First Confirmed Detection of a Bipolar Molecular Outflow from a Young Brown Dwarf

TL;DR

This paper provides the first confirmed evidence of a bipolar molecular outflow from a young brown dwarf, demonstrating that star formation processes extend to planetary-mass objects.

Contribution

It presents the first direct observation of a bipolar molecular outflow in a brown dwarf, showing that such outflows occur at planetary masses as scaled-down versions of stellar processes.

Findings

Detected bipolar molecular outflow from a brown dwarf

Estimated outflow mass of 1.6 x 10^-4 M_Sun

Brown dwarf has a disk with 8 x 10^-3 M_Sun

Abstract

Studying the earliest stages in the birth of stars is crucial for understanding how they form. Brown dwarfs with masses between that of stars and planets are not massive enough to maintain stable hydrogen-burning fusion reactions during most of their lifetime. Their origins are subject to much debate in recent literature because their masses are far below the typical mass where core collapse is expected to occur. We present the first confirmed evidence that brown dwarfs undergo a phase of molecular outflow that is typical of young stars. Using the Submillimeter Array, we have obtained a map of a bipolar molecular outflow from a young brown dwarf. We estimate an outflow mass of 1.6 x 10^-4 M_Sun and a mass-loss rate of 1.4 x 10^-9 M_Sun. These values are over two orders of magnitude smaller than the typical ones for T Tauri stars. From our millimiter continuum data and our own analysis of Spitzer infrared photometry, we estimate that the brown dwarf has a disk with a mass of 8 x 10^-3 M_Sun and an outer disk radius of 80 AU. Our results demonstrate that the bipolar molecular outflow operates down to planetary masses, occurring in brown dwarfs as a scaled-down version of the universal process seen in young stars.