We present results of rst epoch high resolution imaging observations of four extremely distant quasars. The sample includes the only two radio-loud quasars at redshift z > 4 known to the date of observa-The milliarcsecond scale structures of these quasars are dominated by compact cores. The two z > 4 quasars are unresolved on the baselines observed. We show that the apparently less prominent mi...

The results of a sub-millimeter survey of SDSS broad C iv absorption line quasars is discussed. It is found that the sub-millimeter flux distribution of BAL quasars is similar to that of non-BAL quasars. This is consistent with the idea that all quasars contain broad absorption line regions, but only a fraction of them are visible along our line-of-sight. The observations are inconsistent with ...

We have compiled the largest sample of multiwavelength spectral energy distributions (SEDs) of Broad Absorption Line (BAL) quasars to date, from the radio to the X-ray. We present new Spitzer MIPS (24, 70, and 160μm) observations of 38 BAL quasars in addition to data from the literature and public archives. In general, the mid-infrared properties of BAL quasars are consistent with those of non-...

Using the 2MASS Second Incremental Data Release, we have searched for near infrared counterparts to 13214 quasars from the Veron-Cetty & Veron (2000) catalog. We have detected counterparts within 4 for 2277 of the approximately 6320 quasars within the area covered by the 2MASS Second Incremental Data Release. Only 1.6% of these are expected to be chance coincidences. Though this sample is heter...

Quasars continue to be the most luminous objects known in the universe but no longer have the largest redshifts. I review current techniques for finding quasars at z > 5 and the status of current optical surveys. I compare the spectra of known quasars with z ≈ 5 with the spectra of some recently discovered galaxies with z > 5 to see what we may expect in the future from surveys for high redshif...

Measurements ~t 1.2, 1.~, and 2.2 μm have been combined with visual spectrophotometry o~ 21 quasai:s havmg. redshifts z ;:;: 2.66. T~e primary result of this study is that the rest frame vism~.l/ultravIC?let contmua of the high-redshift quasars are well described by a sum of a power-law contmuum with slope -.-0.~ ~nd a 3000 A bump. The rest frame visual/ultraviolet continua of these quasars are...

We explore the relationship between the extended radio and line emission for a radioloud quasar sample including both core-dominated and lobe-dominated quasars. A strong correlation is present between the extended radio and broad-line emission. The core emission is also correlated with the broad-line emission for core-dominated quasars in the sample. The statistic behaviour on the core emission...

The detection of resonance absorption lines against known objects such as individual galaxies and clusters of galaxies is a powerful approach for studying the gas content of these systems. We describe an e cient method of identifying background quasars suitable for absorption line studies. In this nding technique, we identify serendipitous X-ray sources, about 1/8 of which are suitably bright q...

We report on a search for X-ray emission from quasars with redshifts greater than 4 using the ROSAT public database. Our search has doubled the number of z[ 4 quasars detected in X-rays from six to 12. Most of those known prior to this work were radio-loud and X-rayÈselected sources ; our study increases the number of X-rayÈdetected, optically selected z[ 4 quasars from one to seven. We present...

The detection of resonance absorption lines against known objects such as individual galaxies and clusters of galaxies is a powerful approach for studying the gas content of these systems. We describe an efficient method of identifying background quasars suitable for absorption line studies. In this finding technique, we identify serendipitous X-ray sources, about 1/8 of which are suitably brig...