J/ApJS/208/24 Spitzer MIR AGN survey. I. (Lacy+, 2013)
The Spitzer mid-infrared active galactic nucleus survey.
I. Optical and near-infrared spectroscopy of obscured candidates and normal
active galactic nuclei selected in the mid-infrared.
Lacy M., Ridgway S.E., Gates E.L., Nielsen D.M., Petric A.O., Sajina A.,
Urrutia T., Cox Drews S., Harrison C., Seymour N., Storrie-Lombardi L.J.
<Astrophys. J. Suppl. Ser., 208, 24 (2013)>
=2013ApJS..208...24L 2013ApJS..208...24L
ADC_Keywords: Active gal. nuclei ; Galaxies, IR ; Spectroscopy ; X-ray sources ;
Redshifts ; Surveys ; Photometry, UBVRI ; Photometry, infrared ;
Keywords: galaxies: Seyfert - galaxies: starburst - infrared: galaxies -
quasars: general
Abstract:
We present the results of a program of optical and near-infrared
spectroscopic follow-up of candidate active galactic nuclei (AGNs)
selected in the mid-infrared. This survey selects both normal and
obscured AGNs closely matched in luminosity across a wide range, from
Seyfert galaxies with bolometric luminosities L bol∼1010L☉
to highly luminous quasars (Lbol∼1014L☉), all with redshifts
ranging from 0 to 4.3. Samples of candidate AGNs were selected with
mid-infrared color cuts at several different 24µm flux density
limits to ensure a range of luminosities at a given redshift. The
survey consists of 786 candidate AGNs and quasars, of which 672 have
spectroscopic redshifts and classifications. Of these, 137 (20%) are
type 1 AGNs with blue continua, 294 (44%) are type 2 objects with
extinctions AV≳5 toward their AGNs, 96 (14%) are AGNs with lower
extinctions (AV∼1), and 145 (22%) have redshifts, but no clear signs
of AGN activity in their spectra. Of the survey objects 50% have
Lbol>1012L☉, in the quasar regime. We present composite
spectra for type 2 quasars and objects with no signs of AGN activity
in their spectra. We also discuss the mid-infrared - emission-line
luminosity correlation and present the results of cross correlations
with serendipitous X-ray and radio sources.
Description:
A wide range of optical facilities and instruments were used for
spectroscopic follow-up of our AGN candidates. Most of the bright
samples were followed up with 3-5m telescopes and longslit
spectroscopy (Hale with COSMIC, SOAR with Goodman, and Shane with
Kast), whereas the fainter samples were followed up with multifiber
and/or 6-8m class telescopes (Blanco with Hydra, MMT with Hectospec,
and Gemini-South with GMOS (program GS-2008B-C4)). We also obtained
spectra of some of the bright candidates with a successful poor
weather (scheduling band 4) program at Gemini-South (program
GS-2008B-Q86). Some objects had spectra available in archives from the
SDSS, 2dF, (Colless et al. 2001, Cat. VII/250) or 6dF (Jones et al.
2009, Cat. VII/259) surveys and some have redshifts and
classifications in the literature, all found using the NASA
Extragalactic Database (NED). Table 2 gives details of the
spectroscopic observations or literature references as appropriate.
For some high-redshift candidates with ambiguous or low
signal-to-noise optical spectra, we were able to obtain near-infrared
spectra with the IRTF using SpeX (2007 June), Gemini with NIRI
(program GN2009B-C-8), and Triplespec (2008 July and 2011 July) on
Palomar.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 103 16 Samples used
table2.dat 213 963 Mid-IR-selected AGN candidates and follow-up
spectroscopy log
table3.dat 125 786 Properties of the AGN in the spectroscopic survey
table5.dat 133 154 X-ray properties of AGN in the spectroscopic survey
refs.dat 154 46 References
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See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
VII/259 : 6dF galaxy survey final redshift release (Jones+, 2009)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
II/290 : SWIRE Photometric Redshift Catalogue (Rowan-Robinson+, 2008)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/255 : SWIRE ELAIS N1 Source Catalogs (Surace+, 2004)
VII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003)
VII/203 : Las Campanas Redshift Survey (Shectman+ 1996)
VII/155 : Third Reference Cat. of Bright Galaxies (RC3) (de Vaucouleurs+ 1991)
J/MNRAS/421/3060 : Subaru/XMM Deep Field radio imaging. III. (Simpson+, 2012)
J/MNRAS/426/3334 : Australia Telescope Large Area Survey (Mao+, 2012)
J/ApJ/701/1123 : MIR spectroscopic catalog of 150 galaxies (Dasyra+, 2009)
J/ApJ/693/370 : 24um flux-limited sample of galaxies (Weedman+, 2009)
J/A+A/493/339 : XMM-Newton serendipitous Survey. V. (Watson+, 2009)
J/MNRAS/395/1695 : Spitzer MIR spectroscopy of LIRGs (Hernan-Caballero+, 2009)
J/AJ/133/186 : Optical spectroscopy of luminous AGNs & QSOs (Lacy+, 2007)
J/ApJ/663/218 : Opt. Spectroscopy of WIYN Hydra FLS sources (Marleau+, 2007)
J/ApJS/172/383 : AGN candidates in the COSMOS field (Trump+, 2007)
J/ApJ/658/778 : Spitzer mid-IR spectroscopy of z∼2 ULIRGs (Yan+, 2007)
J/A+A/451/881 : ESIS BVR catalog, ELAIS-S1 (Berta+, 2006)
J/AJ/131/2859 : Extragalactic First Look Survey: 24µm data (Fadda+, 2006)
J/AJ/131/114 : The Molonglo Southern 4Jy sample. II (Burgess+, 2006)
J/AJ/132/231 : 24um sources MMT hectospec redshift survey (Papovich+, 2006)
J/MNRAS/372/741 : SXDF 100µJy catalogue (Simpson+, 2006)
J/AJ/132/2409 : Deep ATLAS radio observations of CDFS (Norris+, 2006)
J/MNRAS/355/97 : Chandra/ELAIS mid-infrared sources (Manners+, 2004)
J/AJ/127/3075 : Mid-IR population of ELAIS-S1 sample (La Franca+, 2004)
J/ApJS/126/133 : The FIRST bright quasar survey. II. (White+, 2000)
J/A+A/358/77 : Hamburg/ESO survey for bright QSOs. III. (Wisotzki+, 2000)
J/PASP/97/932 : 3CR Source Identifications (Spinrad+, 1985)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Set Sample name
16 A1 --- n_Set [def] Origin of Spitzer photometry (1)
18- 19 I2 h RAh Field center hour of right ascension (J2000)
20- 21 I2 min RAm Field center minute of right ascension (J2000)
22- 23 I2 s RAs Field center second of right ascension (J2000)
24 A1 --- DE- Field center sign of declination (J2000)
25- 26 I2 deg DEd Field center degree of declination (J2000)
27- 28 I2 arcmin DEm Field center arcminute of declination (J2000)
30- 33 F4.2 mJy S24l [0.6/1.3]? Lower range of 24µm flux
35- 38 F4.2 mJy S24u [1.1/8]? upper range (if lower range exists)
or lower limit for 24µm flux
40- 48 F9.7 sr Area [0.00008/0.004]? Effective area
50- 52 I3 --- N [8/178]? Number of objects with either
spectroscopy attempted or literature-based z
54- 63 A10 --- Sel Color selection (2)
65- 89 A25 --- Inst Follow-up instrument
91- 93 I3 % Comp [15/100]? Completeness (with z quality q≤3; see
Note (1) of table 3)
95- 99 F5.3 --- 90L [0.61/9.6]? 90% flux limit
101-103 I3 --- N90 [4/175]? Number of objects in the 90% complete
samples
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Note (1): Flag as follows:
d = Spitzer photometry from SWIRE (Lonsdale et al. 2003PASP..115..897L 2003PASP..115..897L)
e = Spitzer photometry from SCOSMOS (Sanders et al. 2007ApJS..172...86S 2007ApJS..172...86S).
f = Spitzer photometry from XFLS (Lacy et al. 2005ApJS..161...41L 2005ApJS..161...41L;
Fadda et al. 2006, Cat. J/AJ/131/2859).
Note (2): The selection region was changed from the L07 (Lacy et al., 2007,
Cat. J/AJ/133/186) wedge (Equation (1)) to Equation (2) for the
fainter samples to improve our completeness in low luminosity AGNs.
Expanding the wedge in this way inevitably results in more
contamination, but the spectroscopy is able to remove the objects more
likely to be starbursts from the final AGN sample.
See section 2.1 for further explanations.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 26 A26 --- Name Source name (1)
28- 41 A14 --- Set Sample within the overall survey (see table 1)
43- 59 A17 --- Tel Telescope and instrument of the observation or
literature reference (see refs.dat file)
61- 85 A25 --- Date Date of observation(s); UTC or
"Gemini Science Archive"
87- 93 A7 s Exp Exposure time
95-104 A10 --- Syst Magnitude system and identification of m1-m5:
"AB:ugriz" or "Vega:UBVRI"
106-114 F9.6 mag mag1 [13.51/26.95]? Optical magnitude 1 (u or U)
116-124 F9.6 mag mag2 [9.91/28.05]? Optical magnitude 2 (g or B)
126-134 F9.6 mag mag3 [9.31/25]? Optical magnitude 3 (r or V)
136-144 F9.6 mag mag4 [10.06/24.53]? Optical magnitude 4 (i or R)
146-154 F9.6 mag mag5 [9.43/29.89]? Optical magnitude 5 (z or I)
156-157 I2 --- oflg [0/64] Optical flag (2)
159-168 A10 --- oref Reference for optical magnitudes
(see refs.dat file) (3)
170-174 F5.2 mag Zmag [15.63/18.85]? The Z band Vega magnitude
176-180 F5.2 mag Ymag [15.17/18.41]? T he Y band Vega magnitude
182-187 F6.3 mag Jmag [13.34/22.33]? The J band Vega magnitude
189-193 F5.2 mag Hmag [12.62/21.1]? The H band Vega magnitude
195-199 F5.2 mag Kmag [12.25/20.07]? The K band Vega magnitude
201-202 I2 --- nflg [1/64]? Near-infrared flag (4)
204-213 A10 --- nref Reference for near-infrared magnitudes (see
refs.dat file) (5)
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Note (1): We use the Spitzer Wide-area Infrared Extragalactic Survey
(SWIRE; Lonsdale et al. 2003PASP..115..897L 2003PASP..115..897L; SWHHMMSS.ss+DDMMSS.s
format), the Spitzer Extragalactic First Look Survey (XFLS; Lacy et
al. 2005ApJS..161...41L 2005ApJS..161...41L; Fadda et al. 2006, Cat. J/AJ/131/2859;
XFLSHHMMSS.sss+DDMMSS.ss or XLFSHHMMSS.s+DDMMSS formats), and the
Spitzer Cosmic Evolution Survey (SCOSMOS; Sanders et al.
2007ApJS..172...86S 2007ApJS..172...86S; SCOSMOSHHMMSS.ss+DDMMSS.ss format) to search for
luminous AGNs in an area of sky totaling 54deg2, large enough to
find examples of highly luminous quasars at high redshifts.
Furthermore, we nested our survey in terms of flux density limits at
24um. See section 2 for further explanations.
Note (2): Sum of flags for missing magnitudes Σm2m-1:
1 = m1 limit/missing (m=0);
2 = m2 limit/missing (m=1);
4 = m3 limit/missing (m=2);
8 = m4 limit/missing (m=3);
16 = m5 limit/missing (m=3);
64 = no cataloged optical magnitude.
Note (3): "This paper" refers to estimates from spectroscopic acquisition
images, or by-eye estimates from available imaging, with an
uncertainty ∼0.5mag. The other magnitudes are accurate to ∼0.1mag or
better, see the respective papers for details. "CASU" and "SWIRE"
magnitudes are aperture magnitudes in 2.4 or 3.1 arcsecond diameters,
respectively. The remainder are estimated total magnitudes ("MAG AUTO"
in Sextractor, Bertin & Arnouts, 1996A&AS..117..393B 1996A&AS..117..393B).
Note (4): Sum of flags for missing magnitudes Σm2m-1:
1 = Z limit/missing (m=1);
2 = Y limit/missing (m=2);
4 = J limit/missing (m=3);
8 = H limit/missing (m=4);
16 = K limit/missing (m=5);
64 = No cataloged near-infrared magnitude.
Note (5): For DXS and UDS the 2 arcsecond diameter apertures are quoted,
for VIDEO the Petrosian magnitudes. "This paper" refers to estimates
from spectroscopic acquisition images, with an uncertainty ∼0.5
magnitudes. The other magnitudes are accurate to ∼0.1 magnitudes or
better, see the respective papers for details.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 26 A26 --- Name Source name
28- 41 A14 --- Set Sample within survey
43 A1 --- S [NY] In statistical sample or not; boolean (1)
45- 50 F6.4 --- z [0/4.27]? Redshift
52 I1 --- q_z [1/4]? Quality of z, 1=secure (2)
54 I1 --- Type [1/5]? AGN Type (G1)
59 I1 --- q_Type [1/4]? Quality of type, 1=secure (3)
64- 74 F11.5 uJy S3.6 [10/54446]? Spitzer/IRAC 3.6um band flux density
76- 86 F11.5 uJy S4.5 [16/76602]? Spitzer/IRAC 4.5um band flux density
88- 99 F12.5 uJy S5.8 [42/137201]? Spitzer/IRAC 5.8um band flux density
101-112 F12.5 uJy S8.0 [49/82000]? Spitzer/IRAC 8.0um band flux density
114-125 F12.5 uJy S24 [612/202435] Spitzer/MIPS 24um band flux density
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Note (1): The overall redshift completeness in the samples varied from 100%
for most of the bright samples to ∼20% for some of the faint samples.
In order to obtain a subset of the survey useful for statistical
purposes in S.E. Ridgway et al. (2013, in preparation), a ≥90%
complete subsample was computed for each individual sample by
exploiting the correlation of S24 with emission-line flux (except
for the GMOS-S data, which have a very narrow range in S24). This
procedure was carried out as follows: each sample was sorted in
descending order of S24. The completeness was then calculated as
a function of S24 (assuming all redshifts with qualities 1-3 were
correct). Objects were included in the 90% complete sub-sample until
the completeness as a function of S24 dropped below 90% for the final
time (see Table 1). These 90% complete samples, combined with the 81%
complete, GMOS-S sample, constitute the "statistical sample" of 662
objects. See section 4.1.
Note (2): Quality of z as follows:
1 = secure redshift based on two or more high signal-to-noise features;
2 = less secure redshift, based on multiple features, but with only one or
fewer detected at high signal-to-noise;
3 = uncertain redshift, based on weak spectral features, or
a single strong line;
4 = featureless spectrum, no redshift estimate.
Note (3): Quality of type as follows:
1 = secure classification (broad lines for type-1s, BPT diagram, [NeV]
emission or high-ionization UV lines and a rest-frame optical spectrum
for type-2s; clear (g-i)* color excess compared to normal quasars);
2 = less secure classification (e.g. only partial information for BPT,
low signal-to-noise high-ionization line detections);
3 or 4 = uncertain classification due to lack of strong spectral features
and/or uncertain line identification.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 26 A26 --- Name Source name
28- 32 F5.3 --- z [0/4.27]? Redshift (1)
34 I1 --- Type [1/5]? AGN Type (1)(G1)
36- 46 F11.5 uJy S24 [682/63390] Spitzer/MIPS 24um flux density
48- 50 A3 --- --- [CXO]
52- 67 A16 --- CXO Name in Chandra Source Catalog (CSC);
(JHHMMSS.s+DDMMSS) (2)
69- 76 E8.3 mW/m2 S2-10 [9.1e-16/1.9e-12]? 2-10keV flux from CSC
78- 88 F11.8 --- HR1 [-1/1]? Hardness ratio between the "hard" and
"soft" ACIS bands from CSC
90-111 A22 --- 2XMM Name in 2XMM catalog (2XMM JHHMMSS.s+DDMMSS;
except few 2XMMi) (2)
113-120 E8.3 mW/m2 S0.2-12 [2.e-15/2.5e-12]? 0.2-12keV flux from 2XMM
122-133 E12.9 --- HR2 [-1/1]? Hardness ratio between 0.5-1keV and
1-2keV from 2XMM
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Note (1): Objects with featureless spectra are included (redshift and type
columns are left blank).
Note (2): We matched the objects in our spectroscopic survey in Table 3
(which have either spectroscopy from the literature or from our own
observations) to the 2XMM-DR3 catalog of serendipitous XMM sources
(Watson et al. 2009, Cat. J/A+A/493/339) and the Chandra Source
Catalog (CSC; Evans et al. 2010ApJS..189...37E 2010ApJS..189...37E), finding 108 matches
to the 2XMM and 81 to the CSC (36 of which are in both catalogs). See
section 5 for further explanations.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Ref Reference code
9- 27 A19 --- BibCode Bibcode
29- 54 A26 --- Aut First author's name
56-154 A99 --- Comm Comment
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Global notes:
Note (G1): Type as follows:
1 = normal, unobscured type-1 AGN;
2 = heavily obscured, type-2 AGN;
3 = no indication of an AGN in the optical spectra;
4 = lightly obscured AGN, with broad-lines visible in the rest-frame
optical, but a red continuum.
5 = star; most likely contaminants due to saturated IRAC flux densities
(although probably possessing debris disks to be bright at 24um).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 30-Oct-2013