2009/03/18 by P. Boumis, E. M. Xilouris, J. Alikakos +5
Chemistry · Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Chemistry #Doubly ionized oxygen #Emission spectrum #Flux (metallurgy) #Galaxy #Gamma-ray bursts and supernovae #Interstellar medium #Physics #Spectral line #Supernova #Supernova remnant #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.1051/0004-6361/200811474
12 pages, 6 figures, accepted for publication in A&A
arxiv created 2009/03/18 · openalex publication_date 2009/04/08 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Deep optical CCD images of the supernova remnant G 32.8-0.1 were obtained where filamentary and diffuse emission was discovered. The images were acquired in the emission lines of H<i>α<i/>+[ N ii] and [S ii]. Filamentary and diffuse structures are detected in most areas of the remnant, while no significant [O iii] emission is present. The flux-calibrated images suggest that the optical emission originates from shock-heated gas since the [S ii]/H<i>α<i/> ratio is greater than 1.2. The Spitzer images at 8 <i>μ<i/>m and 24 <i>μ<i/>m show a few filamentary structures to be correlated with the optical filaments, while the radio emission at 1.4 GHz in the same area is found to be very well correlated with the brightest optical filaments. The results from deep long-slit spectra also support the origin of the emission being from shock-heated gas ([S ii]/H<i>α<i/> > 1.5). The absence of [O iii] emission indicates slow shock velocities into the interstellar clouds” (<i>≤<i/>100 km s<sup>-1<sup/>), while the [S ii]6716/6731 ratio indicates electron densities up to ~200 cm<sup>-3<sup/>. The H<i>α<i/> emission is measured to lie between 1.8 to 4.6 10<sup>-17<sup/> erg s<sup>-1<sup/> cm<sup>-2<sup/> arcsec<sup>-2<sup/>, while from VGPS Hi images the distance to the SNR is estimated to be between 6 to 8.5 kpc.