2006/04/19 by M. Macháček, M. Machacek, P. E. J. Nulsen +3 · 6 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.1086/505963
published as Astrophys.J.648:947-955,2006 · second part (sec. 4) of astroph/0508588v1 with expanded intro and discussion; 16 pages, 8 figs., ApJ, submitted
arxiv created 2006/04/19 · openalex publication_date 2006/09/08 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
We use a 54.4 ks Chandra observation to study nuclear outflow activity in NGC 4552 (M89), an elliptical galaxy in the Virgo Cluster. Chandra images in the 0.5-2 keV band show two ringlike features ~1.7 kpc in diameter in the core of NGC 4552, as reported previously by Filho et al. We use spherically symmetric point explosion shock models to argue that the shape of the surface brightness profile across the rims of the rings and the temperature of hot gas in the rings are consistent with a Mach 1.7 shock carrying mean mechanical power L shock ~ 3 × 10 41 ergs s -1 produced by a ~1.4 × 10 55 ergs nuclear outburst ~1-2 Myr ago. We find the gas temperature in the central ~100 pc of the galaxy to be 1.0 ± 0.2 keV, hotter than elsewhere in the galaxy, suggesting that we may be directly observing the reheating of the galaxy ISM by the outburst.