J/ApJ/858/77 DEIMOS 10K spectroscopic survey in COSMOS field (Hasinger+, 2018)
The DEIMOS 10K spectroscopic survey catalog of the COSMOS field.
Hasinger G., Capak P., Salvato M., Barger A.J., Cowie L.L., Faisst A.,
Hemmati S., Kakazu Y., Kartaltepe J., Masters D., Mobasher B., Nayyeri H.,
Sanders D., Scoville N.Z., Suh H., Steinhardt C., Yang F.
<Astrophys. J., 858, 77 (2018)>
=2018ApJ...858...77H 2018ApJ...858...77H
ADC_Keywords: Galaxies, spectra; Redshifts; Optical; Photometry, infrared;
Surveys
Keywords: catalogs ; galaxies: distances and redshifts ; surveys
Abstract:
We present a catalog of 10718 objects in the COSMOS field, observed
through multi-slit spectroscopy with the Deep Imaging Multi-Object
Spectrograph (DEIMOS) on the Keck II telescope in the wavelength range
∼5500-9800Å. The catalog contains 6617 objects with high-quality
spectra (two or more spectral features), and 1798 objects with a
single spectroscopic feature confirmed by the photometric redshift.
For 2024 typically faint objects, we could not obtain reliable
redshifts. The objects have been selected from a variety of input
catalogs based on multi-wavelength observations in the field, and thus
have a diverse selection function, which enables the study of the
diversity in the galaxy population. The magnitude distribution of our
objects is peaked at IAB∼23 and KAB∼21, with a secondary peak at
KAB∼24. We sample a broad redshift distribution in the range 0<z<6,
with one peak at z∼1, and another one around z∼4. We have identified
13 redshift spikes at z>0.65 with chance probabilities <4x10-4, some
of which are clearly related to protocluster structures of sizes
>10Mpc. An object-to-object comparison with a multitude of other
spectroscopic samples in the same field shows that our DEIMOS sample
is among the best in terms of fraction of spectroscopic failures and
relative redshift accuracy. We have determined the fraction of
spectroscopic blends to about 0.8% in our sample. This is likely a
lower limit and at any rate well below the most pessimistic
expectations. Interestingly, we find evidence for strong lensing of
Lyα background emitters within the slits of 12 of our target
galaxies, increasing their apparent density by about a factor of 4.
Description:
The spectroscopic observations in the COSMOS field were conducted with
DEIMOS on the Keck II telescope. The field of view (FOV) of DEIMOS is
approximately 16x4arcmin2. The observing log, covering the years
2007-2017, is shown in Table 2.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 87 103 List of observed slit masks
table3.dat 132 10770 List of spectral identifications
--------------------------------------------------------------------------------
See also:
II/284 : COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
J/ApJS/155/271 : CDF-South: Optical spectroscopy (Szokoly+, 2004)
J/ApJS/155/73 : Photometric redshifts of X-ray sources in CDF-S (Zheng+, 2004)
J/ApJ/644/100 : SDSS quasars in the COSMOS field (Prescott+, 2006)
J/ApJ/671/1227 : Lyα galaxies at z∼4.5 (Dawson+, 2007)
J/ApJS/172/29 : XMM-Newton survey in COSMOS field. I. (Hasinger+, 2007)
J/ApJS/172/70 : zCOSMOS-bright catalog (Lilly+, 2007)
J/ApJS/172/456 : [OII] emitting gal. in COSMOS & SDF fields (Takahashi+, 2007)
J/ApJ/693/8 : High-redshift QSOs in the COSMOS survey (Brusa+, 2009)
J/ApJ/690/1236 : COSMOS photometric redshift catalog (Ilbert+, 2009)
J/ApJS/184/218 : The zCOSMOS 10k-bright spectroscopic sample (Lilly+, 2009)
J/ApJ/696/1195 : COSMOS AGN spectroscopic survey. I. (Trump+, 2009)
J/ApJ/716/348 : The XMM-Newton survey of the COSMOS field (Brusa+, 2010)
J/ApJ/709/572 : COSMOS 70um sources (Kartaltepe+, 2010)
J/ApJ/721/98 : Morphology of 70um COSMOS galaxies (Kartaltepe+, 2010)
J/ApJS/192/5 : Emission-line galaxies from HETDEX pilot survey (Adams+, 2011)
J/ApJ/742/61 : Phot. redshift of AGNs from XMM- and C-COSMOS (Salvato+ 2011)
J/ApJS/201/30 : The Chandra COSMOS survey. III. (Civano+, 2012)
J/ApJ/759/6 : SEDs of type I AGN in COSMOS. I. XMM-COSMOS (Elvis+, 2012)
J/ApJS/198/1 : Photometry catalogs for the Lockman Hole (Fotopoulou+, 2012)
J/ApJ/760/128 : Lyα from 4<z<6 sources in COSMOS (Mallery+, 2012)
J/ApJ/755/169 : 3<z<5 quasar luminosity function in COSMOS (Masters+, 2012)
J/A+A/556/A55 : Multi-color photometry of star-forming gal. (Ilbert+, 2013)
J/MNRAS/443/2679 : GEEC2 spectroscopic survey of Galaxy groups (Balogh+, 2014)
J/A+A/575/A40 : [OII] luminosity function (Comparat+, 2015)
J/ApJ/806/L35 : NIR spectroscopy of COSMOS FIR galaxies (Kartaltepe+, 2015)
J/ApJS/220/12 : FMOS-COSMOS survey III. 0.7<z<2.5 galaxies (Silverman+, 2015)
J/ApJ/815/129 : X-ray AGNs with Subaru/FMOS NIR observations (Suh+, 2015)
J/ApJS/224/24 : The COSMOS2015 catalog (Laigle+, 2016)
J/ApJ/817/34 : C-COSMOS Legacy sources multiwavelength cat. (Marchesi+, 2016)
J/ApJS/225/27 : 3D-HST Survey: grism spectra master catalog (Momcheva+, 2016)
J/ApJ/841/111 : C3R2 survey: high-confidence z from DR1 (Masters+, 2017)
J/ApJS/234/21 : hCOSMOS: Hectospec survey of gal. in COSMOS (Damjanov+, 2018)
http://cosmos.astro.caltech.edu/ : COSMOS home page
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Mask Mask
11- 12 I2 h RAh [9/10] Hour of Right Ascension (J2000)
14- 15 I2 min RAm Minute of Right Ascension (J2000)
17- 18 I2 s RAs Second of Right Ascension (J2000)
20- 20 A1 --- DE- [+] Sign of the Declination (J2000)
21- 22 I2 deg DEd [1/2] Degree of Declination (J2000)
24- 25 I2 arcmin DEm Arcminute of Declination (J2000)
27- 30 F4.1 arcsec DEs Arcsecond of Declination (J2000)
32- 36 F5.1 deg PA [-98/303.2] Position angle, east of north
38- 47 A10 "D/M/Y" obs.date UTC observation date
49- 56 A8 "h:m:s" obs.time UTC observation time
58- 60 F3.1 h Exp [0.3/2] Exposure time, hours
62- 65 F4.2 --- Airmass [1/3] Airmass
67- 71 A5 --- Grating Grating (1)
73- 77 A5 --- Filter Filter (GG455, GG495 or OG550)
79- 81 I3 --- Nsl [43/123] Number of slits assigned
83- 84 I2 --- Nz [30/96] Number of high-quality redshifts
(Q≥1.5)
86- 87 I2 --- Nsep [0/20] Number of serendipitous sources
--------------------------------------------------------------------------------
Note (1): The 600ZD grating yields a wavelength coverage of ∼4800-10000Å
with a dispersion of 0.65Å/pixel and a spectral resolution of R∼2000.
The 830G grating yields a wavelength coverage of ∼6700-10500Å with
a dispersion of 0.47Å/pixel and a spectral resolution of R∼2700.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Identifier (1)
10- 20 F11.7 deg RAdeg [149.3/151] Right Ascension (J2000)
22- 31 F10.8 deg DEdeg [1.4/3] Declination (J2000)
33- 35 I3 --- sel [1/960] Subsample identifier (2)
37- 41 F5.2 mag imag [8/31.5]? I bandpass AB magnitude (3)
43- 47 F5.2 mag Kmag [12/30.4]? K bandpass AB magnitude (3)
49- 54 F6.4 --- zspec [0/6.7]? Spectroscopic redshift
56- 57 I2 --- Qf [0/19] Original spectroscopic quality flag
(4=very secure redshift) (4)
59- 61 F3.1 --- Q [0/2] Comprehensive spectral quality flag
(2=reliable spectroscopic identification;
1=uncertain) (5)
63-132 A70 --- Remarks Remarks (6)
--------------------------------------------------------------------------------
Note (1): Object identifier from the major two photometric catalogues. An
"L" in front of the number refers to the red multiband-band selected
catalogue of Laigle+ (2016, J/ApJS/224/24 ; <COSMOS2015 NNNNNNN> in Simbad).
A "C" in front of the number refers to the i-band selected catalogue of
Capak+ (2007, II/284 ; in Simbad) and
Ilbert+ (2009, J/ApJ/690/1236 ; <[ICS2009] NNNNNNN> in Simbad).
If an object is not present in either of these catalogs it does not have an
identifier (the value is blank).
Note (2): The subsample identifier, sel, is a decimal representation of a
binary flag containing the X-ray, high-z, MIPS, VLA, Herschel,
optically variable sources ("OVV", Salvato+, 2009ApJ...690.1250S 2009ApJ...690.1250S),
OII, PL AGN, Filler and Serendipitous flag following the order in
table 4 and figure 1:
sel=512*X+256*hiz+128*M+64*VLA+32*H+16*OVV+8*OII+4*PL+2*Fil+1*ser
See section 2 for further explanations.
Note (3): Magnitudes based on the ultradeep Subaru Hyper Suprime-Cam
(Tanaka et al. 2017arXiv170600566T 2017arXiv170600566T) and UltraVista (Laigle+
2016, J/ApJS/224/24), the Subaru Suprime-Cam (Ilbert+
2009, J/ApJ/690/1236), and the Hubble ACS (Koekemoer+
2007ApJS..172..196K 2007ApJS..172..196K) photometric catalogs. Because of field-coverage,
bright star cut-outs, blending or other confusion issues not all objects
in the spectroscopic catalogue are covered by a single photometric
catalogue, and we thus have to refer to various different imaging
datasets.
Note (4): Spectroscopic quality flag, Qf, following the original zCOSMOS
scheme (Lilly+ 2009, J/ApJS/184/218, aka the column CClass),
where values 11-19 indicate broad emission lines.
Note (5): Comprehensive quality flag Q combining spectroscopic and
photometric redshift information, following Zheng et al.
(2004, J/ApJS/155/73). The Qf flags 3, 4, 13, 14, 23, 24 are given
the value Q=2, signaling reliable spectroscopic identification. The
Qf flags 1, 2, 9, 11, 12, 19, 21, 22, 29 are given the value Q=1 for
an uncertain spectroscopic identification. However, if the photometric
redshift value for a Q=1 source is matching with the uncertain
spectroscopic redshift within an interval dz/(1+z)<0.1, where
dz=|zspec-zphot|, we raise the quality flag to Q=1.5. An
unsuccessful redshift measurement yields Q=0.
Note (6): Remarks for most objects, in particular indicating the spectral
features detected, e.g. the Lyα and Balmer lines (Hα,
Hβ, Hγ, ...) of hydrogen, or the MgII line, as well as the
[CIV], CIII], CII], [OII], [OIII], NII, and [SII] emission lines.
A "d" behind an emission line designation indicates a detected line
doublet.
A "br" behind an emission line refers to a broad emission line
profile.
An "abs" behind a line indicates its appearance in absorption rather
than emission.
"H&K" and "G" correspond to the Ca-H 3940Å and Ca-K 3960Å
absorption lines and the G 4304Å absorption band, respectively.
Other prominent absorption lines are MgI 5175Å and NaI 5892Å.
Finally, "E+A" features indicate the forest of spectral emission and
absorption features ("ringing") between the [OII] line and Ca-H & K,
characteristic of post-starburst (E+A) galaxies.
--------------------------------------------------------------------------------
Nomenclature note:
Sources in Table3 are <[HCS2018] JDDD.dddd+DD.dddd> in Simbad.
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 21-Mar-2019