Discovery of a Be/X-ray pulsar binary and associated supernova remnant in the Wing of the Small Magellanic Cloud

V. Henault-Brunet1, L.M. Oskinova2, M.A. Guerrero3, W. Sun4, Y.-H. Chu5, C.J. Evans6,1, J.S. Gallagher III7, R.A. Gruendl5, J. Reyes-Iturbide8

1 Institute for Astronomy, University of Edinburgh, UK
2 Institute for Physics and Astronomy, University of Potsdam, Germany
3 Instituto de Astrofisica de Andalucia, Granada, Spain
4 Department of Astronomy, Nanjing University, China
5 Department of Astronomy, University of Illinois, USA
6 Royal Observatory Edinburgh, UK
7 Department of Astronomy, University of Wisconsin-Madison, USA
8 Escuela Superior de Fisica y Matematicas, Mexico

We report on a new Be/X-ray pulsar binary located in the Wing of the Small Magellanic Cloud (SMC). The strong pulsed X-ray source was discovered with the Chandra and XMM-Newton X-ray observatories. The X-ray pulse period of 1062s is consistently determined from both Chandra and XMM-Newton observations, revealing one of the slowest rotating X-ray pulsars known in the SMC. The optical counterpart of the X-ray source is the emission-line star 2dFS 3831. Its B0-0.5(III)e+ spectral type is determined from VLT-FLAMES and 2dF optical spectroscopy, establishing the system as a Be/X-ray binary (Be-XRB). The hard X-ray spectrum is well fitted by a power-law with additional thermal and blackbody components, the latter reminiscent of persistent Be-XRBs. This system is the first evidence of a recent supernova in the low density surroundings of NGC 602. We detect a shell nebula around 2dFS 3831 in H-alpha and [O III] images and conclude that it is most likely a supernova remnant. If it is linked to the supernova explosion that created this new X-ray pulsar, its kinematic age of (2-4) 104yr provides a constraint on the age of the pulsar.

Fetch Pdf-File (oskinova-Be-pulsar.pdf, 2MB)

Back to publication list