J/ApJ/861/37 Luminous WISE-selected quasars in SDSS Stripe 82 (Glikman+, 2018)
Luminous WISE-selected obscured, unobscured, and red quasars in Stripe 82.
Glikman E., Lacy M., LaMassa S., Stern D., Djorgovski S.G., Graham M.J.,
Urrutia T., Lovdal L., Crnogorcevic M., Daniels-Koch H., Hundal C.B.,
Urry M., Gates E.L., Murray S.
<Astrophys. J., 861, 37 (2018)>
=2018ApJ...861...37G 2018ApJ...861...37G
ADC_Keywords: QSOs; Photometry, SDSS; Photometry, infrared; Spectra, optical;
Redshifts; Extinction; X-ray sources
Keywords: galaxies: active; galaxies: Seyfert; infrared: galaxies;
quasars: general; surveys
Abstract:
We present a spectroscopically complete sample of 147
infrared-color-selected active galactic nuclei (AGNs) down to a
22µm flux limit of 20mJy over the ∼270deg2 of the Sloan Digital
Sky Survey Stripe 82 region. Most of these sources are in the QSO
luminosity regime (Lbol≳1012L☉) and are found out to z∼3. We
classify the AGNs into three types, finding 57 blue, unobscured Type-1
(broad-lined) sources; 69 obscured, Type-2 (narrow-lined) sources; and
21 moderately reddened Type-1 sources (broad-lined and E(B-V)>0.25).
We study a subset of this sample in X-rays and analyze their
obscuration to find that our spectroscopic classifications are in
broad agreement with low, moderate, and large amounts of absorption
for Type-1, red Type-1, and Type-2 AGNs, respectively. We also
investigate how their X-ray luminosities correlate with other known
bolometric luminosity indicators such as [OIII] line luminosity
(L[OIII]) and infrared luminosity (L6µm). While the X-ray
correlation with L[OIII] is consistent with previous findings, the
most infrared-luminous sources appear to deviate from established
relations such that they are either underluminous in X-rays or
overluminous in the infrared. Finally, we examine the luminosity
function evolution of our sample, and by AGN type, in combination with
the complementary, infrared-selected, AGN sample of Lacy et al.
(2013), spanning over two orders of magnitude in luminosity. We find
that the two obscured populations evolve differently, with reddened
Type-1 AGNs dominating the obscured AGN fraction (∼30%) for
L5µm>1045erg/s, while the fraction of Type-2 AGNs with
L5µm<1045erg/s rises sharply from 40% to 80% of the overall AGN
population.
Description:
We began by selecting all sources with a flux density brighter than
20mJy in the 22um (W4) band from the "AllWISE" catalog (II/328)
overlapping the Stripe 82 borders (10837 sources). We then match these
sources to the SDSS DR9 spectroscopic database (see V/139). See
section 2 for the sample selection.
We obtained optical and/or near-infrared spectra for all 29 candidates
that lack any spectroscopic identification, as well as for five
sources with redshifts in the literature.
We performed near-infrared spectroscopy at the NASA Infrared Telescope
Facility (IRTF) on UT 2012 September 21-22 and UT 2016 August 17 with
the SpeX spectrograph. On UT 2015 October 8 and November 4 we also
obtained near-infrared spectra of seven QSOs. We used the TripleSpec
(TSpec) cross-dispersed spectrograph on the Apache Point Observatory
3.5m telescope. And, on UT 2017 November 1 we obtained four
near-infrared spectra with the TripleSpec instrument on the Hale 200"
Telescope at Palomar Observatory.
Optical spectra for 18 candidates were obtained with the 3m Shane
telescope at the Lick observatory using the dual-arm Kast Spectrograph
on UT 2012 October 19-21.
One source, W2M J2216+0058, originally studied by Stanford+ (2000,
J/ApJS/131/185), was observed with the Double Spectrograph (DBSP) on
the Hale 200" Telescope at Palomar Observatory on UT 2017 September 14.
We obtained optical spectra of 14 sources with the Low Resolution
Imaging Spectrograph (LRIS) at the Keck I telescope. Three sources
were observed on UT 2015 May 24 (Ws82 J2054+0041, W2M J2118+0023, W2M
J2355-0114), one source was observed on UT 2016 September 8 (Ws82
J0213-0057), another source was observed on UT 2016 September 29 (W2M
J2255+0049), one spectrum was obtained on UT 2017 September 1418 (Ws82
J2346-0038), six spectra were obtained on UT 2017 September 16 (W2M
J0030-0027, Ws82 J0220+0033, Ws82 J0253-0046, W2M J0307-0019, Ws82
J2136-0112, Ws82 J2343-0059), and two final sources were observed on
UT 2017 October 17 (Ws82 0258-0010, Ws82 2330-0012).
We cross-matched our sample of AGNs with the Stripe 82X catalog
(LaMassa+, 2013, J/MNRAS/436/3581 and 2013MNRAS.432.1351L 2013MNRAS.432.1351L) which
combines all archival observations from Chandra and XMM.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 106 40 WISE-selected AGN candidates in Stripe 82
lacking SDSS spectroscopy
table2.dat 91 115 WISE-selected AGN candidates in Stripe 82
with SDSS spectroscopy
table3.dat 66 29 Line diagnostics
table5.dat 73 21 Reddened QSO properties
table7.dat 106 15 X-ray properties of WISE-selected AGN in Stripe 82
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See also:
B/xmm : XMM-Newton Obs. Log (XMM-Newton Science Operation Center, 2012)
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
II/328 : AllWISE Data Release (Cutri+ 2013)
J/ApJS/121/287 : The CfA2S catalog (Huchra+, 1999)
J/A+AS/136/35 : WR galaxies and HII regions catalog (Schaerer+ 1999)
J/ApJS/131/185 : FIRST sample of ultraluminous IR galaxies (Stanford+, 2000)
J/ApJ/607/60 : FIRST-2MASS faint sources (Glikman+, 2004)
J/A+A/418/465 : Mid-infrared and hard X-ray emission in AGN (Lutz+, 2004)
J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)
J/ApJ/640/603 : Catalog of AGNs in the GOODS fields (Treister+, 2006)
J/ApJ/667/673 : FIRST-2MASS red quasar survey (Glikman+, 2007)
J/AJ/133/186 : Opt. spectroscopy of 77 luminous AGNs and QSOs (Lacy+, 2007)
J/ApJ/679/140 : IR measurement of quasar obscuration (Treister+, 2008)
J/ApJ/693/1713 : Spectroscopy of X-ray sources in ECDF-S (Treister+, 2009)
J/ApJ/698/1095 : The FIRST-2MASS red QSO survey. II. (Urrutia+, 2009)
J/ApJS/182/628 : Spitzer quasar and ULIRG evolution study (Veilleux+, 2009)
J/ApJ/708/584 : SEXSI Spitzer catalog (Eckart+, 2010)
J/A+A/525/A37 : Variability of QSOs in SDSS Stripe 82 (Meusinger+, 2011)
J/AJ/142/3 : 1.4GHz observations of Stripe 82 (Hodge+, 2011)
J/ApJ/757/51 : FIRST-2MASS dust-reddened QSO spectra (Glikman+, 2012)
J/ApJ/768/105 : z∼5 QSO LF from SDSS Stripe 82 (McGreer+, 2013)
J/ApJ/772/26 : AGN with WISE. II. The NDWFS Bootes field (Assef+, 2013)
J/ApJS/208/20 : Nine-year WMAP point source catalogs (Bennett+, 2013)
J/ApJ/778/127 : UKIDSS+FIRST+SDSS red QSOs candidates (Glikman+, 2013)
J/ApJS/208/24 : Spitzer MIR AGN survey. I. (Lacy+, 2013)
J/MNRAS/436/3581 : X-ray observations of Stripe 82 (LaMassa+, 2013)
J/ApJ/812/66 : NIR spectra of 5 red quasars at 0.5<z<0.9 (Kim+, 2015)
J/ApJ/807/129 : X-ray to MIR luminosities relation of AGNs (Stern, 2015)
J/ApJ/805/90 : WISE ELIRGs and comparison with QSOs (Tsai+, 2015)
J/ApJ/817/172 : X-ray Observations of Stripe 82 (LaMassa+, 2016)
J/ApJ/824/70 : UV-FIR SED results of SDSS QSOs & their hosts (Dong+, 2016)
J/ApJS/225/1 : SpIES: the Spitzer IRAC Equatorial Survey (Timlin+, 2016)
J/AJ/154/269 : A new photo-z method for quasars in Stripe 82 (Yang+, 2017)
J/MNRAS/464/3431 : Extremely red quasars in BOSS (Hamann+, 2017)
Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Set Ws82 or W2M objects (G1)
6- 24 A19 --- Name Object name (JHHMMSS.ss+DDMMSS.s as in II/328)
26- 30 F5.2 mag gmag [14.3/25.9] SDSS g band AB magnitude
32- 36 F5.2 mag rmag [13.5/23.2] SDSS r band AB magnitude
38- 42 F5.2 mag imag [13/22.4] SDSS i band AB magnitude
44- 48 F5.2 mag Jmag [12.9/19.3]? 2MASS or UKIDSS J band Vega
magnitude (G1)
50- 54 F5.2 mag Kmag [10.8/17]? 2MASS or UKIDSS K band Vega
magnitude (G1)
56- 60 F5.2 mag W1mag [9.2/17] WISE W1 band Vega magnitude
62- 66 F5.2 mag W2mag [8.2/16.1] WISE W2 band Vega magnitude
68- 71 F4.2 mag W3mag [5.3/10] WISE W3 band Vega magnitude
73- 76 F4.2 mag W4mag [2.7/6.6] WISE W4 band Vega magnitude
78- 84 F7.3 --- zsp [0.02/3.2]?=999 Spectroscopic redshift
86- 91 A6 --- Class Classification; See Section 4 (1)
93-102 A10 --- Inst Source of Spectrum (only for Table 1)
104-106 A3 --- Ref Reference (only for Table 1) (2)
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Note (1): For Ws82 J221220.21+003337.9 no Class is given because this source
shows no AGN signatures. See Appendix A for details.
Note (2): Reference as follows:
B92 = Boroson & Green (1992ApJS...80..109B 1992ApJS...80..109B);
G07 = Glikman et al. (2007, J/ApJ/667/673);
H99 = Huchra et al. (1999, J/ApJS/121/287);
S00 = Stanford et al. (2000, J/ApJS/131/185);
S92 = Strauss et al. (1992, VII/185);
S99 = Schaerer et al. (1999, J/A+AS/136/35);
T15 = Tsai et al. (2015, J/ApJ/805/90).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- AName Truncated object name
17- 20 A4 --- Set Ws82 or W2M objects (G1)
22- 40 A19 --- Name Object name (JHHMMSS.ss+DDMMSS.s as in II/328)
42- 42 A1 --- f_Name Object flag(s) (1)
44- 48 F5.2 [-] log(O3/Hb) [-0.3/2.2] log [OIII]/Hβ line ratio
50- 54 F5.2 [-] log(N2/Ha) [-1.3/-0.02]? log [NII]/Hα line ratio
56- 60 F5.2 [-] log(Ne3/O2) [-1.1/0.5] log [NeIII]/[OII] line ratio
62- 66 F5.2 mag g-z [-1.7/2.4] Observed (g-z) SDSS color index,
AB mag
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Note (1): Object flags as follows:
b = This object appears on the boundary of the star-forming region of
the TBT diagram, and has the lowest [OIII]/Hβ ratio in this
sample. We classify this source as a galaxy.
c = This object appears in the star-forming region of both BPT and
TBT diagrams.
d = From the sample with SDSS spectra and appear as blue symbols in Figure 8.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- AName Truncated object name
17- 20 A4 --- Set Ws82 or W2M objects (G1)
22- 40 A19 --- Name Object name (JHHMMSS.ss+DDMMSS.s as in II/328)
42- 46 F5.3 --- zsp [0.1/3.2] Spectroscopic redshift
48- 51 F4.2 mag E(B-V) [0.2/1.3]? Extinction from B-V color excess
53- 56 F4.2 mag Av [1.1/5.3]? V band extinction
58- 71 A14 --- Inst Spectrum source (1)
73- 73 A1 --- f_Inst Spectrum flag (2)
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Note (1): Telescope/Instrument combination for spectrum used except
J2305-0039 (Ws82 J230525.88-003925.7), which is from the proprietary
data in Tsai+ (2015, J/ApJ/805/90).
Note (2): We obtained a spectrum of this source with LRIS from which we
determined the source redshift. However the LIRS spectrum was affected
by a bad column, affecting the continuum shape. Therefore, we use the
lower-signal-to-noise SALT spectrum for determining E(B-V).
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Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- AName Truncated Object name
17- 20 A4 --- Set Ws82 or W2M objects (G1)
22- 40 A19 --- Name Object name (JHHMMSS.ss+DDMMSS.s
as in II/328)
42- 42 A1 --- f_Name a: W2M J2330+0000 was observed twice
44- 49 A6 --- Class Classification; See Section 4
51- 55 F5.3 --- zsp [0.09/0.9]? Spectroscopic redshift
57- 57 A1 --- l_Flux Limit flag on Flux
59- 63 F5.2 10-14mW/m2 Flux [0.5/52] 2-10keV Hard X-ray flux
65- 68 F4.1 10-14mW/m2 E_Flux [0.1/9.4]? Upper uncertainty on Flux
70- 73 F4.1 10-14mW/m2 e_Flux [-6.8/-0.1]? Lower uncertainty on Flux
75- 79 F5.2 [10-7J] Lum [42.7/44.6]? log Hard X-ray Luminosity,
in erg/s units
81- 87 A7 --- Mission Mission Observatory, Chandra or XMM
89- 94 F6.3 --- HR [-0.8/0.9]? Hardness Ratio
96-100 F5.2 [10-7J] L6um [41.6/46.5]? log 6um luminosity, erg/s
102-106 F5.2 [10-7J] L[OIII] [40.4/46.2]? log [OIII] luminosity, erg/s
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Global notes:
Note (G1):
We identify the sources with the prefix "Ws82" which is an
abbreviation of "WISE Stripe 82". Some sources have detections in
2MASS, and we label them with the prefix "W2M" which is an
abbreviation of "WISE 2MASS", as this subset population will be
expanded in a future study. For objects lacking a detection in 2MASS,
we report their near-infrared magnitudes from the UKIRT Infrared Deep
Sky Survey (UKIDSS, II/319), which reaches ∼2.5mag deeper than 2MASS
in the K band.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 10-Jul-2019