J/A+A/472/187 12CO outflows towards submm cores in Perseus (Hatchell+, 2007)
Star Formation in Perseus: III. Outflows.
Hatchell J., Fuller G.A., Richer J.S.
<Astron. Astrophys. 472, 187 (2007)>
=2007A&A...472..187H 2007A&A...472..187H
ADC_Keywords: Interstellar medium; Radio lines
Keywords: submillimeter - stars: formation - stars: evolution -
ISM: jets and outflows
Abstract:
We present a search for outflows towards 51 submillimetre cores in
Perseus. With consistently derived outflow properties from a large
homogeneous dataset within one molecular cloud we can investigate
further the mass dependence and time evolution of protostellar mass
loss. Of the 51 cores, 37 show broad linewings indicative of molecular
outflows. In 13 cases, the linewings could be due to confusion with
neighbouring flows but 9 of those sources also have near-infrared
detections confirming their protostellar nature. The total fraction of
protostars in our sample is 65%. All but four outflow detections are
confirmed as protostellar by Spitzer IR detections and only one
Spitzer source has no outflow, showing that outflow maps at this
sensitivity are equally good at identifying protostars as Spitzer.
Outflow momentum flux correlates both with source luminosity and with
core mass but there is considerable scatter even within this one cloud
despite the homogeneous dataset. We fail to confirm the result of
Bontemps et al. (1996A&A...311..858B 1996A&A...311..858B) that Class I sources show lower
momentum fluxes on average than Class 0 sources, with a KS test
showing a significant probability that the momentum fluxes for both
Class 0s and Class Is are drawn from the same distribution. We find
that outflow power may not show a simple decline between the Class 0
to Class I stages. Our sample includes low momentum flux,
low-luminosity Class 0 sources, possibly at a very early evolutionary
stage. If the only mass loss from the core were due to outflows, cores
would last for 105-108years, longer than current estimates of
1.5-4x105years for the mean lifetime for the embedded phase.
Additional mechanisms for removing mass from protostellar cores may be
necessary.
Description:
FITS cubes of 12CO J=3-2 data are presented for each region. Data were
taken between 2000-2003 with RxB3 on the James Clerk Maxwell
Telescope. The temperature scale is TMB assuming a beam efficiency of
0.63. The angular resolution is 14" and the maps are both sampled and
gridded at 5" spacing. Cubes contain 131 velocity channels with
spacing 0.54 km/s. Sources are either given their common names (eg.
IRAS03292+3039) or the source number in Hatchell et al. (2005, Cat.
J/A+A/440/151, and 2007A&A...468.1009H 2007A&A...468.1009H) (eg. hfr80).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
objects.dat 67 33 Objects
images.dat 136 14 List of files containing in fits subdirectory
fits/* . 14 FITS cubes of 12CO J=3-2 data
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See also:
J/A+A/440/151 : Observations at 850um in Perseus clusters (Hatchell+, 2005)
Byte-by-byte Description of file: objects.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Object name
18- 19 I2 h RAh Right ascension (J2000)
21- 22 I2 min RAm Right ascension (J2000)
24- 27 F4.1 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 37 I2 arcsec DEs Declination (J2000)
42- 67 A26 --- FileName Name of the FITS cube file in subdirectory fits
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Byte-by-byte Description of file: images.dat
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Bytes Format Units Label Explanations
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1- 26 A26 --- FileName Name of the FITS cube file
28- 64 A37 --- Title Title of the file
66- 67 A2 --- Fig Figure number in the paper
69-136 A68 --- Com Dimensions and centre of the FITS cube
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Acknowledgements: Jennifer Hatchell, hatchell(at)astro.ex.ac.uk
References:
Hatchell et al., Paper I 2005A&A...440..151H 2005A&A...440..151H, Cat. J/A+A/440/151
Hatchell et al., Paper II 2007A&A...468.1009H 2007A&A...468.1009H
(End) Patricia Vannier [CDS] 04-Aug-2007