Deep Near‐Infrared Observations of L1014: Revealing the Nature of the Core and Its Embedded Source

Abstract

Recently, the Spitzer Space Telescope discovered L1014-IRS, a mid-infrared source with protostellar colors, toward the heretofore ''starless'' core L1014. We present deep near-infrared observations that show a scattered light nebula extending from L1014-IRS. This nebula resembles those typically associated with protostars and young stellar objects, tracing envelope cavities presumably evacuated by an outflow. The northern lobe of the nebula has an opening angle of $100, while the southern lobe is barely detected. Its morphology suggests that the bipolar cavity and inferred protostellar disk are not inclined more than 30 from an edge-on orientation. The nebula extends at least 8 00 from the source at K s , strongly suggesting that L1014-IRS is embedded within L1014 at a distance of 200 pc rather than in a more distant cloud associated with the Perseus arm at 2.6 kpc. In this case, the apparently low luminosity of L1014-IRS, 0.090 L , is consistent with it having a substellar mass. However, if L1014-IRS is obscured by a circumstellar disk, its luminosity and inferred mass may be greater. Using near-infrared colors of background stars, we investigate characteristics of the L1014 molecular cloud core. We determine a mass of 3.6 M for regions of the core with A V ! 2 mag. A comparison of the radial extinction profile of L1014 with other cores suggests that L1014 may be among the most centrally condensed cores known, perhaps indicative of the earliest stages of brown dwarf or star formation processes.

Far-infrared/submillimetre properties of pre-stellar cores L1521E, L1521F and L1689B as revealed by theHerschelSPIRE instrument – I. Central positions

“…Crapsi et al (2004) explain this by suggesting that L1521F is less chemically evolved and has a molecular hole of radius < 2000 AU. Onishi, Mizuno & Fukui (1999) have speculated that the spatially compact (<30 ) line wings seen in HCO + (3-2) lines may be due to bipolar outflow emission similar to that seen from L1014-IRS by Huard et al, (2006). A well-defined bipolar scattered light nebula seen at short wavelengths (<5 µm) by Bourke et al, (2006) also suggests the presence of molecular outflows in L1521F similar to those from low-mass protostars.…”

Distances to dense cores that contain very low luminosity objects

“…However, Spitzer observations of L1014, which is considered as a starless core, as a part of Spitzer Legacy program "From Molecular Cores to Planet Forming Disks" (or c2d; Evans et al 2003) came as a surprise! The core L1014 was found to contain an embedded source, L1014−IRS, with a very low luminosity of L ∼ 0.09 L (Young et al 2004;Bourke et al 2005;Huard et al 2006). The VeLLOs in fourteen more cores were identified in the full c2d sample (Dunham et al 2008).…”

The Spitzer c2d Survey of Nearby Dense Cores. II. Discovery of a Low-Luminosity Object in the "Evolved Starless Core" L1521F

“…0.1 L , (Young et al 2004;Bourke et al 2005;Huard et al 2006). Interestingly, L1014 shows very little evidence of being an evolved core (Crapsi et al 2005b).…”