Infrared observations of hot gas and cold ice toward the low mass protostar Elias 29
| Jazyk: | angličtina |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
DENSE MOLECULAR CLOUDS
ABSORPTION FEATURES stars : formation extinction LONG-WAVELENGTH SPECTROMETER SPECTRAL ENERGY-DISTRIBUTIONS ISM : abundances YOUNG STELLAR OBJECTS stars : individual : Elias 29 ISM : molecules infrared : ISM : lines and bands RHO-OPHIUCHI CLOUD TAURUS DARK CLOUD ISM : dust Astrophysics::Solar and Stellar Astrophysics DEEPLY EMBEDDED PROTOSTARS SOLID CO Astrophysics::Earth and Planetary Astrophysics Astrophysics::Galaxy Astrophysics HIGH-RESOLUTION |
| Zdroj: | Astronomy & astrophysics. 360(2):683-698 |
| ISSN: | 0004-6361 |
| Popis: | We have obtained the full 1-200 mu m spectrum of the low luminosity (36 L-circle dot) Class I protostar Elias 29 in the rho Ophiuchi molecular cloud. It provides a unique opportunity to study the origin and evolution of interstellar ice and the interrelationship of interstellar ice and hot core gases around low mass protostars. We see abundant hot CO and H2O gas, as well as the absorption bands of CO, CO2, H2O and "6.85 mu m" ices. We compare the abundances and physical conditions of the gas and ices toward Elias 29 with the conditions around several well studied luminous, high mass protostars. The high gas temperature and gas/solid ratios resemble those of relatively evolved high mass objects (e.g. GL 2591). However, none of the ice band profiles shows evidence for significant thermal processing, and in this respect Elias 29 resembles the least evolved luminous protostars, such as NGC 7538 : IRS9. Thus we conclude that the heating of the envelope of the low mass object Elias 29 is qualitatively different from that of high mass protostars. This is possibly related to a different density gradient of the envelope or shielding of the ices in a circumstellar disk. This result is important for our understanding of the evolution of interstellar ices, and their relation to cometary ices. |
| Databáze: | OpenAIRE |
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