Low-mass protostars and dense cores in different evolutionary stages in
  IRAS 00213+6530
  We aim at studying with high angular resolution a dense core associated with
a low-luminosity IRAS source, IRAS 00213+6530, in order to investigate whether
low mass star formation is really taking place in isolation. We performed
observations at 1.2mm with the IRAM 30m telescope, VLA observations at 6cm,
3.6cm, 1.3cm, 7mm, and H2O maser and NH3 lines, and observations with the NASA
70m antenna in CCS and H2O maser. The cm and mm continuum emission, together
with the near infrared data from the 2MASS allowed us to identify 3 YSOs, IRS1,
VLA8A, and VLA8B, with different radio and infrared properties, and which seem
to be in different evolutionary stages. The NH3 emission consists of three
clouds. Two of these, MM1 and MM2, are associated with dust emission, while the
southern cloud is only detected in NH3. The YSOs are embedded in MM1, where we
found evidence of line broadening and temperature enhancements. On the other
hand, the southern cloud and MM2 appear to be quiescent and starless. We
modeled the radial intensity profile at 1.2mm of MM1. The model fits reasonably
well the data, but it underestimates the intensity at small projected distances
from the 1.2mm peak, probably due to the presence of multiple YSOs embedded in
the envelope. There is a differentiation in the relative NH3 abundance with low
values, ~2x10^-8, toward MM1, and high values, up to 10^-6, toward the southern
cloud and MM2, suggesting that these clouds could be in a young evolutionary
stage. IRAS 00213+6530 is harboring a multiple system of low-mass protostars,
indicating that star formation in this cloud is taking place in groups, rather
than in isolation. The low-mass YSOs found in IRAS 00213+6530 are in different
evolutionary stages suggesting that star formation is taking place in different
episodes.
