English
Related papers

Related papers: Probing dust torus radius--luminosity relation: An…

200 papers

The obscuring circumnuclear torus of dusty molecular gas is one of the major components of active galactic nuclei (AGN). The torus can be studied by analyzing the time response of its infrared (IR) dust emission to variations in the AGN…

Astrophysics of Galaxies · Physics 2017-09-22 Triana Almeyda , Andrew Robinson , Michael Richmond , Billy Vazquez , Robert Nikutta

We study the ratio $R$ between the luminosity of the torus and that of the accretion disk, inferred from the relativistic model KERRBB for a sample of approximately 2000 luminosity-selected radio-quiet Type I active galactic nuclei from the…

High Energy Astrophysical Phenomena · Physics 2021-12-15 Samuele Campitiello , Annalisa Celotti , Gabriele Ghisellini , Tullia Sbarrato

Amid rapid advances in time-domain astronomy, multi-wavelength (e.g., optical and infrared) time-domain studies of quasars remain scarce. Here we present a systematic analysis of four quasars initially selected by their Ks-band variability…

Astrophysics of Galaxies · Physics 2025-10-31 Lin Long , Zhen-ya Zheng , Ning Jiang , Chun Xu , Jiaqi Lin , Fang-Ting Yuan , Chunyan Jiang , Ruqiu Lin , Hai-Cheng Feng , Hengxiao Guo , Xiang Ji

We present observations of NGC 1068 covering the $19.7-53.0$ $\mu$m wavelength range using FORCAST and HAWC+ onboard SOFIA. Using these observations, high-angular resolution infrared (IR) and sub-mm observations, we find an observational…

We fitted Spitzer/IRS ~2-35 um spectra of 26 luminous QSOs in attempt to define the main emission components. Our model has three major components: a clumpy torus, dusty narrow line region (NLR) clouds and a blackbody-like dust. The models…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Rivay Mor , Hagai Netzer , Moshe Elitzur

We examine the long-term optical/near-infrared (NIR) flux variability of a "changing-look" active galactic nucleus (AGN) Mrk 590 between 1998 and 2007. Multi-band multi-epoch optical/NIR photometry data from the SDSS Stripe 82 database and…

Astrophysics of Galaxies · Physics 2020-01-08 Mitsuru Kokubo , Takeo Minezaki

The primary source of emission of active galactic nuclei (AGN), the accretion disk, is surrounded by an optically and geometrically thick dusty structure ("the so-called dusty torus"). The infrared radiation emitted by the dust is nothing…

Astrophysics of Galaxies · Physics 2017-01-13 Marko Stalevski , Claudio Ricci , Yoshihiro Ueda , Paulina Lira , Jacopo Fritz , Maarten Baes

In the unified scheme of active galactic nuclei, a dusty torus absorbs and then reprocesses a fraction of the intrinsic luminosity which is emitted at longer wavelengths. Thus, subject to radiative transfer corrections, the fraction of the…

High Energy Astrophysical Phenomena · Physics 2017-11-08 Savithri H. Ezhikode , Poshak Gandhi , Chris Done , Martin Ward , Gulab C. Dewangan , Ranjeev Misra , Ninan Sajeeth Philip

Dust plays a central role in the unification theory of active galactic nuclei (AGNs). Whether the dust that forms the torus around an AGN is tenth-$\mu$m-sized like interstellar grains or much larger has a profound impact on correcting for…

Astrophysics of Galaxies · Physics 2017-05-10 Z. Z. Shao , B. W. Jiang , Aigen Li

We have recently initiated the first spectroscopic dust reverberation programme on active galactic nuclei (AGN) in the near-infrared. Spectroscopy enables measurement of dust properties, such as flux, temperature and covering factor, with…

We use JWST/MIRI MRS spectroscopy of a sample of six local obscured type 1.9/2 active galactic nuclei (AGN) to compare their nuclear mid-IR absorption bands with the level of nuclear obscuration traced by X-rays. This study is the first to…

The dust reverberation mapping is one of powerful methods to investigate the structure of the dusty tori in AGNs, and it has been performed on more than a hundred type 1 AGNs. However, no clear results have been reported on type 2 AGNs…

Astrophysics of Galaxies · Physics 2020-05-27 Hirofumi Noda , Taiki Kawamuro , Mitsuru Kokubo , Takeo Minezaki

We used the CLUMPY torus models and a Bayesian approach to fit the infrared spectral energy distributions (SEDs) and ground-based high-angular resolution mid-infrared spectroscopy of 13 nearby Seyfert galaxies. This allowed us to put tight…

We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after…

Astrophysics of Galaxies · Physics 2014-06-10 S. Koshida , T. Minezaki , Y. Yoshii , Y. Kobayashi , Y. Sakata , S. Sugawara , K. Enya , M. Suganuma , H. Tomita , T. Aoki , B. A. Peterson

We propose a new method to explore the candidate super-Eddington active galactic nuclei (AGNs). We examine the properties of infrared (IR) emission from the inner edge of the dusty torus in AGNs, which are powered by super- or sub-Eddington…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Nozomu Kawakatu , Ken Ohsuga

At distances from the active galaxy nucleus (AGN) where the ambient temperature falls below ~1500-1800 K, dust is able to survive. It is thus possible to have a large dusty structure present which surrounds the AGN. This is the first of two…

Context: We investigate mid-infrared and X-ray properties of the dusty torus in unification scenarios for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain AGN unification scenarios.…

Astrophysics · Physics 2009-11-11 Hannes Horst , Alain Smette , Poshak Gandhi , Wolfgang J. Duschl

We propose a new diagnostic of the ``dusty torus'' model for Seyfert nuclei. Dust grains in the torus are heated by the nuclear continuum, and reradiate mostly in the mid-infrared wavelengths. From the torus geometry, it is predicted that…

Astrophysics · Physics 2009-10-31 Takashi Murayama , Hideaki Mouri , Yoshiaki Taniguchi

We present a statistical analysis of the properties of the obscuring material around active galactic nuclei (AGN). This study represents the first of its kind for an ultra-hard X-ray (14-195keV; Swift/BAT) volume-limited (DL<40 Mpc) sample…

We assume that dust near active galactic nuclei (AGN) is distributed in a torus-like geometry, which may be described by a clumpy medium or a homogeneous disk or as a combination of the two (i.e. a 2-phase medium). The dust particles…

Astrophysics of Galaxies · Physics 2015-11-11 Ralf Siebenmorgen , Frank Heymann , Andreas Efstathiou