Quasar host galaxies revealed by eclipsing damped Lyman alpha systems

حسن فتحی واوسری (پژوهشکده نجوم پژوهشگاه دانش های بنیادی IPM)

Abstract:  Damped Lyman alpha absorption systems (DLAs) with the same redshift as their background quasars, can act as natural coronagraphs, blocking the blazing radiation from the broad line region (BLR) of the quasar, and as a result revealing to us the much fainter emission from the quasar host galaxy. This constitutes a new way to have direct access to the quasar host galaxy, and possibly to the very center of the active galactic nucleus (AGN). We searched the SDSS database and found ~ 200 such eclipsing DLAs that exhibit narrow Lyman-alpha emission in their DLA troughs. We obtained high-resolution echelle spectra of six of these systems using the MagE spectrograph. Remarkably, the 2-dimentional spectra of all these systems reveal that the narrow Lyman-alpha emission in the DLA trough are also spatially extended. In this seminar, I will present the results of our study of these extended Lyman-alpha emission and their eclipsing DLAs.

یکشنبه 3 اردیبهشت ماه 1396، ساعت 15:00

دانشکده فیزیک، طبقه اول کلاس فیزیک 3