Astronomy and Astrophysics – Astrophysics
Scientific paper
1996-11-14
Astronomy and Astrophysics
Astrophysics
27 pages, 22 figures, Latex. Full resolution PostScript available at ftp://cdsarc.u-strasbg.fr/pub/xray/rgps_cygnus.ps.gz To b
Scientific paper
We present the analysis of the point source content of a low galactic latitude region selected from the ROSAT all-sky survey. The test field is centered at l = 90deg, b = 0deg and has an area of 64.5 deg2. A total of 128 soft X-ray sources are detected above a maximum likelihood of 8. Catalogue searches and optical follow-up observations show that in this direction of the galactic plane, 85% of the sources brighter than 0.03 PSPC cts/s are identified with active coronae. F-K type stars represent 67% (+/-13%) of the stellar identifications and M type stars account for 19% (+/- 6%). These results together with those of similar optical campaigns demonstrate that the soft X-ray population of the Milky Way is largely dominated by active stars. The modelling of this population suggests that most of the stars detected by ROSAT in this direction are younger than 1 Gyr. The small number of unidentified sources at low X-ray flux put rather strong constraints on the hypothetical X-ray emission from old neutron stars accreting from the interstellar medium. Our observations clearly rule out models which assume no dynamical heating for this population and a total number of Nns = 10^9 neutron stars in the Galaxy. If accretion on polar caps is the dominant mode then our upper limit may imply Nns ~ 10^8.
Guillout Patrick
Haberl Franck
Motch Ch.
Pakull Manfred
Pietsch Wolfgang
No associations
LandOfFree
The ROSAT Galactic Plane Survey: analysis of a low latitude sample area in Cygnus does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The ROSAT Galactic Plane Survey: analysis of a low latitude sample area in Cygnus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The ROSAT Galactic Plane Survey: analysis of a low latitude sample area in Cygnus will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-604925