CONSTRAINING SUB-PARSEC BINARY SUPERMASSIVE BLACK HOLES IN QUASARS WITH MULTI-EPOCH SPECTROSCOPY. I. THE GENERAL QUASAR POPULATION [PDF]
The Astrophysical Journal, 2013 We perform a systematic search for sub-parsec binary supermassive black holes (BHs) in normal broad-line quasars at z < 0.8, using multi-epoch Sloan Digital Sky Survey (SDSS) spectroscopy of the broad Hβ line.
Yue Shen +3 more
semanticscholar +7 more sources
Astroinformatics of galaxies and quasars: a new general method for photometric redshifts estimation [PDF]
Monthly Notices of the Royal Astronomical Society, 2011 With the availability of the huge amounts of data produced by current and future large multiband photometric surveys, photometric redshifts have become a crucial tool for extragalactic astronomy and cosmology.
O. Laurino +3 more
semanticscholar +9 more sources
Optical and near-UV spectroscopic properties of low-redshift jetted quasars in the main sequence context [PDF]
Monthly notices of the Royal Astronomical Society, 2023 This paper presents new optical and near-UV spectra of 11 extremely powerful jetted quasars, with radio to optical flux density ratio > 103, that concomitantly cover the low-ionization emission of Mg iiλ2800 and h β as well as the Fe ii blends in the ...
S. Terefe +6 more
semanticscholar +1 more source
Discovery of 24 radio-bright quasars at 4:9 [PDF]
Astronomy & Astrophysics, 2022 High redshift quasars ($z>5$) that also shine brightly at radio wavelengths are unique signposts of supermassive black hole activity in the early universe.
A. Gloudemans +20 more
semanticscholar +1 more source
Connection between Emission and Absorption Outflows through the Study of Quasars with Extremely High Velocity Outflows [PDF]
Astrophysical Journal Letters, 2022 A recently discovered class of outflows, extremely high velocity outflows (EHVOs), may be key to understanding feedback processes, as it is likely the most powerful in terms of mass energy. These EHVOs have been observed at redshifts 1.052 < z em < 7.641,
Paola Rodríguez Hidalgo, A. Rankine
semanticscholar +1 more source
Limiting the Abundance of LIGO/Virgo Black Holes with Microlensing Observations of Quasars of Finite Size [PDF]
Astrophysical Journal Letters, 2022 We present a simple but general argument that strongly limits the abundance of primordial black holes (PBHs) (or other unknown population of compact objects) with masses similar to those determined by LIGO/Virgo from BH binary mergers.
A. Esteban-Gutiérrez +5 more
semanticscholar +1 more source
General Physical Properties of Fermi Blazars [PDF]
Astrophysical Journal Supplement Series, 2023 We study the general physical properties of Fermi blazars using the Fermi fourth source catalog data (4FGL-DR2). The quasi-simultaneous multiwavelength data of Fermi blazars are fitted by using the one-zone leptonic model to obtain some physical ...
Yongyun 永云 Chen 陈 +8 more
semanticscholar +1 more source
Multiple Measurements of Quasars Acting as Standard Probes: Exploring the Cosmic Distance Duality Relation at Higher Redshift [PDF]
Astrophysical Journal, 2020 General relativity reproduces main current cosmological observations, assuming the validity of the cosmic distance duality relation (CDDR) at all scales and epochs.
Xiaogang Zheng +5 more
semanticscholar +1 more source
Estimating black hole spin from AGN SED fitting: The impact of general-relativistic ray tracing [PDF]
Monthly notices of the Royal Astronomical Society, 2023 Accretion disc model fitting to optical/UV quasar spectra requires that the highest mass black holes have the highest spin, with implications on the hierarchical growth of supermassive black holes and their host galaxies over cosmic time.
S. Hagen, C. Done
semanticscholar +1 more source
Evolution and explosions of metal enriched supermassive stars: Proton rich general relativistic instability supernovae [PDF]
Monthly notices of the Royal Astronomical Society, 2023 The assembly of supermassive black holes poses a challenge primarily because of observed quasars at high redshift, but additionally because of the current lack of observations of intermediate mass black holes.
Chris Nagele, H. Umeda, Koh Takahashi
semanticscholar +1 more source