Windows Through the Dusty Disks Surrounding the Youngest Low-Mass Protostellar Objects
J. Cernicharo,
1*
A. Noriega-Crespo,
2
D. Cesarsky,
3
B. Lefloch,
14
E. González-Alfonso,
1
F. Najarro,
1
E. Dartois,
5
S. Cabrit
6
The formation and evolution of young low-mass stars are
characterized by important processes of mass loss and accretion
occurring in the innermost regions of their placentary circumstellar
disks. Because of the large obscuration of these disks at optical and infrared wavelengths in the early protostellar stages (class 0 sources), they were previously detected only at radio wavelengths using
interferometric techniques. We have detected with the Infrared Space
Observatory the mid-infrared (mid-IR) emission associated with the
class 0 protostar VLA1 in the HH1-HH2 region located in the Orion
nebula. The emission arises in three wavelength windows (at 5.3, 6.6, and 7.5 micrometers) where the absorption due to ices and silicates has
a local minimum that exposes the central part of the young protostellar
system to mid-IR investigations. The mid-IR emission arises from a
central source with a diameter of 4 astronomical units at an averaged
temperature of ~700 K, deeply embedded in a dense region with a
visual extinction of 80 to 100 magnitudes.
1 Consejo Superior de Investigaciones
Científicas, Instituto de Estructura de la Materia,
Departamento Física Molecular, Serrano 121, 28006 Madrid,
Spain.
2 Space Infrared Telescope Facility (SIRTF) Science
Center, California Institute of Technology, Pasadena, CA 91125, USA.
3 Institut d'Astrophysique Spatiale, Bât. 121, Université de Paris XI, 94500 Orsay Cedex, France.
4 Observatoire de Grenoble, Domaine Universitaire de
Grenoble, 414 rue de la Piscine, 38406 St. Martin d'Hères,
France.
5 Institute de Radioastronomie Millimétrique,
Domaine Universitaire de Grenoble, 300 rue de la Piscine, 38406 St.
Martin d'Hères, France.
6 Départament
d'études de la Matière en Infrarouge et
Millimètrique, UMR 8540 du CNRS, Observatoire de Paris, 61 Av. de
l'Observatoire, F-75014 Paris, France.
*
To whom correspondence should be addressed. E-mail:
cerni{at}astro.iem.csic.es
