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arXiv · 1311.2753

The infrared K-band identification of the DSO/G2 source from VLT and Keck data

Andreas Eckart·M. Horrobin·S. Britzen·M. Zamaninasab·K. Muzic·N. Sabha·B. Shahzamanian·S. Yazici·L. Moser·M. Garcia-Mari·M. Valencia-S.·A. Borkar·M. Bursa·G. Karssen·V. Karas·M. Zajacek·L. Bronfman·R. Finger·B. Jalali·M. Vitale·C. Rauch·D. Kunneriath·J. Moultaka·C. Straubmeier·Y. E. Rashed·K. Markakis·A. Zensus
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Abstract

A fast moving infrared excess source (G2) which is widely interpreted as a core-less gas and dust cloud approaches Sagittarius A* (SgrA*) on a presumably elliptical orbit. VLT K_s-band and Keck K'-band data result in clear continuum identifications and proper motions of this about 19m Dusty S-cluster Object (DSO). In 2002-2007 it is confused with the star S63, but free of confusion again since 2007. Its near-infrared (NIR) colors and a comparison to other sources in the field speak in favor of the DSO being an IR excess star with photospheric continuum emission at 2 microns than a core-less gas and dust cloud. We also find very compact L'-band emission ($<$0.1'') contrasted by the reported extended (0.03'' up to about 0.2'' for the tail) Brgamma emission. The presence of a star will change the expected accretion phenomena, since a stellar Roche lobe may retain a fraction of the material during and after the peri-bothron passage.

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Andreas Eckart, M. Horrobin, S. Britzen, M. Zamaninasab, K. Muzic, N. Sabha, B. Shahzamanian, S. Yazici, L. Moser, M. Garcia-Mari, M. Valencia-S., A. Borkar, M. Bursa, G. Karssen, V. Karas, M. Zajacek, L. Bronfman, R. Finger, B. Jalali, M. Vitale, C. Rauch, D. Kunneriath, J. Moultaka, C. Straubmeier, Y. E. Rashed, K. Markakis, A. Zensus. 2013-11-12. The infrared K-band identification of the DSO/G2 source from VLT and Keck data. https://doi.org/10.1017/s1743921314000726

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