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Astron. Astrophys. 331, 661-668 (1998)

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A multifrequency study of G182.4+4.3:
a new supernova remnant in the Galactic anti-centre

R. Kothes , E. Fürst and W. Reich

Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany

Received 30 April 1997 / Accepted 16 October 1997


A new supernova remnant (G182.4+4.3) in the Galactic anti-centre region has been detected at radio frequencies. Observations at 1400 MHz, 2675 MHz, 4850 MHz, and at 10450 MHz with the Effelsberg 100-m telescope reveal a shell structure of about 50' across. The flux density radio spectral index is [FORMULA], ([FORMULA]). The polarization percentage of the brighter part of the shell is about 40%. At 4850 MHz the polarization percentage near the peak of the shell exceeds 60%. The Faraday rotation measure varies between 0 rad m-2 and 70 rad m-2. The total flux density extrapolated to 1 GHz is [FORMULA]  Jy leading to a radio surface brightness of [FORMULA]  Watt m-2  Hz-1  sr-1. HI line observations of neutral hydrogen show that the column density towards G182.4+4.3 must be [FORMULA]  cm-2. No X-ray emission is visible in the ROSAT all-sky survey at the position of the new supernova remnant. This corresponds to an upper limit of [FORMULA]  counts s-1. Some information on the nature of G182.4+4.3 is obtained from a discussion of these observations: G182.4+4.3 is at a distance of [FORMULA]  kpc and probably expanding according to the classical Sedov equations. Assuming an initial explosion energy of [FORMULA]  erg the following parameters are obtained: [FORMULA]  cm-3, a radius of [FORMULA] pc, a swept-up mass of [FORMULA] M [FORMULA], [FORMULA]  keV, [FORMULA] years, and [FORMULA]  km s-1.

Key words: ISM: individual objects: G182.4+4.3 – ISM: supernova remnants – polarization – radio continuum: ISM

Send offprint requests to: R. Kothes

© European Southern Observatory (ESO) 1998

Online publication: February 16, 1998