OBSERVATIONAL EVIDENCE FOR ACTIVE GALACTIC NUCLEI FEEDBACK AT THE PARSEC SCALE

Journal Article · Wed Aug 10 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/737/1/23· OSTI ID:21579982

Feng, Yuan

In a hot accretion flow, the radiation from the innermost region of the flow propagates outward and heats the electrons at large radii via Compton scattering. It has been shown in previous works that if the radiation is strong enough, L {approx}> 2%L{sub Edd}, the electrons at the Bondi radius (r{sub B} {approx} 10{sup 5} r{sub s} ) will be heated to above the virial temperature; thus, the accretion will be stopped. The accretion will recover after the gas cools down. This results in the oscillation of the black hole activity. In this paper, we show that this mechanism is the origin of the intermittent activity of some compact young radio sources. Such intermittency is required to explain the population of these sources. We calculate the timescales of the black hole oscillation and find that the durations of active and inactive phases are 3 x 10{sup 4}(0.1/{alpha})(M/10{sup 8} M{sub sun})(L/2%L{sub Edd}){sup -1/2} yr and 10{sup 5}({alpha}/0.1)(M/10{sup 8} M{sub sun}) yr, respectively, consistent with those required to explain observations. Such feedback occurring at the parsec scale should be common in low-luminosity active galactic nuclei and should be considered when we consider their matter and energy output.

• OSTI ID: 21579982
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 737; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
BLACK HOLES
FEEDBACK
GALAXY NUCLEI
OSCILLATIONS