Dust properties of the cometary globule Barnard 207 (LDN 1489)

TL;DR

This study characterizes the dust properties of the cometary globule Barnard 207 using multi-wavelength observations, revealing larger dust grains and mantle formation consistent with dust evolution models, and explores turbulence's role in dust distribution.

Contribution

It provides detailed physical and dust grain property analysis of B207, confirming the presence of larger grains and mantle formation, and discusses dust distribution mechanisms within the globule.

Findings

Detection of larger dust grains via coreshine and albedo increase

Dust properties align with the THEMIS dust evolution model

Turbulence may influence dust grain distribution

Abstract

Barnard 207 (B207, LDN 1489, LBN 777), also known as the Vulture Head nebula, is a cometary globule in the Taurus-Auriga-Perseus molecular cloud region. B207 is known to host a Class I protostar, IRAS 04016+2610, located at a projected distance of ~8,400 au from the dense core centre. Using imaging and photometry over a wide wavelength range, from UV to sub-mm, we study the physical properties of B207 and the dust grains contained within. The core density, temperature, and mass are typical of other globules found in the Milky Way interstellar medium (ISM). The increase in the dust albedo with increasing optical wavelengths, along with the detection of coreshine in the near infrared, indicates the presence of larger dust grains in B207. The measured optical, near-, mid- and far-infrared intensities are in agreement with the CMM+AMM and CMM+AMMI dust grain type of The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS), suggesting mantle formation on the dust grains throughout the globule. We investigate the possibility of turbulence being responsible for diffusing dust grains from the central core to external outer layers of B207. However, in situ formation of large dust grains cannot be excluded.