Results 1 to 10 of about 113,643 (296)

Performance of the Quasar Spectral Templates for the Dark Energy Spectroscopic Instrument [PDF]

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, Kyle Dawson, Stephen Bailey, Jiaxi Yu, A. J. Ross, A. Bault, S. Filbert, J. Aguilar, S. Ahlen, David M. Alexander, E. Armengaud, A. Berti, D. Brooks, E. Chaussidon, A. de la Macorra, P. Doel, K. Fanning, V. A. Fawcett, A. Font-Ribera, S. Gontcho A Gontcho, J. Guy, K. Honscheid, S. Juneau, R. Kehoe, T. Kisner, Anthony Kremin, Ting-Wen Lan, M. Landriau, Michael E. Levi, C. Magneville, Paul Martini, Aaron M. Meisner, R. Miquel, J. Moustakas, N. Palanque-Delabrouille, W. J. Percival, F. Prada, C. Ravoux, Graziano Rossi, C. Saulder, M. Siudek, Gregory Tarlé, B. A. Weaver, S. Youles, Zheng Zheng, Rongpu Zhou, Zhimin Zhou   +46 more
doaj   +2 more sources

Quasars and their host galaxies [PDF]

, 2006
This review attempts to describe developments in the fields of quasar and quasar host galaxies in the past five. In this time period, the Sloan and 2dF quasar surveys have added several tens of thousands of quasars, with Sloan quasars being found to z>6.
A. Laor, A. Laor, A. Mesinger, A. Soltan, A. Stockton, A. Stockton, A. Wandel, A.J. Barth, A.R. Marble, B.M. Peterson, C. Leipski, C. Norman, C.A. Onken, C.H. Nelson, C.H. Nelson, C.N. Tadhunter, D. Stern, D.E. Vanden Berk, D.E. Vanden Berk, D.J.E. Floyd, D.P. Schneider, E. Glikman, G. Canalizo, G. Kauffmann, G. Kauffmann, G.A. Shields, G.L. Granato, G.T. Richards, G.T. Richards, J. Everett, J. Silk, J.-H. Woo, J.B. Hutchings, J.H. Krolik, J.N. Bahcall, J.S. Dunlop, J.S. Dunlop, L. Ho, L.A. Nolan, M. Cirasuolo, M. Elvis, M. estergaard, M. Kool de, M. Lacy, M. Lacy, M. Lacy, M. Lacy, M. Lacy, M.D. Gregg, M.J. Disney, M.J. Kukula, M.S. Brotherton, N. Arav, N. Zakamska, P. Padovani, P.B. Hall, Q. Yu, R. Falomo, R. Falomo, R.D. Blandford, R.D. Blandford, R.H. Becker, R.H. Becker, R.J. McLure, R.L. White, R.L. White, R.M. Cutri, R.P. Fender, R.P. Marel van der, S. Vaughan, S.E. Ridgway, S.M. Croom, S.M. Croom, T. Boroson, T.A. Boroson, T.A. Boroson, W. Freudling, W. Vries de, X. Fan, X. Fan, X. Fan, Z. Ivezic   +81 more
core   +3 more sources

Sentinel-2 enabled E. coli and Enterococcus faecal bacteria surveillance in coastal-recreational waters [PDF]

Scientific Reports
Monitoring faecal indicator bacteria (FIB), such as Escherichia coli (E. coli) and Enterococcus, in recreational waters is crucial for public health and environmental safety.
Masuma Chowdhury, Irene Laiz, Ignacio de la Calle   +2 more
doaj   +2 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

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, Mimoza Hafizi, Francesco De Paolis, Esmeralda Guliqani   +3 more
doaj   +1 more source

Galactic Evolution Showing a Constant Circulating Speed of Stars in a Galactic Disc without Requiring Dark Matter

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, V. S. Tsvetkova, V. M. Shulga   +2 more
doaj   +1 more source

Directly Tracing Cool Filamentary Accretion over >100 kpc into the Interstellar Medium of a Quasar Host at z = 1

The Astrophysical Journal Letters, 2022
We report the discovery of giant (50−100 kpc) [O ii ] emitting nebulae with MUSE in the field of TXS 0206−048, a luminous quasar at z = 1.13. “Down-the-barrel” UV spectra of the quasar show absorption at velocities coincident with those of the extended ...
Sean D. Johnson, Joop Schaye, Gregory L. Walth, Jennifer I-Hsiu Li, Gwen C. Rudie, Hsiao-Wen Chen, Mandy C. Chen, Benoît Epinat, Massimo Gaspari, Sebastiano Cantalupo, Wolfram Kollatschny, Zhuoqi (Will) Liu, Sowgat Muzahid   +12 more
doaj   +1 more source

A Thirty-Four Billion Solar Mass Black Hole in SMSS J2157-3602, the Most Luminous Known Quasar [PDF]

, 2020
From near-infrared spectroscopic measurements of the MgII emission line doublet, we estimate the black hole (BH) mass of the quasar, SMSS J215728.21-360215.1, as being (3.4 +/- 0.6) x 10^10 M_sun and refine the redshift of the quasar to be z=4.692.
Bian, Fuyan, Fan, Xiaohui, Onken, Christopher A., Wang, Feige, Wolf, Christian, Yang, Jinyi   +5 more
core   +2 more sources

A Survey for High-redshift Gravitationally Lensed Quasars and Close Quasar Pairs. I. The Discoveries of an Intermediately Lensed Quasar and a Kiloparsec-scale Quasar Pair at z ∼ 5

The Astronomical Journal, 2023
We present the first results from a new survey for high-redshift ( z ≳ 5) gravitationally lensed quasars and close quasar pairs. We carry out candidate selection based on the colors and shapes of objects in public imaging surveys, then conduct follow-up ...
Minghao Yue, Xiaohui Fan, Jinyi Yang, Feige Wang   +3 more
doaj   +1 more source