Results 1 to 10 of about 85,255 (272)
Quasar Clustering and the Lifetime of Quasars [PDF]
The Astrophysical Journal, 2000 Although the population of luminous quasars rises and falls over a period of 10^9 years, the typical lifetime of individual quasars is uncertain by several orders of magnitude.
Baugh C. M. +17 more
core +4 more sources
Russian VLBI network “Quasar”: Current status and outlook
Geodesy and Geodynamics, 2019 This paper presents the past, present and future status of the Russian VLBI network “Quasar”. This network has been developed for at least 20 years by the Institute of Applied Astronomy of the Russian Academy of Sciences (IAA RAS).
A Ipatov +2 more
exaly +3 more sources
Results in Physics, 2019 We report a new stringent limit relating to the space-time variation in the fine-structure constant α=e24πε0ℏc from an analysis of quasar J110325-264515 towards zabs=1.8389. We find Δα/α=(1.56±1.78)×10-6 from a comparison of laboratory wavelengths of [Fe
T D Le
exaly +3 more sources
Spectral Classification of Quasar Subject to Redshift: A Statistical Study
Computer Sciences & Mathematics Forum, 2023 Quasars are astronomical star-like objects having a large ultraviolet flux of radiation accompanied by generally broad emission lines and absorption lines in some cases found at large redshift. The used data is extracted from the Veron Cetti Catalogue of
Prithwish Ghosh, Shinjon Chakraborty
doaj +1 more source
Quasars Probing Quasars. X. The Quasar Pair Spectral Database [PDF]
The Astrophysical Journal Supplement Series, 2018 Abstract The rare close projection of two quasars on the sky provides the opportunity to study the host galaxy environment of a foreground quasar in absorption against the continuum emission of a background quasar. For over a decade the “Quasars probing quasars” series has utilized this technique to further the understanding of galaxy ...
Joseph R. Findlay +10 more
openaire +6 more sources
THE PROPERTIES OF QUASAR HOSTS AT THE PEAK OF THE QUASAR ACTIVITY [PDF]
The Astrophysical Journal, 2009 We present near-infrared imaging obtained with ESO VLT/ISAAC of a sample of 16 low luminosity radio-quiet quasars at the epoch around the peak of the quasar activity (2 < z < 3), aimed at investigating their host galaxies. For 11 quasars, we are able to detect the host galaxies and derive their properties, while for the other five quasars, upper ...
Kotilainen J. K. +5 more
openaire +3 more sources
Investigating Gravitationally Lensed Quasars Observable by Nancy Grace Roman Space Telescope
Galaxies, 2023 In this work, we investigate the possibility of observing quasars, particularly lensed quasars, by the Nancy Grace Roman Space Telescope (Roman).
Lindita Hamolli +3 more
doaj +1 more source
Performance of the Quasar Spectral Templates for the Dark Energy Spectroscopic Instrument
The Astronomical Journal, 2023 Millions of quasar spectra will be collected by the Dark Energy Spectroscopic Instrument (DESI), leading to a fourfold increase in the number of known quasars.
Allyson Brodzeller +46 more
doaj +1 more source
Reports in Advances of Physical Sciences, 2020 It is an unsolved mystery that the rotation velocity of a galactic disc is same at any radial distances. The presence of dark matter is expected, but not observed.
Shigeto Nagao
doaj +1 more source
REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASAR [PDF]
Radio Physics and Radio Astronomy, 2018 Purpose: Studying the spatial structure of the quasar in the Q2237+0305 gravitational lens system in optical spectral range; estimating the central black hole mass.
L. A. Berdina +2 more
doaj +1 more source