3rd (and hopefully final) submitted version (first version had a different filename) Assigned ID: 57 ----- Submission 1 (Thu Jan 20 03:44:23 GMT 2005) ----- Phase I Proposal 57 (BHmassAccuracy_jan19_final_submitted) successfully submitted. ----- Submission 3 (Thu Jan 20 19:36:27 GMT 2005) ----- Phase I Proposal 57 (BHmassAccuracy_jan20_final_submitted) successfully submitted. ----- Submission 4 (Thu Jan 20 19:46:54 GMT 2005) ----- We propose to quantify the accuracy to which black hole masses in high-redshift quasars can be estimated by using single-epoch spectra and scaling relationships that relate broad-line region size to luminosity. This study will be based on the large existing databases of UV and optical HST spectra and ground-based optical spectra from previous monitoring programs on the 36 active galactic nuclei with reverberation-based black hole mass measurements. Scaling relationships based on reverberation results can be and are already being used to estimate black hole masses at high redshift, as they are easy to use and it is the only method of mass estimation that is at present straightforwardly extendable to large samples of distant, luminous quasars. Knowledge of the efficacy, accuracy, and limitations of the methods used to estimate black hole masses at high-z is crucial to our quest to advance our understanding of structure growth and evolution in the early Universe. This study will also address the systematic errors that can be encountered when applying this methodology to narrow-line Seyfert 1 galaxies. We will consider in detail the slope of the radius-luminosity relationship for the C IV emission line in light of recent HST evidence that the slope of this relationship differs from that of the radius-luminosity relationship for the Balmer lines.

AGN/QUASARS 12 91759.00 false 0.0 false false false false false SUPPORTED