J/MNRAS/406/420 UV/far-IR data of infrared excess sources (Georgakakis+, 2010)
Infrared excess sources: Compton thick QSOs, low-luminosity Seyferts or
starbursts?
Georgakakis A., Rowan-Robinson M., Nandra K., Digby-North J.,
Perez-Gonzalez P.G., Barro G.
<Mon. Not. R. Astron. Soc., 406, 420-433 (2010)>
=2010MNRAS.406..420G 2010MNRAS.406..420G
ADC_Keywords: Galaxies, IR ; Photometry, UBVRI ; Photometry, ugriz ;
Photometry, infrared
Keywords: surveys - galaxies: active - galaxies: Seyfert - galaxies: starburst
Abstract:
We explore the nature of Infrared Excess sources (IRX), which are
proposed as candidates for luminous [LX(2-10keV)>1043erg/s]
Compton thick (NH>2x1024cm-2) QSOs at z≈2. Lower redshift,
z≈1, analogues of the distant IRX population are identified by
first redshifting to z=2 the spectral energy distributions (SEDs) of
all sources with secure spectroscopic redshifts in the AEGIS (6488)
and the GOODS-North (1784) surveys and then selecting those that
qualify as IRX sources at that redshift. A total of 19 galaxies are
selected. The mean redshift of the sample is z≈1. We do not find
strong evidence for Compton thick QSOs in the sample. For nine sources
with X-ray counterparts, the X-ray spectra are consistent with Compton
thin active galactic nucleus (AGN). Only three of them show tentative
evidence for Compton thick obscuration. The SEDs of the X-ray
undetected population are consistent with starburst activity.
Description:
The UV to far-IR data used in this study are from the Universidad
Complutense de Madrid (UCM) Cosmological Surveys Data base
(http://guaix.fis.ucm.es/~pgperez) which combines all the photometric
and spectroscopic observations available in prime cosmological survey
fields.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 73 19 Sample
table2.dat 151 14 Multiwavelength SEDs of the AEGIS IRX sources
table3.dat 119 5 Multiwavelength SEDs of the CDF-North IRX sources
table4.dat 92 19 X-ray properties of the sample
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See also:
II/301 : The DEEP2-DR1 Photometric Catalog (Coil+ 2004)
J/ApJ/658/1264 : IR-excess sources in GLIMPSE and MSX (Uzpen+, 2007)
J/ApJS/180/102 : AEGIS-X: Chandra deep survey (Laird+, 2009)
J/ApJ/634/128 : 16µm imaging around the HDF-N (Teplitz+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [irx-]
5- 6 I2 --- irx [1/19] Source number
8- 9 I2 h RAh Right ascension at 3.6um (J2000)
11- 12 I2 min RAm Right ascension at 3.6um (J2000)
14- 18 F5.2 s RAs Right ascension at 3.6um (J2000)
20 A1 --- DE- Declination sign at 3.6um (J2000)
21- 22 I2 deg DEd Declination at 3.6um (J2000)
24- 25 I2 arcmin DEm Declination at 3.6um (J2000)
27- 31 F5.2 arcsec DEs Declination at 3.6um (J2000)
33- 38 F6.4 --- z Spectroscopic redshift
40- 43 I4 --- 24/R Observed 24µm/R flux ratio if the source
were at z=2
45- 47 F3.1 mag R-[3.6] Observed R-[3.6] colour index if the source
were at z=2 (AB system)
49- 53 F5.2 [Lsun] logLsb ?=- IR luminosity (3-1000um) of the
starburst component (1)
55- 59 F5.2 [Lsun] logLtor ?=- IR luminosity (3-1000um) of the AGN torus
component (1)
61- 63 A3 --- MType Morphological type (best-fitting optical
template in the optical)
65- 68 F4.2 mag AV ?=- Dust extinction
70- 73 F4.2 [Msun/yr] logSFR ?=- Star formation rate (2)
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Note (1): estimated from the SED spectral fits (a dash indicates that this
component is not required to fit the data).
Note (2): estimated from the SED fits (a dash indicates no dust reddening).
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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- 4 A4 --- --- [irx-]
5- 6 I2 --- irx [1/14] Source number (1)
8- 12 F5.2 [uJy] logu ?=- CFHT/Megacam u-band flux density
14- 17 F4.2 [uJy] e_logu ? rms uncertainty on logu
19- 23 F5.2 [uJy] logB DEEP2 B-band flux density
25- 28 F4.2 [uJy] e_logB rms uncertainty on logB
30- 34 F5.2 [uJy] logg ?=- CFHT/Megacam g-band flux density
36- 39 F4.2 [uJy] e_logg ? rms uncertainty on logg
41- 45 F5.2 [uJy] logR DEEP2 R-band flux density
47- 50 F4.2 [uJy] e_logR rms uncertainty on logR
52- 56 F5.2 [uJy] logr ?=- CFHT/Megacam r-band flux density
58- 61 F4.2 [uJy] e_logr ? rms uncertainty on logr
63- 66 F4.2 [uJy] logI DEEP2 I-band flux density
68- 71 F4.2 [uJy] e_logI rms uncertainty on logI
73- 76 F4.2 [uJy] logi ?=- CFHT/Megacam i-band flux density
78- 81 F4.2 [uJy] e_logi ? rms uncertainty on logi
83- 86 F4.2 [uJy] logz ?=- CFHT/Megacam z-band flux density
88- 91 F4.2 [uJy] e_logz ? rms uncertainty on logz
93- 96 F4.2 [uJy] log3.6 Spitzer/IRAC 3.6um band flux density
98-101 F4.2 [uJy] e_log3.6 rms uncertainty on log3.6
103-106 F4.2 [uJy] log4.5 Spitzer/IRAC 4.5um band flux density
108-111 F4.2 [uJy] e_log4.5 rms uncertainty on log4.5
113-116 F4.2 [uJy] log5.8 Spitzer/IRAC 5.8um band flux density
118-121 F4.2 [uJy] e_log5.8 rms uncertainty on log5.8
123-126 F4.2 [uJy] log8.0 ?=- Spitzer/IRAC 8.0um band flux density
128-131 F4.2 [uJy] e_log8.0 ? rms uncertainty on log8.0
133-136 F4.2 [uJy] log24 ?=- Spitzer/MIPS 24um band flux density
138-141 F4.2 [uJy] e_log24 ? rms uncertainty on log24
143-146 F4.2 [uJy] log70 ?=- Spitzer/MIPS 70um band flux density
148-151 F4.2 [uJy] e_log70 ? rms uncertainty on log70
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Note (1): None of the sources is detected in the GALEX FUV band.
Source irx-8 has a GALEX NUV log flux density of 0.10±0.03 (uJy units).
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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- 4 A4 --- --- [irx-]
5- 6 I2 --- irx [14/19] Source number (1)
8- 12 F5.2 [uJy] logU ?=- U-band flux density
14- 17 F4.2 [uJy] e_logU ? rms uncertainty on logU
19- 23 F5.2 [uJy] logB B-band flux density
25- 28 F4.2 [uJy] e_logB rms uncertainty on logB
30- 34 F5.2 [uJy] logR ?=- DEEP2 R-band flux density
36- 39 F4.2 [uJy] e_logR ? rms uncertainty on logR
41- 44 F4.2 [uJy] logI DEEP2 I-band flux density
46- 49 F4.2 [uJy] e_logI rms uncertainty on logI
51- 54 F4.2 [uJy] logz ?=- CFHT/Megacam z-band flux density
56- 59 F4.2 [uJy] e_logz ? rms uncertainty on logz
61- 64 F4.2 [uJy] log3.6 Spitzer/IRAC 3.6um band flux density
66- 69 F4.2 [uJy] e_log3.6 rms uncertainty on log3.6
71- 74 F4.2 [uJy] log4.5 Spitzer/IRAC 4.5um band flux density
76- 79 F4.2 [uJy] e_log4.5 rms uncertainty on log4.5
81- 84 F4.2 [uJy] log5.8 Spitzer/IRAC 5.8um band flux density
86- 89 F4.2 [uJy] e_log5.8 rms uncertainty on log5.8
91- 94 F4.2 [uJy] log8.0 ?=- Spitzer/IRAC 8.0um band flux density
96- 99 F4.2 [uJy] e_log8.0 ? rms uncertainty on log8.0
101-104 F4.2 [uJy] log24 ?=- Spitzer/MIPS 24um band flux density
106-109 F4.2 [uJy] e_log24 ? rms uncertainty on log24
111-114 F4.2 [uJy] log70 ?=- Spitzer/MIPS 70um band flux density
116-119 F4.2 [uJy] e_log70 ? rms uncertainty on log70
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Note (1): None of the sources is detected in the GALEX NUV and FUV bands.
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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- 4 A4 --- --- [irx-]
5- 6 I2 --- irx [1/19] Source number
7 A1 --- n_irx [i] flag not explained in the paper
9- 16 A8 --- XID X-ray identification number (2)
18- 21 I4 ct Counts Total counts in the energy range 0.5-10keV (3)
23- 27 F5.1 ct Bkg Background counts in the range 0.5-10keV (3)
29 A1 --- l_NH Limit flag on NH
30- 33 F4.1 10+22cm-2 NH ?=- Best-fitting column density of the cold
absorber (WABS component of XSPEC model)
35- 39 F5.1 10+22cm-2 E_NH ? Error on NH (upper value) 90% conf. level
41- 44 F4.1 10+22cm-2 e_NH ? Error on NH (lower value) 90% conf. level
46- 50 F5.2 --- R ?=- Reflection fraction of the PEXMON model
of XSPEC
52- 55 F4.1 --- E_R ?=- Error on R (upper value) 90% conf. level
57- 60 F4.2 --- e_R ?=- Error on R (lower value) 90% conf. level
61 A1 --- n_R [f] f for fixed value (here -1)
63- 65 F3.1 --- Gamma ?=- Power-law photon index Γ of the
intrinsic AGN power-law spectrum
67- 69 F3.1 --- E_Gamma ?=- Error on Gamma (upper value)
71- 73 F3.1 --- e_Gamma ?=- Error on Gamma (lower value)
74 A1 --- n_Gamma [f] f for fixed value (here 1.9)
76- 80 F5.1 --- Cstat ?=- C-stat of the best-fitting solution
82- 84 I3 --- DOF ?=- degrees of freedom
86 A1 --- l_LX Limit flag on LX
87- 92 F6.3 10+36W LX Obscuration corrected luminosity in the
2-10keV range (in 1043erg/s) (4)
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Note (2): as in Laird et al (2009, Cat. J/ApJS/180/102) for AEGIS and
Georgakakis et al. (2008A&A...484..671G 2008A&A...484..671G) for the CDF-North. Sources without
an X-ray counterpart or low significance (Poisson probability >4x10-6)
X-ray sources do not have an X-ray identification number
Note (3): For sources with insufficient counts to perform X-ray spectral
analysis the total extracted counts in the 2-8keV band are listed.
Note (4): In the case of upper limits or sources with insufficient counts
to perform X-ray spectral analysis, no correction has been applied for
intrinsic obscuration. In those sources fluxes and luminosities in the
2-10keV band are estimated by adopting a power-law spectral index with
Gamma=1.4, i.e. assume that the sources have X-ray spectra similar to that
of the X-ray background. The statistical uncertainty in the luminosity is
less than 10 per cent for X-ray detected sources (Poisson probability
<4x10-6) and about a factor of 2 for low-significance ones.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 09-Apr-2013