J/A+A/527/A145 Chamaeleon I 870um sources (Belloche+, 2011)
The end of star formation in Chamaeleon I ?
A LABOCA census of starless and protostellar cores.
Belloche A., Schuller F., Parise B., Andre P., Hatchell J., Jorgensen J.K.,
Bontemps S., Weiss A., Menten , K.M., Muders D.
<Astron. Astrophys. 527, A145 (2011)>
=2011A&A...527A.145B 2011A&A...527A.145B
ADC_Keywords: Molecular clouds ; Millimetric/submm sources
Keywords: stars: formation - ISM: individual objects: Chamaeleon I -
ISM: structure - evolution - dust, extinction - stars: protostars
Abstract:
Chamaeleon I is the most active region in terms of star formation in
the Chamaeleon molecular cloud complex. Although it is one of the
nearest low-mass star forming regions, its population of prestellar
and protostellar cores is not known and a controversy exists
concerning its history of star formation.
Our goal is to search for prestellar and protostellar cores and
characterize the earliest stages of star formation in this cloud.
Description:
Table 2 lists the sources extracted with GAUSSCLUMPS from the filtered
870 micron continuum emission map of Chamaeleon I obtained with the
bolometer camera LABOCA at the APEX telescope. These sources are
listed in the order in which they were found by GAUSSCLUMPS, i.e.
roughly in order of decreasing peak flux density.
The 870 micron dust continuum emission map of the Chamaeleon I
molecular cloud is available in FITS format. The data were obtained
with the bolometer camera LABOCA at the APEX telescope. They were
calibrated, reduced, co-added, gridded, smoothed to an effective
angular resolution of 21.2" (FWHM), and written in FITS format with
the BoA software. The flux density unit is Jy/21.2"-beam. The
coordinates are equatorial (J2000) and the offsets are in RADIO
projection.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
11 06 48 -77 18.0 Cham I = NAME Cha 1
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 96 118 Sources extracted with Gaussclumps in the 870um
continuum sum map of Cha I at scale 5, and
possible associations found in the SIMBAD database
table5.dat 96 9 Additional compact sources with SIMBAD association
with a formal peak flux density above 3.5σ
in the 870um continuum map of Cha I filtered up
to scale 5
table6.dat 86 60 Characteristics of starless (or Class 0) sources
extracted with Gaussclumps in the 870um
continuum map of Cha I filtered up to scale 5
table8.dat 83 16 Characteristics of YSOs extracted with Gaussclumps
in the 870um continuum map of Cha I filtered
up to scale 5
table9.dat 83 5 Characteristics of the additional compact sources
listed in Table 5
cha1_870.fit 2880 10039 FITS file of the 870 micron continuum emission
map of Chamaeleon I
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Byte-by-byte Description of file: table[25].dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/84] Source sequential number (1)
4- 5 I2 h RAh Right ascension (J2000)
7- 8 I2 min RAm Right ascension (J2000)
10- 14 F5.2 s RAs Right ascension (J2000)
16 A1 --- DE- Declination sign (J2000)
17- 18 I2 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 26 F4.1 arcsec DEs Declination (J2000)
28- 32 F5.3 Jy Fp Peak flux density at 870um (in Jy/21.2"-beam)
34- 38 F5.3 Jy Ftot Total flux density at 870um
40- 44 F5.1 arcsec amaj Major axis (FWHM)
46- 49 F4.1 arcsec amin Minor axis (FWHM)
51- 55 F5.1 deg PA [-90/90] Position angle (east from north)
57- 60 F4.1 arcsec Size ? Mean source size
(geometrical mean of amaj and amin)
62- 63 A2 --- Type Type of source based on the possible
associations found in the SIMBAD database (2)
65- 87 A23 --- SIMBAD Source found in the SIMBAD database within the
FWHM ellipse
89- 91 A3 --- Stype SIMBAD type of the SIMBAD source
93- 96 F4.1 arcsec Dist ? Distance of the possibly associated SIMBAD
source to the fitted peak position of the
LABOCA source
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Note (1): Sequential number 1-84 in table2, and
Additional sequential number 1-5 in table5.
Note (2): Type of source based on the associations found in the SIMBAD
database as follows:
C = starless core or Class 0 protostar
S = young stellar object (Class I or more evolved)
Sc = candidate association with a YSO
R = residual of a stronger nearby source
A = artefact
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Name, Cha1-CNN
10- 11 I2 --- Seq [1/84] Numbering of Gaussclumps sources like
in Table 2
13- 17 F5.1 arcsec FWHM1 Size of the fitted Gaussian (1)
18 A1 --- --- [x]
19- 22 F4.1 arcsec FWHM2 Size of the fitted Gaussian (1)
24- 27 F4.1 kAU FWHMa1 Size of the fitted Gaussian (1)
28 A1 --- --- [x]
29- 31 F3.1 kAU FWHMa2 Size of the fitted Gaussian (1)
33- 35 F3.1 --- Ra Aspect ratio (1)
37- 40 F4.1 10+21cm-2 Npeak Peak H2 column density (2)
42- 45 F4.1 mag AV Visual extinction derived from 2MASS
47- 51 F5.3 Msun Mpeak Mass in the central beam (HPBW = 21.2") (3)
53- 57 F5.3 Msun Mtot Total mass derived from the Gaussian fit (3)
58- 62 F5.3 Msun M50" Mass computed from the flux measured in an
aperture of 50" in diameter (3)
64- 65 I2 % CM Mass concentration Mpeak/M50"
67- 68 I2 % e_CM Statistical rms uncertainty on CM
70- 73 F4.1 10+5cm-3 npeak Beam-averaged free-particle density within
the central beam (4)
75- 78 F4.1 10+5cm-3 n50" Mean free-particle density computed for the
mass M50" in the aperture of diameter
50" (4)
80- 82 F3.1 --- cn Density contrast npeak/n50"
84- 86 F3.1 --- e_cn Statistical rms uncertainty on cn
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Note (1): Sizes smaller than 25.4" were set to 25.4" to compute the deconvolved
sizes, in order to account for a fit inaccuracy corresponding to a 5σ
detection in peak flux density. As a result, the minimum size that can be
measured is about 2100AU. The aspect ratio is the ratio of the deconvolved
sizes along the major and minor axes.
Note (2): Peak H2 column density computed assuming a dust opacity of
0.01cm2/g. The statistical rms uncertainty is 1.1x1021cm-2.
Note (3): The statistical rms uncertainties of Mpeak and M50" are 0.006 and
0.011M☉, respectively.
Note (4): The statistical rms uncertainties of npeak and n50" are
5.6x104 and 7.2x103cm-3, respectively.
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Byte-by-byte Description of file: table[89].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Name, Cha1-SNN
10- 11 I2 --- Seq [1/87] Numbering of Gaussclumps sources like
in table2 (table8) or table5 (table9)
13- 16 F4.1 arcsec FWHM1 Size of the fitted Gaussian (1)
17 A1 --- --- [x]
18- 21 F4.1 arcsec FWHM2 Size of the fitted Gaussian (1)
23- 26 F4.1 kAU FWHMa1 Deconvolved source size (1)
27 A1 --- --- [x]
28- 30 F3.1 kAU FWHMa2 Deconvolved source size (1)
32- 36 F5.1 --- SNR Peak signal-to-noise ratio of the fitted
Gaussian
38- 42 F5.2 10+21cm-2 Npeak Peak H2 column density (2)
44- 47 F4.1 mag AV Visual extinction derived from 2MASS
49- 54 F6.4 Msun Mpeak Mass in the central beam (HPBW=21.2") (3)
56- 61 F6.4 Msun Mtot Total mass derived from the Gaussian fit (3)
63- 68 F6.4 Msun M50" Mass computed from the flux measured in an
aperture of 50" in diameter (3)
70- 72 I3 % CM Mass concentration Mpeak/M50"
74- 76 I3 % e_CM Statistical rms uncertainty on CM
78- 81 A4 --- Class Infrared class of the nearest YSO listed in
column SIMBAD of table 2 (table8) or
table5 (table9)
83 I1 --- Ref Reference (4)
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Note (1): The deconvolved size is computed from the fitted size multiplied by
(1+1/SNR), with SNR the peak signal-to-noise ratio, and therefore is an
upper limit in most cases. A zero value means that the uncertainty was
still underestimated.
Note (2): Peak H2 column density computed assuming a dust temperature of 20K
and a dust opacity of 0.03cm2/g. The statistical rms uncertainty is
1.5x1020cm-2.
Note (3): The statistical rms uncertainties of Mpeak and M50" are 0.0009 and
0.0015M☉, respectively.
Note (4): References as follows:
2 = Luhman et al. (2008, Cat. J/ApJ/675/1375)
3 = Furlan et al. (2009, Cat. J/ApJ/703/1964)
4 = Henning et al. (1993A&A...276..129H 1993A&A...276..129H)
5 = Luhman & Muench (2008, Cat. J/ApJ/684/654)
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Acknowledgements:
Arnaud Belloche, belloche(at)mpifr-bonn.mpg.de
References:
* 14-Feb-2011: table 2 and fits file (from author)
* 06-Feb-2014: tables 5, 6, 8 and 9 added (from electronic version)
(End) Patricia Vannier [CDS] 06-Jan-2011