J/ApJ/943/162 31.3 deg2 Stripe 82X spectral analysis (Peca+, 2023)
On the Cosmic Evolution of AGN Obscuration and the X-Ray Luminosity Function:
XMM-Newton and Chandra Spectral Analysis of the 31.3 deg2 Stripe 82X.
Peca A., Cappelluti N., Urry C.M., LaMassa S., Marchesi S., Ananna T.T.,
B_alokovic M., Sanders D., Auge C., Treister E., Powell M., Turner T.J.,
Kirkpatrick A., Tian C.
<Astrophys. J. 943, 162 (2023)>
=2023ApJ...943..162P 2023ApJ...943..162P (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; X-ray sources ; Active gal. nuclei
Keywords: X-ray surveys - active galactic nuclei - Galaxy evolution -
X-ray active galactic nuclei - cosmology - cosmological evolution -
cosmological models - active galaxies
Abstract:
We present X-ray spectral analysis of XMM-Newton and Chandra
observations in the 31.3deg2 Stripe-82X (S82X) field. Of the 6181
unique X-ray sources in this field, we analyze a sample of 2937
candidate active galactic nuclei (AGNs) with solid redshifts and
sufficient counts determined by simulations. Our results show an
observed population with median values of spectral index , column
density log and intrinsic, de-absorbed, 2-10keV luminosity log, in the
redshift range 0-4. We derive the intrinsic, model-independent,
fraction of AGNs that are obscured (22≤log(NH/cm-2)<24), finding a
significant increase in the obscured AGN fraction with redshift and a
decline with increasing luminosity. The average obscured AGN fraction
is 57±4% for log(LX/erg/s)>43. This work constrains the AGN
obscuration and spectral shape of the still uncertain high-luminosity
and high-redshift regimes (log(LX/erg/s)>45.5, z>3), where the
obscured AGN fraction rises to 64±12%. We report a luminosity and
density evolution of the X-ray luminosity function, with obscured AGNs
dominating at all luminosities at z>2, and unobscured sources
prevailing at log(LX/erg/s)>45 at lower redshifts. Our results agree
with the evolutionary models in which the bulk of AGN activity is
triggered by gas-rich environments and in a downsizing scenario.
Moreover, the black hole accretion density (BHAD) is found to evolve
similarly to the star formation rate density, confirming the
coevolution between AGN and host galaxy, but suggesting different
timescales in their growing history. The derived BHAD evolution shows
that Compton-thick AGNs contribute to the accretion history of AGNs as
much as all other AGN populations combined.
Description:
We exploited the full extent of X-ray and multiband data in the S82X
field by analyzing the X-ray spectra of the 2937 sources with a solid
redshift estimate (LaMassa et al., 2016ApJ...817..172L 2016ApJ...817..172L, Cat.
J/ApJ/817/172; LaMassa et al., 2019ApJ...876...50L 2019ApJ...876...50L, Cat.
J/ApJ/876/50).
Luminosity functions and bias corrections available at
https://github.com/alessandropeca/S82X
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 587 2937 Final master cleaned catalog
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See also:
J/ApJ/817/172 : X-ray Observations of Stripe 82 (LaMassa+, 2016)
J/ApJ/876/50 : X-ray+MIR AGNs in Stripe 82 with eBOSS spectra (LaMassa+, 2019)
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
B_ytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- Source Source ID from (LaMassa et al.,
2016ApJ...817..172L 2016ApJ...817..172L, Cat. J/ApJ/817/172 (srcid)
8- 17 F10.6 deg RAdeg X-ray right ascension (J2000)
19- 28 F10.6 deg DEdeg X-ray declination (J2000)
30- 38 I9 --- ObsId Obs ID from (LaMassa et al.,
2016ApJ...817..172L 2016ApJ...817..172L, Cat. J/ApJ/817/172 (obsid)
40- 47 F8.1 s Texp Effective exposure time [s] (src_exp)
49- 55 F7.2 ct ctsF Full band counts (cts_f)
57- 63 F7.3 ct e_ctsF Full band counts lower error 1 sigma (ctsfel)
65- 71 F7.3 ct E_ctsF Full band counts upper error 1 sigma (ctsfeu)
73- 79 F7.2 ct ctsS Soft band counts (cts_s)
81- 87 F7.3 ct e_ctsS Soft band counts lower error 1 sigma (ctssel)
89- 95 F7.3 ct E_ctsS Soft band counts upper error 1 sigma (ctsseu)
97-103 F7.2 ct ctsH Hard band counts (cts_h)
105-111 F7.3 ct e_ctsH Hard band counts lower error 1 sigma (ctshel)
113-119 F7.3 ct E_ctsH Hard band counts upper error 1 sigma (ctsheu)
121-129 F9.6 --- HR HR computed with BEHR
(Park et al., 2006ApJ...652..610P 2006ApJ...652..610P) (HR)
131-139 F9.6 --- bHR HR lower range computed with BEHR
(Park et al., 2006ApJ...652..610P 2006ApJ...652..610P) (HR_rl)
141-149 F9.6 --- BHR HR upper computed with BEHR
(Park et al., 2006ApJ...652..610P 2006ApJ...652..610P) (HR_ru)
151-162 E12.6 mW/m2 FluxF Full band flux [erg/s/cm2] (flux_f)
164-175 E12.6 mW/m2 b_FluxF Full band flux lower 90%cl range [erg/s/cm2]
(fluxfrl)
177-188 E12.6 mW/m2 B_FluxF Full band flux upper 90%cl range [erg/s/cm2]
(fluxfru)
190-201 E12.6 mW/m2 FluxS Soft band flux [erg/s/cm2] (flux_s)
203-214 E12.6 mW/m2 b_FluxS Soft band flux lower 90%cl range [erg/s/cm2]
(fluxsrl)
216-227 E12.6 mW/m2 B_FluxS Soft band flux upper 90%cl range [erg/s/cm2]
(fluxsru)
229-240 E12.6 mW/m2 FluxH Hard band flux [erg/s/cm2] (flux_h)
242-253 E12.6 mW/m2 b_FluxH Hard band flux lower 90%cl range [erg/s/cm2]
(fluxhrl)
255-266 E12.6 mW/m2 B_FluxH Hard band flux upper 90%cl range [erg/s/cm2]
(fluxhru)
268-279 E12.6 10-7W LobsF Observed Full band luminosity [erg/s] (lumin_of)
281-292 E12.6 10-7W b_LobsF Observed Full band luminosity lower 90%cl range
[erg/s] (luminofrl)
294-305 E12.6 10-7W B_LobsF Observed Full band luminosity upper 90%cl range
[erg/s] (luminofru)
307-318 E12.6 10-7W LobsS Observed Soft band luminosity [erg/s] (lumin_os)
320-331 E12.6 10-7W b_LobsS Observed Soft band luminosity lower 90%cl range
[erg/s] (luminosrl)
333-344 E12.6 10-7W B_LobsS Observed Soft band luminosity upper 90%cl range
[erg/s] (luminosru)
346-357 E12.6 10-7W LobsH Observed Hard band luminosity [erg/s] (lumin_oh)
359-370 E12.6 10-7W b_LobsH Observed Hard band luminosity lower 90%cl range
[erg/s] (luminohrl)
372-383 E12.6 10-7W B_LobsH Observed Hard band luminosity upper 90%cl range
[erg/s] (luminohru)
385-396 E12.6 10-7W LintF Intrinsic Full band luminosity [erg/s] (lumin_f)
398-409 E12.6 10-7W b_LintF Intrinsic Full band luminosity lower 90%cl range
[erg/s] (luminfrl)
411-422 E12.6 10-7W B_LintF Intrinsic Full band luminosity upper 90%cl range
[erg/s] (luminfru)
424-435 E12.6 10-7W LintS Intrinsic Soft band luminosity [erg/s] (lumin_s)
437-448 E12.6 10-7W b_LintS Intrinsic Soft band luminosity lower 90%cl range
[erg/s] (luminsrl)
450-461 E12.6 10-7W B_LintS Intrinsic Soft band luminosity upepr 90%cl range
[erg/s] (luminsru)
463-474 E12.6 10-7W LintH Intrinsic Hard band luminosity [erg/s] (lumin_h)
476-487 E12.6 10-7W b_LintH Intrinsic Hard band luminosity lower 90%cl range
[erg/s] (luminhrl)
489-500 E12.6 10-7W B_LintH Intrinsic Hard band luminosity upper 90%cl range
[erg/s] (luminhru)
502-513 E12.6 cm-2 NH Obscuring column density, [cm-2] (nh)
515-526 E12.6 cm-2 b_NH Obscuring column density, lower 90%cl range
[cm-2] (nh_rl)
528-539 E12.6 cm-2 B_NH Obscuring column density, upper 90%cl range
[cm-2] (nh_ru)
541-548 F8.6 --- gamma Photon Index (gamma)
550-557 F8.6 --- bgamma ?=0 Photon Index lower 90%cl range (gamma_rl)
559-566 F8.6 --- Bgamma ?=0 Photon Index upper 90%cl range (gamma_ru)
568-574 F7.5 --- fscatt ?=- Scattering fraction (fscatt)
576-582 F7.5 --- z B_est redshift (z)
584 I1 --- f_z [1/2] Flag: 1 = z-spec, 2= z-phot (z_flag)
586-587 A2 --- Model Model ID (model) (1)
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Note (1): Model as follows:
M1 = for single power law
M2 = for single power law plus reflection
M3 = for double power law
M4 = for double power law plus reflection
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Acknowledgements:
Alexandro Peca, alessandro.peca(at)miami.edu
(End) Patricia Vannier [CDS] 09-Feb-2023