Starburst-driven Superwinds in Quasar Host Galaxies

Abstract

During five decades astronomers have been puzzled by the presence of strong absorption features including metal lines, observed in the optical and ultraviolet spectra of quasars, signalling in-and outflowing gas winds with relative velocities up to several thousands of km/sec. In particular the location of these winds -close to the quasar, further out in its host galaxy, or in its direct environment -and the possible impact on their surroundings have been issues of intense discussion and uncertainty. Using our Herschel Space Observatory 1 data, we report a tendency for this so-called associated metal absorption to occur along with prodigious star formation in the quasar host galaxy, indicating that the two phenomena are likely to be interrelated, that the gas winds likely occur on the kiloparsec scale and would then have a strong impact on the interstellar medium of the galaxy. This correlation moreover would imply that the unusually high cold dust luminosities in these quasars are connected with ongoing star formation. Given that we find no correlation with the AGN strength, the wind feedback which we establish in these radio-loud objects is most likely associated with their host star formation rather than with their black hole accretion.

Placing LOFAR-detected quasars in C iv emission space: implications for winds, jets and star formation

“…Stone & Richards (2019) investigated instead the narrow C IV absorbers associated with the quasar and found them to be as common in radio-quiet quasars as they are in radio-loud quasars, suggesting that whatever physics governs the associated absorbers -whether they are evidence of a failed accretion disc wind (e.g. Vestergaard 2003) or winds from star formation on kiloparsec scales (Barthel et al 2017) -it is unrelated, at least directly, to the radio emission (see also Chen et al 2020, who found no correlation between the number of absorbers in quasar spectra and radio-loudness).…”

Narrow, intrinsic C iv absorption in quasars as it relates to outflows, orientation, and radio properties

“…They range from momentum-and energy-driven winds (e.g., King 2010;Zubovas & Nayakshin 2014), to radiation line driving (Murray et al 1995, hereafter MCGV95;Proga et al 2000), to radiation pressure on dust (Thompson et al 2005;Keating et al 2012). To explain some (broad) absorption systems at large distances Faucher- rely on 'in situ' radiative shocks in contrast to MCGV95 winds that may be more common for absorbers at smaller distances; see also Barthel et al (2017). Broad reviews of the subject of AGN outflows/feedback can be found in Silk & Rees (1998); Fabian (1999); Begelman (2004); King & Pounds (2015).…”

A Spatially Resolved Survey of Distant Quasar Host Galaxies. II. Photoionization and Kinematics of the ISM

“…All quoted luminosity values are reported in Table 3. Star formation rates derived from Hα (Vayner et al 2021) and when available from total infrared emission (Barthel et al 2017;Podigachoski et al 2015) are presented in Table 3.…”

“…One approach to calculating the bolometric stellar luminosity is simply to use the integrated infrared luminosity from 8-1000 µm measured by fitting the mid to far Barthel et al (2017). Only the SEDs for 3C298, 4C04.81, 4C09.17 and 3C318 contain points with significant detections at wavelengths from the mid-infrared to submm.…”