J/ApJS/181/321 Properties of Spitzer c2d dark clouds (Evans+, 2009)
The Spitzer c2d legacy results:
star-formation rates and efficiencies: evolution and lifetimes.
Evans N.J., Dunham M.M., Jorgensen J.K., Enoch M.L., Merin B.,
Van Dishoeck E.F., Alcala J.M., Myers P.C., Stapelfeldt K.R., Huard T.L.,
Allen L.E., Harvey P.M., Van Kempen T., Blake G.A., Koerner D.W.,
Mundy L.G., Padgett D.L., Sargent A.I.
<Astrophys. J. Suppl. Ser., 181, 321-350 (2009)>
=2009ApJS..181..321E 2009ApJS..181..321E
ADC_Keywords: Infrared sources ; Molecular clouds ; Photometry ; YSOs
Keywords: dust, extinction - infrared: stars - ISM: clouds - stars: formation
Abstract:
The c2d Spitzer Legacy project obtained images and photometry with
both IRAC and MIPS instruments for five large, nearby molecular
clouds. Three of the clouds were also mapped in dust continuum
emission at 1.1mm, and optical spectroscopy has been obtained for
some clouds. This paper combines information drawn from studies of
individual clouds into a combined and updated statistical analysis of
star-formation rates and efficiencies, numbers and lifetimes for
spectral energy distribution (SED) classes, and clustering properties.
Current star-formation efficiencies range from 3% to 6%; if star
formation continues at current rates for 10Myr, efficiencies could
reach 15-30%. Star-formation rates and rates per unit area vary from
cloud to cloud; taken together, the five clouds are producing about
260M☉ of stars per Myr.
Description:
The observations here were all obtained by the c2d project or by GTO
observations that we have included in our data. They have been
described in the publications given hereafter: Five large clouds were
selected for the c2d project: Serpens (Eiroa et al., 2008hsf2.book..693E 2008hsf2.book..693E),
Perseus (Bally et al., 2008hsf1.book..308B 2008hsf1.book..308B), Ophiuchus (Wilking et
al., 2008hsf2.book..351W 2008hsf2.book..351W), Lupus (Comeron, 2008hsf2.book..295C 2008hsf2.book..295C), and
Chamaeleon (Luhman, 2008hsf2.book..169L 2008hsf2.book..169L).
Objects:
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RA (2000) DE Designation(s)
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18 29 49 +01 14.8 Serpens = Name Ser dark cloud
13 02.0 -76 38 Cha II = Name Chamaeleon 2 cloud
15 43 02.1 -34 09 06 Lupus I = Lupus 1
16 09.6 -39 03 Lupus III = Lupus 3
16 03 15 -42 06.5 Lupus IV = Lupus 4
03 39 +32.2 Perseus Cloud = Name Per MCld
16 28 06 -24 32.5 Ophiuchus = Name rho Oph dark cloud
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table8.dat 173 1024 2MASS and Spitzer flux densities of YSOs in the
c2d clouds
table9.dat 136 1024 0.36-0.96um flux densities of YSOs in the c2d clouds
table10.dat 104 1024 3.4-100um flux densities of YSOs in the c2d clouds
table11.dat 79 1024 160-1300um flux densities of YSOs in the c2d clouds
table12.dat 112 1024 Properties of YSOs in the c2d clouds
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See also:
J/ApJ/638/293 : 1.1mm sources in the Perseus Molecular Cloud (Enoch+, 2006)
J/A+A/452/245 : Near-IR photometry of PMS stars in rho Oph (Natta+, 2006)
J/ApJ/663/1149 : Spitzer survey of Serpens YSO population (Harvey+, 2007)
J/ApJ/676/427 : MIPS and IRAC data on ChaII PMS stars (Alcala+, 2008)
J/ApJS/177/551 : Spitzer c2d survey of Lupus dark clouds (Merin+, 2008)
Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [EDJ2009] Running source index number
6- 14 F9.3 mJy F1.25 ? 2MASS J band flux density
16- 26 F11.5 mJy e_F1.25 ? Error in F1.25
28- 36 F9.3 mJy F1.65 ? 2MASS H band flux density
38- 46 F9.4 mJy e_F1.65 ? Error in F1.65
48- 55 F8.2 mJy F2.17 ? 2MASS KS band flux density
57- 64 F8.3 mJy e_F2.17 ? Error in F2.17
66- 74 F9.4 mJy F3.6 ? IRAC 3.6 micron flux density
76- 84 F9.5 mJy e_F3.6 ? Error in F3.6
86- 93 F8.3 mJy F4.5 ? IRAC 4.5 micron flux density
95-103 F9.5 mJy e_F4.5 ? Error in F4.5
105-113 F9.3 mJy F5.8 ? IRAC 5.8 micron flux density
115-122 F8.3 mJy e_F5.8 ? Error in F5.8
124-131 F8.2 mJy F8.0 ? IRAC 8.0 micron flux density
133-140 F8.3 mJy e_F8.0 ? Error in F8.0
142-148 F7.2 mJy F24 ? MIPS 24 micron flux density
150-157 F8.3 mJy e_F24 ? Error in F24
159-164 I6 mJy F70 ? MIPS 70 micron flux density
166-173 F8.1 mJy e_F70 ? Error in F70
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [EDJ2009] Running source index number
6- 9 F4.2 mJy F0.36 ? The U band flux density
11- 17 F7.5 mJy e_F0.36 ? Error in F0.36
19- 26 F8.5 mJy F0.44 ? The B band flux density
28- 34 F7.5 mJy e_F0.44 ? Error in F0.44
36- 40 F5.2 mJy F0.55 ? The V band flux density
42- 47 F6.4 mJy e_F0.55 ? Error in F0.55
49- 57 F9.5 mJy F0.64 ? The R band flux density
59- 66 F8.5 mJy e_F0.64 ? Error in F0.64
68- 75 F8.5 mJy F0.665 ? The Hα12 flux density
77- 84 F8.5 mJy e_F0.665 ? Error in F0.665
86- 92 F7.3 mJy F0.79 ? The I band flux density
94-101 F8.5 mJy e_F0.79 ? Error in F0.79
103-109 F7.3 mJy F0.915 ? The m914 band flux density
111-118 F8.5 mJy e_F0.915 ? Error in F0.915
120-126 F7.3 mJy F0.96 ? The z band flux density
128-136 F9.5 mJy e_F0.96 ? Error in F0.96
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [EDJ2009] Running source index number
6- 10 I5 mJy F3.4 ? The L band flux density
12- 16 F5.1 mJy e_F3.4 ? Error in F3.4
18- 22 I5 mJy F5.0 ? The M band flux density
24- 26 I3 mJy e_F5.0 ? Error in F5.0
28- 32 F5.1 mJy F6.7 ? ISO 6.7 micron flux density
34- 38 F5.2 mJy e_F6.7 ? Error in F6.7
40- 44 I5 mJy F12 ? IRAS 12 micron flux density
46- 51 F6.1 mJy e_F12 ? Error in F12
53- 58 F6.1 mJy F14.3 ? ISO 14.3 micron flux density
60- 63 F4.1 mJy e_F14.3 ? Error in F14.3
65- 70 I6 mJy F25 ? IRAS 25 micron flux density
72- 77 F6.1 mJy e_F25 ? Error in F25
79- 84 I6 mJy F60 ? IRAS 60 micron flux density
86- 90 I5 mJy e_F60 ? Error in F60
92- 98 I7 mJy F100 ? IRAS 100 micron flux density
100-104 I5 mJy e_F100 ? Error in F100
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Byte-by-byte Description of file: table11.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [EDJ2009] Running source index number
6- 10 I5 mJy F160 ? MIPS 160 micron flux density
12- 16 I5 mJy e_F160 ? Error in F160
18- 22 I5 mJy F350 ? The 350 micron flux density
24- 27 I4 mJy e_F350 ? Error in F350
29- 33 I5 mJy F450 ? The 450 micron flux density
35- 39 I5 mJy e_F450 ? Error in F450
41- 44 I4 mJy F850 ? The 850 micron flux density
46- 49 I4 mJy e_F850 ? Error in F850
51- 54 I4 mJy F1100 ? The 1100 micron flux density
56- 61 F6.1 mJy e_F1100 ? Error in F1100
63- 66 I4 mJy F1200 ? The 1200 micron flux density
68- 70 I3 mJy e_F1200 ? Error in F1200
72- 74 I3 mJy F1300 ? The 1300 micron flux density
76- 79 F4.1 mJy e_F1300 ? Error in F1300
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Byte-by-byte Description of file: table12.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [EDJ2009] Running source index number
6- 12 A7 --- Cloud Cloud name containing the source
14- 32 A19 --- SSTc2d Spitzer source name (JHHMMSS.ss+DDMMSS.s)
34- 52 A19 --- Class c2d classification (1)
54- 57 F4.1 mag AV The V band extinction (2)
59- 63 F5.2 --- alpha ? Observed 2-24µm spectral index
65- 66 A2 --- l_Tbol [<≥ ] Limit flag on Tbol
67- 70 I4 K Tbol ? Observed bolometric temperature
72- 73 A2 --- l_Lbol [<≥ ] Limit flag on Lbol
74- 81 F8.5 solLum Lbol ? Observed bolometric luminosity
83- 87 F5.2 --- alphac ? Corrected 2-24µm spectral index
89- 90 A2 --- l_Tbolc [<≥ ] Limit flag on Tbolc
91- 94 I4 K Tbolc ? Corrected bolometric temperature
96- 97 A2 --- l_Lbolc [<≥ ] Limit flag on Lbolc
98-105 F8.4 solLum Lbolc ? Corrected bolometric luminosity
107 A1 --- Env Envelope evidence? (3)
109-112 A4 --- Qual Quality of calculated Lbol and Tbol (4)
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Note (1): Only sources with detections in at least three bands could be
classified at all. Sources are labelled as follows:
Galc = Galaxy candidates
YSOc = Candidates for YSOs. Detections in all four IRAC bands and MIPS-1;
see selection criteria in section 3.1.
red = Flux densities at 24um that are at least 3 times the flux density from
the nearest available IRAC band.
PAH_em = Have colors indicative of a peak in the 8um band.
star+dust = The SED is consistent with that of a stellar photosphere for
wavelengths shorter than a particular band but an excess in that band
of at least 3σ. This band was appended to make a full name such
as "YSOc_star+dust(MP1)" where MP1 implies the first MIPS band,
at 24um or "YSOc_star+dust(IR4)" where IR4 implies the fourth
IRAC band, at 8.0µm.
rising = Lack photometry at enough wavelengths to be classified as YSOc, but
were later added as YSOs based on other information. The available
flux densities rise significantly to longer wavelengths (15 cases)
red1 = Lack photometry at enough wavelengths to be classified as YSOc, but
were later added as YSOs based on other information. Source is
detected only in IRAC-4 or MIPS-1 (3 cases).
Note (2): Value of AV used for de-reddening.
Note (3): Indicates whether or not the source is associated with an
envelope as traced by extended millimeter emission (based primarily
on the sample of Enoch et al., 2008ApJ...684.1240E 2008ApJ...684.1240E).
Note (4): Quality flag as follows:
G = Existing photometry provides sufficient spectral coverage for
reliable calculations.
L_I = the source is associated with an envelope and thus likely an
embedded source, but lacks spectral coverage between 24µm
and 1mm. The calculated values of Lbol and Tbol are thus
considered lower and upper limits, respectively.
L_II = the source is not associated with an envelope and has an observed
α≤-0.3, thus is not likely an embedded source, but no
extinction correction could be derived based on available data,
usually because of a lack of sufficient coverage in the near-IR.
The calculated values of Lbol and Tbol are thus considered
lower limits.
O = Other. These three sources were added to the list of YSOs based
on the searches for embedded protostars presented by Jorgensen
et al. (2007ApJ...656..293J 2007ApJ...656..293J; for Perseus) and Jorgensen et al.
(2008ApJ...683..822J 2008ApJ...683..822J; for Ophiuchus), but they are not associated
with envelopes according to Enoch et al. (2008ApJ...684.1240).
They are only detected at one wavelength (24µm), thus
calculations of α, Tbol, and Lbol are not possible. They are
counted as Class I objects when classifying by α and αc;
they are not counted at all when classifying by Tbol and Tbolc.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 26-Oct-2009