Observations of the darkest regions in the sky: X-ray shadowing by the Bok globule Barnard 68

Author(s)
M. J. Freyberg, D. Breitschwerdt, J. Alves
Abstract

The densest and closest absorbers of the soft X-ray background (SXRB) in

the Milky Way are Bok globules, located just outside the Local Bubble in

the Pipe Nebula at a distance of 125 pc. With column densities of up to

NH ˜ 1023 cm-2, they are ideal

targets for shadowing the SXRB in the energy range 0.1 - 2 keV, thus

giving important information on the spatial and spectral variation of

the foreground X-ray intensity on small scales. Preliminary analysis of

a recent XMM-Newton EPIC observation of the Bok globule Barnard 68 has

revealed a deep X-ray shadow cast by the globule. The shadow is deepest

at an energy of ˜ 800 eV. Oxygen line emission at ˜ 560 and

˜ 660 eV seems to originate at least partially in the foreground.

Organisation(s)
Department of Astrophysics
External organisation(s)
Max-Planck-Institut für extraterrestrische Physik, European Southern Observatory (Germany)
Journal
Memorie Societa Astronomica Italiana
Volume
75
Pages
509
Publication date
2004
Peer reviewed
Yes
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/observations-of-the-darkest-regions-in-the-sky-xray-shadowing-by-the-bok-globule-barnard-68(aca46fe9-d415-4387-92ce-5df8b8715b31).html