Results 1 to 10 of about 314 (129)

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

open access: bronzeThe Astrophysical 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.
Weimin Yi   +8 more
  +5 more sources

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

open access: bronzePublications 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.
J. Michael Shull
openaire   +3 more sources

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

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

Diagnostics of Quasar Broad Absorption Line Geometry: X-Ray Observations and Two-dimensional Optical Spectroscopy [PDF]

open access: bronzeThe Astrophysical Journal, 2005
A new generation of sensitive X-ray measurements are indicating that the existence of X-ray attenuation column densities, NH > 1024 cm-2, is quite common among broad absorption line quasars (BALQSOs). This is significant to the geometry of the broad absorption line (BAL) outflow.
Sebastian Lipari, B. Punsly
openaire   +3 more sources

High Signal‐to‐Noise Echelle Spectroscopy of Quasar Absorption Line Systems with Metals in the Direction of HS 1700+6416 [PDF]

open access: bronzeThe Astrophysical Journal Supplement Series, 1997
We have obtained a high signal-to-noise (30 ? S/N ? 70), high-resolution (FWHM = 20 km s-1) spectrum of the radio-quiet QSO HS 1700+6416 (zem = 2.72) with the echelle spectrograph on the Kitt Peak National Observatory 4 m telescope. We detect 13 metal systems in the optical spectrum of this QSO, including six systems with associated optically thin ...
Todd M. Tripp, Limin Lu, Blair D. Savage
openaire   +2 more sources

Constraining Variable High Velocity Winds from Broad Absorption Line Quasars with Multi-Epoch Spectroscopy [PDF]

open access: green, 2012
2 pages, 2 figures, Conference proceedings for "AGN Winds in Charleston," Charleston, SC, Oct 15-18, 2011.
Haggard, Daryl   +4 more
  +5 more sources

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

open access: greenMonthly 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   +5 more sources

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

open access: greenThe 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   +3 more sources

Keck HIRES Spectroscopy of the FeiiLow‐Ionization Broad Absorption Line Quasar FBQS 0840+3633: Evidence for Two Outflows on Different Scales [PDF]

open access: bronzeThe Astrophysical Journal, 2002
A Keck echelle spectrum of the quasar FBQS 0840+3633 reveals outflowing gas that gives rise to blueshifted absorption lines of many low-ionization species. The gas covers a range of velocities from -700 to -3500 km s-1, with two main components centered at -900 and -2800 km s-1.
Martijn de Kool   +4 more
openaire   +2 more sources

High Resolution Ultraviolet Quasar Absorption Line Spectroscopy of z~1 Galaxy Group [PDF]

open access: green, 2002
4 pages, 1 figure, to appear in "Hubble's Science Legacy: Future Optical-Ultraviolet Astronomy from Space", eds. K.R. Sembach, J.C. Blades, G.D. Illingworth, & R.C.
Jie Ding
openaire   +3 more sources

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