JENAM 2007 Yerevan 20 - 25 August Our non-stable Universe

1. Jet 1 0.30pc Jet 2 Jet 3 0.13pc Jet 5 0.08pc 0.18pc SED's of the driving sources Jet 2 Jet 5 Jet 2 JENAM 2007 Yerevan20 - 25 August Our non-stable Universe Newly detected outflows observed with APEX in the Vela star forming regionMassimo De Luca(1,2), Teresa Giannini(2), Brunella Nisini(2), Dario Lorenzetti(2), Odysseas Dionatos(2)(1)Università di Roma Tor Vergata (Italy), (2)INAF - Osservatorio Astronomico di Roma (Italy) Vela Molecular Cloud D, located on the Galactic plane (700 pc distant) represents one of the most interesting star forming sites in the southern sky. We are performing a multiwavelength study of this region in order to characterize its star formation activity. Here we present some results on outflows driven by low-mass stars as derived from NTT, SPITZER and APEX observations. Near Infrared jets: A H2 1-0S(1) (2.12 μm) survey[1] of dust cores[2] revealed outflowing activity from several low- to intermediate-mass stars. Figures show both H2 (green) and dust (yellow) 1.2 mm emission contours superposed on Spitzer-MIPS 24 mm maps[3] of four jets selected for a first observational run with APEX. In Table 1 we report an estimate of the jet physical parameters, luminosity and dynamical age. This latter suggests that these jets are among the youngest even found. Jet parameters[2]: (a)Assumed L1-0S(1) = LH2/10 (e.g., [4]) and AV = 10 mag. (b)Computed for i = 45° and vshock = 50 km/s. (c)Lbol of the driving source. (d)Only a blue-shifted lobe is visible in the CO map. Driving sources: Spitzer maps allowed us to identify the driving source candidates for three out of four jets (red stars in the Figures). The bolometric luminosity reported in Table 1 is computed by using all available data points, from the NIR bands (2MASS) to 1.2 mm dust continuum emission. The derived SED' s are typical of low-mass very young protostars. Table 1 APEX observations: We observed these four jets by means of APEX, the ESO millimeter facility (APEX-2A heterodyne receiver) selecting the 12CO(3-2) line (345 GHz, 18" HPBW, channel width: 0.5 km/s) to investigate whether or not large scale outflows are associated with the jets and to evaluate the physical conditions of the outflowing material. Results: 4 spectral maps, typically 50" wide with a half beam sampling (9"). Clear evidence of outflowing activity have been found for all jets through the broadening of the line wings. The outflow parameters reported in Table 2 have been computed by following the procedure in [5]. Outflow parameters: (a)Assumed t =1. (b)Computed assuming i = 45°. (c)Due to the very complex CO spectra around jet1, the emission of the gas pertaining to the blue lobe can not be isolated. (d)Map coverage much smaller than the outflow size. The reported parameters should be regarded only as lower limits. Jet 1 Table 2 References: [1]De Luca, M., Giannini, T., Lorenzetti, D., et al. 2007, A&A in press (astro-ph:0704.1228v1) [2]Massi, F., De Luca, M., Elia, D., et al. 2007, A&A 466, 1013 [3]Giannini, T., Lorenzetti, D., De Luca, M., et al. 2007, ApJ submitted [4]Lorenzetti, D., Giannini, T., Vitali, F., Massi, F., Nisini, B. 2002, ApJ 564, 839 [5]Choi, M., Evans, II, N. J., & Jaffe, D. T. 1993, ApJ 417, 624 • Source - jet - outflow: the emerging picture • Both the spectral energy distributions of the driving source candidates and the dynamical ages of jets and outflows indicate these objects as very young protostars, compatibile with Class 0 sources. • Despite the large number of uncertainties (adopted inclination angle and shock velocity, partial mapping), systematic differencies between jet and outflow dynamical ages still exist. This behaviour can be explained by the shorter cooling time of H2 with respect to that of CO; i.e. CO emission is more persistent than H2 emission.