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41. AGN identifications from AKARI and Swift
ID:
ivo://CDS.VizieR/J/ApJ/753/104
Title:
AGN identifications from AKARI and Swift
Short Name:
J/ApJ/753/104
Date:
21 Oct 2021
Publisher:
CDS
Description:
We combine data from two all-sky surveys in order to study the connection between the infrared and hard X-ray (>10keV) properties for local active galactic nuclei (AGNs). The Swift Burst Alert Telescope all-sky survey provides an unbiased, flux-limited selection of hard X-ray-detected AGNs. Cross-correlating the 22 month hard X-ray survey (Tueller et al. 2010, Cat. J/ApJS/186/378) with the AKARI all-sky survey (AKARI/PSCs; Ishihara et al. 2010, Cat. II/297; Yamamura et al. 2010, Cat. II/298), we studied 158 AGNs detected by the AKARI instruments. We find a strong correlation for most AGNs between the infrared (9, 18, and 90{mu}m) and hard X-ray (14-195keV) luminosities, and quantify the correlation for various subsamples of AGNs. Partial correlation analysis confirms the intrinsic correlation after removing the redshift contribution. The correlation for radio galaxies has a slope and normalization identical to that for Seyfert 1 galaxies, implying similar hard X-ray/infrared emission processes in both. In contrast, Compton-thick (CT) sources show a large deficit in the hard X-ray band, because high gas column densities diminish even their hard X-ray luminosities. We propose two photometric diagnostics for source classification: one is an X-ray luminosity versus infrared color diagram, in which type 1 radio-loud AGNs are well isolated from the others in the sample. The other uses the X-ray versus infrared color as a useful redshift-independent indicator for identifying CT AGNs. Importantly, CT AGNs and starburst galaxies in composite systems can also be differentiated in this plane based upon their hard X-ray fluxes and dust temperatures. This diagram may be useful as a new indicator to classify objects in new and upcoming surveys such as WISE and NuSTAR.
42. AGN sample in the northern XMM-XXL field
ID:
ivo://CDS.VizieR/J/MNRAS/459/1602
Title:
AGN sample in the northern XMM-XXL field
Short Name:
J/MNRAS/459/1602
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper we describe and publicly release a catalogue consisting of 8445 point-like X-ray sources detected in the XMM-XXL north survey. For the 2512 AGN which have reliable spectroscopy from SDSS-III/BOSS, we present the X-ray spectral fitting which has been computed with a Bayesian approach. We have also applied an X-ray spectral stacking method to different sub-samples, selected on the basis of the AGN physical properties (L_2-10keV_, z, M_BH_, {lambda}_Edd_ and N_H_). We confirm the well-known Iwasawa-Taniguchi effect in our luminosity-redshift sub-samples, and argue that such an effect is due to a decrease in the covering factor of a distant obscuring 'torus' with increasing X-ray luminosity. By comparing the distribution of the reflection fraction, the ratio of the normalization of the reflected component to the direct radiation, we find that the low-luminosity, low-redshift sub-sample had systematically higher reflection fraction values than the high-redshift, high-luminosity one. On the other hand, no significant difference is found between samples having similar luminosity but different redshift, suggesting that the structure of the torus does not evolve strongly with redshift. Contrary to previous works, we do not find evidence for an increasing photon index at high Eddington ratio. This may be an indication that the structure of the accretion disc changes as the Eddington ratio approaches unity. Comparing our X-ray spectral analysis results with the optical spectral classification, we find that ~20 per cent of optical type-1 AGN show an X-ray absorbing column density higher than 10^21.5^cm^-2^, and about 50 per cent of type-2 AGN have an X-ray absorbing column density less than 10^21.5^cm^-2^. We suggest that the excess X-ray absorption shown in the high-luminosity optical type-1 AGN can be due to small-scale dust-free gas within (or close to) the broad-line region, while in the low-luminosity ones it can be due to a clumpy torus with a large covering factor.
43. AGNs detected by 60 month Swift/BAT survey
ID:
ivo://CDS.VizieR/J/ApJ/749/21
Title:
AGNs detected by 60 month Swift/BAT survey
Short Name:
J/ApJ/749/21
Date:
21 Oct 2021
Publisher:
CDS
Description:
Surveys above 10 keV represent one of the best resources to provide an unbiased census of the population of active galactic nuclei (AGNs). We present the results of 60 months of observation of the hard X-ray sky with Swift/Burst Alert Telescope (BAT). In this time frame, BAT-detected (in the 15-55keV band) 720 sources in an all-sky survey of which 428 are associated with AGNs, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of ~2 larger over similarly complete sets of AGNs. Our sample contains (at least) 15 bona fide Compton-thick AGNs and 3 likely candidates. Compton-thick AGNs represent ~5% of AGN samples detected above 15keV. We use the BAT data set to refine the determination of the log N-log S of AGNs which is extremely important, now that NuSTAR prepares for launch, toward assessing the AGN contribution to the cosmic X-ray background. We show that the log N-log S of AGNs selected above 10 keV is now established to ~10% precision. We derive the luminosity function of Compton-thick AGNs and measure a space density of 7.9^+4.1^_-2.9_x10^-5^/Mpc3 for objects with a de-absorbed luminosity larger than 2x10^42^erg/s. As the BAT AGNs are all mostly local, they allow us to investigate the spatial distribution of AGNs in the nearby universe regardless of absorption. We find concentrations of AGNs that coincide spatially with the largest congregations of matter in the local (<=85Mpc) universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions.
44. AGNs in the MIR using AllWISE data
ID:
ivo://CDS.VizieR/J/ApJS/221/12
Title:
AGNs in the MIR using AllWISE data
Short Name:
J/ApJS/221/12
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an all-sky sample of ~1.4 million active galactic nuclei (AGNs) meeting a two-color infrared photometric selection criteria for AGNs as applied to sources from the Wide-field Infrared Survey Explorer final catalog release (AllWISE). We assess the spatial distribution and optical properties of our sample and find that the results are consistent with expectations for AGNs. These sources have a mean density of ~38 AGNs per square degree on the sky, and their apparent magnitude distribution peaks at g~20, extending to objects as faint as g~26. We test the AGN selection criteria against a large sample of optically identified stars and determine the "leakage" (that is, the probability that a star detected in an optical survey will be misidentified as a quasi-stellar object (QSO) in our sample) rate to be <=4.0x10^-5^. We conclude that our sample contains almost no optically identified stars (<=0.041%), making this sample highly promising for future celestial reference frame work as it significantly increases the number of all-sky, compact extragalactic objects. We further compare our sample to catalogs of known AGNs/QSOs and find a completeness value of >~84% (that is, the probability of correctly identifying a known AGN/QSO is at least 84%) for AGNs brighter than a limiting magnitude of R<~19. Our sample includes approximately 1.1 million previously uncataloged AGNs.
45. AGN UV luminosity function
ID:
ivo://CDS.VizieR/J/MNRAS/488/1035
Title:
AGN UV luminosity function
Short Name:
J/MNRAS/488/1035
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present lists of more than 80000 mostly UV-optical colour-selected AGN from 12 data sets, homogenised with respect to the assumed cosmology, magnitude system, and bandpass correction (if possible). We also present the selection functions for each of the 12 data sets, similarly homogenised. The total sample spans redshifts from z=0 to 7.5. The paper presents a detailed description of the combined sample and determinations of the AGN UV luminosity function throughout this redshift range. The code for developing and analysing AGN luminosity functions is available on GitHub (https://github.com/gkulkarni/QLF). The inferred UV luminosity functions can also be used to derive the contribution of AGN to the cosmic UV background and its effect on the intergalactic medium (IGM). The GitHub repository also includes code for this. Here we also present the luminosity functions in redshift bins, luminosity function evolution models from the paper, the 912{AA} and 1450{AA} volume emissivity of AGN from z=0 to 15, and the hydrogen photoionization rate contribution by AGN in this redshift range.
46. A Homogeneous Bright QSO Survey
ID:
ivo://CDS.VizieR/J/A+AS/112/347
Title:
A Homogeneous Bright QSO Survey
Short Name:
J/A+AS/112/347
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the first paper in a series aimed at defining a statistically significant sample of QSOs in the range 15<B<18.75 and 0.3<z<2.2. The selection is carried out using direct plates obtained at the ESO and UK Schmidt Telescopes, scanned with the COSMOS facility and searched for objects with an ultraviolet excess. Follow-up spectroscopy, carried out at ESO La Silla, is used to classify each candidate. In this initial paper, we describe the scientific objectives of the survey; the selection and observing techniques used. We present the first sample of 285 QSOs (M_B_<-23) in a 153 sq.deg area, covered by the six "deep" fields, intended to obtain significant statistics down B=~18.75 with unprecedented photometric accuracy. From this database, QSO counts are determined in the magnitude range 17<B<18.75.
47. AKARI Asteroid Flux Catalogue Version 1
ID:
ivo://jvo/isas/darts/akari/AKARI-IRC_Catalogue_AllSky_ASTFLUX_1.0
Title:
AKARI Asteroid Flux Catalogue Version 1
Short Name:
AKARI_ASTEROID_V1
Date:
23 Aug 2022 05:22:33
Publisher:
JVO
Description:
The AKARI Asteroid Flux Catalog contains photometric data of 5201 asteroids observed with the Infrared Camera (IRC) on board the Japanese infrared astronomical satellite AKARI. The catalog objects comprise the near-Earth asteroids, the main belt asteroids, the Cybeles, the Hildas, and the Jovian Trojan asteroids. The observations were performed by the all-sky survey in 9 or 18 micron bands as well as the slow-scan observations in 9 or 18 micron bands, and the pointed observations in 4, 7, 11, 15, and/or 24 micron bands.
48. AKARI Far-infrared All-Sky Survey Maps
ID:
ivo://jvo/isas/akari/fis_v1
Title:
AKARI Far-infrared All-Sky Survey Maps
Short Name:
AKARI_FIS_V1
Date:
18 Dec 2022 01:11:53
Publisher:
JVO
Description:
The AKARI Far-infrared All-Sky Survey Maps is produced with the participation of people from the following institutes: University of Tokyo, ISAS/JAXA, Tohoku University, and University of Tsukuba. The image data in this release are produced based on the AKARI All-Sky Survey with 4 far-infrared bands at N60 (65 um), WIDE-S (90 um), WIDE-L (140 um), and N160 (160 um).
49. AKARI/FIS All-Sky Survey Point Source Catalogues
ID:
ivo://CDS.VizieR/II/298
Title:
AKARI/FIS All-Sky Survey Point Source Catalogues
Short Name:
II/298
Date:
21 Oct 2021
Publisher:
CDS
Description:
The AKARI Infrared Astronomical Satellite observed the whole sky in the far infrared (50-180{mu}m) and the mid-infrared (9 and 18{mu}m) between May 2006 and August 2007 (Murakami et al. 2007PASJ...59S.369M) The AKARI/FIS All-Sky Survey Bright Source Catalog Version 1.0 provides positions and fluxes for 427071 point sources in the 4 far-infrared wavelengths centered at 65, 90, 140 and 160{mu}m (see filter characteristics in the "Note (1)" section below)
50. AKARI/IRC mid-IR all-sky Survey
ID:
ivo://CDS.VizieR/II/297
Title:
AKARI/IRC mid-IR all-sky Survey
Short Name:
II/297
Date:
21 Oct 2021
Publisher:
CDS
Description:
The AKARI Infrared Astronomical Satellite observed the whole sky in the far infrared (50-180{mu}m) and the mid-infrared (9 and 18{mu}m) between May 2006 and August 2007 (Murakami et al. 2007PASJ...59S.369M) The AKARI/IRC Point Source Catalogue Version 1.0 provides positions and fluxes for 870,973 sources observed with the InfraRed Camera (IRC): 844,649 sources in the S9W filter, and 194,551 sources in the L18W filter; the "Note (1)" section below provides a summary of the IRC filter characteristics.

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