2011/01/25 by Poshak Gandhi, P. Gandhi, N. Isobe +11 · 2 citations
Physics and Astronomy · #Angular resolution (graph drawing) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #H II region #Infrared #Physics #Spectral line #Spectrograph #Star formation #Subaru Telescope #Supernova #Supernova remnant #astro-ph.GA
paper · pdf · doi:10.1093/pasj/63.sp2.s505
Accepted for publication in PASJ Subaru special issue. High resolution version available temporarily at http://www.astro.isas.jaxa.jp/~pgandhi/pgandhi_m82.pdf
arxiv created 2011/01/25 · openalex publication_date 2011/03/25 · arxiv updated 2015/05/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We present new imaging at 12.81 and 11.7 μm of the central ∼ 40”× 30” (∼ 0.7 kpc × 0.5 kpc) of the starburst galaxy M 82. The observations were carried out with the COMICS mid-infrared (mid-IR) imager on the 8.2 m Subaru Telescope, and are diffraction-limited at an angular resolution of \lt0″4. The images show extensive diffuse structures, including a 7-long linear chimneylike feature and another resembling the edges of a ruptured bubble. This is the clearest view to date of the base of the kpc-scale dusty wind known in this galaxy. These structures do not trace back to a single central point, implying multiple ejection sites for the dust. In general, the distribution of dust probed in the mid-IR anticorrelates with the locations of massive star clusters that appear in the near-infrared. The 10–21 μm mid-IR emission, spatially integrated over the field of view, may be represented by hot dust with temperature of ∼ 160 K. Most discrete sources are found to have extended morphologies. Several radio H II regions are identified for the first time in the mid-IR. The only potential radio supernova remnant to have a mid-IR counterpart is a source which has previously also been suggested to be a weak active galactic nucleus. This source has an X-ray counterpart in Chandra data which appears prominently above 3 keV and is best described as a hot (∼ 2.6 keV) absorbed thermal plasma with a 6.7 keV Fe K emission line, in addition to a weaker and cooler thermal component. The mid-IR detection is consistent with the presence of strong [NeII]λ12.81 μm line emission. The broad-band source properties are complex, but the X-ray spectra do not support the active galactic nucleus hypothesis. We discuss possible interpretations regarding the nature of this source.