Title：Deep 6cm Imaging of the Sgr A Complex with the VLA — Surprising Morphologies Revealed

　　Speaker：Prof. Mark Morris (UCLA)

　　Abstract：The greatly increased sensitivity of the upgraded Jansky Very Large Array has made it possible to produce much deeper radio continuum maps than were ever possible before, although at the cost of working with enormous data sets. We [Jun-Hui Zhao, W. Miller Goss, and myself] have produced new images of the Sgr A complex at the Galactic center that have a dynamic range of about 100,000 from the brightest object in the field — our Galaxy’s supermassive black hole, Sgr A* — to the faint artifacts that are unavoidable with aperture synthesis observations. The maps show a marvelous variety of objects, including numerous new nonthermal radio filaments appearing either as isolated features or as bundles, the supernova remnant Sgr A East and the runaway pulsar wind nebula that we have argued was produced by the core-collapse event that produced Sgr A East. In addition, unexplained features that have hard X-ray counterparts are present in the radio map made at 6-cm wavelength. I will discuss several of these features and their implications for the magnetic field at the Galactic center, for impulsive energy releases from objects in the central parsec, and for powerful dynamical interactions taking place at the present time.

　　Time：25 Oct. (Tuesday), 10:15—11:15am

　　Place：Room 402, Astronomy Building

欢迎各位老师、同学参加！

　　                                              南京大学天文与空间科学学院