## Abstract

We have obtained 850 and 450 μm continuum maps of 21 low-mass cores with SEDs ranging from pre-protostellar to Class I (18 K < T_{bol} < 370 K), using SCUBA at the JCMT. In this paper we present the maps, radial intensity profiles, and photometry. Pre-protostellar cores do not have power-law intensity profiles, whereas the intensity profiles of Class O and Class I sources can be fitted with power laws over a large range of radii. A substantial number of sources have companion sources within a few arcminutes (two out of five pre-protostellar cores, nine out of 16 Class 0/1 sources). The mean separation between sources is 10,800 AU. The median separation is 18,000 AU including sources without companions as a lower limit. The mean value of the spectral index between 450 and 850 μm is 2.8 ± 0.4, with pre-protostellar cores having slightly lower spectral indices (2.5 ± 0.4). The mean mass of the sample, based on the dust emission in a 120″ aperture, is 1.1 ± 0.9 M_{⊙}. For the sources fitted by power-law intensity distributions (I_{v}(b)/I_{v}(0) = (b/b_{0})^{m}), the mean value of m is 1.52 ± 0.45 for Class 0 and I sources at 850 μm and 1.44 ± 0.25 at 450 μm. Based on a simple analysis, assuming the emission is in the Rayleigh-Jeans limit and that T_{d}(r) ∝ r-^{0.4}, these values of m translate into power-law density distributions (n ∝ r^{-p}) with p ∼ 2.1. However, we show that this result may be changed by more careful consideration of effects such as beam size and shape, finite outer radii, more realistic T_{d}(r), and failure of the Rayleigh-Jeans approximation.

Original language | English (US) |
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Pages (from-to) | 249-271 |

Number of pages | 23 |

Journal | Astrophysical Journal, Supplement Series |

Volume | 131 |

Issue number | 1 |

DOIs | |

State | Published - Nov 2000 |

Externally published | Yes |

## Keywords

- Brown dwarfs submillimeter
- Stars: formation
- Stars: low-mass

## ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science