2010/07/26 by Junfeng Wang, G. Fabbiano, Giuseppina Fabbiano +11 · 40 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Ion #Ionization #Nucleus #Outflow #Photoionization #Physics #Thermal #astro-ph.CO #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.1088/2041-8205/719/2/l208
published in The Astrophysical Journal Letters 719(2), L208-L212 (IOP Publishing) · 6 pages, 3 figures, accepted for publication in the ApJ Letters
arxiv created 2010/07/26 · openalex publication_date 2010/08/04 · arxiv updated 2015/05/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the Chandra discovery of soft diffuse X-ray emission in NGC 4151 ( L 0.5–2 keV ∼ 10 39 erg s −1 ), extending ∼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 ∼ 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 4 yr ago). This very short timescale to the last episode of high activity phase may imply such outbursts occupy ≳1% of AGN lifetime.