FLAMINGOS Spectroscopy of New Low‐Mass Members of the Young Cluster IC 348

We present spectroscopy of candidate stellar and substellar members of theyoung cluster IC 348. Using the Florida Multi-Object Imaging Near-InfraredGrism Observational Spectrometer with the 4 meter telescope at Kitt PeakNational Observatory, we have obtained multi-object moderate-resolution(R=1000) J- and H-band spectra of 66 infrared sources (H=12-17) toward IC 348,many of which are difficult to observe spectroscopically at optical wavelengths(I>20) because they are highly reddened and/or intrinsically cool and red. Wehave also observed 19 known cluster members that have optical spectral typesavailable from previous work. By using these latter sources as the spectralclassification standards, we have identified 14 new members of the cluster withtypes of M2-M6 in the sample of 66 new objects. Two additional objects exhibittypes of >M8.5, but cannot be conclusively classified as either field dwarfs orcluster members with available data. We have estimated extinctions,luminosities, and effective temperatures for these 16 M-type objects, placedthem on the H-R diagram, and used the evolutionary models of Chabrier & Baraffeto estimate their masses. If the two candidates at >M8.5 are indeed members,they should be among the least massive known brown dwarfs in IC 348(M/M_sun~0.01).Comment: 15 pages, The Astrophysical Journal, 2004, v618 (January 10