A Remarkable Bow Shock of Hot Dust Surrounding IRS 8

F. Rigaut, T. R. Geballe, J. R. Roy

Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720

E-mail contact: tgeballe@gemini.edu

High resolution H and K images obtained by the Gemini North Telescope of the peculiar infrared source, IRS 8, located roughly 30'' north of the Galactic center, reveal a central pointlike object enveloped in a remarkable bow-shock like structure, whose apex is located 0.22'' (~0.01 pc) to the northeast of the point source. The H-K color of the emission is considerably redder than that of the central star. A UKIRT K band spectrum reveals that the central object of IRS 8 has a featureless continuum and that no shocked line emission (e.g., from H2) is physically associated with the bow. We interpret the bow as resulting from the interaction of the envelope or wind of the central star of IRS 8 with the northern arm of Sgr A West, and its emission as coming from a combination of shock- and radiatively heated dust, with starlight from the central star of IRS 8 and from the Galactic center cluster of hot stars providing most of the heating. IRS 8 may have been flung out of the central cluster as recently as 10,000 years ago.