The heavy elements near QSOs provide unique measures of the star formation and chemical evolution in young galactic nuclei or pre-galactic condensations. Studies of quasar abundances also naturally address a variety of questions regarding the physics of QSO environments, including the Baldwin Effect emphasized at this meeting. Here I review the status of quasar abundance work.

Citation: Schmidt TM, Worseck G, Hennawi JF, Prochaska JX, Crighton NHM, Lukić Z and Oñorbe J (2017) Statistical Detection of the He II Transverse Proximity Effect: Evidence for Sustained Quasar Activity for >25 Million Years. Front. Astron. Space Sci. 4:23. doi: 10.3389/fspas.2017.00023 Statistical Detection of the He II Transverse Proximity Effect: Evidence for Sustained Quasar Activity for >...

Quasars signal a unique phase of galaxy evolution – when massive spheroids are rapidly being assembled, forming stars and growing their central super-massive black holes. Measurements of the metal abundances around quasars provide unique information about these complex evolutionary processes. Here we provide a brief review of the current status and implications of quasar abundance research. The...

The results of an X-ray observation of the nearby core-dominated, super-luminal quasar 4C +73.18 (1928+738) with ASCA are reported. Variations of the 1–10 keV flux on time-scales of the order of 10 hours were found while the 0.5– 1 keV flux remained almost unchanged. The measured flux at 1 keV had increased by ∼ 50% compared with previous observations 18 years ago. The quasar shows a curved spe...

We develop a model for the cosmological role of mergers in the evolution of starbursts, quasars, and spheroidal galaxies. By combining theoretically well-constrained halo and subhalo mass functions as a function of redshift and environment with empirical halo occupation models, we can estimate where galaxies of given properties live at a particular epoch. This allows us to calculate, in an a pr...