Results 1 to 10 of about 47,541 (242)

Luminosity Function of High-Mass X-ray Binaries and Anisotropy in the Distribution of Active Galactic Nuclei toward the Large Magellanic Cloud

open access: yes, 2012
In 2003-2012, the INTEGRAL observatory has performed long-term observations of the Large Magellanic Cloud (LMC). At present, this is one of the deepest hard X-ray (20-60 keV) surveys of extragalactic fields in which more than 20 sources of different ...
A. A. Lutovinov   +17 more
core   +1 more source

Estimation of Central Black Hole Masses in Low-Luminosity Active Galactic Nuclei [PDF]

open access: yesPublications of the Astronomical Society of Japan, 2001
Abstract We analyzed six low-luminosity active galactic nuclei (hereafter LLAGNs), which consist of two bright LINERs (low-ionization nuclear emission line region) with broad H$ \alpha$, and of four bright low-luminosity Seyferts observed by the X-ray satellite ASCA.
Hisamitsu Awaki   +3 more
openaire   +1 more source

NuSTAR Observation of the TeV-detected Radio Galaxy 3C 264: Core Emission and the Hot Accretion Flow Contribution

open access: yesThe Astrophysical Journal
3C 264 is one of the few FRI radio galaxies with detected TeV emission. It is a low-luminosity active galactic nucleus (LLAGN) and is generally associated with a radiatively inefficient accretion flow (RIAF).
Ka-Wah Wong   +6 more
doaj   +1 more source

Techniques for Profile Binning and Analysis of Eigenvector Composite Spectra: Comparing Hbeta and MgII 2800 as Virial Estimators

open access: yes, 2013
We review the basic techniques for extracting information about quasar structure and kinematics from the broad emission lines in quasars. We consider which lines can most effectively serve as virial estimators of black hole mass.
del Olmo, Ascension   +3 more
core   +1 more source

MILLIMETER RADIO CONTINUUM EMISSIONS AS THE ACTIVITY OF SUPERMASSIVE BLACK HOLES IN NEARBY EARLY-TYPE GALAXIES AND LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI [PDF]

open access: yes, 2011
We conducted millimeter continuum observations for samples of nearby early-type galaxies (21 sources) and nearby low-luminosity active galactic nuclei (LLAGNs; 16 sources) at 100 GHz (λ3 mm) using the Nobeyama Millimeter Array (NMA).
A. Doi   +4 more
semanticscholar   +1 more source

Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research

open access: yes, 2004
This review discusses the current status of supermassive black hole research, as seen from a purely observational standpoint. Since the early '90s, rapid technological advances, most notably the launch of the Hubble Space Telescope, the commissioning of ...
A. A. El-Zant   +367 more
core   +1 more source

BROADBAND X-RAY SPECTRA OF TWO LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI NGC 1566 AND NGC 4941 OBSERVED WITH SUZAKU [PDF]

open access: yes, 2013
We report the first broadband X-ray spectra of the low-luminosity active galactic nuclei (LLAGNs), NGC 1566 (type 1.5) and NGC 4941 (type 2), observed with Suzaku and Swift/BAT covering the 0.5–195 keV band.
T. Kawamuro   +3 more
semanticscholar   +1 more source

The Calm Before the (Next) Storm: No Third Outburst in 2019–2020, and Ongoing Monitoring of the Transient AGN IC 3599

open access: yesThe Astrophysical Journal
We report on follow-up observations of the Seyfert 1.9 galaxy IC 3599 with the NASA Neil Gehrels Swift mission. The detection of a second X-ray outburst in 2010 by Swift after the first discovery of a bright X-ray outburst in 1990 by ROSAT led to the ...
Dirk Grupe, S. Komossa, Salem Wolsing
doaj   +1 more source

Monitoring the Morphology of M87* in 2009–2017 with the Event Horizon Telescope

open access: yesThe Astrophysical Journal, 2020
The Event Horizon Telescope (EHT) has recently delivered the first resolved images of M87*, the supermassive black hole in the center of the M87 galaxy. These images were produced using 230 GHz observations performed in 2017 April.
Maciek Wielgus   +218 more
doaj   +1 more source

Home - About - Disclaimer - Privacy