Patrick S. Osmer

Mass Functions of the Active Black Holes in Distant Quasars from the Large Bright Quasar Survey, the Bright Quasar Survey, and the Color-selected Sample of the SDSS Fall Equatorial Stripe

We present mass functions of distant actively accreting supermassive black holes residing in luminous quasars discovered in the Large Bright Quasar Survey (LBQS), the Bright Quasar Survey (BQS), and the Fall Equatorial Stripe of the Sloan Digital Sky Survey (SDSS). The quasars cover a wide range of redshifts from the local universe to z = 5 and were subject to different selection criteria and flux density limits. This makes these samples complementary and can help us gain additional insight on the true underlying black hole mass distribution free from selection effects and mass estimation errors through future studies. By comparing these quasar samples, we see evidence that the active black hole population at redshift four is somewhat different than that at lower redshifts, including that in the nearby universe. In particular, there is a sharp increase in the space density of the detected active black holes (M BH 108 M ☉) between redshifts ~4 and ~2.5. Also, the mass function of the SDSS quasars at 3.6 ≤ z ≤ 5 has a somewhat flatter high-mass-end slope of β = –1.75 ± 0.56, compared to the mass functions based on quasars below z of 3 (BQS and LBQS quasars), which display typical slopes of β ≈ –3.3; the latter are consistent with the mass functions at similar redshifts based on the SDSS Data Release 3 quasar catalog presented by Vestergaard et al. We see clear evidence of cosmic downsizing in the comoving space density distribution of active black holes in the LBQS sample alone. In forthcoming papers, further analysis, comparison, and discussion of these mass functions will be made with other existing black hole mass functions, notably that based on the SDSS DR3 quasar catalog. We present the relationships used to estimate the black hole mass based on the Mg II emission line; the relations are calibrated to the Hβ and C IV relations by means of several thousand high-quality SDSS spectra. Mass estimates of the individual black holes of these samples are also presented.

Luminosity effects and the emission-line properties of quasars with 0 less than z less than 3.8

We present data and a spectral atlas for 76 quasars with 2.97 less than z less than 3.80 and for 33 quasars with z approximately 2, together with measures of 73 quasars from the IUE archives that mostly have z less than 1. The quasars provide a sampling of the luminosity-redshift plane at constant luminosity for 0 less than z less than 3.8, a range of a factor of 40 in luminosity for 3 less than z less than 3.8, and a range of 10(exp 3) in luminosity for z less than 1. We investigate the behavior of the principle emission lines from 1200-2000 A and find: (1) The Baldwin effect at z greater than 3 is definitely present in the C IV lambda 1549 line and in the other strong emission lines in varying degrees except for N v lambda-lambda(1240) and 1400, where the effect is very weak. (2) The component that varies with luminosity has a narrower full width at half maximum (FWHM) than the average line width and appears consistent with the first component of the principal component analysis of the Large Bright Quasar Survey sample by Francis et al. (1992). (3) There is no evidence for redshifted-dependent spectral changes, Baldwin or otherwise, in quasars of the same luminosity in the z approximately 2 and z greater than 3 samples. (4) The Baldwin effect in the IUE, z approximately 2, and z greater than 3 subsamples joins smoothly, although the slope of the effect steepens with increasing luminosity. (5) The results are consistent with the ionization parameter decreasing with increasing luminosity. (6) The large ratio of N v to Ly-alpha and its small change with luminosity are consistent with the arguments of Hamann & Ferland (1993a, b) that the N/C ratio is enhanced in high-luminosity quasars with z greater than 3.

On the optical identification of Sco X-1

Optical identification of position of X-ray astronomical source Sco X-1, noting similarity of certain properties with old novae

Mass functions of the active black holes in distant quasars from the sloan digital sky survey data release 3

We present the mass functions of actively accreting supermassive black holes over the redshift range 0.3 ? z ? 5 for a well-defined, homogeneous sample of 15,180 quasars from the Sloan Digital Sky Survey Data Release 3 (SDSS DR3) within an effective area of 1644 deg2. This sample is the most uniform statistically significant subset available for the DR3 quasar sample. It was used for the DR3 quasar luminosity function, presented by Richards et al., and is the only sample suitable for the determination of the SDSS quasar black hole mass function. The sample extends from i = 15 to i = 19.1 at -->z 3 and to i = 20.2 for -->z 3. The mass functions display a rise and fall in the space density distribution of active black holes at all epochs. Within the uncertainties the high-mass decline is consistent with a constant slope of -->? ? ? 3.3 at all epochs. This slope is similar to the bright-end slope of the luminosity function for epochs below -->z = 4. Our tests suggest that the downturn toward lower mass values is due to incompleteness of the quasar sample with respect to black hole mass. Further details and analysis of these mass functions will be presented in forthcoming papers.

The Multi-Object Double Spectrographs for the Large Binocular Telescope

The Multi-Object Double Spectrographs (MODS) are two identical high-throughput optical low- to medium-resolution CCD spectrometers being deployed at the Large Binocular Telescope (LBT). Operating in the 340-1000nm range, they use a large dichroic to split light into separately-optimized red and blue channels that feature reflective collimators and decentered Maksutov-Schmidt cameras with monolithic 8×3K CCD detectors. A parallel infrared laser closed-loop image motion compensation system nulls spectrograph flexure giving it high calibration stability. The two MODS instruments may be operated together with digital data combination as a single instrument giving the LBT an effective aperture of 11.8-meter, or separately configured to flexibly use the twin 8.4-meter apertures. This paper describes the properties and performance of the completed MODS1 instrument. MODS1 was delivered to LBT in May 2010 and is being prepared for first-light in September 2010.

A Deep Multicolor Survey. II. Initial Spectroscopy and Comparison with Expected Quasar Number Counts

We have used the KPNO 4-meter Mayall telescope to image 0.83 square degrees of sky in six fields at high galactic latitude in six filters spanning 3000-10000\AA\ to magnitude limits ranging from 22.1 to 23.8. As a first use of this database, we have conducted a multicolor survey for quasars. We discuss various methods of selecting outliers in different color-color diagrams and multicolor space that have been used to identify quasars at all redshifts from their colors alone. We discuss the initial results of our program of spectroscopic identification which has so far resulted in the identification of over forty faint quasars, including one at z

Binary nature of the B supergiant in the error box of the Vela X-ray source.

>

XMM-Newton Observations of High-Redshift Quasars*

4, a similar number of compact narrow-emission-line galaxies, and a number of unusual and potentially interesting stars. We use these spectroscopic results, along with extensive simulations of quasar spectra, to study the efficiency of our candidate selection procedures. Finally, we compare the number counts of our quasars and quasar candidates to the expected numbers based on previous studies of the quasar luminosity function. The agreement of our observations with these expectations is good in most cases. However, we do estimate that our survey contains more quasars with B

Quasars with Super-Metal-rich Emission-Line Regions

3 quasars than expected from the results of Warren, Hewett, \& Osmer (1994), both at the 3