Results 51 to 60 of about 22,530 (230)
Star formation in southern Seyfert galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 1998 We have produced radio maps, using the Australia Telescope Compact Array, of the central regions of six southern type 2 Seyfert galaxies (NGC 1365, 4945, 6221, 6810, 7582 and Circinus) with circumnuclear star formation, to estimate the relative contribution of star formation activity compared to activity from the active galactic nucleus (AGN).
Forbes, Duncan A., Norris, R. P.
openaire +5 more sources
M94 as a Unique Testbed for Black Hole Mass Estimates and AGN Activity at Low Luminosities
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 We discuss the peculiar nature of the nucleus of M94 (NGC 4736) in the context of new measurements of the broad Hα emission from HST‐STIS observations. We show that this component is unambiguously associated with the high‐resolution X‐ray, radio, and variable UV sources detected at the optical nucleus of this galaxy.
Anca Constantin +2 more
wiley +1 more source
Physik in unserer Zeit, Volume 56, Issue 1, Page 30-37, January 2025.Galaxien wie die Milchstraße sind umhüllt von einem gigantischen Kokon aus diffusem Gas. Aktuelle Forschungsergebnisse belegen, dass dieses zirkumgalakische Medium eine entscheidende Rolle für die Entstehung und Entwicklung von Galaxien spielt. Zusammenfassung Als zirkumgalaktisches Medium bezeichnet man die gasförmigen Hüllen von Galaxien, die sich ...
Philipp Richter
wiley +1 more source
Recoiling Black Holes: Electromagnetic Signatures, Candidates, and Astrophysical Implications
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Supermassive black holes (SMBHs) may not always reside right at the centers of their host galaxies. This is a prediction of numerical relativity simulations, which imply that the newly formed single SMBH, after binary coalescence in a galaxy merger, can receive kick velocities up to several 1000 km/s due to anisotropic emission of gravitational waves ...
S. Komossa, Francesca Civano
wiley +1 more source
Acta Polytechnica CTU Proceedings, 2014 Of the 271 sources in the 3rd EGRET catalogue, 131 were reported as unidentied, i.e. not associated with any particular class of point source in the sky.
Pieter J. Meintjes +3 more
doaj +1 more source
A New Sample of Gamma-Ray Emitting Jetted Active Galactic Nuclei—Preliminary Results
Universe, 2021 We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT).
Luigi Foschini +10 more
doaj +1 more source
The Close Environment of Seyfert Galaxies and Its Implication for Unification Models [PDF]
, 1999 This paper presents a statistical analysis of the circumgalactic environment of nearby Seyfert galaxies based on a computer-aided search of companion galaxies on the Digitized Sky Survey (DSS). An intrinsic difference between the environment of Seyfert 1
D. Dultzin-Hacyan +15 more
core +3 more sources
Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers
Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto +9 more
wiley +1 more source
The Cosmic History of Black Hole Growth from Deep Multiwavelength Surveys
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Significant progress has been made in the last few years on understanding how supermassive black holes form and grow. In this paper, we begin by reviewing the spectral signatures of active galactic nuclei (AGN) ranging from radio to hard X‐ray wavelengths.
Ezequiel Treister +2 more
wiley +1 more source
Near-infrared spectroscopy of nearby Seyfert galaxies - II. Molecular content and coronal emission [PDF]
, 2003 We present sub-arcsec near-infrared 1.5 - 2.5 micron moderate resolution long-slit spectra of eight nearby Seyfert galaxies ...
Kotilainen, J. +2 more
core +2 more sources