  We present a survey of H2 jets from young protostars in the Vela-D molecular
cloud (VMR-D), based on Spitzer -IRAC data between 3.6 and 8.0 micron. Our
search has led to the identification of 15 jets and about 70 well aligned knots
within 1.2 squared degree. We compare the IRAC maps with observations of the H2
1-0 S(1) line at 2.12 micron, with a Spitzer-MIPS map at 24 and 70 micron, and
with a map of the dust continuum emission at 1.2 mm. We find a association
between molecular jets and dust peaks. The jet candidate exciting sources have
been searched for in the published catalog of the Young Stellar Objects of
VMR-D. We selected all the sources of Class II or earlier which are located
close to the jet center and aligned with it.The association between jet and
exciting source was validated by estimating the differential extinction between
the jet opposite lobes. We are able to find a best-candidate exciting source in
all but two jets. Four exciting sources are not (or very barely) observed at
wavelengths shorter than 24 micron, suggesting they are very young protostars.
Three of them are also associated with the most compact jets. The exciting
source Spectral Energy Distributions have been modeled by means of the
photometric data between 1.2 micron and 1.2 mm. From SEDs fits we derive the
main source parameters, which indicate that most of them are low-mass
protostars. A significant correlation is found between the projected jet length
and the [24] - [70] color, which is consistent with an evolutionary scenario
according to which shorter jets are associated with younger sources. A rough
correlation is found between IRAC line cooling and exciting source bolometric
luminosity, in agreement with the previous literature. The emerging trend
suggests that mass loss and mass accretion are tightly related phenomena and
that both decrease with time.
