QUIESCENT NEUTRON STAR (NS) SPECTRA OFFER US INSIGHTS INTO THE STRUCTURE OF NEUTRON STARS AND THE EQUATION OF STATE OF NUCLEAR MATTER. IF A NS WITH A KNOWN DISTANCE IS IN A TRULY QUIESCENT STATE (I.E. ITS SPECTRUM IS DOMINATED BY COOLING VIA THERMAL RADIATION EMITTED FROM THE NS SURFACE) THEN FITTING THE SPECTRUM WITH A MODERN THERMAL ATMOSPHERE MODEL (CHARACTERIZED BY A NS MASS RADIUS AND SURFACE TEMPERATURE OBSERVED AT INFINITY) WOULD ALLOW US TO CONSTRAIN THE NS MASS-RADIUS RELATIONSHIP AND THEREFORE ITS EQUATION OF STATE. SIMILARLY IF WE HAVE A GOOD ESTIMATE OF THE LONG TERM AVERAGE HEATING OF THE NS VIA ACCRETION ONTO ITS SURFACE DURING BRIGHT PHASES WE CAN LEARN ABOUT COOLING PROCESSES IN THE NS AND HENCE NS STRUCTURE BY STUDYING THE LONG TERM EVOLUTION OF THE COOLING SPECTRUM DURING QUIESCENT PHASES.

Washington University, The

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