2023MNRAS.521.4579S

Low-mass stars like our Sun begin their evolution within cold (10 K) and dense (∼10⁵ cm^–3) cores of gas and dust. The physical structure of starless cores is best probed by thermal emission of dust grains. We present a high-resolution dust continuum study of the starless cores in the B10 region of the Taurus Molecular Cloud. New observations at 1.2 and 2.0 mm (12 and 18 arcsec resolution) with the NIKA2 instrument on the IRAM 30m have probed the inner regions of 14 low-mass starless cores. We perform sophisticated 3D radiative transfer modelling for each of these cores through the radiative transfer framework pandora, which utilizes RADMC-3D. Model best-fits constrain each cores' central density, density slope, aspect ratio, opacity, and interstellar radiation field strength. These 'typical' cores in B10 span central densities from 5 × 10⁴ to 1 × 10⁶ cm^–3, with a mean value of 2.6 × 10⁵ cm^–3. We find the dust opacity laws assumed in the 3D modelling, as well as the estimates from Herschel, have dust emissivity indices, β's, on the lower end of the distribution constrained directly from the NIKA2 maps, which averages to β = 2.01 ± 0.48. From our 3D density structures and archival NH₃ data, we perform a self-consistent virial analysis to assess each core's stability. Ignoring magnetic field contributions, we find nine out of the 14 cores (64 per cent) are either in virial equilibrium or are bound by gravity and external pressure. To push the bounded cores back to equilibrium, an effective magnetic field difference of only ∼15 $\mu$G is needed.