Unbiased water and methanol maser surveys of NGC 1333
  We present the results of unbiased 22 GHz H2O water and 44 GHz class I CH3OH
methanol maser surveys in the central 7x10 arcmin area of NGC 1333 and two
additional mapping observations of a 22 GHz water maser in a ~3x3arcmin area of
the IRAS4A region. In the 22 GHz water maser survey of NGC 1333 with
sensitivity of sigma~0.3Jy, we confirmed masers toward H2O(B) in the region of
HH 7-11 and IRAS4B. We also detected new water masers at ~20arcsec away in the
western direction of IRAS4B or ~25arcsec away in the southern direction of
IRAS4A. We could not however find young stellar objects or molecular outflows
associated with them. They showed two different velocity components of ~0 and
~16 km/s, which are blue- and red-shifted relative to the adopted systemic
velocity of ~7 km/s for NGC 1333. They also showed time variabilities in both
intensity and velocity from multi-epoch observations and an anti-correlation
between the intensities of the blue- and the red-shifted velocity components.
We suggest that the unidentified powering source of these masers might be in
the earliest evolutionary stage of star formation before the onset of molecular
outflows. Finding this kind of water masers is only possible by an unbiased
blind survey. In the 44 GHz methanol maser survey with sensitivity of sigma~0.5
Jy, we confirmed masers toward the IRAS4A2 and the eastern shock region of the
IRAS2A. Both sources are also detected in 95 and 132 GHz methanol maser lines.
In addition, we had new detections of methanol masers at 95 and 132 GHz toward
IRAS4B. In terms of the isotropic luminosity, we detected the methanol maser
sources brighter than ~5x1025 erg/s from our unbiased survey.
