Hubble Space Telescope Images of Post-Starburst Quasars: Galaxy/Black Hole Evolution in Action

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

2. 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. Mike Brotherton: HST Images of Post-Starburst Quasars

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

4. 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) Mike Brotherton: HST Images of Post-Starburst Quasars

5. 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 Mike Brotherton: HST Images of Post-Starburst Quasars

6. 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 Mike Brotherton: HST Images of Post-Starburst Quasars

7. 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?” Mike Brotherton: HST Images of Post-Starburst Quasars

8. 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. Mike Brotherton: HST Images of Post-Starburst Quasars

9. SDSS231055-090107 Sloan Digital Sky Survey Image and Spectrum Mike Brotherton: HST Images of Post-Starburst Quasars

10. SDSS145658+593202 Sloan Digital Sky Survey Image and Spectrum Mike Brotherton: HST Images of Post-Starburst Quasars

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

12. 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 Mike Brotherton: HST Images of Post-Starburst Quasars

13. 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. Mike Brotherton: HST Images of Post-Starburst Quasars