scholarly journals Comprehensive Broadband X-Ray and Multiwavelength Study of Active Galactic Nuclei in 57 Local Luminous and Ultraluminous Infrared Galaxies Observed with NuSTAR and/or Swift/BAT

2021 ◽  
Vol 257 (2) ◽  
pp. 61
Author(s):  
Satoshi Yamada ◽  
Yoshihiro Ueda ◽  
Atsushi Tanimoto ◽  
Masatoshi Imanishi ◽  
Yoshiki Toba ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Infrared Galaxies ◽  
Telescope Array ◽  
X Ray ◽  
Bolometric Luminosity ◽  
Small Column ◽  
Ultraluminous Infrared Galaxy ◽  
Ultraluminous Infrared Galaxies ◽  
Infrared Data

Abstract We perform a systematic X-ray spectroscopic analysis of 57 local luminous and ultraluminous infrared galaxy systems (containing 84 individual galaxies) observed with the Nuclear Spectroscopic Telescope Array and/or Swift/BAT. Combining soft X-ray data obtained with Chandra, XMM-Newton, Suzaku, and/or Swift/XRT, we identify 40 hard (>10 keV) X-ray–detected active galactic nuclei (AGNs) and constrain their torus parameters with the X-ray clumpy torus model XCLUMPY. Among the AGNs at z < 0.03, for which sample biases are minimized, the fraction of Compton-thick (N H ≥ 1024 cm−2) AGNs reaches 64 − 15 + 14 % (6/9 sources) in late mergers, while it is 24 − 10 + 12 % (3/14 sources) in early mergers, consistent with the tendency reported by Ricci et al. We find that the bolometric AGN luminosities derived from the infrared data increase but the X-ray to bolometric luminosity ratios decrease with merger stage. The X-ray-weak AGNs in late mergers ubiquitously show massive outflows at subparsec to kiloparsec scales. Among them, the most luminous AGNs (L bol,AGN ∼ 1046 erg s−1) have relatively small column densities of ≲1023 cm−2 and almost super-Eddington ratios (λ Edd ∼ 1.0). Their torus covering factors (C T (22) ∼ 0.6) are larger than those of Swift/BAT-selected AGNs with similarly high Eddington ratios. These results suggest a scenario where, in the final stage of mergers, multiphase strong outflows are produced due to chaotic quasi-spherical inflows, and the AGN becomes extremely X-ray weak and deeply buried due to obscuration by inflowing and/or outflowing material.

Early science with the LMT: molecular torus in UGC 5101

2020 ◽  
Vol 499 (2) ◽  
pp. 2042-2050
Author(s):  
I Cruz-González ◽  
A I Gómez-Ruiz ◽  
A Caldú-Primo ◽  
E Benítez ◽  
J M Rodríguez-Espinosa ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Rotational Velocity ◽  
Galactic Nuclei ◽  
High Density ◽  
Infrared Galaxies ◽  
X Ray ◽  
Ultraluminous Infrared Galaxies ◽  
Molecular Lines ◽  
Frequency Window ◽  
Integrated Intensities

ABSTRACT As part of the Early Science Large Millimeter Telescope projects, we report the detection of nine double-peaked molecular lines, produced by a rotating molecular torus, in the ultraluminous infrared galaxies (ULIRG) – Compton-thick active galactic nuclei (AGN) galaxy UGC 5101. The double-peaked lines we report correspond to molecular transitions of HCN, HCO+, HNC, N2H+, CS, C18O, 13CO, and two CN lines; plus the detection of C2H that is a blend of six lines. The redshift search receiver spectra covers the 73–113 GHz frequency window. Low- and high-density gas tracers of the torus have different implied rotational velocities, with a rotational velocity of 149 ± 3  km s−1 for the low-density ones (C18O, 13CO) and 174 ± 3  km s−1 for high-density tracers (HCN, HCO+, HNC, N2H+, CS, and CN). In UGC 5101, we find that the ratio of integrated intensities of HCN to 13CO to be unusually large, probably indicating that the gas in the torus is very dense. Both the column densities and abundances are consistent with values found in AGN, starburst, and ULIRG galaxies. The observed abundance ratios cannot discriminate between X-ray and UV-field-dominated regions.

AChandraSurvey of the Nearest Ultraluminous Infrared Galaxies: Obscured Active Galactic Nuclei or Superstarbursts?

2003 ◽  
Vol 592 (2) ◽  
pp. 782-803 ◽  
Author(s):  
A. Ptak ◽  
T. Heckman ◽  
N. A. Levenson ◽  
K. Weaver ◽  
D. Strickland
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Infrared Galaxies ◽  
Ultraluminous Infrared Galaxies

Infrared Power‐Law Galaxies in the Chandra Deep Field–South: Active Galactic Nuclei and Ultraluminous Infrared Galaxies

2006 ◽  
Vol 640 (1) ◽  
pp. 167-184 ◽  
Author(s):  
A. Alonso‐Herrero ◽  
P. G. Perez‐Gonzalez ◽  
D. M. Alexander ◽  
G. H. Rieke ◽  
D. Rigopoulou ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Power Law ◽  
Galactic Nuclei ◽  
Infrared Galaxies ◽  
Ultraluminous Infrared Galaxies

scholarly journals Merging Galaxies with Multiple Nuclei from HST ULIRGs Snapshot Survey

2001 ◽  
Vol 205 ◽  
pp. 172-175
Author(s):  
J. Cui ◽  
X.-Y. Xia ◽  
Z.-G. Deng ◽  
S. Mao ◽  
Z.-L. Zou
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Infrared Galaxies ◽  
Merging Galaxies ◽  
Ultraluminous Infrared Galaxies ◽  
Single Nucleus ◽  
High Fraction ◽  
Survey Sample ◽  
Statistical Studies ◽  
Photometric Measurements

We perform photometric measurements on a large HST snapshot imaging survey sample of 97 ultraluminous infrared galaxies (ULIRGs). We classify all the sources into three categories with multiple, double and single nucleus/nuclei, mainly based on a quantitative criterion of I-band luminosity. The resultant fractions of multiple, double and single nucleus/nuclei ULIRGs are 18%, 39% and 43%, respectively. This supports the multiple merger scenario as a possible origin of ULIRGs, in addition to the commonly-accepted pair merger model. Further statistical studies indicate that the fraction of AGN increases from multiple (18%) to double (39%) and then to single (43%) nucleus/nuclei ULIRGs. For the single nucleus category, there is a high luminosity tail in the luminosity distribution, which corresponds to a Seyfert 1/QSO excess. This supports the statement that active galactic nuclei tend to appear at final merging stage. For multiple and double mergers, we also find a considerably high fraction of very close nucleus pairs (e.g., 2/3 for those separated by less than 5 kpc). This strengthens the conclusion that systems at late merging phase preferentially host ULIRGs.

scholarly journals A Survey of Spectral Features in ISO SWS Spectra of AGNs

1997 ◽  
Vol 159 ◽  
pp. 337-338
Author(s):  
E. Sturm ◽  
D. Lutz ◽  
R. Genzel
Keyword(s):  
Infrared Spectroscopy ◽  
Spectral Range ◽  
Galactic Nuclei ◽  
Spectral Features ◽  
Infrared Galaxies ◽  
Mid Infrared ◽  
Mid Infrared Spectroscopy ◽  
Central Program ◽  
Ultraluminous Infrared Galaxy ◽  
Ultraluminous Infrared Galaxies

Various AGNs, starburst galaxies, and ultraluminous infrared galaxies (ULIRGs) are observed as part of the ISO-SWS central program of mid-infrared spectroscopy on bright galactic nuclei. Prototypical template sources are scanned over the full spectral range of SWS (2.5–45µm) in order to get a complete census of spectral features in this wavelength domain. As an example we present the spectrum of the Seyfert 2 galaxy Circinus. The application of results from this survey to the study of the nature and evolution of other galaxies can be demonstrated by an analysis of the ultraluminous infrared galaxy Arp 220.

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