English

A strongly magnetized pulsar within grasp of the Milky Way's supermassive black hole

Astrophysics of Galaxies 2015-06-16 v4 High Energy Astrophysical Phenomena

Abstract

The center of our Galaxy hosts a supermassive black hole, Sagittarius (Sgr) A*. Young, massive stars within 0.5 pc of SgrA* are evidence of an episode of intense star formation near the black hole a few Myr ago, which might have left behind a young neutron star traveling deep into SgrA*'s gravitational potential. On 2013 April 25, a short X-ray burst was observed from the direction of the Galactic center. Thanks to a series of observations with the Chandra and the Swift satellites, we pinpoint the associated magnetar at an angular distance of 2.4+/-0.3 arcsec from SgrA*, and refine the source spin period and its derivative (P=3.7635537(2) s and \dot{P} = 6.61(4)x10^{-12} s/s), confirmed by quasi simultaneous radio observations performed with the Green Bank (GBT) and Parkes antennas, which also constrain a Dispersion Measure of DM=1750+/-50 pc cm^{-3}, the highest ever observed for a radio pulsar. We have found that this X-ray source is a young magnetar at ~0.07-2 pc from SgrA*. Simulations of its possible motion around SgrA* show that it is likely (~90% probability) in a bound orbit around the black hole. The radiation front produced by the past activity from the magnetar passing through the molecular clouds surrounding the Galactic center region, might be responsible for a large fraction of the light echoes observed in the Fe fluorescence features.

Keywords

Cite

@article{arxiv.1307.6331,
  title  = {A strongly magnetized pulsar within grasp of the Milky Way's supermassive black hole},
  author = {N. Rea and P. Esposito and J. A. Pons and R. Turolla and D. F. Torres and G. L. Israel and A. Possenti and M. Burgay and D. Vigano' and R. Perna and L. Stella and G. Ponti and F. Baganoff and D. Haggard and A. Papitto and A. Camero-Arranz and S. Zane and A. Minter and S. Mereghetti and A. Tiengo and R. Schoedel and M. Feroci and R. Mignani and D. Gotz},
  journal= {arXiv preprint arXiv:1307.6331},
  year   = {2015}
}

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