Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Quick Search
My eDoc
Session History
Support Wiki
Direct access to
document ID:

          Institute: MPI für Astronomie     Collection: Publikationen_mpia     Display Documents

ID: 710016.0, MPI für Astronomie / Publikationen_mpia
The Earliest Phases of Star formation (EPoS). Temperature, density, and kinematic structure of the star-forming core CB 17
Authors:Schmalzl, M.; Launhardt, R.; Stutz, A. M.; Linz, H.; Bourke, T. L.; Beuther, H.; Henning, T.; Krause, O.; Nielbock, M.; Schmiedeke, A.
Date of Publication (YYYY-MM-DD):2014
Title of Journal:Astronomy and Astrophysics
Start Page:id. A7 (11 pp)
Audience:Not Specified
Abstract / Description:Context. The initial conditions for the gravitational collapse of molecular cloud cores and the subsequent birth of stars are still not well constrained. The characteristic cold temperatures (~10 K) in such regions require observations at sub-millimetre and longer wavelengths. The Herschel Space Observatory and complementary ground-based observations presented in this paper have the unprecedented potential to reveal the structure and kinematics of a prototypical core region at the onset of stellar birth. <BR /> Aims: This paper aims to determine the density, temperature, and velocity structure of the star-forming Bok globule CB 17. This isolated region is known to host (at least) two sources at different evolutionary stages: a dense core, SMM1, and a Class I protostar, IRS. <BR /> Methods: We modeled the cold dust emission maps from 100 mum to 1.2 mm with both a modified blackbody technique to determine the optical depth-weighted line-of-sight temperature and column density and a ray-tracing technique to determine the core temperature and volume density structure. Furthermore, we analysed the kinematics of CB17 using the high-density gas tracer N2H+. <BR /> Results: From the ray-tracing analysis, we find a temperature in the centre of SMM1 of T0 = 10.6 K, a flat density profile with radius 9.5 × 103 au, and a central volume density of nH,0 = 2.3 × 105 cm-3. The velocity structure of the N2H+ observations reveal global rotation with a velocity gradient of 4.3 km s-1 pc-1. Superposed on this rotation signature we find a more complex velocity field, which may be indicative of differential motions within the dense core. <BR /> Conclusions: SMM is a core in an early evolutionary stage at the verge of being bound, but the question of whether it is a starless or a protostellar core remains unanswered. The Herschel data (Fig. 2) including N- and T-maps in Fig. 3 are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> ( or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/569/A7">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/569/A7</A>
Free Keywords:dust; extinction; ISM: molecules; ISM: kinematics and dynamics; stars: formation; stars: low-mass; ISM: individual objects: CB 17
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astronomie
Identifiers:ISSN:0004-6361 %R 10.1051/0004-6361/201322176
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.