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Related papers: A Radio Polarimetric Study to Disentangle AGN Acti…

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The central nuclei of galaxies, where super-massive black holes (SMBHs) are thought to reside, can experience phases of activity when they become Active Galactic Nuclei (AGN). An AGN can eject winds, jets, and produce radiation across the…

Astrophysics of Galaxies · Physics 2019-02-18 Francesca Panessa , Ranieri D. Baldi , Ari Laor , Paolo Padovani , Ehud Behar , Ian McHardy

A number of radio galaxies has been detected by Fermi/LAT in the gamma-ray domain. In some cases, like Cen A and M 87, these objects have been seen even in the TeV range by Cherenkov telescopes. Whereas the gamma-ray emission is likely to…

High Energy Astrophysical Phenomena · Physics 2013-02-20 V. Beckmann , S. de Jong , F. Mattana , D. Saez , S. Soldi

Because the disc--jet coupling likely depends on various properties of sources probed, the sample control is always an important but challenging task. In this work, we re-analyzed the INTEGRAL hard X-ray-selected sample of Seyfert galaxies.…

High Energy Astrophysical Phenomena · Physics 2021-03-03 N. Chang , F. G. Xie , X. Liu , L. C. Ho , A. -J. Dong , Z. H. Han , X. Wang

We have studied the relationship between the nuclear (high-resolution) radio emission, at 8.4 GHz (3.6 cm) and 1.4 GHz (20 cm), the [O IV] 25.89um, [Ne III] 15.56um and [Ne II] 12.81um emission lines and the black hole mass accretion rate…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Meléndez , S. B. Kraemer , H. R. Schmitt

The coevolution of supermassive black holes and their host galaxies represents a fundamental question in astrophysics. One approach to investigating this question involves comparing the star-formation rates (SFRs) of active galactic nuclei…

Astrophysics of Galaxies · Physics 2024-11-26 Bojun Zhang , Fan Zou , W. N. Brandt , Shifu Zhu , Nathan Cristello , Qingling Ni , Yongquan Xue , Zhibo Yu

A radio study of a carefully selected sample of 20 Seyfert galaxies that are matched in orientation-independent parameters, which are measures of intrinsic active galactic nuclei (AGN) power and host galaxy properties is presented to test…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Dharam V. Lal , Prajval Shastri , Denise Gabuzda

We present optical spectroscopic observations of 93 galaxies taken from the infra-red selected COLA (Compact Objects in Low Power AGN) sample. The sample spans the range of far-IR luminosities from normal galaxies to LIRGs. Of the galaxies…

We have carried out an extensive radio study with the Very Large Array on the Seyfert 1.5 galaxy Mrk 6 and imaged a spectacular radio structure in the source. The radio emission occurs on three different spatial scales, from ~7.5 kpc…

Astrophysics · Physics 2011-02-11 P. Kharb , C. P. O'Dea , S. A. Baum , E. J. M. Colbert , C. Xu

The dichotomy between radio-loud (RL) and radio-quiet (RQ) active galactic nuclei (AGN) is thought to be intrinsically related to radio jet production. This difference may be explained by the presence of a strong magnetic field (B-field)…

This paper summarizes some of our recent projects which try to illuminate the nature and importance of jets associated with active nuclei and compact objects. After a short introduction on jets in radio galaxies and radio loud quasars the…

Astrophysics · Physics 2007-05-23 Heino Falcke

In this paper we discuss the results of a programme of spectral synthesis modelling of a sample of starburst radio galaxies in the context of scenarios for the triggering of the activity and the evolution of the host galaxies. The starburst…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 C. Tadhunter , J. Holt , R. Gonzalez Delgado , J. Rodriguez Zaurin , M. Villar-Martin , R. Morganti , B. Emonts , C. Ramos Almeida , K. Inskip

We have conducted 22 GHz 1" JVLA imaging of 70 radio-quiet AGN from the Swift-BAT survey. We find radio cores in all but three objects. The radio morphologies of the sample fall into three groups: compact and core-dominated, extended, and…

Astrophysics of Galaxies · Physics 2016-12-14 Krista Lynne Smith , Richard F. Mushotzky , Stuart Vogel , Thomas T. Shimizu , Neal Miller

We have studied the relationship between the high- and low-ionization [O IV] lambda 25.89 micron, [Ne III] lambda 15.56 micron and [Ne II] lambda 12.81 micron emission lines with the aim of constraining the active galactic nuclei (AGN) and…

The VLA has been used at 3.6 and 20 cm to image a sample of about 50 early-type Seyfert galaxies with recessional velocities less than 7,000 km/s and total visual magnitude less than 14.5. The nuclear radio structures of Seyfert 2.0's in…

Astrophysics · Physics 2009-10-31 Neil M. Nagar , Andrew S. Wilson , John S. Mulchaey , Jack F. Gallimore

Large scale, weakly collimated outflows are very common in galaxies with large infrared luminosities. In complex systems in particular, where intense star formation (SF) coexists with an active galactic nucleus (AGN), it is not clear yet…

Astrophysics of Galaxies · Physics 2015-10-21 Claudio Melioli , Elisabete M. de Gouveia Dal Pino

[ABRIDGED] We recently presented evidence of a connection between the brightness profiles of nearby early-type galaxies and the properties of the AGN they host. The radio loudness of the AGN appears to be univocally related to the host's…

Astrophysics · Physics 2009-11-13 Alessandro Capetti , Barbara Balmaverde

We present near-infrared K- (1.9-2.5 micrometer) and L- (2.8-4.2 micrometer) band spectroscopy of 22 Seyfert nuclei. We use two methods to investigate the presence of nuclear starbursts: (1) the Polycyclic Aromatic Hydrocarbon (PAH)…

Astrophysics of Galaxies · Physics 2015-05-20 Nagisa Oi , Masatoshi Imanishi , Keisuke Imase

Seyfert galaxies and quasars were first discovered through optical and radio techniques, but in recent years high-energy emission, that can penetrate central gas and dust, has become essentially the defining characteristic of an AGN. AGNs…

Astrophysics · Physics 2007-05-23 D. M. Worrall

We present 8.4 GHz VLA A-configuration observations of 87 sources from the mid-infrared-selected AGN sample of Rush et al (1993). These 0.25 arcsec resolution observations allow elongated radio structures tens of parsecs in size to be…

Astrophysics · Physics 2009-10-31 Andy Thean , Alan Pedlar , Marek J. Kukula , Stefi A. Baum , Christopher P. O'Dea

There exist strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies. It is however still unclear what the exact role of nuclear activity, in the form of accretion onto these supermassive black…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-17 Marios Karouzos , Markos Trichas , Myungshin Im , Matthew Malkan , the AKARI-NEP team