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

Phan-Bao, Ngoc; Riaz, Basmah; Lee, Chin-Fei; Tang, Ya-Wen; Ho, Paul T. P.; Martín, Eduardo L.; Lim, Jeremy; Ohashi, Nagayoshi; Shang, Hsien
Referencia bibliográfica

The Astrophysical Journal, Volume 689, Issue 2, pp. L141-L144.

Fecha de publicación:
12
2008
Número de autores
9
Número de autores del IAC
2
Número de citas
56
Número de citas referidas
45
Descripción
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 1.6×10-4 Msolar and a mass-loss rate of 1.4×10-9 Msolar. These values are over 2 orders of magnitude smaller than the typical ones for T Tauri stars. From our millimeter continuum data and our own analysis of Spitzer infrared photometry, we estimate that the brown dwarf has a disk with a mass of 8×10-3 Msolar 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.