J/ApJ/936/39 X-Ray redshift catalog for 121 sources (Sicilian+, 2022)
X-Ray Redshifts of Obscured Chandra Source Catalog Active Galactic Nuclei.
Sicilian D., Civano F., Cappelluti N., Buchner J., Peca A.
<Astrophys. J., 936, 39 (2022)>
=2022ApJ...936...39S 2022ApJ...936...39S
ADC_Keywords: X-ray sources; Active gal. nuclei; Redshifts
Keywords: Active galactic nuclei ; X-ray active galactic nuclei ;
Redshift surveys ; X-ray astronomy ; X-ray sources
Abstract:
We have computed obscured active galactic nuclei (AGN) redshifts using
the XZ method, adopting a broad treatment in which we employed a
wide-ranging data set and worked primarily at the XZ counts
sensitivity threshold, culminating with a redshift catalog containing
121 sources that lack documented redshifts. We considered 363 obscured
AGN from the Chandra Source Catalog Release 2.0, 59 of which were
selected using multiwavelength criteria while 304 were X-ray selected.
One third of the data set had crossmatched spectroscopic or
photometric redshifts. These sources, dominated by low-z and low-NH
AGN, were supplemented by 1000 simulations to form a data set for
testing the XZ method. We used a multilayer perceptron neural network
to examine and predict cases in which XZ fails to reproduce the known
redshift, yielding a classifier that can identify and discard poor
redshift estimates. This classifier demonstrated a statistically
significant ∼3σ improvement over the existing XZ redshift
information gain filter. We applied the machine-learning model to
sources with no documented redshifts, resulting in the 121 source new
redshift catalog, all of which were X-ray selected. Our neural
network's performance suggests that nearly 90% of these redshift
estimates are consistent with hypothetical spectroscopic or
photometric measurements, strengthening the notion that redshifts can
be reliably estimated using only X-rays, which is valuable to current
and future missions such as Athena. We have also identified a possible
Compton-thick candidate that warrants further investigation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table10.dat 126 121 X-Ray redshift catalog for the 121 sources in our
fully filtered no-z data set
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See also:
B/simbad : Simbad objects catalogue (M.Wenger 2000)
II/281 : 2MASS 6X Point Source Working Database / Catalog (Cutri+ 2006)
IX/45 : The Chandra Source Catalog, Release 1.1 (Evans+ 2012)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
IX/57 : The Chandra Source Catalog (CSC), Release 2.0 (Evans+, 2019)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/A+A/393/425 : Spectral analysis of Lockman Hole (Mainieri+, 2002)
J/A+A/467/73 : 3σ hard sample of XMDS survey (Tajer+, 2007)
J/MNRAS/413/1206 : XMM survey of 12um selected galaxies (Brightman+, 2011)
J/ApJS/201/30 : The Chandra COSMOS survey. III. (Civano+, 2012)
J/A+A/564/A125 : AGN Torus model comparison of AGN in CDFS (Buchner+, 2014)
J/ApJ/802/89 : Luminosity function of X-ray-selected AGNs (Buchner+, 2015)
J/ApJ/817/34 : C-COSMOS Legacy sources multiwavelength (Marchesi+, 2016)
J/MNRAS/473/4937 : AllWISE ctp to ROSAT/2RXS & XMMSLEW2 cat. (Salvato+, 2018)
J/A+A/618/A66 : Redshifts of obscured AGN (Simmonds+, 2018)
J/MNRAS/505/1954 : Properties and X-rays of RLQs and RQQs quasars (Zhu+, 2021)
J/A+A/661/A5 : The eFEDS AGN catalog (Liu+, 2022)
Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Name Source identifier
23- 31 F9.5 deg RAdeg [1/347] Degree of right ascension (J2000)
33- 41 F9.5 deg DEdeg [-74/76] Degree of declination (J2000)
43- 44 I2 --- Nspec [1/11] Number of available spectra
46- 50 I5 --- Cts [162/92424] Number of Chandra broadband
spectral counts
52- 56 F5.2 --- HR [-0/1] X-ray Hardness Ratio ((H-S)/(H+S);
soft:0.5-2keV and hard:2-7keV)
58- 62 F5.2 [-] logLX [42.45/47.06] log of rest-frame 2-10keV
luminosity
64- 67 F4.2 [-] e_logLX [0.1/3.3] Negative error on logLX
69- 72 F4.2 [-] E_logLX [0.09/3] Positive error on logLX
74- 77 F4.2 --- Gamma [1.54/2.8] Power-law photon index (Γ)
79- 82 F4.2 --- e_Gamma [0/0.3] Negative error on Gamma
84- 87 F4.2 --- E_Gamma [0/0.2] Positive error on Gamma
89- 93 F5.2 --- logNH [22.06/24.01] XZ modelled log NH
95- 98 F4.2 --- e_logNH [0.01/0.7] Negative error on logNH
100-103 F4.2 --- E_logNH [0.01/0.4] Positive error on logNH
105-109 F5.3 --- z [0.014/5] XZ modelled redshift
111-115 F5.3 --- e_z [0.003/1.3] Negative error on z
117-121 F5.3 --- E_z [0.001/1.5] Positive error on z
123-126 F4.2 --- P [0.53/1] MLP-computed probability that the
redshift estimate is successful (P+)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 23-Aug-2024