Journal ArticleDOI
Unified models for active galactic nuclei and quasars
Reads0
Chats0
TLDR
The straw person model (SPM) as mentioned in this paper has been proposed to explain the orientation effects of active galactic nuclei (AGN) and quasars in the line of sight (LOS) images.Abstract:
Because the critical central regions of Active Galactic Nuclei (AGN) and quasars are strongly nonspherical but spatially unresolved, orientation effects have been the source of much confusion. In fact, it now appears that much of the variety in AGN types is just the result of varying orientation relative to the line of sight. We can define an extreme hypothesis,, the straw person model (SPM), in which there are two basic types of AGN: the radio quiets and the radio louds. For each type there is a range in intrinsic luminosity, and the luminosity controls some properties such as the Fanaroff and Riley classes. However, at a given intrinsic luminosity, all other properties such as spectroscopic classification and VLBI component speeds are ascribed to orientation. This model is only a caricature of the unification idea, and is already ruled out on many grounds, but it will be useful for organizing the discussion. I’ll describe what I consider to be convincing evidence that orientation effects are important and widespread. The true situation may be in some sense half way between the SPM and the hypothesis that orientation doesn’t affect classification at aIl. To us optimists, the orienration cup is half full rather than half empty. Although it is too soon to say for sure, the hypothesis that most objects’ classifications would be different if seen from other directions is a tenable one today.read more
Citations
More filters
Journal ArticleDOI
Multi-epoch Modeling of TXS 0506+056 and Implications for Long-term High-energy Neutrino Emission
Maria Petropoulou,Kohta Murase,Marcos Santander,Sara Buson,Sara Buson,A. Tohuvavohu,Taiki Kawamuro,Georgios Vasilopoulos,H. Negoro,Yoshihiro Ueda,Michael H. Siegel,Azadeh Keivani,Nobuyuki Kawai,Apostolos Mastichiadis,Stavros Dimitrakoudis +14 more
TL;DR: In this article, the long-term electromagnetic emission of TXS 05056+056 using optical, X-ray, and gamma-ray data from the All-Sky Automated Survey for Supernovae (ASASAS-SN), the Neil Gehrels Swift Observatory (Swift), the Monitor of All-sky X-Ray Image (MAXI), and the Fermi Large Area Telescope (Fermi-LAT) was analyzed.
Journal ArticleDOI
High-Velocity Bipolar Molecular Emission from an AGN Torus
Jack F. Gallimore,Moshe Elitzur,Moshe Elitzur,Roberto Maiolino,Alessandro Marconi,Alessandro Marconi,Christopher P. O'Dea,Dieter Lutz,Stefi A. Baum,Robert Nikutta,Caterina M. V. Impellizzeri,Richard Davies,Amy Kimball,Eleonora Sani +13 more
TL;DR: In this paper, the authors have detected in ALMA observations CO J = 6 - 5 emission from the nucleus of the Seyfert galaxy NGC 1068, where low-velocity (up to +/- 70 km/s relative to systemic) CO emission resolves into a 12x7 pc structure, roughly aligned with the nuclear radio source.
Journal ArticleDOI
Starbursts and torus evolution in AGN
TL;DR: In this paper, the authors proposed an evolutionary sequence for starburst and AGN phases, where a torus passes through three different phases predetermined by an external mass accretion rate, and a turbulent and stellar wind-driven Q ∼ 1 disk is formed in which the starburst proceeds.
Journal ArticleDOI
Resolving the nuclear obscuring disk in the Compton-thick Seyfert galaxy NGC5643 with ALMA.
A. Alonso-Herrero,M. Pereira-Santaella,Santiago García-Burillo,Ric Davies,Francoise Combes,Daniel Asmus,Andrew Bunker,Tanio Díaz-Santos,Poshak Gandhi,O. González-Martín,Antonio Hernán-Caballero,E. K. S. Hicks,Sebastian F. Hönig,Alvaro Labiano,N. A. Levenson,Chris Packham,C. Ramos Almeida,Claudio Ricci,D. Rigopoulou,David J. Rosario,E. Sani,Martin Ward +21 more
TL;DR: In this paper, the ALMA band 6 $^{12}$CO(2--1) line and rest-frame 232GHz continuum observations of the nearby Compton-thick Seyfert galaxy NGC5643 with angular resolutions 0.11-0.26arcsec (9-21pc).
Journal ArticleDOI
Detection of Polarimetric Variations Associated with the Shortest Time-Scale Variability in S5 0716+714
Mahito Sasada,Makoto Uemura,Akira Arai,Yasushi Fukazawa,Koji S. Kawabata,Takashi Ohsugi,Takuya Yamashita,M. Isogai,Shuji Sato,Masaru Kino +9 more
TL;DR: In this paper, the authors present the results of near-infrared and optical observations of the BL Lac object S5 0716+714, carried out with the KANATA telescope.
References
More filters
Journal ArticleDOI
Phd by thesis
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Journal Article
Superluminal Radio Sources
J. A. Zensus,T. J. Pearson +1 more
TL;DR: There are now at least 23 radio sources in which apparent superluminal motion has been found as mentioned in this paper, and the effect is not limited to the classic examples like 3C 345, but is found in objects with a wide range of characteristic properties.