Search for radio emission from the nearby binary brown dwarf system ε Indi Bab

We have observed the nearest known brown dwarfs, the binary system epsilon Indi Bab (d = 3.626 pc), for 8.6- and 4.8-GHz radio emission with the Australia Telescope Compact Array. If either brown dwarf emits radio flares, then they are respectively at least 5.5 and 1.2 times weaker than LP 944-20, the nearest brown dwarf with detected radio emission. We associate the ROSAT source 1WGA J2203.9 5647 with epsilon Indi Bab since the separation was about 30 arcsec at the time of the ROSAT observation. Assuming the association, then epsilon Indi Bab has an L0.4- 2.4 keV X-ray luminosity of 5.6 x 10(25) erg s(-1) which makes it roughly a factor of 2 less luminous than LP 944-20. The radio non-detections imply that Indi Bab does not violate, or at least does not violate as strongly as LP 944-20, the Gudel-Benz relationship of X-ray and radio emission.