The W Band Survey: Searching for Water-bearing Brown dwarfs
Tanvi Sharma1*, Wen-Ping Chen1, W-Band authors2
1Graduate Institute of Astronomy, NCU, Zhongli, Taiwan
2W Band Team, UK
* Presenter:Tanvi Sharma,
Brown dwarfs in star-forming regions serve as ideal labs to study and constrain the theories pertaining to their formation. Their cool atmospheres allow molecule formation like water, methane for spectral type later than M6. This study makes use of the water absorption feature to detect such substellar candidates.
Here we present the preliminary analysis of CFHT- WIRCAM data which makes use of a novel, custom-made W-band filter ( centered at 1.45 micron). Three-band photometry from J, H, and W is used to construct a reddening insensitive index (Q) to differentiate substellar candidates from field objects based on the water absorption feature. We inspect the potential candidates selected according to their Q values for the region, specifically the ones with unknown spectral types in literature. One of the aims of this survey is to provide candidates for spectroscopic follow up for confirmation of substellar nature and checks on physical properties. We work to study the effect of extinction towards star-forming regions on Q, and thus understand the reliability of selection criteria to eventually reduce false positives or negatives. We also aim to provide the proper motion of these substellar objects using near-infrared images from CFHT, to justify their association with Rho Ophiuchi cloud complex. We also discuss the future prospects of this work.

Keywords: substellar objects, brown dwarfs, W-Band, reddening insensitive index