Astronomy and Astrophysics Letters dedicated to ISO

LWS-spectroscopy of Herbig Haro objects and molecular outflows in the Cha II dark cloud

B. Nisini - D.Lorenzetti - M.Cohen - C.Ceccarelli1 - T.Giannini - R.Liseau - S.Molinari - A. Radicchi - P.Saraceno - L.Spinoglio - E.Tommasi - P.E. Clegg - P.A.R. Ade - C.Armand - M.J. Barlow - M. Burgdorf - E. Caux - P. Cerulli - S.E. Church et al.

Abstract:

We present the first far infrared spectra of the Herbig Haro objects HH 52-53-54 and of IRAS 12496-7650, all located in the nearby star forming region known as Chamaleon II dark cloud, obtained with the Long Wavelength Spectrometer (LWS) onboard the Infrared Space Observatory (ISO). The richest spectrum is found in HH54, showing molecular transitions (CO with Ju from 19 to 14, water vapour mainly in its ortho form and OH) and low excitation fine structure lines ([OI]63, 145 microns, [CII]158 microns). In HH52 and HH53,only the [OI] and [CII] lines are detected. The LWS spectrum of IRAS 12496-7650 shows both fine structure and CO lines. The [CII]158 micron line is ubiquitous in the region, as proved by its presence in all ISO pointings, including the raster scan maps. The fine structure lines are used to evaluate the physical parameters of the emitting regions. In particular, the mass loss rates of each outflow present in the region, are derived from the [OI]63 micron line luminosity.

Keywords:
Stars: formation - Stars: individual: IRAS 12496-7650 - ISM: jets and outflows - ISM: individual objects: HH52,53,54 - Infrared: ISM:lines

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