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Astron. Astrophys. 323, 585-592 (1997)

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The X-ray shadow in the south-east of the Large Magellanic Cloud

M.J. , Blondiau , J. , Kerp , U. , Mebold , U. and Klein

Radioastronomisches Institut der Universität Bonn, Auf dem Hügel 71, D- 53121 Bonn, Germany

Received 30 January 1996 / Accepted 6 January 1997


We analyze mosaiked ROSAT PSPC pointings towards the Large Magellanic Cloud (LMC). Focussing on the area south-east of 30 Doradus roughly at the position of RA(2000) = [FORMULA] and DEC(2000) = - [FORMULA], we verify the existence of an X-ray absorption feature. The ROSAT data imply that X-ray attenuating material is located in front of a diffuse X-ray source that extends from the eastern boundary of the LMC to west of the giant molecular cloud south of 30 Dor. The difference of the absorbing hydrogen column densities, derived from the ROSAT data, between the X-ray bright "wedge" region and dark "shadow" region is about [FORMULA]. This column density difference is consistent with the value derived from IRAS 100 [FORMULA] m emission map of this region which leads to total hydrogen column densities of [FORMULA] towards the X-ray bright and [FORMULA] towards the X-ray dark regions. The agreement between these values derived from the ROSAT and IRAS data suggest that a part of the extended diffuse X-ray emission is located on the far side of the giant molecular cloud.

This kind of 3-D structure is independently verified by radio continuum observations. The X-ray attenuating gas is positionally associated with the polarized radio continuum emission of a giant magnetic loop emerging out of the plane of the LMC. Faraday depolarization implies that this magnetized loop penetrates deep into - or beyond - the LMC, possibly commencing in the X-ray emitting plasma of the LMC.

Key words: galaxies: ISM; Magellanic Clouds – ISM: structure – X-rays: ISM – diffuse radiation

Send offprint requests to: M.J. Blondiau

© European Southern Observatory (ESO) 1997

Online publication: June 5, 1998