Mike Brotherton: HST Images of Post-Starburst Quasars Hubble Space Telescope Images of Post-Starburst Quasars: Galaxy/Black Hole Evolution in Action Mike Brotherton mbrother@uwyo.edu University of Wyoming Mobile Phone: 307-399-9524 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Mike Brotherton: HST Images of Post-Starburst Quasars Hubble images Red light images, about 120 thousand light-years on a side (10 arcseconds), of 29 post-starburst quasars, some 3.5 billion light-years away, chosen by spectral signatures of quasars and starbursts of a few hundred million years of age. Predominantly interacting systems, with nearby companions, double nuclei tidal tails, disturbances, and evidence of recent mergers (e.g., shells). Chosen from spectra. 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Spectra of Stars, Spectra of Quasars Average quasar, from Brotherton et al. (2001) Stars from Horizons by Seeds 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

A Prototype Post-Starburst Quasar Late 1990s, UN J1025-0040 (Brotherton et al. 1999, ApJ, 520, L87) About 7 billion light years distant Rare Identified by the spectrum Broad emission lines of a quasar Balmer jump feature and Balmer absorption lines from stellar population about 400 million years old and more than ten billion solar masses (the Milky Way is on order of a hundred billion solar masses) 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

A Prototype Post-Starburst Quasar Keck Observatory imaging in the near-infrared (K-band) Extended, disturbed appearance, with a companion galaxy Some shallower Hubble imaging also consistent with identifying the host galaxy as a merger product 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Significance to Galaxy Evolution Long-recognized hints of a quasar-starburst connection “M-sigma” relation, suggesting that the central black hole mass is tightly tied to the host galaxy mass and that both quantities may grow together over time Similar evolution in quasar population and universal star formation rates, with both more common in the past and less common today Detailed models and numerical simulations supporting hierarchical galaxy formation, observed properties of galaxies and black holes 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Significance to Galaxy Evolution Simplest Picture Galaxy merger (e.g., two gas-rich spirals) -> Starburst (hidden by dust) AKA luminous infrared galaxy -> black hole is fueled and ignites as quasar, blowing out dust -> quasar fades, leaving merged system, eventually a massive elliptical galaxy Post-Starburst Quasar: a transition phase known as “blow out?” 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Post-Starburst Quasars in the Sloan Digital Sky Survey About 15000 spectra measured, with 600 finally selected as post-starburst quasars. No a priori knowledge of what these objects look like in the sky. Most quasars from look like point sources (starlike) from ground-based telescopes, maybe with a little surrounding “fuzz” in high-quality images. 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Mike Brotherton: HST Images of Post-Starburst Quasars SDSS231055-090107 Sloan Digital Sky Survey Image and Spectrum 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Mike Brotherton: HST Images of Post-Starburst Quasars SDSS145658+593202 Sloan Digital Sky Survey Image and Spectrum 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Mike Brotherton: HST Images of Post-Starburst Quasars SDSS023700-010130 Sloan Digital Sky Survey Image and Spectrum 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Mike Brotherton: HST Images of Post-Starburst Quasars Hubble images Most post-starburst quasars seen to be interacting or merging systems Merged galaxies present Merging galaxies present Pre-merger systems present Galaxy Evolution Complex! Much more quantitative follow-up work to be done modeling ages, masses, etc., using many more facilities 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars

Mike Brotherton: HST Images of Post-Starburst Quasars Team Members Mike Brotherton (Wyoming) Mobile Phone: 307-399-9524 Sabrina Cales, Zhaohui Shang, Rajib Ganguly (University of Wyoming) Aleks Diamond-Stanic (Univ. of Arizona) Dan Vanden Berk (Penn State) Gabriella Canalizo (UC-Riverside) This work is supported by NASA and the National Science Foundation. 11/28/2018 Mike Brotherton: HST Images of Post-Starburst Quasars