J/ApJ/806/L35 NIR spectroscopy of COSMOS FIR galaxies (Kartaltepe+, 2015)
Rest-frame optical emission lines in far-infrared-selected galaxies at z<1.7
from the FMOS-COSMOS survey.
Kartaltepe J.S., Sanders D.B., Silverman J.D., Kashino D., Chu J.,
Zahid H., Hasinger G., Kewley L., Matsuoka K., Nagao T., Riguccini L.,
Salvato M., Schawinski K., Taniguchi Y., Treister E., Capak P., Daddi E.,
Ohta K.
<Astrophys. J., 806, L35 (2015)>
=2015ApJ...806L..35K 2015ApJ...806L..35K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR ; Redshifts ; Spectra, infrared ; X-ray sources
Keywords: cosmology: observations; galaxies: active; galaxies: evolution;
galaxies: high-redshift; infrared: galaxies; surveys
Abstract:
We have used FMOS on Subaru to obtain near-infrared spectroscopy of
123 far-infrared-selected galaxies in COSMOS and the key rest-frame
optical emission lines. This is the largest sample of infrared
galaxies with near-infrared spectroscopy at these redshifts. The
far-infrared selection results in a sample of galaxies that are
massive systems that span a range of metallicities in comparison with
previous optically selected surveys, and thus has a higher active
galactic nucleus (AGN) fraction and better samples the AGN branch. We
establish the presence of AGNs and starbursts in this sample of
(U)LIRGs selected as Herschel-PACS and Spitzer-MIPS detections in two
redshift bins (z∼0.7 and z∼1.5) and test the redshift dependence of
diagnostics used to separate AGNs from star formation dominated
galaxies. In addition, we construct a low-redshift (z∼0.1) comparison
sample of infrared-selected galaxies and find that the evolution from
z∼1.5 to today is consistent with an evolving AGN selection line and a
range of ISM conditions and metallicities from the models of Kewley et
al. (2013ApJ...774L..10K 2013ApJ...774L..10K). We find that a large fraction of (U)LIRGs
are BPT-selected AGNs using their new redshift-dependent
classification line. We compare the position of known X-ray-detected
AGNs (67 in total) with the BPT selection and find that the new
classification line accurately selects most of these objects (>70%).
Furthermore, we identify 35 new (likely obscured) AGNs not selected as
such by their X-ray emission. Our results have direct implications for
AGN selection at higher redshift with either current (MOSFIRE, KMOS)
or future (PFS, MOONS) spectroscopic efforts with near-infrared
spectral coverage.
Description:
The FMOS survey of the COSMOS field is divided into two parts -a now
complete low-resolution survey (R∼600; J. S. Kartaltepe et al. 2015,
in preparation) and an ongoing high-resolution survey (R∼2000;
Silverman et al. 2015ApJ...812L..23S 2015ApJ...812L..23S). Here, we focus on observations
from the low-resolution survey (range 0.9-1.8um).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 89 119 IR-selected Subaru/FMOS source properties
--------------------------------------------------------------------------------
See also:
VIII/95 : Herschel Multi-tiered Extragalactic Survey (Oliver+, 2012)
VII/265 : COSMOS Morphological Catalog (V1.1) (Tasca+ 2009)
II/284 : COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
J/MNRAS/428/1128 : UDS/COSMOS HiZELS galaxies (Sobral+, 2013)
J/ApJS/201/30 : The Chandra COSMOS survey. III. (Civano+, 2012)
J/A+A/532/A90 : PACS Evolutionary Probe (PEP-DR1) catalogs (Lutz+, 2011)
J/ApJ/721/98 : Morphology of 70um COSMOS galaxies (Kartaltepe+, 2010)
J/ApJ/716/348 : The XMM-Newton survey of the COSMOS field (Brusa+, 2010)
J/ApJ/709/884 : Role of starburst-AGN composites in LIRG mergers (Yuan+, 2010)
J/ApJ/709/572 : COSMOS 70um sources (Kartaltepe+, 2010)
J/ApJ/696/1195 : COSMOS AGN spectroscopic survey. I. (Trump+, 2009)
J/ApJS/184/158 : Chandra COSMOS survey I. (Elvis+, 2009)
J/ApJS/172/70 : zCOSMOS-bright catalog (Lilly+, 2007)
J/ApJS/172/29 : XMM-Newton survey in COSMOS field. I. (Hasinger+, 2007)
J/ApJ/660/167 : Spitzer AGN candidates in CDFN (Donley+, 2007)
J/ApJS/143/315 : Ultraluminous galaxies IRAS 1Jy sample. II. (Veilleux+, 2002)
http://wwwmpa.mpa-garching.mpg.de/SDSS/DR7/ : MPA-JHU DR7 release
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- --- [COSMOS]
8- 28 A21 --- COSMOS Source identifier (JHHMMSS.sss+DDMMSS.ss)
30- 38 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
40- 48 F9.7 deg DEdeg Declination in decimal degrees (J2000)
50- 55 F6.4 --- z [0.5/1.7] Spectroscopic redshift
57- 60 F4.1 [Lsun] logLIR [10.7/13] Log MIR-FIR SED luminosity (1)
62- 67 F6.2 [10-7W] logLX [42.5/45.2]?=-99 Log Chandra 2-10keV X-ray
luminosity; erg/s
69- 76 F8.5 --- N2/Ha [-1.2/0.2] The [NII](6548,6584) to
Hα ratio
78- 85 F8.5 --- O3/Hb [-1.5/1.4] The [OIII](4959,5007) to
Hβ ratio
87 I1 --- IR-AGN? [0/1] An IR identified AGN? (1=yes)
89 I1 --- BPT-AGN? [0/1] Baldwin, Phillips & Terlevich
1981PASP...93....5B 1981PASP...93....5B identified AGN? (1=yes)
--------------------------------------------------------------------------------
Note (1): Using the IRAC 8 micron, MIPS 24 micron, 70 micron, PACS 100 micron
and 160 micron, and SPIRE 250 micron photometry.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 21-Oct-2015