looking through abell 68

Looking Through Abell 68 [NASA/ESA]

Astronomy 381S - Spring 2014

Seminar in Theoretical Astrophysics

M 3:30 · RLM 15.216B · Not for credit Spring 2014

Professor

Milos Milosavljevic

RLM 17.220 · (512) 471-3397 · email

Schedule

Date

Speaker

Title

 

Jan 13

Milos Milosavljevic

University of Texas at Austin

Organizational meeting.

 

Jan 20

Martin Luther King, Jr. Holiday: University closed. No talks scheduled.

 

Jan 27

An Astronomy Faculty Meeting is being held at this time. Scheduled Astro Theory talks are being postponed until next week.

 

Feb 3

Chalence Safranek-Shrader

University of Texas at Austin

"Formation of the First Low-Mass Stars from Cosmological Initial Conditions"

 

Feb 3

Milos Milosavljevic

University of Texas at Austin

Journal Club: "Primordial Supermassive Stars and Convection in RGB and AGB Atmospheres"

 

Feb 10

No talk scheduled.

 

Feb 17

Alan Sluder

University of Texas at Austin

"The Role of Population III Supernovae in Galactic Chemical Evolution"

 

Feb 24

Wenbin Lu

University of Texas at Austin

"Are There Very Massive (Maybe Pop-III) Stars Around a GRB Progenitor?"

abstract

 

Mar 3

Chiara Ceccobello

University of Amsterdam, Netherlands

(host: Pawan Kumar) "Inverse-Compton drag of a Highly Magnetized GRB jet in Stellar Envelope"

The collimation and evolution of relativistic outflows in gamma-ray bursts (GRBs) are determined by their interaction with the stellar envelope through which they propagate before reaching the distance where energy is dissipated and gamma-rays are produced. We consider the case of a Poynting flux dominated relativistic outflow and show that it suffers strong IC scattering drag near the stellar surface and the outer parts of the jet are slowed down to sub-relativistic speed especially if its initial magnetization parameter is between 10^3 and 10^6. However, if the temperature of the cocoon surrounding the jet were to be larger than about 10 keV, and the magnetization is larger than 10^7, then an optically thick layer of electrons and positrons forms at the interface of the cocoon and the jet, and this pair screen protects the interior of the jet from IC drag. Pairs in the screen annihilate when the jet emerges above the stellar surface giving rise to a brief pulse of about 100 MeV radiation.

close

 

Mar 10

Spring Break: March 10-14. No talk scheduled.

 

Mar 17

No talk scheduled.

 

Mar 24

Thomas B. McCord

Bear Fight Institute (BFI)

Special Planets/Life/ISM Seminar: (host: Bill Cochran) "The Composition of Vesta and Ceres from the Dawn Mission"

 

Mar 31

Christa Gall

Dark Center, Copenhagen

(host: Volker Bromm) "Dust in the Early Universe: Overview"

 

Apr 7

No talk scheduled.

 

Apr 14

Krista Soderlund

UT Institute of Geophysics

(Joint Seminar in Theory/ISM/Planets) "Convective Dynamics in the Interiors of Ice Giants and Icy Satellites"

 

Apr 21

No talk scheduled.

 

Apr 28

No talk scheduled.