Locating Star-Forming Regions in Quasar Host Galaxies

Abstract

We present a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope. Our observations are motivated by recent evidence for a close relationship between black hole growth and the stellar mass evolution in its host galaxy. We use narrow-band [O II] $\lambda$3727, H$\beta$, [O III] $\lambda$5007 and Pa$\alpha$ images, taken with the WFPC2 and NICMOS instruments, to map the morphology of line-emitting regions, and, after extinction corrections, diagnose the excitation mechanism and infer star-formation rates. Significant challenges in this type of work are the separation of the quasar light from the stellar continuum and the quasar-excited gas from the star-forming regions. To this end, we present a novel technique for image decomposition and subtraction of quasar light. Our primary result is the detection of extended line-emitting regions with sizes ranging from 0.5 to 5 kpc and distributed symmetrically around the nucleus, powered primarily by star formation. We determine star-formation rates of order a few tens of M${}_{\odot }$/yr. The host galaxies of our target quasars have stellar masses of order $10^{11}$ M${}_{\odot }$ and specific star formation rates on a par with those of M82 and luminous infrared galaxies. As such they fall at the upper envelope or just above the star-formation mass sequence in the specific star formation vs stellar mass diagram. We see a clear trend of increasing star formation rate with quasar luminosity, reinforcing the link between the growth of the stellar mass of the host and the black hole mass found by other authors.

Accepted for publication in M.N.R.A.S

References in corpus (15)

• The Host Galaxies and Classification of Active Galactic Nuclei
• The GALEX Ultraviolet Atlas of Nearby Galaxies
• From rings to bulges: evidence for rapid secular galaxy evolution at z~2 from integral field spectroscopy in the SINS survey
• Massive molecular outflows and negative feedback in ULIRGs observed by Herschel-PACS
• The effect of galaxy mass ratio on merger--driven starbursts
• A Close Look at Star Formation around Active Galactic Nuclei
• The bulk of the black hole growth since z~1 occurs in a secular universe: No major merger-AGN connection
• Spitzer Quasar and ULIRG Evolution Study (QUEST): II. The Spectral Energy Distributions of Palomar-Green Quasars
• Spitzer Quasar and ULIRG evolution study (QUEST): I. The origin of the far infrared continuum of QSOs
• The suppression of star formation by powerful active galactic nuclei
• Star formation in the hosts of high-z QSOs: Evidence from Spitzer PAH detections
• The Mid-infrared Fine-structure Lines of Neon as an Indicator of Star For mation Rate in Galaxies
• Hubble Space Telescope H-Band Imaging Survey of Massive Gas-Rich Mergers
• Host dynamics and origin of Palomar-Green QSOs
• The Properties of Post-Starburst Quasars Based on Optical Spectroscopy

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• Extreme star formation events in quasar hosts over $0.5<\text{z}<4$
• AGN Feedback in SDSS-IV MaNGA: AGNs have Suppressed Central Star Formation Rates
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• Star Formation and AGN Feedback in the Local Universe: Combining LOFAR and MaNGA
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• Comparing narrow and broad-line AGNs, in a new diagnostic diagram for emission-line galaxies based on WISE data
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• Lack of Correlations between Cold Molecular Gas and AGN Properties in Type 1 AGNs at $z\lesssim 0.5$
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