The Galactic centre mini-spiral in the mm-regime

0374254 - ASÚ 2013 RIV FR eng J - Journal Article
Kunneriath, Devaky - Eckart, A. - Vogel, S. N. - Teuben, P. - Muzic, K. - Schoedel, R. - García-Marín, M. - Moultaka, J. - Staguhn, J. - Straubmeier, C. - Zensus, J. A. - Valencia-S, M. - Karas, Vladimír
The Galactic centre mini-spiral in the mm-regime.
Astronomy & Astrophysics. Roč. 538, February (2012), A127/1-A127/8. ISSN 0004-6361. E-ISSN 1432-0746
Grant - others:ESA(XE) ESA-PECS project No. 98040
Institutional research plan: CEZ:AV0Z10030501
Keywords : galactic centre * black holes
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 5.084, year: 2012

Our observations were carried out at 1.3 mm and 3 mm with the mm interferometric array CARMA in California in March and April 2009, with the MIR instrument VISIR at ESO’s VLT in June 2006, and the NIR Brγ with VLT NACO in August 2009. We present high resolution maps of the mini-spiral, and obtain a spectral index of ~0.5 for Sgr A*, indicating an inverted synchrotron spectrum. We find electron densities within the range 0.8-1.5   10^4 cm-3 for the mini-spiral from the radio continuum maps, along with a dust mass contribution of ~0.25 M_S from the MIR dust continuum, and extinctions ranging from 1.8–3 in the Brγ line. We observe a mixture of negative and positive spectral indices, which we interpret as evidence that there are a range of contributions to the thermal free-free emission by the ionized gas emission and by dust at 1.3 mm.
Permanent Link: http://hdl.handle.net/11104/0207214