Abstract
H2 emission has been detected in the bipolar proto-planetaiy nebula IRAS 17150 - 3224 from the 1 -0 S(1), 1-0 S(0), and 2-1 S(1) transitions in the 2 μm region. Line ratios suggest that this emission is due to collisional excitation. High-resolution imaging with NICMOS on HSTshows that the emission comes from four regions: clumps near the ends of the lobes (the brightest region), the lobes in general, a particular region outside the northwest lobe, and a faint loop in the equatorial region. Spatially resolved high-resolution spectra at 2.12 μm reveal that the H2 1-0 S(1) line has a velocity width of about 35 km s-1 in the lobes, consistent with C-type shocks. The emission from the clumps in the lobes appears to arise from the impact of a fast wind with the slower moving material in the AGB wind.
Original language | English (US) |
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Pages (from-to) | 237-245 |
Number of pages | 9 |
Journal | Astrophysical Journal |
Volume | 650 |
Issue number | 1 I |
DOIs | |
State | Published - Oct 10 2006 |
Keywords
- Circumstellar matter
- Infrared: stars
- Planetary nebulae: general stars: AGB and post-AGB
- Stars: mass loss
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science