======================================================================== G C N E W S * Newsflash * - The Newsletter for Galactic Center Research - gcnews@mpifr-bonn.mpg.de http://www.mpifr-bonn.mpg.de/gcnews ======================================================================== Vol. 10, No. 22 Nov 2, 1999 Recently submitted papers: -------------------------- Email : ott@ibm-s-1.mpe-garching.MPG.DE Title : The Sgr A* Stellar Cluster: New NIR Imaging and Spectroscopy Author(s): Andreas Eckart, Thomas Ott, and Reinhard Genzel Institute: Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstr., 85740 Garching Paper : Accepted by A & A EPrint : astro-ph/9911011 Abstract: We report preliminary results based on new near-infrared observations of the central stellar cluster of our Galaxy conducted with the infrared spectrometer ISAAC at the ESO VLT UT1 and the MPE speckle camera SHARP at the ESO NTT. We obtained lambda /Delta lambda >= 3000 K-band spectroscopy of the 2.058 micron He I, 2.165 micron Br gamma emission lines, and 2.29 micron CO bandhead absorption line. These data demonstrate clearly that there is no strong CO bandhead absorption originating in the northern part (S1/S2 area) of the central stellar cluster at the position of Sgr A^*. This makes it likely that these K~14.5 stars are O9 - B0.5 stars with masses of 15 to 20 M_o. Weaker CO bandhead absorption in the southern part of the cluster (S10/S11 area) could be due to contributions from neighbouring stars. We also report the detection of Br gamma line emission at the position of the central stellar cluster which could be associated with the 'mini-spiral' rather than with the Sgr A* cluster itself. At the NTT we obtained another epoch epoch of proper motion measurments. The changes of source positions are consistent with the proper motion velocities derived from earlier epochs. ------------------------------------------------------------------------ (Older versions of the Newsflash can be found at the gcnews web-page) ======================================================================== Edited by Angela Cotera Heino Falcke (cotera@ipac.caltech.edu) (hfalcke@mpifr-bonn.mpg.de) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - For Abstract submission please send the (La)Tex file of your paper to gcnews@mpifr-bonn.mpg.de ========================================================================