======================================================================== 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. 12, No. 14 Oct 13, 2000 Recently submitted papers: -------------------------- 1) A deep submillimetre survey of the Galactic Centre (Pierce-Price et al., ApJL) 2) Warm H_2 in the Galactic center region (Rodriguez-Fernandez et al., A&A) ------------------------------------------------------------------------ Email : dpip100@mrao.cam.ac.uk Title : A deep submillimetre survey of the Galactic Centre Author(s): D. Pierce-Price(1), J. S. Richer(1), J. S. Greaves(2), W. S. Holland(2), T. Jenness(2), A. N. Lasenby(1), G. J. White(3,1), H. E. Matthews(4,2), D. Ward-Thompson(5), W. R. F. Dent(6), R. Zylka(7), P. Mezger(8), T. Hasegawa(9), T. Oka(10), A. Omont(11) and G. Gilmore(12) Institute: (1) Cavendish Astrophysics, Cavendish Laboratory, Madingley Road, Cambridge, CB3 0HE, UK (2) Joint Astronomy Centre, 660 N. A`oh\=ok\=u Place, Hilo, HI 96720 (3) Department of Physics, Queen Mary and Westfield College, University of London, Mile End Road, London E1 4NS, UK (4) National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7, Canada (5) Department of Physics and Astronomy, Cardiff University, 5 The Parade, Cardiff CF2 3YB, Wales, UK (6) Astronomy Technology Centre, Blackford Hill, Edinburgh, EH9 3HJ, UK (7) ITA, Universitaet Heidelberg, Tiergartenstrasse 15, D-69121 Heidelberg, Germany (8) Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn, Germany (9) Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015, Japan (10) Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan (11) Institut d'Astrophysique de Paris, CNRS, 98bis Boulevard Arago, F 75014 Paris, France (12) Institute of Astronomy,University of Cambridge, Madingley Road, Cambridge. CB3 0HA, UK Paper : ApJL, in press EPrint : astro-ph/0010236 Abstract: We present first results from a submillimetre continuum survey of the Galactic Centre `Central Molecular Zone' (CMZ), made with SCUBA on the James Clerk Maxwell Telescope. SCUBA's scan-map mode has allowed us to make extremely wide-field maps of thermal dust emission with unprecedented speed and sensitivity. We also discuss some issues related to the elimination of artefacts in scan-map data. Our simultaneous 850/450 micron maps have a total size of approximately 2.8*0.5\arcdeg (400*75 \pc) elongated along the galactic plane. It covers the Sgr A region--including Sgr A*, the circumnuclear disc, and the +20 km/s and +50 km/s clouds; the area around the Pistol; Sgr B2--the brightest feature on the map; and at its Galactic Western and Eastern edges the Sgr C and Sgr D regions. There are many striking features such as filaments and shell-like structures, as well as point sources such as Sgr A* itself. The total mass in the Central Molecular Zone is greater than that revealed in previous optically-thin molecular line maps by a factor of 3, and new details are revealed on scales down to 0.33 \pc across this 400 \pc-wide region. ------------------------------------------------------------------------ Email : nemesio@oan.es Title : Warm H_2 in the Galactic center region Author(s): N.J. Rodriguez-Fernandez(1), J. Martin-Pintado(1), A. Fuente(1), P. de Vicente(1), T.L. Wilson(2,3), and S. Huettemeister(4) Institute: (1) Observatorio Astronomico Nacional, IGN, Apartado 1143, E-28800 Alcala de Henares, Spain; nemesio@oan.es and (2) Max-Planck-Institut fuer Radioastronomie, Postfach 2024, D-53010 Bonn, Germany and (3) Sub-mm Telescope Observatory, Steward Observatory, The University of Arizona, Tucson, AZ 85728, USA and (4) Radioastronomisches Institute der Universitaet Bonn, Auf dem Huegel 71, D-53121 Bonn, Germany Paper : A&A, in press EPrint : astro-ph/0010182 Abstract: We present ISO observations of several \Hd pure-rotational lines (from S(0) to S(5)) towards a sample of 16 molecular clouds distributed along the central 500 pc of the Galaxy. We also present \CuoO and \utCO \juce and \jdu observations of these sources made with the IRAM-30m telescope. With the CO data we derive \Hd densities of 10^3.5-4.0 \cmmt and \Hd column densities of a few 10^22 \cmmd. We have corrected the \Hd data for 30 magnitudes of visual extinction using a self-consistent method. In every source, we find that the \Hd emission exhibits a large temperature gradient. The S(0) and S(1) lines trace temperatures (T) of 150 K while the S(4) and S(5) lines indicate temperatures of 600 K. The warm \Hd column density is typically 1-2* 10^22 \cmmd, and is predominantly gas with T=150 K. This is the first direct estimate of the total column density of the warm molecular gas in the Galactic center region. These warm \Hd column densities represent a fraction of 30 % of the gas traced by the CO isotopes emission. The cooling by \Hd in the warm component is comparable to that by CO. Comparing our \Hd and CO data with available ammonia (\NHt) observations from literature one obtains relatively high \NHt abundances of a few 10^-7 in both the warm and the cold gas. A single shock or Photo-Dissociation Region (PDR) cannot explain all the observed \Hd lines. Alternatives for the heating mechanisms are discussed. ------------------------------------------------------------------------ (Older versions of the Newsflash can be found at the gcnews web-page) ======================================================================== Edited by Angela Cotera Heino Falcke & Sera Markoff (cotera@as.arizona.edu) (hfalcke,smarkoff@mpifr-bonn.mpg.de) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - For Abstract submission please send the (La)Tex file of your paper to gcnews@mpifr-bonn.mpg.de ========================================================================