Astronomy & Astrophysics Seminar

Two talks this week.

Refreshments available.

Date: Wed, 12 Sep 2018, 1:30 pm – 2:30 pm
Type: Seminar
Location: 1400 BPS Bldg.

Talk 1:

Speaker: Ryan Connolly, MSU

Title: Neutron Star Crusts: Nature is Elusive

Accreting neutron stars serve as natural labora­tories for prob­ing the physics of dense mat­ter. By compar­ing various computa­tional models against observa­tions of neu­tron stars during and after accre­tion out­bursts, we can infer proper­ties of the star that we can't measure direct­ly and test theories of nuclear physics in regimes we can't repli­cate in the lab. How­ever, as our under­stand­ing of the relevant micro­physics im­proves and models be­come more detailed, new chal­lenges have appeared in fit­ting the observa­tions of cool­ing neu­tron stars trans­ients. I will dis­cuss a few of these areas of ten­sion be­tween observa­tion and theory, specific­ally re­lated to the composi­tion of the crust as well as the crust-core inter­face, and some possi­bilities for recon­ciling the dif­ferences moving for­ward.

Talk 2:

Speaker: Laura Shishkovsky, MSU

Title: The MAVERIC Survey: Black Holes in Globular Clusters

Globular clusters are expected to have large popula­tions of stel­lar-mass black holes at early stages in their life­times. These stel­lar-mass black holes were long pre­dicted to have been kicked out of globu­lar clus­ters through gravita­tional inter­ac­tions during the clus­ters' evo­lu­tion, with some clus­ters retain­ing only one or two stel­lar-mass black holes and most clus­ters not retain­ing any. How­ever, recent dis­coveries of stel­lar-mass black hole candi­dates in globu­lar clus­ters have called this nar­rative into ques­tion. With the goal of assess­ing the fre­quency of accreting stel­lar-mass black hole sys­tems in globu­lar clus­ters, we have under­taken a deep radio con­tinuum sur­vey of 33 Milky Way globu­lar clus­ters using the Karl G. Jansky Very Large Array. Here we pre­sent our method of select­ing candi­dates, pre­liminary results, and implica­tions for the dynami­cal forma­tion of binary black holes observ­able as gravita­tional wave sources.