First UNLV/Caltech Astrophysics Workshop Held

The first UNLV/Caltech astrophysics workshop was held in the Department of Physics and Astronomy on Apr. 11-12. The theme of this workshop is radio transients, specifically, a new type of cosmological transients named Fast Radio Bursts (FRBs). Sixteen external scientists from Caltech, National Radio Astronomical Observatory (NRAO), NASA Jet Propulsion Laboratory (JPL), Cornell Univ., Univ. West Virginia, Univ. Washington, Univ. McGill gathered at UNLV and discussed with Prof. Bing Zhang’s group and other faculty members, postdoc fellows and students in the department these mysterious cosmic transients. The workshop was opened with a welcome speech by the department chair Prof. Stephen Lepp, which is followed by more than 20 talks with a lot of discussion sessions in between. Prof. Zhang and graduate students Ye Li and Divya Palaswamy gave oral presentations at the workshop. During the workshop, UNLV astronomers also discussed with Caltech astronomers possible future collaborations in the direction of radio astronomy.

Prof. Rebecca Martin and Mario Livio featured in UNLV News

UNLV News reports on Rebecca Martin and Mario Livio's paper on a possible Super-Earth.

May 6, 2016 3:30PM BPB-217. Dipanjan Mitra. On the nature of coherent radio emission from pulsars.

Pulsars, are rotating and radiating neutron stars and are superb astrophysical laboratories of extreme physics. A typical neutron star has radius of ∼ 10 km, magnetic field of ∼ 10¹² Gauss, density of ∼ 10¹⁷ kg/m³, rotating at a frequency ∼ 1 Hz and has a surface gravity of ∼ 10¹²m/s². We observe pulsars as a sequence of periodic pulses mostly in the radio wavelength. What is mind-boggling is that the radio emission arises from a kilometer-sized emission patch which is at a distance of ∼ 10¹⁹ meter from us, and yet we see it!! The equivalent blackbody temperature of this radio emission is in the range 10²⁵--10³⁰ K, which exceeds the limit for any incoherent emission process. The physical mechanism of how this emission is generated is considered as one of the most challenging problems in astrophysics. In this talk I will discuss the wide spectrum of physical phenomena (like the QED phenomenon of magnetic pair creation, effect on the structure of neutron star surface, relativistic plasma dynamics etc) that takes place around the fast rotating, highly magnetized neutron star. These processes lead to generation of a highly relativistic flow of electron positron plasma in which we believe the radio emission is excited by a process called coherent curvature radiation, where charged ``bunches'' are accelerated in curved magnetic field. I will mention how evidence from high quality radio and X-ray observations of pulsars is putting stringent constraints to these ideas.