Red Quasars and Quasar/Galaxy Evolution

University Of California-Riverside, Riverside CA

Investigators

Abstract

Part 1 Quasars are mysterious astronomical objects. They are brighter than 100 billion stars like our Sun, but so far away that they appear very faint in our nighttime sky. We study them with large telescopes, like the ones at the Keck Observatory on the summit of Mauna Kea in Hawaii. Measurements like that show that quasars are very massive black holes surrounded by hot gas that is being pulled into the black hole by the hole's enormous gravity. The gas falling into the black hole goes faster and faster the closer it gets. This produces extreme heat that makes the gas around the black hole glow brighter than an entire galaxy full of stars. The black hole surrounded by bright glowing gas is what we call a quasar. They live in the centers of all large galaxies like our Milky Way, but only at certain early times in a galaxy's life when there is a lot of gas available to fall into the black hole. Some of the gas trying to fall into the black hole is, instead, ejected at high speeds due to the intense heat and radiation. This produces a powerful wind that spreads across the galaxy. This project will study a particular group of quasars that appear to be very young and very bright, with extremely powerful winds that might alter the growth and development of the galaxies around them. Project goals are to understand how the powerful winds from quasars are created, and then study the effects those winds have on the surrounding galaxies. Another important goal is to turn the data obtained for this project into music that will be used for science education and outreach in our local communities. Part 2 Quasars are distant signposts that mark important episodes in the growth and development of large galaxies. Quasars produce the light energy of a 100 billion Suns due to matter heating up as it falls into a massive black hole. They deep inside young galaxies that are, themselves, gaining mass from their surroundings and rapidly making stars. Quasars with red colors caused by dust obscuration (similar to red sunsets) are believed to identify a critical transition phase in galaxy formation between the initial dusty "burst" of star formation and the eventual emergence of normal blue (unobscured) quasars. Powerful outflows driven by the quasars and/or the accompanying starbursts are thought to be critically important during this transition phase, providing "feedback" to the surroundings that regulates the amounts of black hole accretion, disrupts star formation in the surrounding galaxy, and expels much of the host galaxy's gas and dust. This project describes a 3-year program to 1) study red quasars and quasar outflows/feedback to test the evolutionary links between quasars and galaxy formation, and 2) pursue an exciting new avenue of public outreach based on the sonification of astronomical data. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.