1999A&A...342..213K


Query : 1999A&A...342..213K

1999A&A...342..213K - Astronomy and Astrophysics, volume 342, 213-232 (1999/2-1)

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

KERP J., BURTON W.B., EGGER R., FREYBERG M.J., HARTMANN D., KALBERLA P.M.W., MEBOLD U. and PIETZ J.

Abstract (from CDS):

We 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 NHI 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.

Abstract Copyright:

Journal keyword(s): ISM: clouds - Galaxy: halo - Galaxy: kinematics and dynamics - X-rays: ISM

CDS comments: p. 223: velocity bridges = [PKK96] VB 112+48, 115+47, 112+57.5

Simbad objects: 14

goto View the references in ADS

Number of rows : 14
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 NAME HVC Complex A HVC 08 36 +64.4           ~ 124 0
2 HVC 212+24+89 HVC 10 07.3 -12 16           ~ 16 0
3 HVC 263+27+153 HVC 10 16.6 -23 43           ~ 4 1
4 HVC 267+26+217 HVC 10 28.1 -26 41           ~ 7 0
5 NAME HVC Complex M HVC 10 48.2 +48 00           ~ 74 0
6 WV 66 Cld 10 51 -07.5           ~ 2 0
7 [PKK96] VB 112+57.5 ? 13 37 +59.0           ~ 2 0
8 [PKK96] VB 115+47 ? 13 53 +69.0           ~ 2 0
9 [PKK96] VB 112+48 ? 14 09 +67.0           ~ 2 0
10 NAME HVC Complex C HVC 16 34.8 +63 07           ~ 240 1
11 LVC 088.7+36.5-2 Cld 17 05 04.7 +59 37 12           ~ 10 0
12 [H68] D HVC 18 29.9 +54 10           ~ 6 0
13 NAME GCN Complex HVC 19 32 -14.           ~ 14 0
14 Mrk 509 Sy1 20 44 09.7504483224 -10 43 24.727155528   13.35 13.12 10.7   ~ 1197 0

To bookmark this query, right click on this link: simbad:objects in 1999A&A...342..213K and select 'bookmark this link' or equivalent in the popup menu


2022.05.21-03:00:12

© Université de Strasbourg/CNRS

    • Contact