Oak Ridge National Laboratory

Physics Division

Physics Division Seminars

Physics Division Seminars bring us speakers on a variety of physics related subjects. Usually these are held in the Building 6008 large Conference Room, at 3:00 pm on the chosen day, but times and locations may vary. For more information, contact our seminar chairman,

Alfredo Galindo-Uribarri
Tel (Office): (865) 574-6124  (FAX): (865) 574-1268


Thu., November 17, 2011, at 3:00 p.m. (refreshments at 2:40 p.m.)

Can supernovae illuminate the strangeness of neutron stars?

Irina Sagert, Michigan State University, East Lansing, MI
Building 6008 Conference Room

With observed masses in the range of 1.2-2 solar masses and radii of the order of 10 km, neutron stars contain matter at densities far beyond nuclear saturation. The composition of matter under these conditions is still today unknown, whereas ideas range from pure nucleonic configurations to the appearance of strangeness in form of hyperons or quarks. The recent finding of a two-solar-mass neutron star, PSR J1614-2230, initiated a hot debate as to whether hyperons and quarks can be present in neutron star interiors.

The appearance of strangeness is often associated with the softening of the nuclear equation of state, which is not compatible with large neutron star masses as the one of PSR J1614-2230. However, various studies show that quark and hyperonic matter can have rather stiff equations of state and therefore populate the interior of high mass neutron stars. As a consequence, the composition of high-density neutron star matter remains a topic of intense debate, awaiting further astrophysical observations to solve the mystery. Maybe core-collapse supernovae, the birth site of neutron stars, can help to shed some light on the strangeness of neutron star interiors.