EDP Sciences
Free Access
Volume 372, Number 2, June III 2001
Page(s) 651 - 662
Section Diffuse matter in space
DOI https://doi.org/10.1051/0004-6361:20010503

A&A 372, 651-662 (2001)
DOI: 10.1051/0004-6361:20010503

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

L. Sidoli1, S. Mereghetti2, A. Treves3, A. N. Parmar1, R. Turolla4 and F. Favata1

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

(Received 19 January 2001 / Accepted 2 April 2001 )

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 ~ $6\times10^{34}$ 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.

Key words: Galaxy: center -- ISM: clouds: individual: Sgr B, Sgr C, Sgr D -- ISM: supernova remnants: individual: G1.05 -- 0.15 -- X -- rays: ISM -- X -- rays: stars: individual: SAX J1748.2 -- 2808

Offprint request: L. Sidoli, lsidoli@astro.estec.esa.nl

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