X-ray-Underluminous Active Galactic Nuclei Relative to Broad Emission Lines in Ultraluminous Infrared Galaxies

2004 ◽  
Vol 127 (2) ◽  
pp. 758-764 ◽  
Author(s):  
Masatoshi Imanishi ◽  
Yuichi Terashima
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Emission Lines ◽  
Infrared Galaxies ◽  
X Ray ◽  
Broad Emission ◽  
Ultraluminous Infrared Galaxies

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.

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.

scholarly journals The polarized signal from broad emission lines in AGNs

2019 ◽  
Vol 491 (1) ◽  
pp. 1-12 ◽  
Author(s):  
P Lira ◽  
R W Goosmann ◽  
M Kishimoto ◽  
R Cartier
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Position Angle ◽  
Emission Lines ◽  
Type I ◽  
Line Profiles ◽  
Scattering Media ◽  
Broad Emission ◽  
Line Region ◽  
Scattering Signal

ABSTRACT Using the stokes Monte Carlo radiative transfer code, we revisit the predictions of the spectropolarimetric signal from a disc-like broad emission line region (BLR) in type I active galactic nuclei due to equatorial scattering. We reproduce the findings of previous works, but only for a scatterer that is much more optically and geometrically thick than previously proposed. We also find that when taking into account the polarized emission from all regions of the scatterer, the swing of the polarization position angle (PA) is in the opposite direction to that originally proposed. Furthermore, we find that the presence of outflows in the scattering media can significantly change the observed line profiles, with the PA of the scattering signal being enhanced in the presence of radially outflowing winds. Finally, a characteristically different PA profile, shaped like an ‘M’, is seen when the scatterer is co-spatial with the BLR and radially outflowing.

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
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