Shanghai Astronomical Observatory Astrophysics Colloquium

Title：New advances in the diffuse ultraviolet background

Speaker：Prof. Jayant Murthy (Indian Institute of Astrophysics)

Zoom：831 0898 6175 password: 6360

Time：3:00 pm June 15th (Thursday)

Abstract：

Although an important part of our Galaxy, interstellar dust is difficult to characterize. Historically, most of our information about dust has come from observations of extinction curves against background stars but these are limited to those directions where there are suitable stars. Infrared observations of the thermal emission from dust heated by the interstellar radiation field fills the sky and has yielded considerable information about the properties and the distribution of the dust. Ultraviolet observations of the scattered light from the dust have been difficult and sparse until the launch of the GALEX mission. I will discuss my extraction of this diffuse light from the GALEX data and what it tells us about the properties of interstellar dust. My primary focus will be on the modeling I am now doing and on its successes and deficiencies. I will also present our latest results on the background at the Galactic poles where we have discovered a new component of the extragalactic radiation field, one for which we do not yet know the source. I will also present some ideas for small UV payloads to further investigate the background, including a payload we have manifested on the Chinese Space Station.

CV：

JM got his PhD from Johns Hopkins University in 1987. He was an NRC postdoc at the Goddard Space Flight Center for two years before rejoining JHU as a Research Professor. He joined IIA in 2000 and retired as a Senior Professor in 2021.

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