44 : Structural data for gal. between 0.2<z<2.7 (Damjanov+, 2011)
J/ApJS/200/8 : AGES: the AGN and Galaxy Evolution Survey (Kochanek+, 2012)
J/A+A/544/A156 : UltraVISTA Catalogue Release DR1 (McCracken+, 2012)
J/ApJS/206/8 : COSMOS/UltraVISTA Ks-selected catalogs v4.1 (Muzzin+, 2013)
J/ApJ/762/77 : PM2GC mass-limited sample surface photom. (Poggianti+, 2013)
J/MNRAS/441/203 : Massive quiescent ETG in clusters (Delaye+ 2014)
J/ApJS/213/35 : SHELS: galaxy redshift survey for R≤20.6 (Geller+, 2014)
J/ApJS/220/12 : FMOS-COSMOS survey III. 0.7<z<2.5 galaxies (Silverman+, 2015)
J/ApJS/224/11 : SHELS: redshift survey of the F1 DLS field (Geller+, 2016)
J/ApJ/821/101 : Stellar MFP for massive quiescent z<0.7 gal. (Zahid+, 2016)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg RAdeg [149.4/150.8] Right Ascension (J2000)
12- 19 F8.6 deg DEdeg [1.6/2.9] Declination (J2000)
21- 29 A9 --- Inst Instrument used for spectroscopy
("hectospec", "SDSS" or "BOSS")
31- 36 I6 --- [MMS2013] [1/262338] UltraVISTA ID from
Muzzin+ (2013, J/ApJS/206/8)
38- 44 F7.5 --- z [0.001/1.3] Spectroscopic redshift
46- 52 F7.5 --- e_z [0/0.0006] Uncertainty in z
54- 60 F7.2 --- Dn4000 [0.4/7.5]?=-999 Dn4000 break
62- 68 F7.2 --- e_Dn4000 [0.01/3.7]?=-999 Uncertainty in Dn4000
70- 73 I4 km/s sigma [91/950]?=-999 Measured velocity dispersion
before fiber aperture correction
75- 78 I4 km/s e_sigma [6/462]?=-999 Uncertainty in sigma
80- 86 F7.2 [Msun] LogM [6.2/11.93]?=-999 Stellar mass
88- 93 F6.2 [Msun] E_LogM [0.03/0.6]?=999 Superior uncertainty in LogM
95-100 F6.2 [Msun] e_LogM [0.03/0.7]?=999 Inferior uncertainty in LogM
102-109 A8 --- Comm Comment (1)
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Note (1): Comment as follows:
hCOS20.6 = r<20.6mag (90% complete) (1968 occurrences);
hCOSMOS = 20.6mag<r<21.3 mag (2431 occurrences).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Mar-2018