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Related papers: Nuclear vs. Circumnuclear Activity

200 papers

In order to characterize the amount of recent or ongoing stellar formation in the circumnuclear region of active galaxies on a statistically sound basis, we have studied the stellar component of the nuclear spectra in three different…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 P. Rafanelli , R. D'Abrusco , S. Ciroi , V. Cracco , F. Di Mille , L. Vaona

We present a spectroscopic study of the incidence of AGN nuclear activity in two samples of isolated galaxies (Karachentseva, V.E. & Varela, J.). Our results show that the incidence of non-thermal nuclear activity is about 43% and 31% for…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Francisco Hernandez-Ibarra , Deborah Dultzin , Yair Krongold , Ascencion Del Olmo , Jaime Perea , Jesus Gonzalez

We present subarcsecond resolution mid-infrared (MIR) images obtained with 8-10 m-class ground-based telescopes of a complete volume-limited (DL<40 Mpc) sample of 24 Seyfert galaxies selected from the Swift/BAT nine month catalog. We use…

There is an ongoing debate concerning the driver of nuclear activity in galaxies, with AGN either being triggered by major or minor galactic mergers or, alternatively, through secular processes like cooling gas accretion and/or formation of…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-19 Marios Karouzos , Matt J. Jarvis , David Bonfield

Observations at ultraviolet, optical and near-infrared wavelengths have shown the existence of recent star formation in the nuclear regions of Seyfert 2 (Sy2) galaxies that suggest a connection between the Starburst and the Seyfert…

Astrophysics · Physics 2007-05-23 Rosa M. Gonzalez Delgado

In a matched sample of Seyfert and quiescent galaxies we simultaneously probe the stellar and molecular gas kinematics from 1 kpc down to 50 pc with the aim of identifying the dynamical processes dictating black hole accretion rates. This…

Active galaxies are often associated with starbursts, which are possible sources of fuelling for the nuclear black holes. By means of optical (3500-7500 A) spectroscopic and narrow-band photometric data (H_alpha+[NII]6548,6583 and…

Astrophysics · Physics 2007-05-23 A. Romano , A. Rifatto , S. Ciroi , P. Rafanelli , M. Dopita

We study galaxies that host both nuclear star clusters and active galactic nuclei (AGN) implying the presence of a massive black hole. We select a sample of 176 galaxies with previously detected nuclear star clusters that range from…

Astrophysics · Physics 2009-11-13 Anil Seth , Marcel Agueros , Duane Lee , Antara Basu-Zych

Nuclear stellar clusters are a common phenomenon in spirals and in starbursts galaxies, and they may be a natural consequence of the star formation processes in the central regions of galaxies. HST UV imaging of a few Seyfert 2 galaxies…

Astrophysics · Physics 2015-05-13 R. M. González Delgado , V. Muñoz Marin , E. Pérez , H. Schmitt , R. Cid Fernandes

Of the mechanisms proposed to bring gaseous fuel into the central starburst regions of a galaxy, non-axisymmetries in the gravitational potential set up by interactions or by bars are among the most promising. Nevertheless, direct…

Astrophysics · Physics 2009-11-10 Johan H. Knapen

We use a recent near-infrared imaging survey of samples of Seyfert and normal galaxies to study the role of bars in the fueling of nuclear activity. The active galaxy sample includes Seyfert galaxies in the Revised Shapely-Ames (RSA) and…

Astrophysics · Physics 2009-10-30 John S. Mulchaey , Michael W. Regan

We study the nuclear activity of galaxies in local compact groups. We use a spectroscopic sample of 238 galaxies in 58 compact groups from the Sloan Digital Sky Survey data release 7 to estimate the fraction of AGN-host galaxies in compact…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Jubee Sohn , Ho Seong Hwang , Myung Gyoon Lee , Gwang-Ho Lee , Jong Chul Lee

We investigate the relation between the characteristics of the circumnuclear stellar population and both the galaxy morphology and the presence of close companions for a sample of 35 Seyfert 2 nuclei. Fifteen galaxies present unambiguous…

The morphology of galaxies reflects their assembly history and ongoing dynamical perturbations from the environment. Analyzing i-band images from the Pan-STARRS1 Survey, we study the optical morphological asymmetry of the host galaxies of a…

Astrophysics of Galaxies · Physics 2022-02-02 Yulin Zhao , Yang A. Li , Jinyi Shangguan , Ming-Yang Zhuang , Luis C. Ho

Why are the nuclei of some galaxies more active than others? If most galaxies harbor a central massive black hole, the main difference is probably in how well it is fueled by its surroundings. We investigate the hypothesis that such a…

Astrophysics · Physics 2009-11-10 L. K. Hunt , M. A. Malkan

The existence of correlations between nuclear properties of galaxies, such as the mass of their central black holes, and larger scale features, like the bulge mass and luminosity, represent a fundamental constraint on galaxy evolution.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 G. La Mura , D. Bindoni , S. Ciroi , V. Cracco , R. D'Abrusco , P. Rafanelli , L. Vaona

In a companion paper, Maiolino et al. (2000) presented various observational evidences for "anomalous" dust properties in the circumnuclear region of AGNs and, in particular, the reduced E(B-V)/N_H and Av/N_H ratios, the absence of the…

Astrophysics · Physics 2009-10-31 R. Maiolino , A. Marconi , E. Oliva

We use the sample of emission-line nuclei derived from a recently completed optical spectroscopic survey of nearby galaxies to quantify the incidence of local (z = 0) nuclear activity. Consistent with previous studies, we find detectable…

Astrophysics · Physics 2009-10-30 Luis C. Ho , Alexei V. Filippenko , Wallace L. W. Sargent

Motivated by theoretical expectations that Nuclear Star Clusters (NSCs) in galactic centers may provide a favorable environment for super-massive black holes to form and/or efficiently grow, we set out to measure the fraction of nearby…

High Energy Astrophysical Phenomena · Physics 2017-05-31 Adi Foord , Elena Gallo , Edmund Hodges-Kluck , Brendan P. Miller , Vivienne F. Baldassare , Kayhan Gultekin , Oleg Y. Gnedin

Circumnuclear star forming regions (CNSFR) are massive clusters found close to galactic nuclei. These entities give us an excellent opportunity to study star formation in environments with high metallicity and to relate it with active…

Astrophysics of Galaxies · Physics 2025-04-02 S. Zamora , Ángeles I. Díaz