Universität zu Köln

Howard, A. D. P., Whitworth, A. P., Marsh, K. A., Clarke, S. D., Griffin, M. J., Smith, M. W. L. and Lomax, D. (2019). L1495 revisited: a PPMAP view of a star-forming filament. Mon. Not. Roy. Astron. Soc., 489 (1). S. 962 - 977. OXFORD: OXFORD UNIV PRESS. ISSN 1365-2966

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Abstract

We have analysed the Herschel and SCUBA-2 dust continuum observations of the main filament in the Taurus L1495 star-forming region, using the Bayesian fitting procedure PPMAP. (i) If we construct an average profile along the whole length of the filament, it has FWHM similar or equal to 0.087 +/- 0.003 pc; but the closeness to previous estimates is coincidental. (ii) If we analyse small local sections of the filament, the column-density profile approximates well to the form predicted for hydrostatic equilibrium of an isothermal cylinder. (iii) The ability of PPMAP to distinguish dust emitting at different temperatures, and thereby to discriminate between the warm outer layers of the filament and the cold inner layers near the spine, leads to a significant reduction in the surface-density, Sigma, and hence in the line-density, mu. If we adopt the canonical value for the critical line-density at a gas-kinetic temperature of 10K, mu(CRIT) similar or equal to 16M(circle dot) pc(-1), the filament is on average trans-critical, with (mu) over bar similar to mu(CRIT); local sections where mu > mu(CRIT) tend to lie close to prestellar cores. (iv) The ability of PPMAP to distinguish different types of dust, i.e. dust characterized by different values of the emissivity index, beta, reveals that the dust in the filament has a lower emissivity index, beta less than or similar to 1.5, than the dust outside the filament, ss greater than or similar to 1.7, implying that the physical conditions in the filament have effected a change in the properties of the dust.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Howard, A. D. P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Whitworth, A. P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Marsh, K. A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Clarke, S. D. UNSPECIFIED UNSPECIFIED UNSPECIFIED Griffin, M. J. UNSPECIFIED UNSPECIFIED UNSPECIFIED Smith, M. W. L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Lomax, D. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-132649
DOI:	10.1093/mnras/stz2234
Journal or Publication Title:	Mon. Not. Roy. Astron. Soc.
Volume:	489
Number:	1
Page Range:	S. 962 - 977
Date:	2019
Publisher:	OXFORD UNIV PRESS
Place of Publication:	OXFORD
ISSN:	1365-2966
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language TAURUS MOLECULAR CLOUD; INTERSTELLAR DUST; DENSE CORES; SCUBA-2; TEMPERATURE; NOISE; JCMT Multiple languages Astronomy & Astrophysics Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/13264