J/ApJ/872/134 A uniformly selected, all-sky, optical AGN catalog (Zaw+, 2019)
A uniformly selected, all-sky, optical AGN catalog.
Zaw I., Chen Y.-P., Farrar G.R
<Astrophys. J. 872, 134 (2019)>
=2019ApJ...872..134Z 2019ApJ...872..134Z (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Redshifts ; Spectroscopy
Keywords: catalogs - galaxies: active - line: identification
Abstract:
We have constructed an all-sky catalog of optical active galactic
nuclei (AGNs) with z<0.09, based on optical spectroscopy, from
the parent sample of galaxies in the 2MASS Redshift Survey, a
near-complete census of the nearby universe. Our catalog consists of
1929 broad-line AGNs and 6562 narrow-line AGNs that satisfy the
Kauffmann et al. (2003MNRAS.346.1055K 2003MNRAS.346.1055K) criteria, of which 3607 also
satisfy the Kewley et al. (2006MNRAS.372..961K 2006MNRAS.372..961K) criteria. We also
report emission-line widths, fluxes, flux errors, and signal-to-noise
ratios (S/Ns) of all the galaxies in our spectroscopic sample,
allowing users to customize the selection criteria. Although we
uniformly processed the spectra of galaxies from a homogeneous parent
sample, inhomogeneities persist owing to the differences in the
quality of the obtained spectra, taken with different instruments, and
the unavailability of spectra for ∼20% of the galaxies. We quantify
how the differences in spectral quality affect not only the AGN
detection rates but also ratios of broad-line to narrow-line AGNs. We
find that the inhomogeneities primarily stem from the continuum S/N in
the spectra near the emission lines of interest. We fit for the AGN
fraction as a function of continuum S/N and assign AGN likelihoods to
galaxies that were not identified as AGNs using the available spectra.
This correction results in a catalog suitable for statistical studies.
This work also paves the way for a truly homogeneous and complete
nearby AGN catalog by identifying galaxies whose AGN status needs to
be verified with higher-quality spectra, quantifying the spectral
quality necessary to do so.
Description:
We take the 2MRS (Huchra et al., 2012, Cat. J/ApJS/199/26) as the
parent sample for constructing our all-sky optical AGN catalog. The
2MRS galaxy catalog, a compilation of redshifts for 43,533 galaxies
with Ks≤11.75 (mean z=0.03) and Galactic latitude |b|>5°
(8° toward the Galactic bulge) in the Two Micron All-Sky Survey
(2MASS; Skrutskie et al. 2006, Cat. VII/233), is a near-complete (91%
of the sky) census of galaxies in the nearby (z≲0.09) universe
(above the flux limit). Nearly half of redshifts in 2MRS were taken
from large surveys for which the digital spectra are publicly
available, namely, the 6dF Galaxy Survey (6dF; Jones et al.,
2004MNRAS.355..747J 2004MNRAS.355..747J, 2009MNRAS.399..683J 2009MNRAS.399..683J, Cat. VII/259) and the Sloan
Digital Sky Survey (SDSS; Aihara et al. 2011ApJS..193...29A 2011ApJS..193...29A). For an
additional quarter of galaxies for which no redshift measurements were
available, the 2MRS team took spectra with the long-slit FAst
Spectrograph for the Tillinghast telescope (Fabricant et al.,
1998PASP..110...79F 1998PASP..110...79F, FAST) on the 1.5m Tillinghast reflector at the
Fred L. Whipple Observatory for northern galaxies and the CHIRON
spectrograph on the 1.5m SMARTS telescope and R-C grating
spectrograph on the V.M. Blanco 4.0m telescope at the Cerro Tololo
Inter-American Observatory (CTIO) for southern galaxies. For the
remaining quarter of galaxies, redshifts were compiled from the NASA
Extragalactic Database (NED), from more than 550 references, and the
optical spectroscopic CfA Redshift Catalog (ZCAT, Cat. VII/193).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 422 8491 The AGN catalog for 8491 objects
table4.dat 367 18095 Non-AGN galaxies for 18095 objects
table5.dat 101 16947 The 2MRS galaxies not in spectroscopic sample
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See also:
VII/259 : 6dF galaxy survey final redshift release (Jones+, 2009)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
VII/193 : The CfA Redshift Catalogue, Version June 1995 (Huchra+ 1995)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- 2MASS 2MASS identifier
17- 18 A2 --- n_2MASS [*# ] Note on 2MASS (1)
20- 31 E12.6 deg RAdeg Right Ascension in decimal degrees (J2000)
33- 45 E13.6 deg DEdeg Declination in decimal degrees (J2000)
47- 51 I5 km/s Vel Velocity
53 A1 --- CAT Spectral source (G1)
55- 57 A3 --- Type Source type (3)
59- 70 E12.6 --- S/N1 Signal-to-Noise between 4660-4810A; Hbeta
72- 83 E12.6 --- S/N2 Signal-to-Noise between 6350-6540A; Halpha
85- 94 E10.4 mag KMAG Absolute K band magnitude,
extinction corrected.
96-113 E18.12 --- SSPChi2 Reduced Χ2 from SSP fitting
115-132 E18.12 km/s HaFWHMB ? Broad Hα FWHM
134-151 E18.12 10-20W/m2 HaFluxB ? Broad Hα flux (G2)
153-170 E18.12 10-20W/m2 e_HaFluxB ? Uncertainty in Ha-FluxB (G2)
172-189 E18.12 10-20W/m2 HbFlux ?=0 Total Hβ flux (G2)
191-209 E19.12 10-20W/m2 HaFlux ?=0 Total Hα flux (G2)
211-229 E19.12 10-20W/m2 O3Flux ?=0 Total [OIII] 5007Å flux (G2)
231-249 E19.12 10-20W/m2 N2Flux ?=0 Total [NII] 6584Å flux (G2)
251-269 E19.12 10-20W/m2 S2aFlux ?=0 Total [SII] 6716Å flux (G2)
271-289 E19.12 10-20W/m2 S2bFlux ?=0 Total [SII] 6731Å flux (G2)
291-308 E18.12 10-20W/m2 e_HbFlux Uncertainty in Hb-Flux
310-327 E18.12 10-20W/m2 e_HaFlux Uncertainty in Ha-Flux
329-346 E18.12 10-20W/m2 e_O3Flux Uncertainty in O3-Flux
348-365 E18.12 10-20W/m2 e_N2Flux Uncertainty in N2-Flux
367-384 E18.12 10-20W/m2 e_S2aFlux ? Uncertainty in S2a-Flux
386-403 E18.12 10-20W/m2 e_S2bFlux ?=0 Uncertainty in S2b-Flux
405-422 E18.12 km/s HbFWHMB ?=0 Broad Hβ FWHM
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Note (1): Note on 2MASS name as follows:
* = spectrum did not have an accompanying error spectrum
# = "local fitting" was used to estimate the galaxy contribution
Note (3): Source type as follows:
T1 = Type 1
K01 = Type 2 with Kewley et al. (2001ApJ...556..121K 2001ApJ...556..121K) criteria
K03 = Type 2 with Kauffmann et al. (2003MNRAS.346.1055K 2003MNRAS.346.1055K) criteria
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- 2MASS 2MASS identifier
18- 29 E12.6 deg RAdeg Right Ascension in decimal degrees (J2000)
31- 43 E13.6 deg DEdeg Declination in decimal degrees (J2000)
45- 49 I5 km/s Vel Velocity
51 A1 --- CAT Spectral source (G1)
53- 55 A3 --- Type Source type (2)
57- 69 E13.6 --- S/N1 Signal-to-Noise between 4660-4810A; Hbeta
71- 83 E13.6 --- S/N2 Signal-to-Noise between 6350-6540A; Halpha
85- 96 E12.4 --- Prob1 Likelihood source is a Type 1 AGN
98-109 E12.6 --- Prob2 Likelihood source is a Type 2 AGN
111-122 E12.6 --- ProbAGN Likelihood source is an AGN
124-133 E10.4 mag KsMAG Absolute Ks band isophotal magnitude,
extinction corrected
135-153 E19.12 10-20W/m2 HbFlux ?=0 Total Hβ flux (G2)
155-173 E19.12 10-20W/m2 HaFlux ?=0 Total Hα flux (G2)
175-193 E19.12 10-20W/m2 O3Flux ?=0 Total [O III] 5007A flux (G2)
195-213 E19.12 10-20W/m2 N2Flux ?=0 Total [N II] 6584A flux (G2)
215-233 E19.12 10-20W/m2 S2aFlux ?=0 Total [S II] 6716A flux (G2)
235-253 E19.12 10-20W/m2 S2bFlux ?=0 Total [S II] 6731A flux (G2)
255-273 E19.12 10-20W/m2 e_HbFlux ? Uncertainty in Hb-Flux (3)
274-291 E18.12 10-20W/m2 e_HaFlux ? Uncertainty in Ha-Flux (3)
293-310 E18.12 10-20W/m2 e_O3Flux ? Uncertainty in O3-Flux (3)
312-329 E18.12 10-20W/m2 e_N2Flux ? Uncertainty in N2-Flux (3)
331-348 E18.12 10-20W/m2 e_S2aFlux ? Uncertainty in S2a-Flux (3)
350-367 E18.12 10-20W/m2 e_S2bFlux ? Uncertainty in S2b-Flux (3)
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Note (2): Source type as follows:
Emi = Emission line galaxy
-- = Non-emission line galaxy
Note (3): The leading "?"s in the explanation columns is a flag to the
reader indicating that these columns have at least one blank row.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS identifier
18- 29 E12.6 deg RAdeg Right Ascension in decimal degrees (J2000)
31- 43 E13.6 deg DEdeg Declination in decimal degrees (J2000)
45- 54 E10.4 mag KsMAG Absolute Ks band isophotal magnitude,
extinction corrected
56- 60 I5 km/s Vel Velocity; heliocentric reference frame
62 A1 --- CAT Source of 2MRS redshift (G1)
64- 75 E12.6 --- Prob1 Likelihood source is a Type 1 AGN
77- 88 E12.6 --- Prob2 Likelihood source is a Type 2 AGN
90-101 E12.6 --- ProbAGN Likelihood source is an AGN
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Global notes:
Note (G1): The source catalog designations follow the 2MASS Redshift Survey
(Huchra et al., 2012ApJS..199...26H 2012ApJS..199...26H, Cat. J/ApJS/199/26). See
http://tdc-www.cfa.harvard.edu/2mrs/2mrs_readme.html for details.
Codes as follows:
6 = 6dF
C = CTIO
F = FAST
S = SDSS
D = McDonald Observatory
M = Modified NED
N = NED
O = ZCAT
Note (G2): In units of 1e-17 erg/s/cm2 for the SDSS spectra and arbitrary
units for the galaxies with 6dF, FAST, and CTIO spectra since
those do not have absolute flux calibration.
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Acknowledgements:
Ingyin Zaw, ingyin.zaw(at)nyu.edu
(End) Ingyin Zaw [NYUAD, UAE], Patricia Vannier [CDS] 25-Feb-2019