Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2B021

HST Images of Protostellar Disks and Envelopes in Orion

Booker, Joseph (University of Toledo)
Fischer, Will (University of Toledo)
Megeath, Tom (University of Toledo)
Tobin, John (NRAO)
Kounkel, Marina (University of Michigan)
Poteet, Charles (RPI)
Ali, Babar (NHSC/IPAC/Caltech)
Furlan, Elise (NHSC/IPAC/Caltech/NOAO)
Stanke, Thomas (ESO)
Stutz, Amelia (MPIA)

We present near-infrared HST NICMOS+WFC3 images of disk shadows, envelopes, and envelope cavities of 244 Orion protostars at better than 100 AU spatial resolution. Orion is home to half the young stellar objects in the nearest 500 pc and is a largely unexplored ground for scattered-light studies of protostellar envelopes and disks. This region is the focus of HOPS, the Herschel Orion Protostar Survey, a multi-observatory study of protostars using Herschel, Spitzer, Hubble, and APEX. Scattered light images allow us to break degeneracies in fitting the 1-870 micron spectral energy distributions (see posters by E. Furlan and W. Fischer), in particular by constraining the inclination of the source and the opening angle of the envelope cavity. We present a grid of ~2900 models of the scattered light images to show how the nebulosity depends on cavity shape and inclination. For edge-on protostars, the comparison of the HST images to models allows us to determine the properties of protostellar disks by their shape in absorption against the scattered light and by the shadows they cast in the envelope. We present an initial example of HOPS 136 (Fischer et al. in prep.), where we have used the NICMOS data to provide strong constraints on the disk radius, mass, and structure, and we present a sample of 15 edge-on sources that are the subject of a similar analysis.

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