2013MNRAS.430.1208P -
Mon. Not. R. Astron. Soc., 430, 1208-1218 (2013/April-1)
Searching for T dwarfs in IC 2391 using methane imaging.
PARKER S.R. and TINNEY C.G.
Abstract (from CDS):
We have performed a 970 arcmin2 (1.75 pc2) survey of the young cluster IC 2391 using the High Acuity Wide field K-band Imager on the Very Large Telescope. Observations were made in both the CH4 and H filters, targeting the methane absorption found in T dwarfs. From our survey of the cluster, five candidate T dwarfs were found. This is substantially smaller than the number that would be found by an equivalent near-infrared broad-band imaging survey, and allowed rapid spectroscopy of all five candidates. Follow-up spectroscopy was carried out using the Folded-port Infrared Echellette on Magellan. These spectra confirm that none of these objects are T dwarfs. This negative result emphasizes the critical importance of follow-up spectroscopy for any photometrically selected candidates, even those from methane imaging. Simulations of the photometric data set, combined with data for known IC 2391 members, imply that the power-law mass function in IC 2391 between 0.003 and 0.13 M☉ has a slope of α < 1.7.
Abstract Copyright:
© 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society (2013)
Journal keyword(s):
brown dwarfs - stars: low-mass
Nomenclature:
Fig. 5, Table 3: [PT2013] N (Nos 1-5).
Simbad objects:
22
View the references in ADS