# KU Physics & Astronomy LOcally Organized Assembly (PALOOZA) meeting 2020-2021

Feb 23 – 26, 2021
Zoom Passcode: 990417
America/Chicago timezone

## Merger Signatures in Cold Quasars

Feb 26, 2021, 6:05 PM
10m
Zoom Link: https://kansas.zoom.us/j/92389769214 (Zoom Passcode: 990417)

#### Zoom Passcode: 990417

Zoom Link: https://kansas.zoom.us/j/92389769214 Zoom Passcode: 990417 Zoom Meeting ID: 923 8976 9214

### Speaker

Casey Carlile (University of Kansas)

### Description

Cold Quasars ($\rm L_x > 10^{44}$ erg/s, $\rm S_{250} > 30$ mJy) are a recently discovered, extremely rare galaxy. They are luminous in both the X-ray and infrared wavelengths and can have up to seven times as much star formation as normal quasars. They are predicted to be a step in the progression between the starburst galaxies that have undergone a recent galaxy merger and blue, unobscured quasars. However, they mainly look like blue point sources in Sloan Digital Sky Survey imaging. In order to test whether Cold Quasars are produced by mergers, we examine the deep images from the Hyper Suprime-Cam of the Subaru Telescope. We fit multiple models using GALFIT to look for double nuclei or asymmetrical residuals. We find that Cold Quasars are more asymmetrical than a control sample of unobscured, blue quasars, supporting a scenario in which the Cold Quasar phase occurs at the very end of a merger, directly preceding blow out and quenching.

Type of contribution Oral contribution (10 minutes)

### Primary authors

Casey Carlile (University of Kansas) Dr Allison Kirkpatrick (University of Kansas) Dr Eilat Glikman (Middlebury College)

### Presentation materials

There are no materials yet.