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arXiv · 1803.06359

SMSS J130522.47-293113.0: a high-latitude stellar X-ray source with pc-scale outflow relics?

G. S. Da Costa·R. Soria·S. A. Farrell·D. Bayliss·M. S. Bessell·F. P. A. Vogt·G. Zhou·S. D. Points·T. C. Beers·Á. R. López-Sánchez·K. W. Bannister·M. Bell·P. J. Hancock·D. Burlon·B. M. Gaensler·E. M. Sadler·S. Tingay·S. C. Keller·B. P. Schmidt·P. Tisserand
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Abstract

We report the discovery of an unusual stellar system, SMSS J130522.47-293113.0. The optical spectrum is dominated by a blue continuum together with emission lines of hydrogen, neutral and ionized helium, and the N III, C III blend at around 4640-4650 Angstrom. The emission line profiles vary in strength and position on timescales as short as 1 day, while optical photometry reveals fluctuations of as much as ~0.2 mag in g on timescales as short as 10-15 min. The system is a weak X-ray source (f_{0.3-10} = (1.2 +/- 0.1) x 10^{-13} ergs cm^{-2} s^{-1} in the 0.3-10 keV band) but is not detected at radio wavelengths (3-sigma upper limit of 50 microJy at 5.5 GHz). The most intriguing property of the system, however, is the existence of two "blobs", a few arcsec in size, that are symmetrically located 3.8 arcmin (2.2 pc for our preferred system distance of ~2 kpc) each side of the central object. The blobs are detected in optical and near-IR broadband images but do not show any excess emission in Halpha images. We discuss the interpretation of the system, suggesting that the central object is most likely a nova-like CV, and that the blobs are relics of a pc-scale accretion-powered collimated outflow.

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G. S. Da Costa, R. Soria, S. A. Farrell, D. Bayliss, M. S. Bessell, F. P. A. Vogt, G. Zhou, S. D. Points, T. C. Beers, Á. R. López-Sánchez, K. W. Bannister, M. Bell, P. J. Hancock, D. Burlon, B. M. Gaensler, E. M. Sadler, S. Tingay, S. C. Keller, B. P. Schmidt, P. Tisserand. 2018-03-16. SMSS J130522.47-293113.0: a high-latitude stellar X-ray source with pc-scale outflow relics?. https://doi.org/10.1093/mnras/sty680

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