Radio and IR study of the massive star-forming region IRAS 16353−4636
Instituto Argentino de Radioastronomía, CCT – La Plata (CONICET), C.C.5, (1894)
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2 Facultad de Cs. Astronómicas y Geofísicas, UNLP, Paseo del Bosque s/n, (1900) La Plata, Argentina
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3 Departament d’Astronomia i Meteorologia and Institut de Ciènces del Cosmos (ICC), Universitat de Barcelona (IEEC – UB), Martí i Franquès 1, 08028 Barcelona, Spain
4 Laboratoire AIM (UMR 7158 CEA/DSM-CNRS-Université Paris Diderot), Irfu/Service d’Astrophysique, Centre de Saclay, Bât. 709, 91191 Gif-sur-Yvette Cedex, France
5 Australia Telescope National Facility, CSIRO, PO Box 76, Epping, NSW 1710, Australia
6 Instituto de Astronomía y Física del Espacio (IAFE), C.C. 67, Suc. 28, ( 1428 ) Buenos Aires, Argentina
7 Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia 58089, México
8 IALP, UNLP-CONICET, Argentina
Accepted: 19 July 2010
Context. With the latest infrared surveys, the number of massive protostellar candidates has increased significantly. New studies have posed additional questions on important issues about the formation, evolution, and other phenomena related to them. Complementary to infrared data, radio observations are a good tool to study the nature of these objects, and to diagnose the formation stage.
Aims. Here we study the far-infrared source IRAS 16353–4636 with the aim of understanding its nature and origin. In particular, we search for young stellar objects (YSOs), possible outflow structure, and the presence of non-thermal emission.
Methods. Using high-resolution, multi-wavelength radio continuum data obtained with the Australia Telescope Compact Array⋆, we image IRAS 16353–4636 and its environment from 1.4 to 19.6 GHz, and derive the distribution of the spectral index at maximum angular resolution. We also present new JHKs photometry and spectroscopy data obtained at ESO NTT⋆⋆. 13CO and archival H i line data, and infrared databases (MSX, GLIMPSE, MIPSGal) are also inspected.
Results. The radio continuum emission associated with IRAS 16353–4636 was found to be extended (~10 arcsec), with a bow-shaped morphology above 4.8 GHz, and a strong peak persistent at all frequencies. The NIR photometry led us to identify ten near-IR sources and classify them according to their color. We used the H i line data to derive the source distance, and analyzed the kinematical information from the CO and NIR lines detected.
Conclusions. We have identified the source IRAS 16353−4636 as a new protostellar cluster. In this cluster we recognized three distinct sources: a low-mass YSO, a high-mass YSO, and a mildly confined region of intense and non-thermal radio emission. We propose the latter corresponds to the terminal part of an outflow.
Key words: stars: early-type / radio continuum: stars / radiation mechanisms: non-thermal
© ESO, 2010