Results 41 to 50 of about 6,949,336 (206)
Quasars as standard candles II [PDF]
Astronomy & Astrophysics, 2019 A tight non-linear relation between the X-ray and the optical-ultraviolet (UV) emission has been observed in active galactic nuclei (AGN) over a wide range of redshift and several orders of magnitude in luminosity, suggesting the existence of an ...
F. Salvestrini +4 more
semanticscholar +1 more source
The Motion of a Body in Newtonian Theories [PDF]
, 2010 A theorem due to Bob Geroch and Pong Soo Jang [“Motion of a Body in General Relativity.” Journal of Mathematical Physics 16(1), (1975)] provides the sense in which the geodesic principle has the status of a theorem in General Relativity (GR).
Weatherall, James Owen +1 more
core +1 more source
Erratum: Is every strong lens model unhappy in its own way? Uniform modelling of a sample of 13 quadruply+ imaged quasars [PDF]
Monthly notices of the Royal Astronomical Society, 2018 Strong-gravitational lens systems with quadruply imaged quasars (quads) are unique probes to address several fundamental problems in cosmology and astrophysics.
A. Shajib +72 more
semanticscholar +1 more source
Pulsations of primordial supermassive stars induced by a general relativistic instability; visible to JWST at z$>$12 [PDF]
, 2022 The origin of high-redshift quasars and their supermassive black hole engines is unclear. One promising solution is the collapse of a primordial supermassive star.
Chris Nagele +3 more
semanticscholar +1 more source
Outflow-related radio emission in radio-quiet quasars [PDF]
Monthly notices of the Royal Astronomical SocietyIn this work, we revisit the relationship between [O III] line width w90 (as the indicator of AGN outflow velocity) and the radio emission in RQQs by employing a large sample of Type I quasars (∼37, 000) selected from the Sloan Digital Sky Survey (SDSS)
Mai Liao +3 more
semanticscholar +1 more source
An ALMA CO(2–1) Survey of Nearby Palomar–Green Quasars [PDF]
Astrophysical Journal Supplement Series, 2019 The properties of the molecular gas can shed light on the physical conditions of quasar host galaxies and the effect of feedback from accreting supermassive black holes.
J. Shangguan +4 more
semanticscholar +1 more source
Decoding signatures of extra dimensions and estimating spin of quasars from the continuum spectrum [PDF]
Physical Review D, 2019 Continuum spectrum emitted by the accretion disk around quasars hold a wealth of information regarding the strong gravitational field produced by the massive central object.
Indrani Banerjee +2 more
semanticscholar +1 more source
Jet efficiencies and black hole spins in jetted quasars [PDF]
, 2020 The mechanisms responsible for the production of relativistic jets from supermassive black holes (SMBHs) accreting at near-Eddington rates are not well-understood.
Gustavo Soares, R. Nemmen
semanticscholar +1 more source
PHOTOMETRIC REDSHIFTS AND QUASAR PROBABILITIES FROM A SINGLE, DATA-DRIVEN GENERATIVE MODEL [PDF]
The Astrophysical Journal, 2012 We describe a technique for simultaneously classifying and estimating the redshift of quasars. It can separate quasars from stars in arbitrary redshift ranges, estimate full posterior distribution functions for the redshift, and naturally incorporate flux uncertainties, missing data, and multi-wavelength photometry.
Bovy, Jo +9 more
openaire +2 more sources
, 2020 In this work, we obtain measurements of the Hubble constant in the context of modified gravity theories. We set up our theoretical framework by considering viable cosmological $f(R)$ and $f(T)$ models, and we analyzed them through the use of geometrical ...
R. D’Agostino, Rafael C. Nunes
semanticscholar +1 more source