Results 41 to 50 of about 81,623 (245)

Quasar-galaxy associations [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 1995
uuencoded Postscript file (including figures and tables), SUSSEX-AST 94/8 ...
Thomas, P. A.   +2 more
openaire   +6 more sources

What We Talk about When We Talk about Blazars?

open access: yesFrontiers in Astronomy and Space Sciences, 2017
After the discovery of powerful relativistic jets from Narrow-Line Seyfert 1 Galaxies, and the understanding of their similarity with those of blazars, a problem of terminology was born.
Luigi Foschini
doaj   +1 more source

Predicting the Yields of z > 6.5 Quasar Surveys in the Era of Roman and Rubin

open access: yesThe Astrophysical Journal, 2023
About 70 luminous quasars discovered at z > 6.5 are strongly biased toward the bright end, thus not providing a comprehensive view of quasar abundance beyond the cosmic dawn. We present the predicted results of the Roman/Rubin high-redshift quasar survey,
Wei Leong Tee   +5 more
doaj   +1 more source

Microlensing variability in the gravitationally lensed quasar Q2237+0305 = the Einstein Cross, I. Spectrophotometric monitoring with the VLT [PDF]

open access: yes, 2008
We present the results of the first long-term (2.2 years) spectroscopic monitoring of a gravitationally lensed quasar, namely the Einstein Cross Q2237+0305.
A. Eigenbrod   +62 more
core   +2 more sources

COOL-LAMPS. Discovery of COOL J0335−1927, a Gravitationally Lensed Quasar at z = 3.27 with an Image Separation of 23.″3

open access: yesThe Astrophysical Journal Letters, 2023
We report the discovery of COOL J0335−1927, a quasar at z = 3.27 lensed into three images with a maximum separation of 23.″3 by a galaxy cluster at z = 0.4178. To date, this is the highest redshift wide-separation lensed quasar known.
Kate Napier   +20 more
doaj   +1 more source

Large-scale homogeneity in the distribution of quasars in the Hercules-Corona Borealis Great Wall region [PDF]

open access: yesSerbian Astronomical Journal, 2022
In light of recent debates on the existence of a gigaparsec-scale structure traced by gamma-ray bursts, namely the Hercules-Corona Borealis Great Wall (HCBGW), we revisit large-scale homogeneity in the spatial distribution of quasars. Our volume-
Fujii Hirokazu
doaj   +1 more source

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses XIII: Time delays and 9-yr optical monitoring of the lensed quasar RX J1131-1231 [PDF]

open access: yes, 2013
We present the results from nine years of optically monitoring the gravitationally lensed z=0.658 quasar RX J1131-1231. The R-band light curves of the four individual images of the quasar were obtained using deconvolution photometry for a total of 707 ...
A. M. Mosquera   +61 more
core   +2 more sources

The road to quasars [PDF]

open access: yesProceedings of the International Astronomical Union, 2014
AbstractAlthough the extragalactic nature of 3C 48 and other quasi stellar radio sources was discussed as early as 1960 by John Bolton and others, it was rejected largely because of preconceived ideas about what appeared to be unrealistically high radio and optical luminosities.
openaire   +3 more sources

Compatibility of the large quasar groups with the concordance cosmological model [PDF]

open access: yes, 2016
We study the compatibility of large quasar groups with the concordance cosmological model. Large quasar groups are very large spatial associations of quasars in the cosmic web, with sizes of 50–250 h−1 Mpc.
Campusano, Luis E.   +5 more
core   +2 more sources

Statistics of Galactic-scale Quasar Pairs at Cosmic Noon

open access: yesThe Astrophysical Journal, 2023
The statistics of galactic-scale quasar pairs can elucidate our understanding of the dynamical evolution of supermassive black hole (SMBH) pairs, the duty cycles of quasar activity in mergers, or even the nature of dark matter, but they have been ...
Yue Shen   +10 more
doaj   +1 more source

Home - About - Disclaimer - Privacy