Pulsar Timing Constraints on Cumulative and Individual Mass of Stars in the Galactic Center

Abstract

We consider the time derivatives of the period $P$ of pulsars at the Galactic Center due to variations in their orbital Doppler shifts. We show that in conjunction with a measurement of a pulsar's proper motion and its projected separation from the supermassive black hole, Sgr A*,measuring two of the three derivatives $\dot{P}$, $\ddot{P}$, or $\stackrel{...}{P}$ sets a constraint that allows for the recovery of the complete six phase space coordinates of the pulsar's orbit, as well as the enclosed mass within the orbit. Thus, one can use multiple pulsars at different distances from Sgr A* to determine the radial mass distribution of stars and stellar remnants at the Galactic center. Furthermore, we consider the effect of passing stars on the pulsar's period derivatives and show how it can be exploited to measure the characteristic stellar mass in the Galactic Center.

6 pages, 5 figures; including additional discussion on the contribution of individual stars

References in corpus (4)

• The ATNF Pulsar Catalogue
• A Precise Proper Motion for the Crab Pulsar, and the Difficulty of Testing Spin-Kick Alignment for Young Neutron Stars
• Timing and Flux Evolution of the Galactic Center Magnetar SGR J1745-2900
• Tracing intermediate-mass black holes in the Galactic Centre