A deep look at the T-type brown dwarf binary ε Indi Bab with Chandra and the Australia Telescope Compact Array

We present deep observations of the nearby T-type brown dwarf binary epsilon Indi Bab in radio with the Australia Telescope Compact Array and in X-rays with the Chandra X-Ray Observatory. Despite long integration times, the binary ( composed of T1 and T6 dwarfs) was not detected in either wavelength regime. We reached 3 sigma upper limits of 1.23 X 10(12) and 1.74 X 10(12) ergs s(-1) Hz(-1) for the radio luminosity at 4.8 and 8.64 GHz, respectively; in X-rays, the upper limit in the 0.1-10 keV band was 3.16 X 10(23) ergs s(-1). We discuss the above results in the framework of magnetic activity in ultracool, low-mass dwarfs.