A spectroscopic examination of accretion diagnostics for near solar mass stars in IC 348

High-resolution optical and moderate-resolution near-infrared spectra were obtained for 40 near solar mass (similar to 2.0-0.5 M(circle dot)) members of the 2-3 Myr old cluster IC 348 in order to examine established accretion diagnostics and the coupling between inner disk gas and hot, micron-sized dust grains inferred from thermal and mid-infrared excesses. The stellar sample was drawn from the cluster census of Luhman in 2003 with membership being confirmed by radial velocity analysis and the presence of strong Li I lambda 6708 absorption. Of the stars included in this survey, 12 were classified by Lada in 2006 as hosting primordial, optically thick circumstellar disks, 5 as weak or transition disk systems, and 23 as non-excess stars using the measured slope of the stellar spectral energy distribution (SED) through the four Infrared Array Camera channels (3.6-8.0 mu m) of Spitzer Space Telescope. Using the velocity width of Ha as an accretion indicator, we find that 11 primordial disk candidates are suspected accretors, suggesting a strong correlation between gaseous inner disks and optically thick dust emission. Of the five weak or transition disk systems observed, two (L21 and L67) exhibit spectroscopic features indicative of accretion. The presence of gas within the inner disk of these systems, which are free of infrared excess emission shortward of similar to 4.5 mu m, may place constraints upon the physical mechanism responsible for inner disk clearing. Mass accretion rates ((M) over dot) were determined for all suspected accretors using continuum excess measurements near lambda 6500 and established relationships between He I lambda 5876, Ha, Ca II lambda 8542, Pa beta, and Br gamma line fluxes andaccretion luminosity. ((M) over dot) values were found to range from log ((M) over dot) = -8.7 to -7.2 M(circle dot) yr(-1), with a median value of -8.1 M(circle dot) yr(-1). Magnetospheric accretion models of H alpha, Pa beta, and Br gamma emission by Muzerolle et al. and Kurosawa et al. are found to be in relative agreement with observed fluxes and derived ((M) over dot) estimates. He I lambda 10830 with its metastable lower level is confirmed to be a critical indicator of magnetospheric accretion, although deep subcontinuum absorption profiles often associated with its emission are not fully understood. No statistically significant correlation is found between ((M) over dot) and the slope of the SED from 3.6 to 8.0 mu m or from 8.0 to 24.0 mu m; however, the small number of suspected accretors examined does not allow broader conclusions to be drawn.