L1448 IRS 2: A HIRES‐identified Class 0 Protostar

Abstract

We present far-infrared and submillimeter images and millimeter-continuum photometry for L1448 IRS 2, a low-luminosity (5.2 L☉), embedded young stellar object discovered by IRAS. New far-infrared maps were produced from the archival IRAS data via high-resolution (HIRES) processing, the name given to the implementation of the maximum correlation method for image construction from the IRAS data streams. The HIRES-processed images of L1448 IRS 2 presented here have effective resolutions of ~35'' × 28'', ~35'' × 37'', and ~45'' × 40'' at 25, 60, and 100 μm, respectively, which represent an order of magnitude improvement over previously available far-infrared maps. L1448 IRS 2 was mapped at 450 and 850 μm, and we acquired continuum photometry at 1.3 mm. With these new data, we plot the most complete spectral energy distribution for L1448 IRS 2 to date. We also present sensitive 12CO J=1→0 emission-line maps of a 47' × 7' area of the L1448 dark cloud, centered on L1448 IRS 2, obtained with the on-the-fly imaging capability of the NRAO 12 m telescope. As a direct consequence of this mapping, we have discovered a parsec-scale molecular outflow associated with L1448 IRS 2. The combined continuum and molecular line data confirm the classification of L1448 IRS 2 as a new member of the rare, short-lived (a few × 104 yr), Class 0 phase of protostellar evolution. The use of HIRES imaging of IRAS data as a promising tool for identifying protostellar candidates is demonstrated by the example of L1448 IRS 2.