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Astro Lunch Talks

Astro Lunch Talks
Wednesdays, 11:45am-1:00pm, 76-1275 Carlson Learning Center.
Topics will be emailed prior to the talk. Please contact Ben Sargent for more information. 
 
Upcoming Talk Details
Date/Time: January 28th 12:00pm 76-1275
 
Speaker: David Merritt
TITLE:  Gravitational Encounters in the Relativistic Regime

ABSTRACT:Stellar systems evolve over long timescales, as gravitational encounters between stars gradually modify their orbits. Near the center of a galaxy containing a supermassive black hole, classical relaxation theory predicts the formation of a “Bahcall-Wolf cusp”, a steeply-rising density of stars. However we do not observe such a cusp at the center of the Milky Way. I will discuss a possible reason for this discrepancy. The character of the orbital motion changes as a function of distance from a supermassive black hole, and these changes imply corresponding changes in the nature of gravitational encounters. Classical solutions like Bahcall and Wolf's are only valid beyond a certain distance; as one approaches more closely to the black hole, the effects of general relativity become increasingly important. I discuss what has been learned so far about statistical mechanics in the relativistic regime, and present solutions to the Fokker-Planck equation for f(E,L) that are valid much closer to the black hole than Bahcall & Wolf’s. Applications of these results to the Galactic center will be presented.


2014-2015 Academic Year Scheduled Dates
Date Speaker Title
8/20/2014
Yasaman Yazdi
Firewall Phenomenology with Astrophysical Neutrinos
9/3/2014
Adrian Hamers
Secular dynamics of hierarchical quadruple systems
9/17/2014
Andy Lipnicky
Exploring the Effects of Dwarf Galaxies on HI Disks
9/19/2014
Dennis Bowen
Simulating Binary Black Holes in their Astrophysical Environment
9/24/2014
Triana Almeyda
Modeling the Reverberation Response of the Dusty Torus Emission from AGN
10/1/2014
Kristina Punzi
An Unbiased Radio Emission Line Survey of the Protoplanetary Disk Orbiting LkCa 15
10/29/2014
Michael Barbosu & Anthony Hennig
RIT Space Exploration (SPEX) Group and the Cubesat proposal
11/5/2014
Richard O'Shaughnessy
Understanding the precession and inspiral of binary black holes
11/21/2014
Laura Parker
Galaxy Evolution in the Group Environment 
12/3/2014
Sukanya Chakrabarti
Clustered Cepheid variables in Norma:  a distant dwarf galaxy in the plane of the Milky Way
1/28/2015
David Merritt

Gravitational Encounters in the Relativistic Regime

2/4/2015
TBA
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2/18/2015
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3/4/2015
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3/18/2015
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4/1/2015
TBA
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4/15/2015
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4/29/2015
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5/6/2015
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Past Talks
2013-2014 Academic Year Astro Lunch Talks