8 papers · 1 filter
The Power of Exploratory Chandra Observations
S. C. Gallagher, G. T. Richards, W. N. Brandt +1
With its excellent spatial resolution, low background, and hard-band response, the Chandra X-ray Observatory is ideal for performing exploratory surveys. These efficient, sensitive…
SDSS Quasars and Dust Reddening
Patrick B. Hall, Philip Hopkins, Michael Strauss +2
The Sloan Digital Sky Survey can be used to detect and characterize red and reddened quasars. In Richards et al. (2003), we showed that 6% of SDSS quasars have red colors consisten…
Constraints on Quasar Continuum, BELR, and BALR Physics from SDSS Composite Spectra
Gordon T. Richards, Patrick B. Hall, Timothy A. Reichard +3
We review recent results on quasars from the SDSS as they relate to our understanding of the UV/optical continuum, the broad emission line region, and the broad absorption line reg…
Quasar Radio Dichotomy: Two Peaks, or not Two Peaks, that is the Question
Z. Ivezic, G. T. Richards, P. B. Hall +8
Recent claims by Ivezic et al. (2002) that the distribution of the radio-to-optical flux ratio, R, for quasars is bimodal (the so-called quasar radio dichotomy) were questioned on…
Counts of Low-redshift SDSS Quasar Candidates
Z. Ivezic, R. H. Lupton, D. E. Johnston +10
We analyze the counts of low-redshift quasar candidates selected using nine-epoch SDSS imaging data. The co-added catalogs are more than 1 mag deeper than single-epoch SDSS data, a…
X-rays from the First Massive Black Holes
W. N. Brandt, C. Vignali, D. P. Schneider +7
X-ray studies of high-redshift (z > 4) active galaxies have advanced substantially over the past few years, largely due to results from the new generation of X-ray observatories. A…