Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 10, 2008 | Published
Journal Article Open

Formation of a Quasar Host Galaxy through a Wet Merger 1.4 Billion Years after the Big Bang

Abstract

We present high-resolution Very Large Array imaging of the molecular gas in the host galaxy of the highredshift quasar BRI 1335-0417 (z = 4.41). Our CO(J = 2 → 1) observations have a linear resolution of 0.15" (1.0 kpc) and resolve the molecular gas emission both spatially and in velocity. The molecular gas in BRI 1335-0417 is extended on scales of 5 kpc, and shows a complex structure. At least three distinct components encompassing about two-thirds of the total molecular mass of 9.2 x 10^10⊙ are identified in velocity space, which are embedded in a structure that harbors about one-third of the total molecular mass in the system. The brightest CO(J = 2 → 1) line emission region has a peak brightness temperature of 61 ± 9 K within 1 kpc diameter, which is comparable to the kinetic gas temperature as predicted from the CO line excitation. This is also comparable to the gas temperatures found in the central regions of nearby ultraluminous infrared galaxies, which are however much more compact than 1 kpc. The spatial and velocity structure of the molecular reservoir in BRI 1335-0417 is inconsistent with a simple gravitationally bound disk, but resembles a merging system. Our observations are consistent with a major, gas-rich ("wet") merger that both feeds an accreting supermassive black hole (causing the bright quasar activity), and fuels a massive starburst that builds up the stellar bulge in this galaxy. Our study of this z > 4 quasar host galaxy may thus be the most direct observational evidence that wet mergers at high redshift are related to AGN activity.

Additional Information

© 2008 The American Astronomical Society. Received 2008 July 11; accepted 2008 August 27; published 2008 September 11. We thank the anonymous referee for valuable comments that helped to improve the manuscript. D. R. acknowledges support from NASA through Hubble Fellowship grant HST-HF- 01212.01-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5- 26555, and from the Deutsche Forschungsgemeinschaft (DFG) Priority Program 1177. C. C. acknowledges support from the Max-Planck-Gesellschaft and the Alexander von Humboldt- Stiftung through the Max-Planck-Forschungspreis 2005.

Attached Files

Published - REIapjl08.pdf

Files

REIapjl08.pdf
Files (256.1 kB)
Name Size Download all
md5:44a32758a4b0d75d9c791ce4277a0e1a
256.1 kB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 17, 2023