Low‐Mass Star Formation and the Initial Mass Function in IC 348

We have performed deep infrared and optical spectroscopy of virtually the entire stellar population within the 5' × 5' core of IC 348, measuring K (2.2 μm) band and optical spectral types that are in good agreement. We have also identified several sources that may be substellar depending on the choice of temperature scales and evolutionary tracks, with three particularly late-type objects (M7.5-M8) that are likely bonafide brown dwarfs. In conjunction with the theoretical evolutionary tracks of D'Antona however, the derived IMF is dependent on the evolutionary tracks and the detailed shape of the IMF should be viewed with caution until these models are tested against observations, particularly at low masses (10 Å) or Brγ (>1 Å) emission or K-band continuum veiling (rK ≥ 0.5). Since no sources older than 3 Myr show evidence for massive disks, disk lifetimes in the core of IC 348 appear to be shorter than those observed in Taurus or in the outer regions of IC 348.