J/A+A/635/A34 Catalog of dense cores in Orion B from Herschel (Konyves+, 2020)
Properties of the dense core population in Orion B as seen by the Herschel Gould
Belt survey.
Konyves V., Andre P., Arzoumanian D., Schneider N., Men'shchikov A.,
Bontemps S., Ladjelate B., Didelon P., Pezzuto S., Benedettini M.,
Bracco A., Di Francesco J., Goodwin S., Rygl K. L. J., Shimajiri Y.,
Spinoglio L., Ward-Thompson D., White G. J.
<Astron. Astrophys. 635, A34 (2020)>
=2020A&A...635A..34K 2020A&A...635A..34K (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Regional catalog ; Infrared sources ; Interstellar medium ;
Combined data ; Photometry, millimetric/submm
Keywords: stars: formation - ISM: clouds - ISM: structure -
ISM: individual objects: Orion B complex - submillimeter: ISM
Abstract:
We present a detailed study of the Orion B molecular cloud complex
(d∼400pc), which was imaged with the PACS and SPIRE photometric
cameras at wavelengths from 70-micron to 500-micron as part of the
Herschel Gould Belt survey (HGBS). We release new high-resolution maps
of column density and dust temperature for the whole complex, derived
in the same consistent manner as for other HGBS regions. In the
filamentary subregions NGC2023 and 2024, NGC2068 and 2071, and L1622,
a total of 1768 starless dense cores were identified based on Herschel
data, 490-804 (∼28-45%) of which are self-gravitating prestellar cores
that will likely form stars in the future. A total of 76 protostellar
dense cores were also found. The typical lifetime of the prestellar
cores was estimated to be tpreOrionB=1.7(-0.6/+0.8)Myr. The
prestellar core mass function (CMF) derived for the whole sample of
prestellar cores peaks at ∼0.5Msun (in dN/dlogM format) and is
consistent with a power-law with logarithmic slope -1.27±0.24 at the
high-mass end, compared to the Salpeter slope of -1.35. In the Orion B
region, we confirm the existence of a transition in prestellar core
formation efficiency (CFE) around a fiducial value AVbg∼7mag in
background visual extinction, which is similar to the trend observed
with Herschel in other regions, such as the Aquila cloud. This is not
a sharp threshold, however, but a smooth transition between a regime
with very low prestellar CFE at AVbg<5 and a regime with higher,
roughly constant CFE at AVbg≳10. The total mass in the form of
prestellar cores represents only a modest fraction (∼20%) of the dense
molecular cloud gas above AVbg≳7mag. About 60-80% of the
prestellar cores are closely associated with filaments, and this
fraction increases up to >90% when a more complete sample of
filamentary structures is considered. Interestingly, the median
separation observed between nearest core neighbors corresponds to the
typical inner filament width of ∼0.1pc, which is commonly observed in
nearby molecular clouds, including Orion B. Analysis of the CMF
observed as a function of background cloud column density shows that
the most massive prestellar cores are spatially segregated in the
highest column density areas, and suggests that both higher- and
lower-mass prestellar cores may form in denser filaments.
Description:
Based on Herschel Gould Belt survey (Andre et al.,
2010A&A...518L.102A 2010A&A...518L.102A) observations of the Orion B cloud complex, and
using the multi-scale, multi-wavelength source extraction algorithm
getsources (Men'shchikov et al., 2012A&A...542A..81M 2012A&A...542A..81M), we identified a
total of 1844 dense cores, including 1768 starless cores and 76
protostellar cores.
The observed properties of all dense cores are given in tablea1.dat,
and their derived properties are listed in tablea2.dat. At the end of
tablea1.dat, observed properties of 26 additional tentative cores are
also listed, see Sect. 3.5.2 of the paper for details.
Objects:
----------------------------------------------
RA (2000) DE Designation(s)
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05 41 43.0 -01 54 44 Orion B = NAME Ori B
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 999 1870 Observed properties of dense cores in Orion B
tablea2.dat 165 1844 Derived properties of dense cores in Orion B
list.dat 105 2 List of fits images
fits/* . 2 Individual fits images
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See also:
J/ApJ/559/307 : Sub-mm mapping in Orion B molecular cloud (Johnstone+, 2001)
J/ApJ/639/259 : Sub-mm clumps in Orion B South molecular cloud
(Johnstone+, 2007)
J/A+A/610/A12 : Clustering the Orion B giant molecular cloud (Bron+, 2018)
J/A+A/634/A115 : Orion B9 dense cores H2D+ spectra (Miettinen, 2020)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/1870] Core running number
8- 22 A15 --- Name Core name, HHMMSS.s+DDMMSS,
to be added after HGBS_J
26- 27 I2 h RAh Right ascension (J2000)
29- 30 I2 min RAm Right ascension (J2000)
32- 36 F5.2 s RAs Right ascension (J2000)
40 A1 --- DE- Declination sign (J2000)
41- 42 I2 deg DEd Declination (J2000)
44- 45 I2 arcmin DEm Declination (J2000)
47- 50 F4.1 arcsec DEs Declination (J2000)
53- 59 F7.1 --- Signi070 Detection significance at 70um (1)
62- 70 E9.3 Jy/beam Sp070 Peak flux density at 70um
73- 79 E7.2 Jy/beam e_Sp070 Error on peak flux density at 70um
85- 90 F6.2 --- Sp070/Sbg070 Contrast over local background at 70um
97-105 E9.3 Jy/beam Sconv070 Smoothed peak flux density at 70um
(in Jy/beam500) (2)
109-117 E9.3 Jy Stot070 Integrated flux density at 70um
120-126 E7.2 Jy e_Stot070 Error on integrated flux density at 70um
132-134 I3 arcsec FWHMa070 ?=-1 Major FWHM diameter at 70um (3)
142-144 I3 arcsec FWHMb070 ?=-1 Minor FWHM diameter at 70um (3)
151-153 I3 deg PA070 []?=-1 Position angle at 70um (3)(4)
157-163 F7.1 --- Signi160 Detection significance at 160um (1)
166-174 E9.3 Jy/beam Sp160 Peak flux density at 160um
177-183 E7.2 Jy/beam e_Sp160 Error on peak flux density at 160um
189-194 F6.2 --- Sp160/Sbg160 Contrast over local background at 160um
201-209 E9.3 Jy/beam Sconv160 Smoothed peak flux density at 160um
(in Jy/beam500) (2)
213-221 E9.3 Jy Stot160 Integrated flux density at 160um
224-230 E7.2 Jy e_Stot160 Error on integrated flux density
at 160um
236-238 I3 arcsec FWHMa160 ?=-1 Major FWHM diameter at 160um (3)
247-248 I2 arcsec FWHMb160 ?=-1 Minor FWHM diameter at 160um (3)
255-257 I3 deg PA160 []?=-1 Position angle at 160um (3)(4)
261-267 F7.1 --- Signi250 Detection significance at 250um (1)
270-278 E9.3 Jy/beam Sp250 Peak flux density at 250um
281-287 E7.2 Jy/beam e_Sp250 Error on peak flux density at 250um
293-298 F6.2 --- Sp250/Sbg250 Contrast over local background at 250um
305-313 E9.3 Jy/beam Sconv250 Smoothed peak flux density at 250um
(in Jy/beam500) (2)
317-325 E9.3 Jy Stot250 Integrated flux density at 250um
328-334 E7.2 Jy e_Stot250 Error on integrated flux density
at 250um
341-342 I2 arcsec FWHMa250 ?=-1 Major FWHM diameter at 250um (3)
351-352 I2 arcsec FWHMb250 ?=-1 Minor FWHM diameter at 250um (3)
359-361 I3 deg PA250 []?=-1 Position angle at 250um (3)(4)
366-371 F6.1 --- Signi350 Detection significance at 350um (1)
374-382 E9.3 Jy/beam Sp350 Peak flux density at 350um
385-391 E7.2 Jy/beam e_Sp350 Error on peak flux density at 350um
397-402 F6.2 --- Sp350/Sbg350 Contrast over local background at 350um
409-417 E9.3 Jy/beam Sconv350 Smoothed peak flux density at 350um
(in Jy/beam500) (2)
421-429 E9.3 Jy Stot350 Integrated flux density at 350um
432-438 E7.2 Jy e_Stot350 Error on integrated flux density
at 350um
445-446 I2 arcsec FWHMa350 Major FWHM diameter of core at 350um
455-456 I2 arcsec FWHMb350 Minor FWHM diameter of core at 350um
463-465 I3 deg PA350 [] Position angle of core at 350um (4)
470-475 F6.1 --- Signi500 Detection significance at 500um (1)
478-486 E9.3 Jy Sp500 Peak flux density at 500um (in Jy/beam)
489-495 E7.2 Jy/beam e_Sp500 Error on peak flux density at 500um
501-506 F6.2 --- Sp500/Sbg500 Contrast over local background at 500um
512-520 E9.3 Jy Stot500 Integrated flux density at 500um
523-529 E7.2 Jy e_Stot500 Error on integrated flux density
at 500um
535-537 I3 arcsec FWHMa500 Major FWHM diameter of core at 500um
546-547 I2 arcsec FWHMb500 Minor FWHM diameter of core at 500um
554-556 I3 deg PA500 [] Position angle of core at 500um (4)
560-565 F6.1 --- SigniNH2 Detection significance at column density
572-576 E5.1 10+21cm-2 NpH2 Peak H2 column density at 18.2"
resolution
584-588 F5.2 --- NpH2/Nbg Contrast over local background at
column density
597-600 E4.1 10+21cm-2 NconvH2 Peak H2 column density at 36.3"
resolution
609-612 E4.1 10+21cm-2 NbgH2 Local background H2 column density
622-623 I2 arcsec FWHMaNH2 Major FWHM diameter of core at NH2
632-633 I2 arcsec FWHMbNH2 Minor FWHM diameter of core at NH2
640-642 I3 deg PANH2 Position angle of core at NH2 (4)
649 I1 --- NSED [1/5] Number of significant Herschel
bands
658 I1 --- Coretype [0/3] Core type (5)
672 I1 --- NSPITZER SPITZER association (6)
682-988 A307 --- NSIMBAD SIMBAD counterparts within 6-arcsec
992-999 A8 --- Com Comments (N region)
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Note (1): Detection significance, derived by getsources (Men'shchikov et al.,
2012A&A...542A..81M 2012A&A...542A..81M), is 0.0 if the core is not visible in clean single scales.
Note (2): Peak flux density at the specified wavelength, measured after
smoothing the data to a 36.3" beam.
Note (3): A special value of -1 is given when no size measurement was possible.
Note (4): Position angle of the core major axis, measured east of north.
Note (5): Core type as follows:
1 = starless
2 = prestellar
3 = protostellar
0 = tentative
Note (6): Closest Spitzer-identified YSO from Megeath et al.
(2012AJ....144..192M 2012AJ....144..192M) within 6-arcsec of the Herschel peak position
as follows:
0 = no match
1 = match was found
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/1844] Core running number
6- 20 A15 --- Name Core name, HHMMSS.s+DDMMSS,
to be added after HGBS_J
22- 23 I2 h RAh Right ascension (J2000)
25- 26 I2 min RAm Right ascension (J2000)
28- 32 F5.2 s RAs Right ascension (J2000)
34 A1 --- DE- Declination sign (J2000)
35- 36 I2 deg DEd Declination (J2000)
38- 39 I2 arcmin DEm Declination (J2000)
41- 44 F4.1 arcsec DEs Declination (J2000)
46- 52 E7.2 pc Rd Deconvolved core radius (1)
54- 60 E7.2 pc Robs Observed core radius (2)
62- 66 F5.2 Msun Mcore Estimated core mass
68- 72 F5.2 Msun e_Mcore Uncertainty in the core mass
74- 77 F4.1 K Tdust Dust temperature from SED fitting
79- 81 F3.1 K e_Tdust Uncertainty in the dust temperature
83- 87 F5.1 10+21cm-2 NH2peak Peak H2 column density at 36.3" resolution
89- 93 F5.1 10+21cm-2 NH2av Average NH2 derived with Robs
95- 99 F5.1 10+21cm-2 NH2avd Average NH2 derived with Rd
101-105 F5.1 10+4cm-3 nH2peak Beam-averaged peak volume density
107-111 F5.1 10+4cm-3 nH2av Average core volume density from Robs
113-117 F5.1 10+4cm-3 nH2avd Average volume density from Rd
119-123 F5.1 --- alphaBE Bonnor-Ebert mass ratio
125 I1 --- Coretype Core type (3)
127-165 A39 --- Com Comments (4)
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Note (1): Geometrical average between the major and minor FWHM sizes of the core
[pc], measured in the high-resolution column density map after
deconvolution from the 18.2-arcsec HPBW resolution of the map.
Note (2): Geometrical average between the major and minor FWHM sizes of the core
[pc], measured in the high-resolution column density map before deconvolution
from the 18.2-arcsec HPBW resolution of the map.
Note (3): Core type as follows:
1 = starless
2 = prestellar
3 = protostellar
Note (4): Comments may be "no SED fit", "tentative bound", or "N region",
see Sects. 3.6, 3.7 of the paper for details.
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20 I1 arcsec/pix scale [3] Scale of the image
22- 25 I4 --- Nx [8170] Number of pixels along X-axis
27- 31 I5 --- Ny [10370] Number of pixels along Y-axis
33- 38 I6 Kibyte size [330955] Size of FITS file
40- 76 A37 --- FileName Name of FITS file, in subdirectory fits
78-105 A28 --- Title Title of the FITS file
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Acknowledgements:
Vera Konyves, vkonyves(at)uclan.ac.uk, vera.konyves(at)gmail.com
Philippe Andre, pandre(at)cea.fr
(End) V. Konyves [CEA/Saclay, France - UCLan, UK], P. Vannier [CDS] 24-Feb-2020