Results 111 to 120 of about 117,210 (326)
Astronomische Nachrichten, EarlyView.ABSTRACT The discovery of radio‐quiet, x‐ray thermally emitting isolated neutron stars (XINSs) in the ROSAT All‐Sky Survey revealed a previously overlooked component of the neutron star population. Advancements in x‐ray instrumentation and the availability of deep, wide‐area optical surveys now enable us to explore XINSs at fainter x‐ray fluxes and ...
Adriana Mancini Pires +11 more
wiley +1 more source
Some Constraints on Quasar Progenitors and Quasar Evolution [PDF]
Symposium - International Astronomical Union, 1986 There is strong evidence that quasars are powered by the gravitational energy released by in fall of matter into a compact supermassive object which is most likely a black hole with mass M>106 to 109MO. The question then arises as to how such massive black holes came to be formed. What sort of objects were the progenitors?
openaire +2 more sources
QSO MUSEUM I: a sample of 61 extended Ly α-emission nebulae surroundingz∼ 3 quasars [PDF]
Monthly notices of the Royal Astronomical Society, 2018 Motivated by the discovery of rare enormous Lyman α nebulae (ELAN) around z ∼ 2 quasars, we initiated a long-term campaign with the MUSE/VLT instrument to directly uncover the astrophysics of the gas around quasars.
F. A. Battaia +8 more
semanticscholar +1 more source
The Astrophysical JournalWe investigate the group-scale environment of 15 luminous quasars (luminosity L _3000 > 10 ^46 erg s ^−1 ) from the Cosmic Ultraviolet Baryon Survey (CUBS) at redshift z ≈ 1.
Jennifer I-Hsiu Li +13 more
doaj +1 more source
Using a complete spectroscopic survey to find red quasars and test the KX method [PDF]
, 2007 We present an investigation of quasar colour-redshift parameter space in order to search for radio-quiet red quasars and to test the ability of a variant of the KX quasar selection method to detect quasars over a full range of colour without bias. This is achieved by combining IRIS2 imaging with the complete Fornax Cluster Spectroscopic Survey to probe
arxiv +1 more source
, 2000 We present an empirical investigation of the colors of quasars in the Sloan Digital Sky Survey (SDSS) photometric system. The sample studied includes 2625 quasars with SDSS photometry.
A. J. Connolly +70 more
core +1 more source
Dust Reddening in SDSS Quasars [PDF]
, 2004 We explore the form of extragalactic reddening toward quasars using a sample of 9566 quasars with redshifts 0 0.2, where the extinction is relative to quasars with modal colors.
Ariana S +10 more
core +3 more sources
Dust Emission in an Accretion-rate-limited Sample of z ≳ 6 Quasars [PDF]
Astrophysical Journal, 2018 We present Atacama Large Millimeter Array 1 mm observations of the rest-frame far-infrared (FIR) dust continuum in 27 quasars at redshifts 6.0 ≲ z < 6.7.
B. Venemans +11 more
semanticscholar +1 more source
DESI z ≳ 5 Quasar Survey. I. A First Sample of 400 New Quasars at z ∼ 4.7–6.6
The Astrophysical Journal Supplement Series, 2023 We report the first results of a high-redshift ( z ≳ 5) quasar survey using the Dark Energy Spectroscopic Instrument (DESI). As a DESI secondary target program, this survey is designed to carry out a systematic search and investigation of quasars at 4.8 <
Jinyi Yang +41 more
doaj +1 more source
What makes red quasars red? Observational evidence for dust extinction from line ratio analysis
, 2017 Red quasars are very red in the optical through near-infrared (NIR) wavelengths, which is possibly due to dust extinction in their host galaxies as expected in a scenario in which red quasars are an intermediate population between merger-driven star ...
Im, Myungshin, Kim, Dohyeong
core +1 more source