A search for soft X-ray emission associated with prominent high-velocity-cloud complexes

Simple item page
dc.creatorKerp, J.
dc.creatorBurton, W. B.
dc.creatorEgger, R.
dc.creatorFreyberg, M. J.
dc.creatorHartmann, Dap
dc.creatorKalberla, P. M. W.
dc.creatorMebold, U.
dc.creatorPietz, J.
dc.date1998-10-20
dc.date.accessioned2026-07-07T02:28:29Z
dc.date.available2026-07-07T02:28:29Z
dc.descriptionWe correlate the ROSAT 1/4 keV all-sky survey with the Leiden/Dwingeloo HI survey, looking for soft X-ray signatures of prominent high-velocity-cloud (HVC) complexes. We study the transfer of 1/4 keV photons through the interstellar medium in order to distinguish variations in the soft X-ray background (SXRB) intensity caused by photoelectric absorption effects from those due to excess X-ray emission. The X-ray data are modelled as a combination of emission from the Local Hot Bubble (LHB) and emission from a distant plasma in the galactic halo and extragalactic sources. The X-ray radiation intensity of the galactic halo and extragalactic X-ray background is modulated by the photoelectric absorption of the intervening galactic interstellar matter. We show that large- and small-scale intensity variations of the 1/4 keV SXRB are caused by photoelectric absorption which is predominantly traced by the total N(HI) distribution. The extensive coverage of the two surveys supports evidence for a hot, X-ray emitting corona. We show that this leads to a good representation of the SXRB observations. For four large areas on the sky, we search for regions where the modelled and observed X-ray emission differ. We find that there is excess X-ray emission towards regions near HVC complexes C, D, and GCN. We suggest that the excess X-ray emission is positionally correlated with the high-velocity clouds. Some lines of sight towards HVCs also pass through significant amounts of intermediate-velocity gas, so we cannot constrain the possible role played by IVC gas in these directions of HVC and IVC overlap, in determining the X-ray excesses.
dc.description16 pages, 8 figures, accepted for publication in Astronomy & Astrophysics main journal
dc.identifierhttps://arxiv.org/abs/astro-ph/9810307
dc.identifierhttp://arxiv.org/abs/astro-ph/9810307
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/13142
dc.subjectAstrophysics
dc.titleA search for soft X-ray emission associated with prominent high-velocity-cloud complexes
dc.typetext

Files

Collections

arXiv