Results 1 to 10 of about 325 (134)

Spectroscopy of Broad Absorption Line Quasars at 3 ≲ Z ≲ 5. I. Evidence for Quasar Winds Shaping Broad/Narrow Emission Line Regions [PDF]

open access: yesAstrophysical Journal, 2020
Abstract We present an observational study of 22 broad absorption line quasars (BAL QSOs) at based on optical/near-IR spectroscopy, aiming to investigate quasar winds and their effects.
Jinyi Yang, John Timlin, Weimin Yi
exaly   +4 more sources

High-Resolution Spectroscopy of Quasars and Quasar Absorption-Line Systems [PDF]

open access: yesPublications of the Astronomical Society of the Pacific, 1995
Topic cover in this paper included new observations of QSO absorption lines by the Keck Telescope HIRES spectrometer and the Hubble Space Telescope. An overview of the major scientific issues in this field is followed by a brief summary of a panel discussion that addressed future instrumental possibilities that could answer some of these questions.
exaly   +2 more sources

XMM-NewtonSpectroscopy of the Highly Polarized and Luminous Broad Absorption Line Quasar CSO 755 [PDF]

open access: yesThe Astronomical Journal, 2005
7 pages (emulateapj), 3 figures.
Shemmer O.   +6 more
openaire   +4 more sources

Upper limits on the 21 cm power spectrum at z = 5.9 from quasar absorption line spectroscopy [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society: Letters, 2016
Abstract We present upper limits on the 21 cm power spectrum at z = 5.9 calculated from the model-independent limit on the neutral fraction of the intergalactic medium of $x_{{\rm H\,\small {I}}} < 0.06 + 0.05\ (1\sigma )$ derived from dark pixel statistics of quasar absorption spectra.
Pober, Jonathan C.   +2 more
openaire   +3 more sources

The Study of the Circumgalactic Medium with Quasar Pairs

open access: yesThe Astrophysical Journal Supplement Series, 2023
We have collected 10,025 foreground–background quasar pairs with projected distances d _p < 500 kpc from the large quasar catalog of the Sloan Digital Sky Survey DR16Q. We investigate the properties of the Mg ii absorption lines with W _r > 0.15 Å around
Zhi-Fu Chen   +7 more
doaj   +1 more source

Subaru High-Resolution Spectroscopy of Complex Metal Absorption Lines of the Quasar HS 1603+3820 [PDF]

open access: yesThe Astronomical Journal, 2003
35 pages, 11 figures, accepted for publication in the Astronomical ...
Misawa, Toru   +6 more
openaire   +2 more sources

VLT+UVES Spectroscopy of the CaiiLow‐Ionization Broad Absorption Line Quasar SDSS J030000.56+004828.0 [PDF]

open access: yesThe Astrophysical Journal, 2003
We study high-resolution spectra of the "overlapping-trough" low-ionization broad absorption line (LoBAL) quasar SDSS J030000.56+004828.0. The Ca II, Mg II, and Mg I column densities in this object are the largest reported to date for any BAL outflow. The broad Ca II absorption is mildly blended, but the blending can be disentangled to measure the Ca ...
Hall, PB   +6 more
openaire   +1 more source

Associated Absorption Lines in the Radio‐loud Quasar 3C 351: Far‐Ultraviolet Echelle Spectroscopy from theHubble Space Telescope [PDF]

open access: yesThe Astrophysical Journal, 2002
As one of the most luminous radio-loud quasars showing intrinsic ultraviolet (UV) and X-ray absorption, 3C 351 provides a laboratory for studying the kinematics and physical conditions of such ionized absorbers. We present an analysis of the intrinsic absorption lines in the high-resolution ($\sim$ 7 km/s) far-UV spectrum which was obtained from ...
Yuan, Q.   +5 more
openaire   +2 more sources

Evidence of First Stars-enriched Gas in High-redshift Absorbers

open access: yesThe Astrophysical Journal, 2023
The first stars were born from chemically pristine gas. They were likely massive, and thus they rapidly exploded as supernovae, enriching the surrounding gas with the first heavy elements.
Andrea Saccardi   +8 more
doaj   +1 more source

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