J/MNRAS/503/2598 Intrinsic AGN emission post-Herschel view (Bernhard+, 2021)
The post-Herschel view of intrinsic AGN emission:
constructing templates for galaxy and AGN emission at IR wavelengths.
Bernhard E., Tadhunter C., Mullaney J.R., Grimmett L.P., Rosario D.J.,
Alexander D.M.
<Mon. Not. R. Astron. Soc., 503, 2598-2621 (2021)>
=2021MNRAS.503.2598B 2021MNRAS.503.2598B (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; X-ray sources ; Infrared sources
Keywords: methods: statistical - galaxies: active - galaxies: Seyfert -
galaxies: starburst - X-rays: galaxies
Abstract:
Measuring the star-forming properties of active galactic nucleus (AGN)
hosts is key to our understanding of galaxy formation and evolution.
However, this topic remains debated, partly due to the difficulties in
separating the infrared (i.e. 1-1000um) emission into AGN and
star-forming components. Taking advantage of archival far-infrared
data from Herschel, we present a new set of AGN and galaxy infrared
templates and introduce the spectral energy distribution fitting code
IRAGNSEP. Both can be used to measure infrared host galaxy properties,
free of AGN contamination. To build these, we used a sample of 100
local (z<0.3), low-to-high luminosity AGNs (i.e.
Lbol∼1042-46erg/s), selected from the 105-month Swift-BAT X-ray
survey, which have archival Spitzer-IRS spectra and Herschel
photometry. We first built a set of seven galaxy templates using a
sample of 55 star-forming galaxies selected via infrared diagnostics.
Using these templates, combined with a flexible model for the AGN
contribution, we extracted the intrinsic infrared emission of our AGN
sample. We further demonstrate that we can reduce the diversity in the
intrinsic shapes of AGN spectral energy distributions down to a set of
three AGN templates, of which two represent AGN continuum, and one
represents silicate emission. Our results indicate that, on average,
the contribution of AGNs to the far-infrared (λ≥50um) is not
as high as suggested by some recent work. We further show that the
need for two infrared AGN continuum templates could be related to
nuclear obscuration, where one of our templates appears dominated by
the emission of the extended polar dust.
Description:
We have investigated the intrinsic AGN IR emission of AGNs selected
from the 105-month Swift-BAT all-sky hard X-ray survey. Our sample
is typical of local (z<0.3) low-to-high X-ray luminosity AGNs (i.e.
Lbol∼1042-46erg/s; see Fig. 1). For the IR counterparts, we used
archival Spitzer-IRS spectra (5um<lambda<40um), as well as
Herschel-PACS and Herschel-SPIRE photometry (70-500um) for which we
have corrected the flux for spatially extended emission (see Section
2.2.1). Our final sample consists of 100 AGN SEDs covering most of the
IR portion of the electromagnetic spectrum.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec12.dat 230 112 Main properties of the 112 sources in our
AGN sample
tablec3.dat 44 100 IR properties
tablec45.dat 234 110 Basic properties of this sample of 110 galaxies
tablec6.dat 39 55 Results of the fits
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Byte-by-byte Description of file: tablec12.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID Sequential number
5- 23 A19 --- BAT BAT name (SWIFT JHHMM.s+DDMM)
25- 47 A23 --- CTP Counterpart name
49- 50 I2 h RAh Right ascension (J2000)
52- 53 I2 min RAm Right ascension (J2000)
55- 60 F6.3 s RAs Right ascension (J2000)
62 A1 --- DE- Declination sign (J2000)
63- 64 I2 deg DEd Declination (J2000)
66- 67 I2 arcmin DEm Declination (J2000)
69- 74 F6.3 arcsec DEs Declination (J2000)
76- 80 F5.3 --- z Redshift
82- 85 F4.1 [10-7W] logLX X-ray luminosity
87- 91 A5 --- Type Galaxy type
93- 97 F5.2 [cm/s2] logNH ? H column density
99-106 F8.2 mJy F70 Flux at 70um
108-114 F7.2 mJy e_F70 Flux at 70um error
116-119 A4 --- f_F70 Flux at 70um flag
121-129 F9.2 mJy F100 ?=0 Flux at 100um
131-137 F7.2 mJy e_F100 ?=0 Flux at 100um error
139-142 A4 --- f_F100 Flux at 100um flag
144-152 F9.2 mJy F160 ?=0 Flux at 160um
154-160 F7.2 mJy e_F160 ?=0 Flux at 160um error
162-165 A4 --- f_F160 Flux at 160um flag
167-174 F8.2 mJy F250 ?=0 Flux at 250um
176-182 F7.2 mJy e_F250 ?=0 Flux at 250um error
184-187 A4 --- f_F250 Flux at 250um flag
189-196 F8.2 mJy F350 ?=0 Flux at 350um
198-204 F7.2 mJy e_F350 ?=0 Flux at 350um error
206-209 A4 --- f_F350 Flux at 350um flag
211-218 F8.2 mJy F500 ?=0 Flux at 500um
220-225 F6.2 mJy e_F500 ?=0 Flux at 500um error
227-230 A4 --- f_F500 Flux at 500um flag
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Byte-by-byte Description of file: tablec3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID Sequential number
5- 11 F7.3 --- S9.7 ?=-99 Total absorption at 9.7um converted
to S9.7 (1)
13- 18 F6.3 [10-7W] logLIRH Host infrared luminosity
20- 24 F5.3 [10-7W] e_logLIRH Host infrared luminosity error
26- 30 F5.3 --- AGNfrac AGN fraction
32- 38 F7.3 --- SFR Star-formation rate
40- 44 F5.3 --- e_SFR Star-formation rate error
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Note (1): Total absorption at 9.7um converted to S9.7, using,
S9.7=-ln(FObs8.7um/FInt9.7um), where
(FObs8.7um and FInt9.7um are the observed and the intrinsic
(i.e. de-absorbed) fluxes at 9.7um, respectively.
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Byte-by-byte Description of file: tablec45.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID Sequential number
5- 12 I8 --- aorkey AOR key
14- 40 A27 --- CTP Counterpart name
42- 43 I2 h RAh Right ascension (J2000)
45- 46 I2 min RAm Right ascension (J2000)
48- 53 F6.3 s RAs Right ascension (J2000)
55 A1 --- DE- Declination sign (J2000)
56- 57 I2 deg DEd Declination (J2000)
59- 60 I2 arcmin DEm Declination (J2000)
62- 67 F6.3 arcsec DEs Declination (J2000)
69- 75 F7.5 --- z Redshift
77- 85 F9.2 mJy F70 ?=0 Flux at 70um
87- 94 F8.2 mJy e_F70 ?=0 Flux at 70um error
96- 99 A4 --- f_F70 Flux at 70um flag
101-109 F9.2 mJy F100 ?=0 Flux at 100um
111-118 F8.2 mJy e_F100 ?=0 Flux at 100um error
120-123 A4 --- f_F100 Flux at 100um flag
125-134 F10.2 mJy F160 ?=0 Flux at 160um
136-143 F8.2 mJy e_F160 ?=0 Flux at 160um error
145-148 A4 --- f_F160 Flux at 160um flag
150-158 F9.2 mJy F250 ?=0 Flux at 250um
160-167 F8.2 mJy e_F250 ?=0 Flux at 250um error
169-172 A4 --- f_F250 Flux at 250um flag
174-182 F9.2 mJy F350 ?=0 Flux at 350um
184-190 F7.2 mJy e_F350 []?=0 Flux at 350um error
192-195 A4 --- f_F350 Flux at 350um flag
197-204 F8.2 mJy F500 ?=0 Flux at 500um
206-212 F7.2 mJy e_F500 []?=0 Flux at 500um error
214-217 A4 --- f_F500 Flux at 500um flag
219-223 F5.3 um EQW6.2 Equivalent width of the PAH6.2um
225-229 F5.3 mag W1-W2 ? W1-W2 colour index
231-234 A4 --- Notes Notes
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Byte-by-byte Description of file: tablec6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID Sequential number
5- 10 F6.3 [Msun] logMdust Dust mass
12- 17 F6.3 K Tdust Dust temperature
19- 24 F6.3 [Msun] logMPAH PAH mass
26- 31 F6.3 K TPAH PAH temperature
33- 39 F7.3 --- tau9.7 ?=-99 Optical depth at 9.7um
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 18-Jan-2024