Mid-infrared spectra of Class I protostars in Taurus
Por:
Watson D.M., Kemper F., Calvet N., Keller L.D., Furlan E., Hartmann L., Forrest W.J., Chen C.H., Uchida K.I., Green J.D., Sargent B., Sloan G.C., Herter T.L., Brandl B.R., Houck J.R., Najita J., D'Alessio P., Myers P.C., Barry D.J., Hall P., Morris P.W.
Publicada:
1 ene 2004
Resumen:
We present Spitzer Space Telescope Infrared Spectrograph observations in the 5.3-20 ?m range of five young stellar objects in Taurus that have Class I continuum spectral energy distributions (?F ???n, n ? 0), often taken to represent the youngest stellar objects in this star formation region. The spectra include a rich collection of broad absorption features that we identify with amorphous silicates and various ices, notably those of carbon dioxide and water. We show that the absorption features are produced mainly in the envelopes of these systems. The apparent depths of silicate and 15.2 ?m CO2 ice features vary among the objects in a manner that is consistent with a variation of inclination with respect to the line of sight, contribution to the silicate features from material throughout the envelopes, and an origin for the CO2 ice feature in the outer parts of the envelope. Thus, these features provide new and useful constraints on models of the physical structure of Class I protostars.
Filiaciones:
Watson D.M.:
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171, United States
Kemper F.:
Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1562, United States
Calvet N.:
Harvard-Smithsonian Ctr. Astrophys., 60 Garden Street, Cambridge, MA 02138, United States
Keller L.D.:
Department of Physics, Ithaca College, Ithaca, NY 14850, United States
Furlan E.:
Ctr. for Radiophysics and Space Res., Cornell University, Space Sciences Building, Ithaca, NY 14853-6801, United States
Hartmann L.:
Harvard-Smithsonian Ctr. Astrophys., 60 Garden Street, Cambridge, MA 02138, United States
Forrest W.J.:
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171, United States
Chen C.H.:
Jet Propulsion Laboratory, MC 169-506, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
Uchida K.I.:
Ctr. for Radiophysics and Space Res., Cornell University, Space Sciences Building, Ithaca, NY 14853-6801, United States
Green J.D.:
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171, United States
Sargent B.:
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171, United States
Sloan G.C.:
Ctr. for Radiophysics and Space Res., Cornell University, Space Sciences Building, Ithaca, NY 14853-6801, United States
Herter T.L.:
Ctr. for Radiophysics and Space Res., Cornell University, Space Sciences Building, Ithaca, NY 14853-6801, United States
Brandl B.R.:
Sterrewacht Leiden, P.O. Box 9513, 2300 RA Leiden, Netherlands
Houck J.R.:
Ctr. for Radiophysics and Space Res., Cornell University, Space Sciences Building, Ithaca, NY 14853-6801, United States
Najita J.:
Natl. Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719, United States
D'Alessio P.:
Ctro. de Radioastronomia Y Astrofis., UNAM, Apartado Postal 3-72 (Xangari), 58089 Morelia, Michoacán, Mexico
Myers P.C.:
Harvard-Smithsonian Ctr. Astrophys., 60 Garden Street, Cambridge, MA 02138, United States
Barry D.J.:
Ctr. for Radiophysics and Space Res., Cornell University, Space Sciences Building, Ithaca, NY 14853-6801, United States
Hall P.:
Ctr. for Radiophysics and Space Res., Cornell University, Space Sciences Building, Ithaca, NY 14853-6801, United States
Morris P.W.:
Spitzer Science Center, Infrared Proc. and Analysis Center, California Institute of Technology, Pasadena, CA 91125, United States
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