J/MNRAS/492/1887 Physical properties of the CDFS X-ray sources (Guo+, 2020)
Physical properties of the CDFS X-ray sources through fitting spectral energy
distributions.
Guo X., Gu Q., Ding N., Contini E., Chen Y.
<Mon. Not. R. Astron. Soc., 492, 1887-1901 (2020)>
=2020MNRAS.492.1887G 2020MNRAS.492.1887G (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Galaxies ; Redshifts ; X-ray sources ;
Photometry, infrared ; Photometry, ultraviolet
Keywords: galaxies: active - galaxies: fundamental parameters -
galaxies: nuclei - galaxies: statistics
Abstract:
The physical parameters of galaxies and/or active galactic nucleus
(AGNs) can be derived by fitting their multiband spectral energy
distributions (SEDs). By using CIGALE code, we perform multiband SED
fitting (from ultraviolet to infrared) for 791 X-ray sources (518 AGNs
and 273 normal galaxies) in the 7 Ms Chandra Deep Field-south survey
(CDFS). We consider the contributions from AGNs and adopt more
accurate redshifts than published before. Therefore, more accurate
star formation rates (SFRs) and stellar masses (M*) are derived. We
classify the 518 AGNs into type-I and type-II based on their optical
spectra and their SEDs. Moreover, six AGN candidates are selected from
the 273 normal galaxies based on their SEDs. Our main results are as
follows: (1) the host galaxies of AGNs have larger M* than normal
galaxies, implying that AGNs prefer to host in massive galaxies; (2)
the specific star formation rates (sSFRs) of AGN host galaxies are
different from those of normal galaxies, suggesting that AGN feedback
may play an important role in the star formation activity; (3) we find
that the fraction of optically obscured AGNs in CDFS decreases with
the increase of intrinsic X-ray luminosity, which is consistent with
previous studies; and (4) the host galaxies of type-I AGNs tend to
have lower M* than type-II AGNs, which may suggest that dust in the
host galaxy may also contribute to the optical obscuration of AGNs.
Description:
Luo et al. (2017ApJS..228....2L 2017ApJS..228....2L, Cat. J/ApJS/228/2) provide a
catalogue of X-ray sources for the approximate 7 Ms of the CDFS, which
covers a sky area of 484.2arcmin2. The 7 Ms catalogue contains 1008
X-ray sources, including 711 AGNs, 285 normal galaxies, and 12 stars.
Straatman et al. (2016ApJ...830...51S 2016ApJ...830...51S, Cat. J/ApJ/830/51) provided
photometric catalogs (ZFOURGE) for the CDFS, Cosmic Evolution Survey
(COSMOS) and Ultra Deep Survey (UDS).
To obtain multiband photometric data of the X-ray sources, we
cross-match the 7 Ms catalogue and the ZFOURGE catalogue with matching
radius of 1arcsec. Our matching resulted in 836 X-ray sources. To
perform multiband SED fitting, we construct a sample based on the
following four criteria: (1) the source is not a star or a source near
stars (3arcsec); (2) the source is not one of the six transient events
identified by Zheng et al. (2017ApJ...849..127Z 2017ApJ...849..127Z); (3) the source has a
large signal-to-noise ratio in the K band (S/N>5); (4) the source has
at least 5 band photometric points.
A final sample (791 sources) is constructed based on these four
criteria, which includes 518 AGNs and 273 normal galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 29 78 The redshifts of 78 X-ray sources are not from
7 Ms catalogue
table3.dat 108 791 Source catalogue
tabled1.dat 133 791 Output parameters of SED fitting and parameters
mentioned in the paper
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See also:
J/ApJS/228/2 : Chandra Deep Field-South survey: 7Ms sources (Luo+, 2017)
J/ApJ/830/51 : FourStar galaxy evolution survey (ZFOURGE) (Straatman+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- XID [78/908] X-ray source ID from Luo et al.
(2017ApJS..228....2L 2017ApJS..228....2L, Cat. J/ApJS/228/2)
5- 9 F5.3 --- z Redshift
11- 18 E8.3 10-7W LXcor Absorption-corrected intrinsic 0.5-7.0keV
luminosity (1)
20- 25 A6 --- Class [AGN /Galaxy] Object classification from
Luo et al. (2017ApJS..228....2L 2017ApJS..228....2L,
Cat. J/ApJS/228/2)
27- 29 A3 --- r_z Reference for z (2)
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Note (1): Since the redshifts of these sources in the 7 Ms catalogue are
replaced by more accurate redshifts, the X-ray luminosities need to
be corrected. The corrected X-ray luminosity is derived by:
Lc/Luc=R(z)2(1+z)Γ-2/(R(z7Ms)2(1+z7Ms)Γ-2)
where Lc and Luc are corrected X-ray luminosity and uncorrected
X-ray luminosity (the apparent luminosity and the intrinsic
luminosity) in 7 Ms catalogue, z and z7Ms are our redshift and
redshift from 7 Ms catalogue, and R(z) is the luminosity distance.
For the intrinsic luminosity, Γ is the fixed photon index of
1.8 when Γeff is smaller than 1.8; while Γ is the
effective power-law photon index of Γeff when Γeff is
larger than 1.8.
Note (2): References as follows:
H17 = Herenz et al. (2017A&A...606A..12H 2017A&A...606A..12H, Cat. J/A+A/606/A12)
I17 = Inami et al. (2017A&A...608A...2I 2017A&A...608A...2I, Cat. J/A+A/608/A2)
M16 = Momcheva et al. (2016ApJS..225...27M 2016ApJS..225...27M, Cat. J/ApJS/225/27), 3D-HST survey
P18 = Pentericci et al. (2018A&A...616A.174P 2018A&A...616A.174P, Cat. V/151), VANDELS survey
S16 = Straatman et al. (2016ApJ...830...51S 2016ApJ...830...51S, Cat. J/ApJ/830/51), ZFOURGE
survey
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- XID [45/961] X-ray source ID from Luo et al.
(2017ApJS..228....2L 2017ApJS..228....2L, Cat. J/ApJS/228/2)
5- 9 F5.3 --- z Redshift
11- 14 A4 --- ztype [phot/spec] Redshift type (photometric or
spectroscopic)
16- 26 F11.6 Msun/yr SFR Star formation rate
28- 35 E8.3 Msun Mass Stellar mass
37- 43 A7 --- Class Source classification (AGN, Galaxy, Type-I
or Type-II)
45- 52 A8 --- q_Class [Secure /Insecure] Quality of Class
54- 60 A7 --- ClassSED SED classification of the source (AGN,
Galaxy, Type-I or Type-II)
62- 69 A8 --- q_ClassSED [Secure /Insecure] Quality of ClassSED
71- 77 A7 --- ClassS04 [Type-I /Type-II] Spectral classification
from Szokoly et al. (2004ApJS..155..271S 2004ApJS..155..271S,
Cat. J/ApJS/155/271)
79- 85 A7 --- ClassM05 [Type-I /Type-II] Spectral classification
from Mignoli et al. (2005A&A...437..883M 2005A&A...437..883M,
Cat. J/A+A/437/883)
87-108 A22 --- Remarks Remarks
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Byte-by-byte Description of file: tabled1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- XID [45/961] X-ray source ID from Luo et al.
(2017ApJS..228....2L 2017ApJS..228....2L, Cat. J/ApJS/228/2)
5- 13 E9.4 Msun/yr SFR Star formation rate (1)
15- 23 E9.4 Msun/yr e_SFR Error on SFR (1)
25- 33 E9.4 Msun Mass Stellar mass (1)
35- 43 E9.4 Msun e_Mass Error on Mass (1)
45- 53 E9.4 10-7W Ldust Dust luminosity (1)
55- 63 E9.4 10-7W e_Ldust Error on Ldust (1)
65- 73 E9.4 --- fAGN ?=0 Fraction of AGN (1)
75- 83 E9.4 --- e_fAGN ?=0 Error on fAGN (1)
85- 93 E9.4 10-7W LAGN ?=0 AGN luminosity (1)
95-103 E9.4 10-7W e_LAGN ?=0 Error on LAGN (1)
105-113 E9.4 10-7W LUV Rest-frame UV luminosity (2)
115-123 E9.4 10-7W LIR Rest-frame IR luminosity (2)
125-133 E9.4 10-7W nuLnu6um ?=0 Rest-frame 6µm luminosity for AGN
component as derived from SED fitting (3)
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Note (1): Real output parameters and their error of SED fitting
Note (2): Rest-frame UV and IR luminosities are used to estimate SFR
(see Section 3.2)
Note (3): νLν(6µm) is used to ruled out the bias of X-ray selected AGN
sample in Section 4.3.
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 15-Mar-2023