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arXiv · 1501.01396

New Extinction and Mass Estimates from Optical Photometry of the Very Low Mass Brown Dwarf Companion CT Chamaeleontis B with the Magellan AO System

Ya-Lin Wu·Laird M. Close·Jared R. Males·Travis S. Barman·Katie M. Morzinski·Katherine B. Follette·Vanessa Bailey·Timothy J. Rodigas·Philip Hinz·Alfio Puglisi·Marco Xompero·Runa Briguglio
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Abstract

We used the Magellan adaptive optics (MagAO) system and its VisAO CCD camera to image the young low mass brown dwarf companion CT Chamaeleontis B for the first time at visible wavelengths. We detect it at r', i', z', and Ys. With our new photometry and Teff~2500 K derived from the shape its K-band spectrum, we find that CT Cha B has Av = 3.4+/-1.1 mag, and a mass of 14-24 Mj according to the DUSTY evolutionary tracks and its 1-5 Myr age. The overluminosity of our r' detection indicates that the companion has significant Halpha emission and a mass accretion rate ~6*10^-10 Msun/yr, similar to some substellar companions. Proper motion analysis shows that another point source within 2" of CT Cha A is not physical. This paper demonstrates how visible wavelength AO photometry (r', i', z', Ys) allows for a better estimate of extinction, luminosity, and mass accretion rate of young substellar companions.

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Ya-Lin Wu, Laird M. Close, Jared R. Males, Travis S. Barman, Katie M. Morzinski, Katherine B. Follette, Vanessa Bailey, Timothy J. Rodigas, Philip Hinz, Alfio Puglisi, Marco Xompero, Runa Briguglio. 2015-01-07. New Extinction and Mass Estimates from Optical Photometry of the Very Low Mass Brown Dwarf Companion CT Chamaeleontis B with the Magellan AO System. https://doi.org/10.1088/0004-637x%2F801%2F1%2F4

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