The Galactic Centre pulsar population.

The recent discovery of a magnetar in the Galactic centre region has allowed Spitler et al. to characterize the interstellar scattering in that direction. They find that the temporal broadening of the pulse profile of the magnetar is substantially less than that predicted by models of the electron density of that region. This raises the question of what the plausible limits for the number of potentially observable pulsars - i.e., the number of pulsars beaming towards the Earth - in the Galactic centre are. In this paper, using reasonable assumptions - namely, (i) the luminosity function of pulsars in the Galactic centre region is the same as that in the field, (ii) the region has had a constant pulsar formation rate, (iii) the spin and luminosity evolution of magnetars and pulsars are similar, and (iv) the scattering in the direction of the Galactic centre magnetar is representative of the entire inner parsec - we show that the potentially observable population of pulsars in the inner parsec has a conservative upper limit of $\sim$ 200, and that it is premature to conclude that the number of pulsars in this region is small. We also show that the observational results so far are consistent with this number and make predictions for future radio pulsar surveys of the Galactic centre.

[1]  J. Dexter,et al.  THE PECULIAR PULSAR POPULATION OF THE CENTRAL PARSEC , 2013, 1310.7022.

[2]  H. Falcke,et al.  PULSE BROADENING MEASUREMENTS FROM THE GALACTIC CENTER PULSAR J1745–2900 , 2013, 1309.4673.

[3]  Adam Deller,et al.  THE ANGULAR BROADENING OF THE GALACTIC CENTER PULSAR SGR J1745-29: A NEW CONSTRAINT ON THE SCATTERING MEDIUM , 2013, 1309.4672.

[4]  R. P. Eatough,et al.  A strong magnetic field around the supermassive black hole at the centre of the Galaxy , 2013, Nature.

[5]  M. Feroci,et al.  A STRONGLY MAGNETIZED PULSAR WITHIN THE GRASP OF THE MILKY WAY'S SUPERMASSIVE BLACK HOLE , 2013, 1307.6331.

[6]  S. Johnston,et al.  Radio properties of the magnetar near sagittarius A* from observations with the Australia telescope compact array , 2013, 1305.3036.

[7]  N. Gehrels,et al.  SWIFT DISCOVERY OF A NEW SOFT GAMMA REPEATER, SGR J1745−29, NEAR SAGITTARIUS A* , 2013, 1305.2128.

[8]  Kristin K. Madsen,et al.  NuSTAR DISCOVERY OF A 3.76 s TRANSIENT MAGNETAR NEAR SAGITTARIUS A* , 2013, 1305.1945.

[9]  D. Lorimer,et al.  The pulsar spectral index distribution , 2013, 1302.2053.

[10]  N. Wex,et al.  PROSPECTS FOR PROBING THE SPACETIME OF Sgr A* WITH PULSARS , 2011, 1112.2151.

[11]  J. Cordes,et al.  MULTIWAVELENGTH CONSTRAINTS ON PULSAR POPULATIONS IN THE GALACTIC CENTER , 2011, 1111.4216.

[12]  S. P. Portegies Zwart,et al.  MAPPING THE GALACTIC CENTER WITH GRAVITATIONAL WAVE MEASUREMENTS USING PULSAR TIMING , 2011, 1110.6172.

[13]  R. Lynch,et al.  YOUNG RADIO PULSARS IN GALACTIC GLOBULAR CLUSTERS , 2011, 1108.4402.

[14]  M. Mclaughlin,et al.  A 6.5-GHz multibeam pulsar survey , 2010, 1009.5873.

[15]  S. Burke-Spolaor,et al.  A RADIO-LOUD MAGNETAR IN X-RAY QUIESCENCE , 2010, 1007.1052.

[16]  R. Genzel,et al.  The galactic center massive black hole and nuclear star cluster , 2010, 1006.0064.

[17]  India,et al.  A HIGH-FREQUENCY SEARCH FOR PULSARS WITHIN THE CENTRAL PARSEC OF Sgr A* , 2010, 1004.1643.

[18]  J. Cordes,et al.  DISCOVERY OF THREE PULSARS FROM A GALACTIC CENTER PULSAR POPULATION , 2009, 0908.1331.

[19]  W. Cotton,et al.  Green Bank Telescope Multiwavelength Survey of the Galactic Center Region , 2008, 0801.4294.

[20]  M. Mclaughlin,et al.  Discovery of two pulsars towards the Galactic Centre , 2006, astro-ph/0606465.

[21]  V. Kaspi,et al.  Birth and Evolution of Isolated Radio Pulsars , 2005, astro-ph/0512585.

[22]  R. Manchester,et al.  The Australia Telescope National Facility Pulsar Catalogue , 2005 .

[23]  A. Loeb,et al.  Probing the Spacetime around Sagittarius A* with Radio Pulsars , 2003, astro-ph/0309744.

[24]  E. Serabyn,et al.  An Extended Star Formation History for the Galactic Center from Hubble Space Telescope NICMOS Observations , 2003, astro-ph/0309757.

[25]  R. Manchester,et al.  The Australia Telescope National Facility Pulsar Catalogue , 2003, astro-ph/0309219.

[26]  F. Camilo,et al.  The Parkes Multibeam Pulsar Survey – II. Discovery and timing of 120 pulsars , 2002, astro-ph/0204238.

[27]  F. Camilo,et al.  The Parkes multi-beam pulsar survey - I. Observing and data analysis systems, discovery and timing of 100 pulsars , 2001, astro-ph/0106522.

[28]  R. Manchester,et al.  On the Evolution of Pulsar Beams , 1998 .

[29]  J. Cordes,et al.  Finding Radio Pulsars in and beyond the Galactic Center , 1996, astro-ph/9608028.

[30]  D. Lorimer,et al.  Multifrequency flux density measurements of 280 pulsars , 1995 .

[31]  Y. Sofue.  Giant Explosion at the Galactic Center and Huge Shocked Shells in the Halo , 1994, astro-ph/9402034.