we propose very deep isocam and isophot imaging observations to detect the class -i (pre-class 0) protostellar core in the nearby dark cloud l183. our recent analysis of a deep kao image at 160 mu show that the southern ammonia condensation has a peak at 160 mu. moreover, our recent c18o observations combined with other molecular line observations indicate some activity which is reflected in line broadening, but without any typical outflow signatures. we therefore believe that this southern condensation contains a class -i protostar (boss & yorke 1995). this class lies between precollapse clouds and the protostellar core (class 0 protostars) where molecular outflows are present. the predicted temperature of the source is of order 200 k which is only observable with iso. the duration of the class -i stage is expected to be very short, of order 10^4 yrs. the class -i stage should only be detectable with iso. we want to observe the ammonia core at the shorter wavelengths with cam at 7 and 15 micron, and with pht at 60 micron, i.e. at wavelengths where a faint (luke-) warm source should peak. due to the proximity of l183 (d=100 pc) and the excellent sensitivity of iso, we should be able to detect any point like object for which the luminosity is higher than 10^-5 lsun with isocam and 10^-3 lsun with isophot. in case of a detection, this will be the first observation of a true protostar. combined with our fir / submillimetre continuum data we will be able to determine the spectral energy, density, and temperature distribution of the central warm core and its cold envelope on scales down to 600 au.
Instrument
CAM01 , PHT22
Temporal Coverage
1997-08-20T21:50:30Z/1997-08-28T03:05:16Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, Stark et al., 1998, 'A PROTOSTAR IN THE SOUTHERN AMMONIA CORE OF L183questionMark', 1.0, European Space Agency, https://doi.org/10.5270/esa-0r0wdj0
