J/MNRAS/459/342 Dense cores in Taurus L1495 cloud (Marsh+, 2016)
A census of dense cores in the Taurus L1495 cloud from the
Herschel Gould Belt Survey.
Marsh K.A., Kirk J.M., Andre P., Griffin M.J., Konyves V., Palmeirim P.,
Men'shchikov A., Ward-thompson D., Benedettini M., Bresnahan D.W.,
Di Francesco J., Elia D., Motte F., Peretto N., Pezzuto S., Roy A.,
Sadavoy S., Schneider N., Spinoglio L., White G.J.
<Mon. Not. R. Astron. Soc., 459, 342-356 (2016)>
=2016MNRAS.459..342M 2016MNRAS.459..342M (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Photometry, millimetric/submm ; Morphology
Keywords: stars: formation - stars: luminosity function, mass function -
ISM: clouds - ISM: individual objects: L1495 -
local interstellar matter - submillimetre: ISM
Abstract:
We present a catalogue of dense cores in a ∼4°x2° field of
the Taurus star-forming region, inclusive of the L1495 cloud, derived
from Herschel SPIRE and PACS observations in the 70µm, 160µm,
250µm, 350µm, and 500µm continuum bands. Estimates of mean
dust temperature and total mass are derived using modified blackbody
fits to the spectral energy distributions. We detect 525 starless
cores of which ∼10-20 per cent are gravitationally bound and
therefore presumably prestellar. Our census of unbound objects is
∼85 per cent complete for M>0.015M☉ in low-density regions
(AV≲5mag), while the bound (prestellar) subset is ∼85 per cent
complete for M>0.1M☉ overall. The prestellar core mass function
(CMF) is consistent with lognormal form, resembling the stellar system
initial mass function, as has been reported previously. All of the
inferred prestellar cores lie on filamentary structures whose column
densities exceed the expected threshold for filamentary collapse, in
agreement with previous reports. Unlike the prestellar CMF, the
unbound starless CMF is not lognormal, but instead is consistent with
a power-law form below 0.3M☉ and shows no evidence for a
low-mass turnover. It resembles previously reported mass distributions
for CO clumps at low masses (M≲0.3M☉). The volume density PDF,
however, is accurately lognormal except at high densities. It is
consistent with the effects of self-gravity on magnetized supersonic
turbulence. The only significant deviation from lognormality is a
high-density tail which can be attributed unambiguously to prestellar
cores.
Description:
The observational data on which the present catalogue is based
consists of a set of images of the L1495 cloud in the Taurus
star-forming region, made as part of the HGBS (Andre et al. 2010). The
data were taken using PACS at 70, 160, 250, 350 and 500 microns in
fast-scanning (60"/s) parallel mode.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 467 536 TAURUS-L1495 observed core catalog
tableb2.dat 156 536 TAURUS-L1495 derived core catalog
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See also:
http://gouldbelt-herschel.cea.fr/ : Herschel Gould Belt Home Page
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/536] Source number (Source_number)
5- 19 A15 --- Name Source name (Source_name)
21 I1 h RAh Right ascension (J2000) (RA2000h)
23- 24 I2 min RAm Right ascension (J2000) (RA2000m)
26- 30 F5.2 s RAs Right ascension (J2000) (RA2000s)
31 A1 --- DE- Declination sign (J2000)
32- 33 I2 deg DEd Declination (J2000) (DEC2000d)
35- 36 I2 arcmin DEm Declination (J2000) (DEC2000m)
38- 42 F5.2 arcsec DEs Declination (J2000) (DEC2000m)
44- 49 F6.1 --- sig70 Detection significance at 70um (Sig_70)
51- 58 E8.5 Jy/beam I70peak Estimate of the peak intensity at 70um
((I_70)peak)
60- 66 E7.4 Jy/beam e_I70peak Error in the estimate of the peak intensity
(e(I70)peak)
68- 73 F6.2 --- C70 Contrast over the local background at 70um
((I_70)peak/Ibg)
75- 82 E8.5 Jy/beam I70conv Peak intensity at 70um after smoothing to a
resolution corresponding to the 500um
((I_70)conv500)
84- 92 E9.5 Jy S70 Estimate of the total flux at 70um (S_70)
94-100 E7.4 Jy e_S70 Error in estimate of the total flux at 70um
(eS70)
102-104 I3 arcsec a70 Estimate of size along major axis at 70um
(a_70)
106-108 I3 arcsec b70 Estimate of size along minor axis at 70um
(b_70)
110-112 I3 deg PA70 Position angle of source major axis at 70um
(E to N) (PA_70)
114-118 F5.1 --- sig160 Detection significance at 160um (Sig_160)
120-127 E8.5 Jy/beam I160peak Estimate of the peak intensity at 160um
((I_160)peak)
129-134 F6.4 Jy/beam e_I160peak Error in the estimate of the peak intensity
at 160um (e(I160)peak)
136-140 F5.2 --- C160 Contrast of the peak intensity at 160um over
the local background ((I_160)peak/Ibg)
142-149 E8.5 Jy/beam I160conv Peak intensity at 160um after smoothing to
a resolution corresponding to the 500um
((I_160)conv500)
151-158 E8.5 Jy S160 Estimate of the total flux at 160um (S_160)
160-165 F6.4 Jy e_S160 Error in estimate of the total flux at
160um (eS160)
167-169 I3 arcsec a160 Estimate of size along major axis at 160um
(a_160)
171-173 I3 arcsec b160 Estimate of size along minor axis at 160um
(b_160)
175-177 I3 deg PA160 Position angle of source major axis at 160um
(E to N) (PA_160)
179-183 F5.1 --- sig250 Detection significance at 250um (Sig_250)
185-191 F7.4 Jy/beam I250peak Estimate of the peak intensity at 250um
((I_250)peak)
193-199 E7.4 Jy/beam e_I250peak Error in the estimate of the peak intensity
at 250um (e(I250)peak)
201-205 F5.2 --- C250 Contrast over the local background at 250um
((I_250)peak/Ibg)
207-212 F6.3 Jy/beam I250conv Peak intensity at 250um after smoothing to a
resolution corresponding to the 500um
((I_250)conv500)
214-220 F7.4 Jy S250 Estimate of the total flux at 250um (S_250)
222-228 E7.4 Jy e_S250 Error in estimate of the total flux at
250um (eS250)
230-232 I3 arcsec a250 Estimate of size along major axis at 250um
(a_250)
234-236 I3 arcsec b250 Estimate of size along minor axis at 250um
(b_250)
238-240 I3 deg PA250 Position angle of source major axis at 250um
(E to N) (PA_250)
242-246 F5.1 --- sig350 Detection significance at 350um (Sig_350)
248-253 F6.4 Jy/beam I350peak Estimate of the peak intensity at 350um
((I_350)peak)
255-261 E7.4 Jy/beam e_I350peak Error in the estimate of the peak intensity
at 350um (e(I350)peak)
263-268 F6.2 --- C350 Contrast over the local background at 350um
((I_350)peak/Ibg)
270-275 F6.4 Jy/beam I350conv Peak intensity at 350um after smoothing to
a resolution corresponding to the 500um
((I_350)conv500)
277-283 F7.4 Jy S350 Estimate of the total flux at 350um (S_350)
285-291 E7.4 Jy e_S350 Error in estimate of the total flux at
350um (eS350)
293-295 I3 arcsec a350 Estimate of size along major axis at 350um
(a_350)
297-299 I3 arcsec b350 Estimate of size along minor axis at 350um
(b_350)
301-303 I3 deg PA350 Position angle of source major axis at 350um
(E to N) (PA_350)
305-309 F5.1 --- sig500 Detection significance at 500um (Sig_500)
311-317 F7.4 Jy/beam I500peak Estimate of the peak intensity at 500um
((I_500)peak)
319-325 E7.4 Jy/beam e_I500peak Error in the estimate of the peak intensity
at 500um (e(I5000)peak)
327-331 F5.2 --- C500 Contrast over the local background at 500um
((I_500)peak/Ibg)
333-340 F8.5 Jy S500 Estimate of the total flux at 500um (S_500)
342-348 E7.4 Jy e_S500 Error in estimate of the total flux at
500um (eS500)
350-352 I3 arcsec a500 Estimate of size along major axis at 500um
(a_500)
354-356 I3 arcsec b500 Estimate of size along minor axis at 500um
(b_500)
358-360 I3 deg PA500 Position angle of source major axis at 500um
(E to N) (PA_500)
362-366 F5.1 --- sigNH2 Detection significance from single scales on
high-res column density map (Sig(N_H2))
368-371 F4.1 10+21cm-2 NH2peak Peak column density at 18.2" resolution,
estimated by getsources ((N_H2)peak)
373-376 F4.2 --- CNH2 Contrast of peak column density over the
local background ((NH2)peak/(NH2)bg)
378-381 F4.1 10+21cm-2 NH2conv Peak column density after smoothing to a
resolution corresponding to the 500um
((N_H2)conv500)
383-386 F4.1 10+21cm-2 NH2bg Column density of local background
((N_H2)bg)
388-390 I3 arcsec aNH2 Estimate of source size along major axis in
column density map (a(NH2))
392-394 I3 arcsec bNH2 Estimate of source size along minor axis in
column density map (b(NH2))
396-398 I3 deg PANH2 Position angle of source major axis in
column density map (PA(NH2))
400 I1 --- Nsed Number of bands in which the source is
significant (Sig_lambda > 5) (N_SED)
402 I1 --- Cflag [0/2] CSAR flag (CSAR_flag) (1)
404 I1 --- CType [1/4] Core type (Core_type) (G1)
406-429 A24 --- Simbad Simbad ID of nearest match if within 1
arcmin of Herschel position (SIMBAD_assoc)
431-467 A37 --- Com Comments
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Note on (1): CSAR flag as follows:
2 = if the getsources core has a counterpart detected by CSAR
(Kirk et al. 2013MNRAS.432.1424K 2013MNRAS.432.1424K) within 6 arcsec of its peak position
1 = if no close CSAR counterpart was found but the peak position of a CSAR
source lies within the FWHM contour of the getsources core in the
high-resolution column density map
0 = otherwise
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Byte-by-byte Description of file: tableb2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/536] Source number (Source_number)
5- 19 A15 --- Name Source name (Source_name)
21 I1 h RAh Right ascension (J2000) (RA2000h)
23- 24 I2 min RAm Right ascension (J2000) (RA2000m)
26- 30 F5.2 s RAs Right ascension (J2000) (RA2000s)
31 A1 --- DE- Declination sign (J2000)
32- 33 I2 deg DEd Declination (J2000) (DEC2000d)
35- 36 I2 arcmin DEm Declination (J2000) (DEC2000m)
38- 42 F5.2 arcsec DEs Declination (J2000) (DEC2000m)
44- 48 F5.3 pc Rad Core radius as observed (radius)
50- 54 F5.3 --- RadBeam Core radius with 18.2 arcsec beam
(radius_beam)
56- 60 F5.3 Msun Mcore Core mass (Core_mass)
62- 66 F5.3 Msun e_Mcore Uncertainty in core mass (eCoremass)
68- 71 F4.1 K Tdust Dust temperature (Dust_T)
73- 76 F4.1 K e_Tdust Uncertainty in dust temperature (eDustT)
78- 81 F4.1 10+21cm-2 NH2peak Peak H2 column density at 500um ((N_H2)peak)
83- 87 F5.2 10+21cm-2 o Average column density observed
(Avecolumna)
89- 93 F5.2 10+21cm-2 d Average column density deconvolved
(Avecolumnb)
95- 99 F5.1 10+4cm-3 nH2peak Beam-averaged peak volume density
((n_H2)peak)
101-105 F5.2 10+4cm-3 <nH2>o Average volume density observed
(Avevolumea)
107-112 F6.2 10+4cm-3 <nH2>d Average volume density deconvolved
(Avevolumeb)
114-119 F6.1 --- Mratio Bonnor-Ebert mass ratio (Bonnor-Ebert)
121 I1 --- CType [1/4] Core type (Core_type) (G1)
123-156 A34 --- Com Comments
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Global notes:
Note on (G1): Core type as follows:
1 = unbound starless
2 = prestellar
3 = candidate prestellar (non-robust)
4 = dense core with embedded protostar
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Acknowledgements:
Eva Verdugo, everdugo(at)sciops.esa.int
Miriam Aberasturi Vega, maberasturi(at)sciops.esa.int
(End) Miriam Aberasturi Vega [Herschel], Patricia Vannier [CDS] 05-Apr-2017