Confirmation of the VeLLO L1148−IRS: star formation at very low (column) density

• Published in: Monthly notices of the Royal Astronomical Society Vol. 416; no. 3; pp. 2341 - 2358
• Main Authors: Kauffmann, J., Bertoldi, F., Bourke, T. L., Myers, P. C., Lee, C. W., Huard, T. L.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.2011; Wiley-Blackwell; Oxford University Press
• Subjects: Astronomy; Astrophysics; brown dwarfs; Earth, ocean, space; Exact sciences and technology; infrared: stars; ISM: individual objects: L1148; ISM: jets and outflows; Luminosity; Star & galaxy formation; Stars & galaxies; stars: formation; stars: low-mass; stars: formation; ISM: jets and outflows; brown dwarfs; ISM: individual objects: L1148; stars: low-mass; infrared: stars; Stellar cores; Luminosity; Column density; Star formation; Low-mass stars; Brown dwarf stars; Jets; Radiative transfer; Infrared star
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2011.19205.x

We report the detection of a compact (∼5 arcsec; about 1800 au projected size) CO outflow from L1148−IRS. This confirms that this Spitzer source is physically associated with the nearby (≈325 pc) L1148 dense core. Radiative transfer modelling suggests an internal luminosity of 0.08 to 0.13 L⊙. This validates L1148−IRS as a Very Low Luminosity Object (VeLLO; L≤ 0.1 L⊙). The L1148 dense core has unusually low densities and column densities for a star-forming core. It is difficult to understand how L1148−IRS might have formed under these conditions. Independent of the exact final mass of this VeLLO (which is likely <0.24 M⊙), L1148−IRS and similar VeLLOs might hold some clues about the isolated formation of brown dwarfs.