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TAPIR Seminar

Friday, April 26, 2024
2:00pm to 3:00pm
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Online and In-Person Event
Resonant shattering flares as probes of neutron star structure and nuclear symmetry
Duncan Neill, Research Associate, Department of Physics, University of Bath,

In person: 370 Cahill. To Join via Zoom: 868 5298 8404

ABSTRACT: Neutron stars (NSs) are compact remnants of massive stars, containing matter that is ultra-dense, cold and neutron rich. Presently, these conditions can not be simultaneously reproduced in terrestrial experiments, making NSs interesting laboratories in which to study nuclear interactions in extreme conditions. However, NS properties measured with current techniques – such as tidal deformability inferred from gravitational waves (GWs) – are sensitive to matter within the star's core. While this is interesting for examining the possible appearance of exotic phases of matter in the NS core, the range of possible exotic phases limits the ability of these measurements to complement terrestrial studies, as we can not confidently select a type of model with which to describe the NS core.

    In contrast to current techniques, asteroseismology can be used to probe matter throughout NSs, allowing for constraints to be placed on lower density regions where we are confident that matter is nucleonic. While much of the potential of NS asteroseismology will have to wait for future generations of GW interferometers, we consider a signature of NS quasi-normal modes that could be detected by current instruments: resonant shattering flares (RSFs). These flares are produced when a NS mode is resonantly excited by the tidal field of the star's binary partner shortly before merger, causing the solid outer layers of the NS to shatter. I will discuss how observations of RSFs could be used to constrain properties of matter within the NS crust and subsequently aid current terrestrial efforts to study the nuclear symmetry energy. As there has yet to be any certain detections of RSFs, I will also present estimates of what these flares might look like and how common they may be. Finally, I will examine whether known precursors of short gamma-ray burst could be RSFs, and what the implications of such a conclusion would be.

For more information, please contact JoAnn Boyd by phone at 626-395-4280 or by email at joann@caltech.edu.