Results 131 to 140 of about 47,708 (236)

The Demography of Super-Massive Black Holes: Growing Monsters at the Heart of Galaxies

open access: yes, 2009
Supermassive black holes (BHs) appear to be ubiquitous at the center of all galaxies which have been observed at high enough sensitivities and resolution with the Hubble Space Telescope.
Alexander   +208 more
core   +1 more source

No Galaxy-scale [C ii] Fast Outflow in the z = 6.72 Red Quasar HSC J1205–0000

open access: yesThe Astrophysical Journal
HSC 120505.09-000027.9 (J1205–0000) is one of the highest redshift ( z = 6.72) dust-reddened quasars (red quasars) known to date. We present an improved analysis of Atacama Large Millimeter/submillimeter Array data of the [C  ii ] 158 μ m line and the ...
Mahoshi Sawamura   +19 more
doaj   +1 more source

Compact Nuclei in Galaxies at Moderate Redshift:II. Their Nature and Implications for the AGN Luminosity Function

open access: yes, 1998
This study explores the space density and properties of active galaxies to z=0.8. We have investigated the frequency and nature of unresolved nuclei in galaxies at moderate redshift as indicators of nuclear activity such as Active Galactic Nuclei (AGN ...
Avni Y.   +13 more
core   +1 more source

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

Multiple Emission Regions in Jets of the Low-Luminosity Active Galactic Nucleus in NGC 4278

open access: yesThe Astrophysical Journal
The Large High Altitude Air Shower Observatory (LHAASO) has detected very-high-energy gamma rays from the low-ionization nuclear emission-line region galaxy NGC 4278, which has a low-luminosity active galactic nucleus (LLAGN) and symmetric, mildly ...
Samik Dutta, Nayantara Gupta
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

The DELVE Quadruple Quasar Search. I. A Lensed Low-luminosity Active Galactic Nucleus

open access: yesThe Astronomical Journal
A quadruply lensed source, J125856.3–031944, has been discovered using the DELVE survey and Wide-field Infrared Survey Explorer W1–W2 colors. Follow-up direct imaging carried out with the Magellan Baade 6.5 m telescope is analyzed, as is spectroscopy ...
Paul L. Schechter   +27 more
doaj   +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

Comparing Observed Properties of Winds in Low-luminosity Active Galactic Nuclei with Theoretical Predictions

open access: yesThe Astrophysical Journal
Theoretical and numerical simulations of black hole hot accretion flows have shown the ubiquitous existence of winds and predicted their properties, such as velocity and mass flux.
Fangzheng Shi   +3 more
doaj   +1 more source

ReveaLLAGN 0: First Look at JWST MIRI Data of Sombrero and NGC 1052

open access: yesThe Astrophysical Journal
We present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGNs. We focus on two observations with the Mid-Infrared Instrument (MIRI)’s Medium-Resolution Spectrometer of the ...
Kameron Goold   +30 more
doaj   +1 more source

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