hh jets and molecular outflows represent probably different aspects of the same physical phenomena : the formation of stars and their first stages of evolution. this conexion between hh jets and molecular outflows has been strongly confirmed recently by cernicharo and reipurth (1996) in hh111 where they have found extremely high velocity co bullets just and the end of the optical jet, i.e. the jet appears to coexist with previous ejections of matter from the newly formed star similar to that found in class 0 sources. in proposal hh_jets we have obtained a cvf of hh1-2 and images of hh111. in hh1-2 we have detected the exciting source of the optical jet and we have discovered a dust counterpart to this jet. figure 1 shows a isocam map taken with the lw2 filter and pixel size of 6 of the hh1-2 region. the central source (which is not visible in the near infrared) appears very prominently (see figure 2 and 3). running northwest of this source we have found collimated emission coinciding in position and size with the molecular emission of h2 in its ro-vibrational band at 2 um. the emission over the jet (see figure 3) is featureless which means that we are observing emission from warm dust. it appears very strong 6 arcsec north of the star with a completely different spectrum. the enhancement of the emission can be seen in several positions. the exciting source exhibits a spectrum typical of a deeply embedded young star (see figures 2 and 3). absorption features due to silicates, h2o (6 um), co2 (15 um) and the unknown 6.7 um band are easily identified. the co2 feature is so strong that it can observed at several positions. there is no doubt that we are observing the cocoon around the central star. in the direction of the hh2 object we have found two different kind of shocks (see figure 4): a dissociative shock showing only strong neii emission and one no-dissociative shock exhibiting all the pure rotational lines of h2 from s(2) to s(8). the proposed follow up will constitute an important input to the study of the formation of young stars, the physical properties of their circumstellar disk and the temperature of the dust jet.
Instrument
CAM04
Temporal Coverage
1998-04-06T17:30:50Z/1998-04-06T18:32:34Z
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, CERNICHARO et al., 1999, 'DISCOVERY OF A DUST JET AND A CIRCUMSTELLAR DISK IN HH1-2 FOLLOW UP OF PROPOSAL HH_JETS', 1.0, European Space Agency, https://doi.org/10.5270/esa-ubkwgro
