Gemini Multi-Object Spectrograph Integral Field Unit Spectroscopy of the 167-317 (LV2) Proplyd in Orion

Abstract

We present high spatial resolution spectroscopic observations of the proplyd 167-317 (LV2) near the Trapezium cluster in the Orion Nebula, obtained during the system verification run of the Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (IFU) at the Gemini South Observatory. We have detected 38 forbidden and permitted emission lines associated with the proplyd and its redshifted jet. We have been able to detect three velocity components in the profiles of some of these lines: a peak with a 28–33 km s-1 systemic velocity that is associated with the photoevaporated proplyd flow, a highly redshifted component associated with a previously reported jet (which has receding velocities of about 80–120 km s-1 with respect to the systemic velocity and which is spatially distributed to the southeast of the proplyd), and a less obvious, approaching structure that may possibly be associated with a faint counterjet with a systemic velocity of -75 ± 15 km s-1. We find evidence that the redshifted jet has a variable velocity, with slow fluctuations as a function of the distance from the proplyd. We present several background-subtracted, spatially distributed emission-line maps, and we use this information to obtain the dynamical characteristics over the observed field. Using a simple model and extinction-corrected Hα fluxes, we estimate the mass-loss rate for both the proplyd photoevaporated flow and the redshifted microjet, obtaining proplyd = (6.2 ± 0.6) × 10-7 M⊙ yr-1 and jet = (2.0 ± 0.7) × 10-8 M⊙ yr-1, respectively.