HST Images and Near-Infrared Polarimetric Images of the Orion Nebula Source PC 190

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Session 48 -- Young Stars
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

[48.03] HST Images and Near-Infrared Polarimetric Images of the Orion Nebula Source PC 190

M.W. Castelaz (East Tenn. St. U.), J. Kastner (MIT), D. Weintraub (Vanderbilt U.), B. McCollum (CSC)

We are using archived HST images of the Orion Nebula to study the relationship between point sources and dark patches of dust apparent in images of the Orion Nebula. We have obtained J, H, and K polarimetric images of the nebula to complement this study. These images were obtained at Kitt Peak in November 1993 using the near-IR SQIID camera and polarimeter mounted at the Cassegrain focus of the KPNO 1.3-m telescope. As part of the study of these 5.5 arcmin x 5.5 arcmin photopolarimetric images, we have taken a close look at one of the sources: PC 190 (Prosser et al. 1994, ApJ, 421, 517). Prosser et al. state that PC 190 is a star with associated nebulosity and is one of the proplyds identified by O'Dell (=OWH 1; OAEDell. Wen, \& Hu 1993, ApJ, 410, 696). High spatial resolution near-infrared images show that PC 190 is extended (=TCC097; McCaughren \& Stauffer 1994 AJ, 108, 1382). In addition, Felli et al. (1993, A\&AS, 98, 137) identify PC 190 as a compact radio source. Felli et al. suggest that the radio source may be an ionized disk surrounding a flaring pre- main-sequence star; this interpretation is also supported by Stauffer et al. (1994, AJ, 108, 1375).

The HST images show extended structure pointing from PC 190 away from the Trapezium. The near-infrared K-band images show asymmetric structure extending about 7 arcseconds with an orientation similar to that apparent in the HST images. We use the H and K photopolarimetric images to estimate extinction in the extended nebulosity and discuss the variation in color with distance from the point source. The K-band polarization map of PC 190 is complicated by polarization of material by IRc2. We will present the polarization map of PC 190 and discuss the net effect of polarization due to the nebulosity of PC 190, and the polarization due to IRc2.

The HST Archive Research work is supported by STScI HST Archive Research Grant AR-4645.01-92A.

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