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absorption line

Overview page. Subjects: Astronomy and Astrophysics.

A dark feature in the spectrum of a star, formed by cooler gas in the star's outer layers (the photosphere) that absorbs radiation emitted by hotter gas below. The Fraunhofer lines in the...

See overview in Oxford Index

Microlensing of broad absorption line quasars

G. F. Lewis and K. E. Belle.

in Monthly Notices of the Royal Astronomical Society

June 1998; p ublished online June 1998 .

Journal Article. Subjects: Astronomy and Astrophysics. 0 words.

The physical nature of the material responsible for the high-velocity broad absorption line (BAL) features seen in a small fraction of quasar spectra has been the subject of debate since...

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Variability in Low Ionization Broad Absorption Line outflows

M. Vivek, R. Srianand, P. Petitjean, V. Mohan, A. Mahabal and S. Samui.

in Monthly Notices of the Royal Astronomical Society

P ublished online March 2014 .

Journal Article. Subjects: Astronomy and Astrophysics. 11758 words.

We present results of our time variability studies of Mg ii and Al iii absorption lines in a sample of 22 Low Ionization Broad Absorption Line QSOs (LoBAL QSOs) at 0.2 ≤ z em ≤ ...

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absorption line

Overview page. Subjects: Astronomy and Astrophysics.

A dark feature in the spectrum of a star, formed by cooler gas in the star's outer layers (the photosphere) that absorbs radiation emitted by hotter gas below. The Fraunhofer lines in the...

See overview in Oxford Index

absorption line

Edited by Ian Ridpath.

in A Dictionary of Astronomy

P ublished online February 2018 .

Reference Entry. Subjects: Astronomy and Astrophysics; Astronomical Instrumentation, Methods, and Techniques; Galaxies. 72 words.

A dark feature in the spectrum of a star, formed by cooler gas in the star’s outer layers (the *...

absorption line

Ian Ridpath.

in A Dictionary of Astronomy

January 2012; p ublished online January 2012 .

Reference Entry. Subjects: Astronomy and Astrophysics. 69 words.

A dark feature in the spectrum of a star, formed by cooler gas in the star's outer layers (the *

absorption line

Edited by Richard Cammack, Teresa Atwood, Peter Campbell, Howard Parish, Anthony Smith, Frank Vella and John Stirling.

in Oxford Dictionary of Biochemistry and Molecular Biology

January 2006; p ublished online January 2008 .

Reference Entry. Subjects: Biochemistry. 8 words.

an alternative name for absorption band.

On the origins of C iv absorption profile diversity in broad absorption line quasars

Alexei Baskin, Ari Laor and Fred Hamann.

in Monthly Notices of the Royal Astronomical Society

P ublished online March 2015 .

Journal Article. Subjects: Astronomy and Astrophysics. 9031 words.

There is a large diversity in the C iv broad absorption line (BAL) profile among BAL quasars (BALQs). We quantify this diversity by exploring the distribution of the C iv BAL properties,...

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Radiation pressure confinement – IV. Application to broad absorption line outflows

Alexei Baskin, Ari Laor and Jonathan Stern.

in Monthly Notices of the Royal Astronomical Society

P ublished online October 2014 .

Journal Article. Subjects: Astronomy and Astrophysics. 11057 words.

A fraction of quasars present broad absorption lines, produced by outflowing gas with typical velocities of 3000–10 000 km s−1. If the outflowing gas fills a significant fraction of the...

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Constraining FeLoBAL outflows from absorption line variability

S. M. McGraw, J. C. Shields, F. W. Hamann, D. M. Capellupo, S. C. Gallagher and W. N. Brandt.

in Monthly Notices of the Royal Astronomical Society

P ublished online August 2015 .

Journal Article. Subjects: Astronomy and Astrophysics. 11933 words.

Iron low-ionization broad absorption lines (FeLoBALs) trace a rare class of quasar outflows with large column densities and potentially large kinetic energies that might be important for...

The earliest galaxies seen in 21 cm line absorption

Yidong Xu, Andrea Ferrara and Xuelei Chen.

in Monthly Notices of the Royal Astronomical Society

January 2011; p ublished online January 2011 .

Journal Article. Subjects: Astronomy and Astrophysics. 15903 words.

We investigate the 21 cm absorption lines produced by non-linear structures during the early stage of reionization, i.e. the starless minihaloes and the dwarf galaxies. After a detailed...

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A simple disc wind model for broad absorption line quasars

N. Higginbottom, C. Knigge,  K. S. Long, S. A. Sim and J. H. Matthews.

in Monthly Notices of the Royal Astronomical Society

December 2013; p ublished online September 2013 .

Journal Article. Subjects: Astronomy and Astrophysics. 12683 words.

Approximately 20 per cent of quasi-stellar objects (QSOs) exhibit broad, blue-shifted absorption lines in their ultraviolet spectra. Such features provide clear evidence for significant...

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Intranight optical variability of radio-loud broad absorption line quasars

Ravi Joshi and Hum Chand.

in Monthly Notices of the Royal Astronomical Society

February 2013; p ublished online December 2012 .

Journal Article. Subjects: Astronomy and Astrophysics. 5252 words.

We present the results of an optical photometric monitoring programme of 10 extremely radio-loud broad absorption lines (RL-BALQSOs) with radio-loudness parameter, R, greater than 100 and...

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Properties of X-ray-selected broad absorption-line quasars*

A. J. Blustin, T. Dwelly, M. J. Page, I. M. McHardy, N. Seymour, J. A. Kennea, N. S. Loaring, K. O. Mason and K. Sekiguchi.

in Monthly Notices of the Royal Astronomical Society

November 2008; p ublished online October 2008 .

Journal Article. Subjects: Astronomy and Astrophysics. 7557 words.

Broad absorption-line quasars (commonly termed BALQSOs) contain the most dramatic examples of active galactic nucleus (AGN) driven winds. The high absorbing columns in these winds, ∼1024cm−2null...

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The redshift distribution of absorption-line systems in QSO spectra

A. I. Ryabinkov, A. D. Kaminker and D. A. Varshalovich.

in Monthly Notices of the Royal Astronomical Society

April 2007; p ublished online April 2007 .

Journal Article. Subjects: Astronomy and Astrophysics. 8314 words.

A statistical analysis of the space–time distribution of absorption-line systems (ALSs) observed in QSO spectra within the cosmological redshift interval z= 0.0–3.7 is carried out on the...

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High-dispersion absorption-line spectroscopy of AE Aqr

J. Echevarría, Robert Connon Smith, R. Costero, S. Zharikov and R. Michel.

in Monthly Notices of the Royal Astronomical Society

July 2008; p ublished online July 2008 .

Journal Article. Subjects: Astronomy and Astrophysics. 8823 words.

High-dispersion time-resolved spectroscopy of the unique magnetic cataclysmic variable AE Aqr is presented. A radial velocity analysis of the absorption lines yields K 2= 168.7...

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The orientation and polarization of broad absorption line quasars★

M. A. DiPompeo, M. S. Brotherton and C. De Breuck.

in Monthly Notices of the Royal Astronomical Society

January 2013; p ublished online October 2012 .

Journal Article. Subjects: Astronomy and Astrophysics. 8280 words.

We present new spectropolarimetric observations of eight radio-loud broad absorption line (BAL) quasars, and combine these new data with our previous spectropolarimetric atlases (of both...

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Absorption-line systems in simulated galaxies fed by cold streams

Michele Fumagalli, J. Xavier Prochaska, Daniel Kasen, Avishai Dekel, Daniel Ceverino and Joel R. Primack.

in Monthly Notices of the Royal Astronomical Society

December 2011; p ublished online December 2011 .

Journal Article. Subjects: Astronomy and Astrophysics. 18585 words.

Hydro-cosmological simulations reveal that massive galaxies at high redshift are fed by long narrow streams of merging galaxies and a smoother component of cold gas. We post-process seven...

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The intrinsic fraction of broad-absorption line quasars

Christian Knigge, Simone Scaringi, Michael R. Goad and Christopher E. Cottis.

in Monthly Notices of the Royal Astronomical Society

May 2008; p ublished online April 2008 .

Journal Article. Subjects: Astronomy and Astrophysics. 8619 words.

We carefully reconsider the problem of classifying broad-absorption line quasars (BALQSOs) and derive a new, unbiased estimate of the intrinsic BALQSO fraction from the Sloan Digital Sky...

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Quasar broad absorption line variability measurements using reconstructions of unabsorbed spectra

C. Wildy, M. R. Goad and J. T. Allen.

in Monthly Notices of the Royal Astronomical Society

January 2014; p ublished online November 2013 .

Journal Article. Subjects: Astronomy and Astrophysics. 12530 words.

We present a two-epoch Sloan Digital Sky Survey and Gemini/GMOS+William Herschel Telescope/ISIS variability study of 50 broad absorption line (BAL) quasars of redshift range 1.9 < z < 4.2,...

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Broad absorption line variability in radio-loud quasars

C. A. Welling, B. P. Miller, W. N. Brandt, D. M. Capellupo and R. R. Gibson.

in Monthly Notices of the Royal Astronomical Society

P ublished online April 2014 .

Journal Article. Subjects: Astronomy and Astrophysics. 11233 words.

We investigate C iv broad absorption line (BAL) variability within a sample of 46 radio-loud quasars (RLQs), selected from Sloan Digital Sky Survey (SDSS)/Faint Images of the Radio Sky at...

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