| 1. |
- Hernandez, Olivier, et al.
(author)
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GHαFaS: Galaxy Hα Fabry-Perot System for the William Herschel Telescope
- 2008
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In: Publications of the Astronomical Society of the Pacific: PASP. - : IOP Publishing. - 0004-6280 .- 1538-3873. ; 120, s. 15-
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Journal article (pop. science, debate, etc.)abstract
- GHαFaS, a new Fabry-Perot system, is now available at the William Herschel Telescope (WHT). It was mounted, for the first time, at the Nasmyth focus of the 4.2-m WHT on La Palma in 2007 July. Using modern technology, with a spectral resolution of the order R˜15,000, and with a seeing-limited spatial resolution, GHαFaS will provide a new look at the Hα-emitting gas over a 4.8' circular field in the nearby universe. Many science programs can be done on a 4.2-m class telescope in world-class seeing conditions with a scanning Fabry-Perot. Not only galaxies but H II regions, planetary nebulae, supernova remnants, and the diffuse interstellar medium are subjects for which unique data can be aquired rapidly. Astronomers from the Laboratoire d'Astrophysique Expérimentale (LAE) in Montréal, the Laboratoire d'Astrophysique de Marseille (LAM-OAMP), and the Instituto de Astrofísica de Canarias (IAC), have inaugurated GHαFaS by studying in detail the dynamics of some nearby spiral galaxies. A robust set of state-of-the-art tools for reducing and analyzing the data cubes obtained with GHαFaS has also been developed.
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| 2. |
- Long, Knox S., et al.
(author)
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Supernova Remnants in M83 as Observed with MUSE
- 2022
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In: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 929:2
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Journal article (peer-reviewed)abstract
- Here we describe a new study of the supernova remnants (SNRs) and SNR candidates in nearby face-on spiral galaxy M83, based primarily on MUSE integral field spectroscopy. Our revised catalog of SNR candidates in M83 has 366 objects, 81 of which are reported here for the first time. Of these, 229 lie within the MUSE observation region, 160 of which have spectra with [S ii]:Hα ratios exceeding 0.4, the value generally accepted as confirmation that an emission nebula is shock-heated. Combined with 51 SNR candidates outside the MUSE region with high [S ii]:Hα ratios, there are 211 spectroscopically confirmed SNRs in M83, the largest number of confirmed SNRs in any external galaxy. MUSE's combination of relatively high spectral resolution and broad wavelength coverage has allowed us to explore two other properties of SNRs that could serve as the basis of future SNR searches. Specifically, most of the objects identified as SNRs on the basis of [S ii]:Hα ratios exhibit more velocity broadening and lower ratios of [S iii]:[S ii] emission than H ii regions. A search for nebulae with the very broad emission lines expected from young, rapidly expanding remnants revealed none, except for the previously identified B12-174a. The SNRs identified in M83 are, with few exceptions, middle-aged interstellar medium (ISM) dominated ones. Smaller-diameter candidates show a larger range of velocity broadening and a larger range of gas densities than the larger-diameter objects, as expected if the SNRs expanding into denser gas brighten and then fade from view at smaller diameters than those expanding into a more tenuous ISM.
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