J/MNRAS/457/110 Northern XMM-XXL field AGN catalog (Menzel+, 2016)
A spectroscopic survey of X-ray-selected AGNs in the northern XMM-XXL field.
Menzel M.-L., Merloni A., Georgakakis A., Salvato M., Aubourg E.,
Brandt W.N., Brusa M., Buchner J., Dwelly T., Nandra K., Paris I.,
Petitjean P., Schwope A.
<Mon. Not. R. Astron. Soc., 457, 110-132 (2016)>
=2016MNRAS.457..110M 2016MNRAS.457..110M (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Active gal. nuclei ; X-ray sources ; Photometry, SDSS ;
Photometry, infrared
Keywords: techniques: spectroscopic - galaxies: active -
quasars: emission lines - galaxies: starburst - infrared: galaxies -
X-rays: galaxies
Abstract:
This paper presents a survey of X-ray-selected active galactic nuclei
(AGNs) with optical spectroscopic follow-up in a ∼18deg2 area of
the equatorial XMM-XXL north field. A sample of 8445 point-like X-ray
sources detected by XMM-Newton above a limiting flux of
F0.5-10keV>10-15erg/cm2/s was matched to optical (Sloan Digital
Sky Survey, SDSS) and infrared (IR; WISE) counterparts. We followed up
3042 sources brighter than r=22.5mag with the SDSS Baryon
Oscillation Spectroscopic Survey (BOSS) spectrograph. The spectra
yielded a reliable redshift measurement for 2578 AGNs in the redshift
range z=0.02-5.0, with 0.5-2keV luminosities ranging from
1039-1046erg/s. This is currently the largest published
spectroscopic sample of X-ray-selected AGNs in a contiguous area. The
BOSS spectra of AGN candidates show a distribution of optical line
widths which is clearly bimodal, allowing an efficient separation
between broad- and narrow-emission line AGNs. The former dominate our
sample (70 per cent) due to the relatively bright X-ray flux limit
and the optical BOSS magnitude limit. We classify the narrow-emission
line objects (22 per cent of the full sample) using standard
optical emission line diagnostics: the majority have line ratios
indicating the dominant source of ionization is the AGN. A small
number (8 per cent of the full sample) exhibit the typical narrow
line ratios of star-forming galaxies, or only have absorption lines in
their spectra. We term the latter two classes 'elusive' AGN, which
would not be easy to identify correctly without their X-ray emission.
We also compare X-ray (XMM-Newton), optical colour (SDSS) and and IR
(WISE) AGN selections in this field. X-ray observations reveal, by
far, the largest number of AGN. The overlap between the selections,
which is a strong function of the imaging depth in a given band, is
also remarkably small. We show using spectral stacking that a large
fraction of the X-ray AGNs would not be selectable via optical or IR
colours due to host galaxy contamination. A substantial fraction of
AGN may therefore be missed by these longer wavelength selection
methods.
Description:
The XMM-Newton XXL survey (XMM-XXL, PI Pierre) is a medium-depth (10ks
per pointing) X-ray survey that covers a total area of 50deg2 split
into two fields equal in size. In this paper, we focus on the
equatorial sub-region of the XMM-XXL (XMM-XXL north), which overlaps
with the SDSS-DR8 imaging survey (Aihara et al., 2011ApJS..193...29A 2011ApJS..193...29A).
The XMM-XXL north observations were distributed around the area of the
original 11deg2 XMM-LSS survey (Clerc et al., 2014MNRAS.444.2723C 2014MNRAS.444.2723C)
and therefore build upon and extend that sample.
The X-ray data used in this paper are primarily from the XMM-XXL and
XMM-LSS surveys. We also include however, any additional XMM-Newton
pointings that are contiguous to the area covered by those programmes,
such as the XMM-Newton observations of the Subaru/XMM-Newton Deep
Survey (SXDS; Ueda et al., 2008, Cat. J/ApJS/179/124)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 534 8445 Catalog
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See also:
IX/49 : XXL Survey: First results (Pierre+, 2016)
J/MNRAS/459/1602 : AGN sample in the northern XMM-XXL field (Liu+, 2016)
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- UXID UXID (1)
10- 16 F7.4 deg RAXdeg XMM Right ascension (J2000) (RA_XMM) (1)
18- 25 F8.5 deg DEXdeg XMM Declination (J2000) (DEC_XMM) (1)
27- 31 F5.3 deg e_RAXdeg Error RA-and Declination (RADECERR_XMM) (1)
33- 41 E9.4 mW/m2 Ffull ?=- Full X-ray flux 0.5-10keV (FLUX_FULL) (1)
43- 51 E9.4 mW/m2 Fsoft ?=- Soft X-ray flux 0.5-2keV (FLUX_SOFT) (1)
53- 61 E9.4 mW/m2 Fhard ?=- Hard X-ray flux 2-10keV (FLUX_HARD) (1)
63- 71 E9.4 10-7W Lfull ?=- Full X-ray luminosity 0.5-10keV
(LUM_FULL) (1)
73- 81 E9.4 10-7W Lsoft ?=- Soft X-ray luminosity 0.5-2keV
(LUM_SOFT) (1)
83- 91 E9.4 10-7W Lhard ?=- Hard X-ray luminosity 2-10keV
(LUM_HARD) (1)
93-111 A19 --- OBJID SDSS-ID from SDSS DR-8
113-122 F10.7 deg RASdeg ?=- SDSS DR8 Right ascension (J2000) (RA_SDSS)
124-133 F10.7 deg DESdeg ?=- SDSS DR8 Declination (J2000) (DEC_SDSS)
135-143 F9.7 deg e_RASdeg ?=- Error for Right ascension from SDSS DR8
(RAERR_SDSS)
145-154 F10.7 deg e_DESdeg ?=- Error Declination from SDSS DR8
(DECERR_SDSS)
156-163 F8.4 --- LRXS ?=- Likelihood-Ratio of the matching with SDSS
counterpart (LR_XMMSDSS) (2)
165-170 F6.3 mag umag ?=- Psf-magnitude for u band from SDSS DR8
(AB) (PSFMAGU)
172-177 F6.3 mag gmag ?=- Psf-magnitude for g band from SDSS DR8
(AB) (PSFMAGG)
179-184 F6.3 mag rmag ?=- Psf-magnitude for r band from SDSS DR8
(AB) (PSFMAGR)
186-191 F6.3 mag imag ?=- Psf-magnitude for i band from SDSS DR8
(AB) (PSFMAGI)
193-198 F6.3 mag zmag ?=- Psf-magnitude for z band from SDSS DR8
(AB) (PSFMAGZ)
200-207 F8.3 mag e_umag ?=- Error on umag (AB) (PSFERRMAGU)
209-215 F7.3 mag e_gmag ?=- Error on gmag (AB) (PSFERRMAGG)
217-223 F7.3 mag e_rmag ?=- Error on rmag (AB) (PSFERRMAGR)
225-230 F6.3 mag e_imag ?=- Error on imag (AB) (PSFERRMAGI)
232-238 F7.3 mag e_zmag ?=- Error on zmag (AB) (PSFERRMAGZ)
240-245 F6.3 mag umod ?=- Model-magnitudes for u band from SDSS DR8
(AB) (MODELMAGU)
247-252 F6.3 mag gmod ?=- Model-magnitudes for g band from SDSS DR8
(AB) (MODELMAGG)
254-259 F6.3 mag rmod ?=- Model-magnitudes for r band from SDSS DR8
(AB) (MODELMAGR)
261-266 F6.3 mag imod ?=- Model-magnitudes for i band from SDSS DR8
(AB) (MODELMAGI)
268-273 F6.3 mag zmod ?=- Model-magnitudes for z band from SDSS DR8
(AB) (MODELMAGZ)
275-280 F6.3 mag e_umod ?=- Error for umod (MODELERRMAGU)
282-286 F5.3 mag e_gmod ?=- Error for gmod (MODELERRMAGG)
288-292 F5.3 mag e_rmod ?=- Error for rmod (MODELERRMAGR)
294-298 F5.3 mag e_imod ?=- Error for imod (MODELERRMAGI)
300-305 F6.3 mag e_zmod ?=- Error for zmod (MODELERRMAGZ)
307 I1 --- Type [3/6]?=- Optical morphology (4)
309-314 F6.4 --- PQSOsum ?=- Summed XDQSO QSO probability from
Bovy et al. (2011ApJ...729..141B 2011ApJ...729..141B) (PQSOSUM)
316 I1 --- Good [0/2]?=- BOSS good flag from Bovy et al.
(2011ApJ...729..141B 2011ApJ...729..141B) (GOOD)
318-336 A19 --- WISE Designation from allWISE
(JHHMMSS.ss+DDMMSS.s) (WISE_DESIGN)
338-347 F10.7 deg RAWdeg ?=- allWISE Right ascension (J2000) (RA_WISE)
349-358 F10.7 deg DEWdeg ?=- allWISE Declination (J2000) (DEC_WISE)
360-365 F6.4 deg e_RAWdeg ?=- One-sigma uncertainty for Right ascension
from allWISE (RASIG_WISE)
367-372 F6.4 deg e_DEWdeg ?=- One-sigma uncertainty for Declination
from allWISE (DECSIG_WISE)
374-381 F8.4 --- LRXW ?=- Likelihood-Ratio of the matching with WISE
counterpart (Georgakakis et al.,
2011MNRAS.414..992G 2011MNRAS.414..992G) (LR_XMMWISE) (3)
383-388 F6.3 mag W1mag ?=- Mpro-magnitude of W1 band from allWISE
(Vega) (MPROMAGW1)
390-395 F6.3 mag W2mag ?=- Mpro-magnitude of W2 band from allWISE
(Vega) (MPROMAGW2)
397-402 F6.3 mag W3mag ?=- Mpro-magnitude of W3 band from allWISE
(Vega) (MPROMAGW3)
404-408 F5.3 mag W4mag ?=- Mpro-magnitude of W4 band from allWISE
(Vega) (MPROMAGW4)
410-414 F5.3 mag e_W1mag ?=- Profile-fit photometric measurement
uncertainty for W1 band from allWISE (Vega)
(MPROSIGMAGW1)
416-420 F5.3 mag e_W2mag ?=- Profile-fit photometric measurement
uncertainty for W2 band from allWISE (Vega)
(MPROSIGMAGW2)
422-426 F5.3 mag e_W3mag ?=- Profile-fit photometric measurement
uncertainty for W3 band from allWISE (Vega)
(MPROSIGMAGW3)
428-432 F5.3 mag e_W4mag ?=- Profile-fit photometric measurement
uncertainty for W4 band from allWISE (Vega)
(MPROSIGMAGW4)
434 I1 --- Clean [0/1]?=- Exclusion of diffraction spikes,
halos, optical ghosts and blended sources
(CLEAN) (5)
437-440 I4 --- Plate ?=- BOSS plate number (PLATE)
443-446 I4 --- Fiber ?=- BOSS fibre-ID number (FIBERID)
448-452 I5 --- MJD ?=- BOSS MJD (MJD)
454-462 F9.6 --- zBoss ?=- Redshift from the automatic BOSS pipeline
(Z_BOSS)
464-476 E13.7 --- e_zBoss [-6/29]?=- Error for Z_BOSS (ZERR_BOSS)
478-480 I3 --- zwarning ?=- Redshift warning flag from the automatic
BOSS pipeline (ZWARNING)
482-488 F7.4 --- SNmedall ?=- Average S/N ratio of all five SDSS bands
from the automatic BOSS pipeline
(SNMEDIANALL)
490-497 F8.6 --- z ?=- Redshift after visual inspection and
refit of spectrum with spreduce1d.pro (Z)
499-511 E13.6 --- e_z [-6/4]?=- Error for Z (ZERR)
513-517 I5 --- q_z [1/30]?=- Redshift confidence flag from visual
inspection (Z_CONF) (6)
519-528 A10 --- Class Classification for q_z=3 spectra (CLASS) (7)
530-534 A5 --- St/BL Star/BL Lac classification (STAR/BLLAC)
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Note (1): from Liu et al. (2016, Cat. J/MNRAS/459/1602)
Note (2): for the optical counterpart choose LSXS (LR_XMMSDSS) > 1.5
Note (3): for the infrared counterpart choose LSXW (LR_XMMWISE) > 0.5
Note (4): Optical morphology as follows: 3 = galaxy like, 6 = star like (TYPE)
Note (5): Exclusion flags (ccflag=0 for W1 and W2, NB≤2) as follows:
1 = photometric conditions are fulfilled
0 = photometric conditions are not fullfilled
Note (6): Redshift confidence flag as follows:
3 = reliable redshift
2 = not robust redshift
1 = bad spectrum
30 = reliable visual redshift and pipeline failure
20 = not robust visual redshift and pipeline failure
Note (7): Classification as follows:
BLAGN1 = broad-line AGN of type 1
NLAGN2 = narrow-line AGN of type 2
NLAGN2cand = narrow-line AGN of type 2 candidate
eAGN-ALG = elusive absorption line galaxy
eAGN-SFG = elusive AGN with star formation
NOC = not classified
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 17-Oct-2016