Radio and IRAS observations of two nebulae around WO stars: G2.4+1.4 in the Galaxy and Sandage H II region 3 in IC 1613
1995; IOP Publishing; Volume: 439; Linguagem: Inglês
10.1086/175203
ISSN1538-4357
Autores Tópico(s)Galaxies: Formation, Evolution, Phenomena
Resumoview Abstract Citations (23) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Radio and IRAS Observations of Two Nebulae around WO Stars: G2.4+1.4 in the Galaxy and Sandage H II Region 3 in IC 1613 Goss, W. M. ; Lozinskaya, Titiana A. Abstract We present new VLA and IRAS observations of two H II regions around WO stars: G2.4+ 1.4 associated with WR 102 in the Galaxy and the Sandage H II region 3 around the WO star in the Local Group galaxy IC 1613. A radio image of G2.4+ 1.4 was made with a resolution of approximately 0.3 pc using the VLA at 1.49 GHz. The radio source shows a thin filamentary shell of 9 x 10 pc (wind-blown bubble) superposed on a more diffuse H II region of about 13-14 pc; the radio shell extends farther to the north and west than indicated by previous radio observations. The radio morphology is in excellent agreement with the deep Hα images. The radio source has a thermal spectrum. The mass of the ionized gas in the shell is about 100 M_sun_, and that of the diffuse H II region is about 150-170 M_sun_. IRAS FRESCO images show a prominent source G2.4+ 1.4 at all IRAS bands. The source at 60 and 100 microns agrees in shape and position with the bright part of the optical and radio shell. If we assign the IRAS flux densities to heated dust rather than atomic lines, the mass of inferred gas is in reasonable agreement with the values derived from the 1.49 GHz data. There is a large shell-like IR feature 35 pc in size with G2.4 + 1.4 and WR 102 located at its brightest and hottest edge. A thermal radio source with the flux density ~0.6 mJy has been detected from the Sandage H II region 3 around the WO star in 1C 1613. With a mean density of 3.5 cm^-3^, an emission measure of 1.1 x 10^3^ pc cm^-6^ cm, and a mass of ionized gas of 2.8 x 10^4^ M_sun_, this object is similar to many of the low-luminosity H II regions in the LMC. The WO star could be the only source of ionization. IRAS FRESCO images of the galaxy IC 1613 show a giant complex of dust and gas 2-3 kpc in size. This complex includes a region of active star formation with a supernova remnant, all known WR stars, and the majority of the giant H II regions in the galaxy. The southern component of the IR complex encompasses the WO nebula Sandage 3. Publication: The Astrophysical Journal Pub Date: February 1995 DOI: 10.1086/175203 Bibcode: 1995ApJ...439..637G Keywords: H Ii Regions; Infrared Astronomy; Interstellar Matter; Milky Way Galaxy; Radio Astronomy; Stellar Envelopes; Wolf-Rayet Stars; Data Reduction; Infrared Astronomy Satellite; Infrared Imagery; Radio Observation; Radio Spectra; Very Large Array (Vla); Astrophysics; GALAXIES: INDIVIDUAL ALPHANUMERIC: IC 1613; ISM: H II REGIONS; RADIO CONTINUUM: ISM; STARS: WOLF-RAYET full text sources ADS | data products SIMBAD (11) NED (3)
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