Star formation in the Vela Molecular Clouds: A new protostar powering a bipolar jet

¹ INAF - Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monteporzio Catone, Italy e-mail: [giannini;caratti;lorenzetti;nisini;vitali]@mporzio.astro.it
² INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy e-mail: [fmassi;lindapod]@arcetri.astro.it
³ Università degli Studi di Firenze, Piazza S.Marco 4, 50121 Firenze, Italy
⁴ Università degli Studi di Roma “Tor Vergata”, via della Ricerca Scientifica 1, 00133 Roma, Italy
⁵ Stockholm Observatory, AlbaNova University Centre, 10691 Stockholm, Sweden e-mail: rene@astro.su.se
⁶ European Southern Observatory, Casilla 19001, Santiago 19, Chile e-mail: glocurto@eso.org

Received: 6 September 2004
Accepted: 24 November 2004

Abstract

We have performed a detailed study of the star-forming region associated with the IRAS source 08448-4343 in the cloud D of the Vela Molecular Ridge. Our investigation covers a wide spectral range from the near IR, through the thermal IR to the mm-band exploiting both imaging and spectroscopic facilities in each spectral regime. A picture emerges of a dust structure which hosts a near IR cluster and multiple well-collimated H₂ jets; these jets originate from different sources lying in a compact region at the cluster centre. The peak of the 1.2 mm map does not coincide with the IRAS peak, thus tracing a less evolved and denser region with a colder dust with respect to that traced by IRAS. This view is also confirmed by the observations of CS transitions from to . The mm peak can be associated with the position of a red object, already proposed in previous studies as the driving source of the main jet in the field. This jet, extended along more than 0.3 pc, is composed of individual knots whose radial velocities decrease with increasing distance from the central source, which is resolved into at least six 2 μm peaks. The reddest and coldest of these peaks is well aligned with the inner knots of the jet. The spectral energy distribution of the central source resembles that of an intermediate luminosity, Class I protostar, whose youth is discussed in terms of the efficiency of the energy transfer into the jet.