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Scholars Day 2007, Wednesday, April 11

High-Velicity Ejecta From Broad Absorption Line Quasi-Stellar Objects - Poster

Quasi-Stellar Objects (QSOs) are the Universe’s most luminous objects, powered by supermassive black holes at the centers of galaxies. About 10% of QSO spectra exhibit absorption troughs extending up to 30,000 km s^-1 from the QSO itself. These Broad Absorption Lines (BALs) arise either in clouds accelerated by radiation pressure or in winds blown off a surrounding torus of cooler gas by the intense luminosity of the central disk. We present results from a search for extremely high velocity (>30,000 km s^-1) CIV absorbers in BAL QSOs. We selected QSOs with redshift z > 1.5, for which the QSO CIV line is shifted into the visible spectrum. Only QSOs with positive Balnicity Index as measured by Trump et al. (2006) were considered. Our final sample comprises ~1600 BAL QSOs containing 222 measured CIV absorption systems. We compare their occurrence in velocity space to those found in a sample of 15150 non-BAL QSOs.

Presenter: Bogdan Kurtev (Undergraduate Student)
Topic: Astronomy
Location: Fireside Lounge, Union
Time: 9 am (Session I)