题 目:Observing the Galactic Center with APEX
报告人:Dr. Miguel Requena-Torres
(Max-Planck-Institut für Radioastronomie)
摘 要:
Located at only 8.5 Kpc, the Galactic center (GC), is the closer galactic nuclei that we can study. The spatial resolution that we can achieve in it is impossible for extragalactic nuclei nowadays, and even in the future with ALMA. The physical and chemical conditions of the interstellar gas in the nucleus of the Milky Way (approximately the central 500 pc) differ substantially from the conditions of the interstellar matter in the disk of the Galaxy. In our Galactic nucleus we can find the central supermassive black hole, Sgr A*, the central star cluster, the circumnuclear disk (CND), and the supernova remnant Sgr A East. Shocks, X-ray- and photon-dominated regions affect the molecular clouds chemistry in these active regions.
The APEX telescope, located at the Chanjnantor plateau in the southern hemisphere, is one of the best sites for the submillimeter observation of the GC. The CHAMP+ heterodyne array has been used to obtain high spatial and spectral resolution maps of the CO (6-5) and (7-6) transitions and CI. Continuum information comes together with LaBoca and Saboca bolometer cameras from the APEX telescope. All the main structures in the GC (e.g., the arched filaments, the sickle, the 20 and 50 km/s clouds, the CS-peak and the CND) can be clearly seen in the high excitation CO lines. Together with previous observations from IRAM 30-m and CSO telescopes, the CO shows variations in the temperature of the molecular clouds between 10 and 160 K, approximately.
We will try to understand the physics and the chemistry that are affecting the central 50 pc of our Galaxy to disentangle the extra galactic observations, where all those processes are within one telescope beam.
时 间:2009年10月26日下午3:30
地 点:(北京西路2号)紫台大楼327教室
紫金山天文台学术委员会学术交流工作委员会
2009年10月15日