Results 71 to 80 of about 771 (176)
Powerful Radio-loud Quasars Are Triggered by Galaxy Mergers in the Cosmic Bright Ages
The Astrophysical JournalWhile supermassive black holes are ubiquitous features of galactic nuclei, only a small minority are observed during episodes of luminous accretion. The physical mechanism(s) driving the onset of fueling and ignition in these active galactic nuclei (AGN)
Peter Breiding +17 more
doaj +1 more source
Astronomische Nachrichten, Volume 346, Issue 3-4, March-May 2025.ABSTRACT The discovery of radio‐quiet, x‐ray thermally emitting isolated neutron stars (XINSs) in the ROSAT All‐Sky Survey revealed a previously overlooked component of the neutron star population. Advancements in x‐ray instrumentation and the availability of deep, wide‐area optical surveys now enable us to explore XINSs at fainter x‐ray fluxes and ...
Adriana Mancini Pires +11 more
wiley +1 more source
UEG Week 2022 Moderated Posters
, 2022 United European Gastroenterology Journal, Volume 10, Issue S8, Page 185-472, October 2022.
wiley +1 more source
A Surprising Excess of Radio Emission in Extremely Stable Quasars: A Unique Clue to Jet Launching?
The Astrophysical JournalQuasars are generally divided into jetted radio-loud and nonjetted radio-quiet ones, but why only 10% of quasars are radio-loud has been puzzling for decades.
Wen-Yong Kang +8 more
doaj +1 more source
Evolution of the X‐ray Emission of Radio‐quiet Quasars [PDF]
The Astrophysical Journal, 2007 We report new Chandra observations of seven optically faint, z \sim 4 radio-quiet quasars. We have combined these new observations with previous Chandra observations of radio-quiet quasars to create a sample of 174 sources. These sources have 0.1 < z < 4.7, and 10^{44} ergs s^{-1} < nu L_{nu} (2500 Å) < 10^{48} ergs s^{-1}.
Kelly, Brandon C. +4 more
openaire +2 more sources
Evidence of Gas Depletion in Quasars with Moderate Radio Emission
The Astrophysical JournalThe energy released by active galactic nuclei (AGNs) is considered to have a profound impact on the cold gas properties of their host galaxies, potentially heating or removing the gas and further suppressing star formation.
Yuhan Wen +6 more
doaj +1 more source
The Jet-Disk Coupling of Seyfert Galaxies from a Complete Hard X-ray Sample
Universe, 2020 We analyze the jet-disk coupling for different subsamples from a complete hard X-ray Seyfert sample to study the coupling indices and their relation to accretion rate.
Xiang Liu +3 more
doaj +1 more source
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 Astrophysical Journal Supplement SeriesWe present multifrequency and high-resolution studies of a sample of 24 radio transient sources discovered by comparing the NRAO VLA Sky Survey and the Very Large Array Sky Survey.
Magdalena Kunert-Bajraszewska +8 more
doaj +1 more source
Medical Physics, Volume 51, Issue 4, Page 2354-2366, April 2024.Abstract Background Cardiac radioablation is a noninvasive stereotactic body radiation therapy (SBRT) technique to treat patients with refractory ventricular tachycardia (VT) by delivering a single high‐dose fraction to the VT isthmus. Cardiorespiratory motion induces position uncertainties resulting in decreased dose conformality.
Osman Akdag +6 more
wiley +1 more source