J/ApJ/928/78 Extreme emission line galaxies in COSMOS & NEP (Rosenwasser+, 2022)
Subaru/Hyper Suprime-Cam z-broadband excess selection of extreme emission line
galaxies at z<1.
Rosenwasser B.E., Taylor A.J., Barger A.J., Cowie L.L., Hu E.M.,
Jones L.H., Songaila A.
<Astrophys. J., 928, 78 (2022)>
=2022ApJ...928...78R 2022ApJ...928...78R
ADC_Keywords: Galaxies, spectra; Redshifts; Photometry, ugriz
Keywords: Emission line galaxies ; Broad band photometry ; Galaxy evolution
Abstract:
We present a search for extreme emission line galaxies (EELGs) at z<1
in the COSMOS and North Ecliptic Pole (NEP) fields with imaging from
Subaru/Hyper Suprime-Cam (HSC) and a combination of new and existing
spectroscopy. We select EELGs on the basis of substantial excess flux
in the z broad band, which is sensitive to Hα at 0.3≲z≲0.42
and [OIII]λ5007 at 0.7≲z≲0.86. We identify 10470 galaxies
with zexcesses in the COSMOS data set and 91385 in the NEP field. We
cross- reference the COSMOS EELG sample with the zCOSMOS and DEIMOS
10k spectral catalogs, finding 1395 spectroscopic matches. We made an
additional 71 (46 unique) spectroscopic measurements with Y<23 using
the HYDRA multiobject spectrograph on the WIYN 3.5m telescope, and
204 spectroscopic measurements from the DEIMOS spectrograph on the
Keck II telescope, providing a total of 1441/10470 spectroscopic
redshifts for the EELG sample in COSMOS (∼14%). We confirm that
1418 (∼98%) are Hα or [OIII]λ5007 emitters in the above
stated redshift ranges. We also identify 240 redshifted Hα and
[OIII]λ5007 emitters in the NEP using spectra taken with
WIYN/HYDRA and Keck/DEIMOS. Using broadband-selection techniques in
the g-r-i color space, we distinguish between Hα and
[OIII]λ5007 emitters with 98.6% accuracy. We test our EELG
selection by constructing Hα and [OIII]λ5007 luminosity
functions and comparing to recent literature results. We conclude that
broadband magnitudes from HSC, the Vera C. Rubin Observatory, and
other deep optical multiband surveys can be used to select EELGs in a
straightforward manner.
Description:
Our COSMOS magnitudes come from the Hyper Suprime-Cam Subaru Strategic
Program DR3 (HSC-SSP PDR3; see details in Aihara+ 2022PASJ...74..247A 2022PASJ...74..247A).
We use the COSMOS Deep and UltraDeep data sets, and we select a
subregion covering 3.15deg2.
Our NEP imaging data come from the Hawaii EROsita Ecliptic pole Survey
(HEROES) and consist of 34.2deg2 of deep grizY broadband and NB816,
NB921 narrowband imaging. The full details on the observations and
data reduction for HEROES are given in Songaila+ 2018ApJ...859...91S 2018ApJ...859...91S
See Section 2.
In order to characterize the z-excess selection for use with existing
and future multiband catalogs, we calibrated the photometric selection
above using newly observed and archival spectroscopic redshifts.
First, we matched our COSMOS photometric sample to three spectroscopic
surveys in the COSMOS field:
zCOSMOS Bright 20k (Lilly+ 2009, J/ApJS/184/218),
DEIMOS 10k (Hasinger+ 2018, J/ApJ/858/77), and our WIYN-targeted
samples. We performed additional spectroscopic follow-up for a small
number of COSMOS sources with Y≲23 using the multiobject spectrograph
HYDRA on the 3.5m WIYN telescope at Kitt Peak National Observatory.
The observations were made in a series of runs in 2016 January,
February, and March.
We used the same HYDRA configuration to observe sources in the
spectroscopically unexplored NEP during runs in 2017 June, 2017
October, 2018 May, and 2018 September.
We supplemented our catalog of WIYN/HYDRA spectra with sources from
various Keck/DEIMOS runs. See Section 3.
We assume ΩM=0.3, ΩΛ=0.7, and H0=70km/s/Mpc
throughout. All magnitudes are provided in the AB magnitude system,
where an AB magnitude is defined by mAB=-2.5logfν-48.60, and
fν, the flux of the source, is given in units of erg/cm2/s/Hz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 68 298 Selected spectroscopic redshifts
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See also:
VII/292 : DESI Legacy Imaging Surveys DR8 photometric redshifts (Duncan, 2022)
J/ApJ/668/853 : Spectroscopy of UltraStrong Em. Line gal. (Kakazu+, 2007)
J/ApJ/657/738 : SDF galaxies multi-photometry (Ly+, 2007)
J/ApJS/172/456 : [OII] emitting galaxies in COSMOS & SDF (Takahashi+, 2007)
J/ApJS/184/158 : Chandra COSMOS survey I. (Elvis+, 2009)
J/ApJS/184/218 : The zCOSMOS 10k-bright spectroscopic sample (Lilly+, 2009)
J/A+A/510/A56 : zCOSMOS type-2 AGN (Bongiorno, 2010)
J/ApJ/742/111 : Extreme emission-line gal. in CANDELS (van der Wel+, 2011)
J/MNRAS/428/1128 : UDS/COSMOS HiZELS galaxies (Sobral+, 2013)
J/A+A/578/A105 : EELGs out to z∼1 in zCOSMOS (Amorin+, 2015)
J/MNRAS/451/2303 : CF-HiZELS survey (Sobral+, 2015)
J/ApJS/224/24 : The COSMOS2015 catalog (Laigle+, 2016)
J/A+A/592/A122 : Starburst gal. in the COSMOS field (Hinojosa-Goni+, 2016)
J/MNRAS/471/629 : Bootes-HiZELS. Em-line gal. at z=0.4-4.7 (Matthee+, 2017)
J/ApJ/847/38 : Extreme emission line galaxies at z≲0.05 (Yang+, 2017)
J/ApJ/858/77 : DEIMOS 10K sp. survey in COSMOS field (Hasinger+, 2018)
J/ApJ/860/83 : Extreme [OIII] emitters at z∼0.5 from SDSS-DR14 (Li+, 2018)
J/ApJ/854/29 : High-EW [OIII] and Ha emitters from 3D-HST (Maseda+, 2018)
J/ApJS/258/11 : The COSMOS2020 catalog (Weaver+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Field Field identifier ("NEP" or "COSMOS")
8- 16 F9.5 deg RAdeg [149/274.5] Right Ascension (J2000)
18- 25 F8.5 deg DEdeg [1.4/69] Declination (J2000)
27- 31 F5.2 mag gmag [18.69/24.1] Apparent g band AB magnitude
33- 37 F5.2 mag rmag [18.4/23.8] Apparent r band AB magnitude
39- 43 F5.2 mag imag [18.4/23.5] Apparent i band AB magnitude
45- 49 F5.2 mag zmag [17.7/22.8] Apparent z band AB magnitude
51- 55 F5.2 mag Ymag [18.16/23] Apparent Y band AB magnitude
57- 61 F5.3 --- z [0.3/0.9] Spectroscopic redshift
63- 68 A6 --- Inst Instrument used ("HYDRA" or "DEIMOS")
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-Jan-2024