X-ray emission from the giant molecular clouds in the Galactic Center region and the discovery of new X-ray sources

L. Sidoli(1), S. Mereghetti(2), A. Treves(3), A.N. Parmar(1), R. Turolla(4), & F. Favata(1)

(1) Astrophysics Division, Space Science Department of ESA, ESTEC, Postbus 299, NL-2200 AG Noordwijk, The Netherlands
(2) Istituto di Fisica Cosmica G.Occhialini, C.N.R., Via Bassini 15, I-20133 Milano, Italy
(3) Università degli Studi dell'Insubria, Polo di Como, Dipartimento di Scienze Chimiche, Fisiche, e Matematiche, Via Lucini 3, I-22100, Como, Italy
(4) Università di Padova, Dipartimento di Fisica, Via Marzolo 8, I-35131, Padova, Italy

Paper: A&A 2001, in press

EPrint Server: astro-ph/0104121

Abstract:

We report the results of X-ray (2-10 keV) observations of the giant molecular clouds Sgr B, Sgr C and Sgr D in the Galactic Center region, together with the discovery of the point-like source SAX J1748.2-2808. The data have been obtained with the MECS instrument on the BeppoSAX satellite. The core of Sgr B2 has an X-ray luminosity of 6*10³⁴ erg s^-1 and its spectrum is characterized by a strong Fe emission line at 6.5 keV with an equivalent width of 2 keV. Faint diffuse X-ray emission is detected from Sgr C and from the SNR G1.05-0.15 (Sgr D). A new, unresolved source with a strong Fe line has been discovered in the Sgr D region. This source, SAX J1748.2-2808, is probably associated with a SiO and OH maser source at the Galactic Center distance. If so, its luminosity is 10³⁴ erg s^-1. We propose that the X-ray emission from SAX J1748.2-2808 is produced either by protostars or by a giant molecular cloud core. Emission from sources similar to SAX J1748.2-2808 could have an impact on the expected contribution on the observed Fe line emission from the Galactic ridge.

Preprints available from the authors at lsidoli@astro.estec.esa.nl , or the raw TeX (no figures) if you click here.

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