Issue |
A&A
Volume 547, November 2012
|
|
---|---|---|
Article Number | A54 | |
Number of page(s) | 13 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361/201219501 | |
Published online | 25 October 2012 |
Herschel observations of B1-bS and B1-bN: two first hydrostatic core candidates in the Perseus star-forming cloud⋆,⋆⋆
1
IAPS – INAF, via Fosso del Cavaliere 100,
00133
Roma,
Italy
e-mail: pezzuto@iaps.inaf.it
2
Dipartimento di Fisica, Università del Salento,
CP 193, 73100
Lecce,
Italy
3
National Research Council Canada, Herzberg Institute of
Astrophysics, 5071 West Saanich
Road, Victoria BC,
V9E 2E7,
Canada
4
Department of Physics and Astronomy, University of
Victoria, PO Box 355, STN
CSC, Victoria BC,
V8W 3P6,
Canada
5
Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot,
IRFU/Service d’Astrophysique, CEA Saclay, 91191
Gif-sur-Yvette,
France
6
CESR, Observatoire Midi-Pyrénées (CNRS-UPS), Université de
Toulouse, BP
44346, 31028
Toulouse,
France
7
Canadian Institute for Theoretical Astrophysics, University of
Toronto, 60 St. George Street,
Toronto, ON
M5S 3H8,
Canada
8
LAB/OASU-UMR5804, CNRS – University of Bordeaux,
33270
Floirac,
France
9
ESO, Karl Schwarzschild-Strasse 2, 85748
Garching bei München,
Germany
10 Jeremiah Horrocks Institute, University of Central
Lancashire, PR1 2HE, UK
11
Department of Physics and Astrophysics, Open
University, Walton
Hall, Milton Keynes
MK7 6AA,
UK
12
14 Rutherford Appleton Laboratory, Chilton
OX11 0QX,
UK
Received:
27
April
2012
Accepted:
24
September
2012
We report far-infrared Herschel observations obtained between 70 μm and 500 μm of two star-forming dusty condensations, [HKM99] B1-bS and [HKM99] B1-bN, in the B1 region of the Perseus star-forming cloud. In the western part of the Perseus cloud, B1-bS is the only source detected in all six PACS and SPIRE photometric bands, but it is not visible in the Spitzer map at 24 μm. B1-bN is clearly detected between 100 μm and 250 μm. We have fitted the spectral energy distributions of these sources to derive their physical properties, and find that a simple greybody model fails to reproduce the observed spectral energy distributions. At least a two-component model is required, consisting of a central source surrounded by a dusty envelope. The properties derived from the fit, however, suggest that the central source is not a Class 0 object. We then conclude that while B1-bS and B1-bN appear to be more evolved than a pre-stellar core, the best-fit models suggest that their central objects are younger than a Class 0 source. Hence, they may be good candidates to be examples of the first hydrostatic core phase. The projected distance between B1-bS and B1-bN is a few Jeans lengths. If their physical separation is close to this value, this pair would allow studying the mutual interactions between two forming stars at a very early stage of their evolution.
Key words: stars: protostars / stars: individual: [HKM99] B1-bS / stars: individual: [HKM99] B1-bN / stars: individual: [EYG2006] Bolo 81 / stars: individual: [EDJ2009] 295
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.
Appendices are available in electronic form at http://www.aanda.org
© ESO, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.