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Title: EXTENDED X-RAY EMISSION IN THE H I CAVITY OF NGC 4151: GALAXY-SCALE ACTIVE GALACTIC NUCLEUS FEEDBACK?

Journal Article · · Astrophysical Journal Letters
; ; ; ;  [1];  [2]; ;  [3]
  1. Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)
  2. Astrophysics Research Institute, Liverpool John Moores University, Birkenhead CH41 1LD (United Kingdom)
  3. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)

We present the Chandra discovery of soft diffuse X-ray emission in NGC 4151 (L{sub 0.5-2 keV} {approx} 10{sup 39} erg s{sup -1}), extending {approx}2 kpc from the active nucleus and filling in the cavity of the H I material. The best fit to the X-ray spectrum requires either a kT {approx} 0.25 keV thermal plasma or a photoionized component. In the thermal scenario, hot gas heated by the nuclear outflow would be confined by the thermal pressure of the H I gas and the dynamic pressure of inflowing neutral material in the galactic disk. In the case of photoionization, the nucleus must have experienced an Eddington limit outburst. For both scenarios, the active galactic nucleus (AGN)-host interaction in NGC 4151 must have occurred relatively recently (some 10{sup 4} yr ago). This very short timescale to the last episode of high activity phase may imply such outbursts occupy {approx_gt}1% of AGN lifetime.

OSTI ID:
21450954
Journal Information:
Astrophysical Journal Letters, Vol. 719, Issue 2; Other Information: DOI: 10.1088/2041-8205/719/2/L208; ISSN 2041-8205
Country of Publication:
United States
Language:
English