scholarly journals The sharpest view of the local AGN population at mid-infrared wavelengths

2013 ◽  
Vol 9 (S304) ◽  
pp. 225-226
Author(s):  
Daniel Asmus ◽  
Sebastian F. Hönig ◽  
Poshak Gandhi ◽  
Alain Smette ◽  
Wolfgang J. Duschl
Keyword(s):  
Active Galactic Nuclei ◽  
Angular Resolution ◽  
Spatial Scales ◽  
Galactic Nuclei ◽  
High Angular Resolution ◽  
Mid Infrared ◽  
X Ray ◽  
Infrared Wavelengths ◽  
Photometric Measurements

AbstractWe present the largest mid-infrared (MIR) atlas of active galactic nuclei at sub-arcsec spatial scales containing 253 objects with a median redshift of 0.016. It comprises all available ground-based high-angular resolution MIR observations performed to date with 8-meter class telescopes and includes 895 photometric measurements. All types of AGN are present in the atlas, which also includes 80 per cent of the 9-month BAT AGN sample. Therefore, this atlas and its subsamples are very well-suited for AGN unification studies. A first application of the atlas is the extension of the MIR–X-ray luminosity correlation for AGN.

scholarly journals NuSTAR observations of four nearby X-ray faint AGNs: low luminosity or heavy obscuration?

2020 ◽  
Vol 497 (1) ◽  
pp. 229-245 ◽  
Author(s):  
A Annuar ◽  
D M Alexander ◽  
P Gandhi ◽  
G B Lansbury ◽  
D Asmus ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Active Galactic Nuclei ◽  
Angular Resolution ◽  
Broad Band ◽  
Galactic Nuclei ◽  
Current Data ◽  
High Angular Resolution ◽  
X Ray ◽  
Ir Imaging ◽  
Nuclear Dust

ABSTRACT We present NuSTAR (Nuclear Spectroscopic Telescope Array) observations of four active galactic nuclei (AGNs) located within 15 Mpc. These AGNs, namely ESO 121-G6, NGC 660, NGC 3486, and NGC 5195, have observed X-ray luminosities of L2–10 keV,obs ≲ 1039 erg s−1, classifying them as low-luminosity AGN (LLAGN). We perform broad-band X-ray spectral analysis for the AGN by combining our NuSTAR data with Chandra or XMM–Newton observations to directly measure their column densities (NH) and infer their intrinsic power. We complement our X-ray data with archival and new high-angular resolution mid-infrared (mid-IR) data for all objects, except NGC 5195. Based on our X-ray spectral analysis, we found that both ESO 121-G6 and NGC 660 are heavily obscured (NH > 1023 cm−2; L2–10 keV,int ∼ 1041 erg s−1), and NGC 660 may be Compton thick. We also note that the X-ray flux and spectral slope for ESO 121-G6 have significantly changed over the last decade, indicating significant changes in the obscuration and potentially accretion rate. On the other hand, NGC 3486 and NGC 5195 appear to be unobscured and just mildly obscured, respectively, with L2–10 keV,int < 1039 erg s−1, i.e. genuine LLAGN. Both of the heavily obscured AGNs have Lbol > 1041 erg s−1 and λEdd ≳ 10−3, and are detected in high-angular resolution mid-IR imaging, indicating the presence of obscuring dust on nuclear scale. NGC 3486, however, is undetected in high-resolution mid-IR imaging, and the current data do not provide stringent constraints on the presence or absence of obscuring nuclear dust in the AGN.

scholarly journals Mid‐Infrared Properties and Color Selection for X‐Ray‐Detected Active Galactic Nuclei in the MUSYC Extended Chandra Deep Field–South

2008 ◽  
Vol 680 (1) ◽  
pp. 130-142 ◽  
Author(s):  
Carolin N. Cardamone ◽  
C. Megan Urry ◽  
Maaike Damen ◽  
Pieter van Dokkum ◽  
Ezequiel Treister ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Mid Infrared ◽  
X Ray ◽  
Color Selection ◽  
Selection For

scholarly journals The subarcsecond mid-infrared view of local active galactic nuclei – II. The mid-infrared–X-ray correlation

2015 ◽  
Vol 454 (1) ◽  
pp. 766-803 ◽  
Author(s):  
D. Asmus ◽  
P. Gandhi ◽  
S. F. Hönig ◽  
A. Smette ◽  
W. J. Duschl
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Mid Infrared ◽  
X Ray

scholarly journals A MULTI-WAVELENGTH STUDY OF LOW-REDSHIFT CLUSTERS OF GALAXIES. I. COMPARISON OF X-RAY AND MID-INFRARED SELECTED ACTIVE GALACTIC NUCLEI

2011 ◽  
Vol 729 (1) ◽  
pp. 22 ◽  
Author(s):  
David W. Atlee ◽  
Paul Martini ◽  
Roberto J. Assef ◽  
Daniel D. Kelson ◽  
John S. Mulchaey
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Clusters Of Galaxies ◽  
Mid Infrared ◽  
X Ray ◽  
Multi Wavelength

scholarly journals Optical Spectroscopy and X-Ray Detections of a Sample of Quasars and Active Galactic Nuclei Selected in the Mid-Infrared from TwoSpitzer Space TelescopeWide-Area Surveys

2006 ◽  
Vol 133 (1) ◽  
pp. 186-205 ◽  
Author(s):  
M. Lacy ◽  
A. O. Petric ◽  
A. Sajina ◽  
G. Canalizo ◽  
L. J. Storrie-Lombardi ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Optical Spectroscopy ◽  
Galactic Nuclei ◽  
Mid Infrared ◽  
X Ray

JET CONFINEMENT BY NONLINEAR MAGNETO-TORSIONAL OSCILLATIONS

2008 ◽  
Vol 17 (10) ◽  
pp. 1695-1706
Author(s):  
G. S. BISNOVATYI-KOGAN
Keyword(s):  
Magnetic Field ◽  
Active Galactic Nuclei ◽  
Angular Resolution ◽  
Galactic Nuclei ◽  
Simplified Model ◽  
High Angular Resolution ◽  
Cylinder Axis ◽  
Azimuthal Magnetic Field ◽  
Torsional Oscillations ◽  
Oscillations Of A Cylinder

Many quasars and active galactic nuclei are connected with long, thin jets. When observed with high angular resolution, these jets show a structure with bright knots separated by relatively dark regions. We consider magnetic collimation, connected with torsional oscillations of a cylinder with elongated magnetic field, and periodically distributed initial rotation around the cylinder axis. The stabilizing azimuthal magnetic field is created here by torsional oscillations. An approximate, simplified model is developed. The parameters for which jets may be stabilized by torsional oscillations are estimated quantitatively.

scholarly journals Discovering exotic AGN behind the Magellanic Clouds

2019 ◽  
Vol 15 (S356) ◽  
pp. 335-338
Author(s):  
Clara M. Pennock ◽  
Jacco Th. van Loon ◽  
Cameron P. M. Bell ◽  
Miroslav D. Filipović ◽  
Tana D. Joseph ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Magellanic Clouds ◽  
Machine Learning Algorithms ◽  
High Angular Resolution ◽  
Electromagnetic Spectrum ◽  
Data Set ◽  
X Ray ◽  
The Galaxy ◽  
Galaxy Populations

AbstractThe nearby Magellanic Clouds system covers more than 200 square degrees on the sky. Much of it has been mapped across the electromagnetic spectrum at high angular resolution and sensitivity –X-ray (XMM-Newton), UV (UVIT), optical (SMASH), IR (VISTA, WISE, Spitzer, Herschel), radio (ATCA, ASKAP, MeerKAT). This provides us with an excellent dataset to explore the galaxy populations behind the stellar-rich Magellanic Clouds. We seek to identify and characterise AGN via machine learning algorithms on this exquisite data set. Our project focuses not on establishing sequences and distributions of common types of galaxies and active galactic nuclei (AGN), but seeks to identify extreme examples, building on the recent accidental discoveries of unique AGN behind the Magellanic Clouds.

scholarly journals A 5.5–35 μm Spectral Analysis of Active Galactic Nuclei

2009 ◽  
Vol 5 (S267) ◽  
pp. 137-137
Author(s):  
D. A. Sales ◽  
M. G. Pastoriza ◽  
R. Riffel
Keyword(s):  
Spectral Analysis ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Spectroscopic Properties ◽  
Starburst Galaxies ◽  
Emission Lines ◽  
Raw Data ◽  
Mid Infrared ◽  
Infrared Wavelengths ◽  
The Continuum

The spectroscopic properties of a sample of nine Seyfert 1, six NLS1, 26 Seyfert 2, and three starburst galaxies have been studied at mid-infrared wavelengths in order to determine if the frequency of detection of the brightest emission lines and the continuum shape are correlated with the degree of activity. The raw data were obtained from the Spitzer Infrared Spectrograph (IRS) archive and reduced with the pipeline (version 17.2). The spectra of the galaxies were grouped by type of activity. We conclude through this study that in general the continuum shape of the active galactic nuclei (AGN) is flat between 5 μm and 12 μm, and strong variations are found at longer wavelengths in this sample.

scholarly journals XMM–Newton study of X-ray sources in the field of Willman 1 dwarf spheroidal galaxy★

2020 ◽  
Vol 499 (3) ◽  
pp. 3111-3129
Author(s):  
Sara Saeedi ◽  
Manami Sasaki
Keyword(s):  
Active Galactic Nuclei ◽  
Cross Correlation ◽  
Flux Ratio ◽  
Galactic Nuclei ◽  
Symbiotic Star ◽  
X Ray ◽  
Dwarf Spheroidal Galaxies ◽  
Infrared Wavelengths ◽  
Optical Flux ◽  
M Dwarf

ABSTRACT We present the results of the analysis of three XMM–Newton observations of the Willman 1 dwarf spheroidal galaxy (Wil 1). X-ray sources are classified on the basis of spectral analysis, hardness ratios, X-ray-to-optical flux ratio, X-ray variability, and cross-correlation with available catalogues in optical and infrared wavelengths. We catalogued 97 sources in the field of Wil 1. Our classification shows the presence of a β-type symbiotic star in Wil 1. We classified one M dwarf foreground star in the field of Wil 1. Moreover, 54 sources are classified as background active galactic nuclei and galaxies. Our study shows that the luminosity of the X-ray sources of Wil 1 does not exceed ∼1034 erg s−1 in the energy range of 0.2–12.0 keV, which is similar to observed luminosities of sources in nearby dwarf spheroidal galaxies.

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