Characterization of a Large Sample of Be-type Emission-line Stars with SDSS-III/APOGEE

Chojnowski, Drew; Beaton, R.; Burton, A.; Cunha, K. M.; Eikenberry, S. S.; Frinchaboy, P. M.; Hasselquist, S.; Hearty, F. R.; Holtzman, J. A.; Majewski, S. R.; Meszaros, Sz.; Nidever, D. L.; O'Connell, R. W.; Perez, A.; Schiavon, R. P.; Schultheis, M.; Shetrone, M. D.; Skrutskie, M. F.; Whelan, D. G.; Wilson, J. C.; Wisniewski, J. P.; Zasowski, G.
Bibliographical reference

American Astronomical Society, AAS Meeting #221, #144.08

Advertised on:
1
2013
Number of authors
22
IAC number of authors
1
Citations
0
Refereed citations
0
Description
In just one year of operation, the SDSS-III/APOGEE survey has amassed the largest collection ever of high-resolution, H-band spectra for Be-type emission-line stars. Of the 300 fibers used in each APOGEE observation, 35 are reserved for hot, telluric-absorption standard stars that are selected from the bluest stars (in J-Ks color) in each field and which are required to be evenly distributed across the plate to trace spatially-variable telluric contamination. The 73 Be stars (245 individual spectra) targeted thus far were visually identified among the 6435 telluric standards as those showing any sign of emission in Br11, the strongest Brackett series line in APOGEE's spectral range. While 26/73 stars were previously tagged as emission-line stars in the literature, the rest are new finds. The double-peaked hydrogen emission lines, viewed in unprecedented detail via APOGEE, are presumably formed in disks or shells surrounding rapidly-rotating, early-type stars. A wide range of intensities, widths, and profile morphologies are included in the sample, allowing for a broad characterization of the Be phenomenon in general. Repeated observations of most of the stars provide information on temporal line profile variation and the Be star binary fraction. Here we use the Brackett emission lines to derive radial velocities and line diagnostics (including FWHM, FWFM, V/R, peak separation) to help classify the sources.