J/MNRAS/500/4257 Dense cores in the Serpens region from HGBS (Fiorellino+, 2021)
The census of dense cores in the Serpens region from the Herschel Gould Belt
Survey.
Fiorellino E., Elia D., Andre P., Men'shchikov A., Pezzuto S., Schisano E.,
Konyves V., Arzoumanian D., Benedettini M., Ward-Thompson D., Bracco A.,
Di Francesco J., Bontemps S., Kirk J., Motte F., Molinari S.
<Mon. Not. R. Astron. Soc., 500, 4257-4276 (2021)>
=2021MNRAS.500.4257F 2021MNRAS.500.4257F (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; Interstellar medium ; Photometry, infrared ;
Photometry, millimetric/submm
Keywords: stars: formation - ISM: clouds - ISM: individual: Serpens -
ISM: structure - infrared: ISM - submillimetre: ISM
Abstract:
The Herschel Gould Belt survey mapped the nearby (d<500pc)
star-forming regions to understand better how the prestellar phase
influences the star formation process. Here, we report a complete
census of dense cores in a ∼15deg2 area of the Serpens star-forming
region located between d∼420 and 484pc. The PACS and SPIRE cameras
imaged this cloud from 70 to 500µm. With the multiwavelength source
extraction algorithm getsources, we extract 833 sources, of which 709
are starless cores and 124 are candidate protostellar cores. We obtain
temperatures and masses for all the sample, classifying the starless
cores in 604 prestellar cores and 105 unbound cores. Our census of
sources is 80 per cent complete for M>0.8M☉ overall. We produce
the core mass function (CMF) and compare it with the initial mass
function (IMF). The prestellar CMF is consistent with lognormal trend
up to ∼2 M☉, after which it follows a power law with slope of
-2.05±0.34. The tail of its CMF is steeper but still compatible with
the IMF for the region we studied in this work. We also extract the
filaments network of the Serpens region, finding that 81 per cent of
prestellar cores lie on filamentary structures. The spatial
association between cores and filamentary structure supports the
paradigm, suggested by other Herschel observations, that prestellar
cores mostly form on filaments. Serpens is confirmed to be a young,
low-mass and active star-forming region.
Description:
Herschel observations of the Serpens/Aquila East complex include two
sub-regions: a box of approximately ∼2.2x2.5 square degrees to the
east, centred on RA=18h29m32s, Dec.=+0°40'42" that includes
Serpens Main; the box of approximately ∼2.3x4.4deg2, centred on
RA=18h38m48s, Dec.=-0°00'37", is the Aquila East. Observations
were taken on 2010 October 16-18, ObsIDs 1342206676/95 and
1342206694/96 for Serpens Main and Aquila East, respectively. Data
were taken using PACS at 70µm and 160µm, and SPIRE at 250, 350,
and 500µm. Two orthogonal scan maps were performed in parallel mode
at 60arcsec/s. Data taken during the turnarounds were included.
The data reduction procedure was different for PACS and SPIRE
observations. SPIRE data were reduced entirely with HIPE Version 10.1,
provided by Herschel Science Center, producing the images using its
'naive' map-making procedure and destriper module (Herschel Science
Ground Segment Consortium 2011ascl.soft11001H). Differently, PACS data
were reduced with HIPE v10.1 and images were obtained using UNIMAP
Version 6.4.1 (Piazzo et al. 2015MNRAS.447.1471P 2015MNRAS.447.1471P) for the map making
and destriping phase.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 622 833 Catalogue of dense cores identified in HGBS maps
of Serpens
tablea2.dat 168 833 Derived properties of dense cores identified in
HGBS maps of Serpens
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Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [1/833] Core running number
5- 19 A15 --- Name Core name HBBS J (HHMMSS.s+DDMMSS)
21- 22 I2 h RAh Right ascension (J2000)
24- 25 I2 min RAm Right ascension (J2000)
27- 31 F5.2 s RAs Right ascension (J2000)
33 A1 --- DE- Declination sign (J2000)
34- 35 I2 deg DEd Declination (J2000)
37- 38 I2 arcmin DEm Declination (J2000)
40- 43 F4.1 arcsec DEs Declination (J2000)
45- 52 F8.3 --- Sig70 ?=0 Detection significance from
monochromatic single scales in the
image at 70µm
54- 62 E9.3 Jy/beam I70p Peak intensity at 70µm estimated by
getsources
64- 70 E7.2 Jy/beam e_I70p Error on I70p
72- 77 F6.2 --- I70p/Ibg Ratio of the background-subtracted peak
intensity to the local background
intensity at 70µm
79- 87 E9.3 Jy/beam I70cv500 Peak intensity at 70µm after
smoothing to a resolution
corresponding to the 500 micron beam
89- 97 E9.3 Jy S70 Integrated flux density at 70µm as
estimated by getsources
99- 105 E7.2 Jy e_S70 Error on S70
107- 109 I3 arcsec a70 ?=-1 Estimate of source size (FWHM)
along major axis at 70µm
111- 113 I3 arcsec b70 ?=-1 Estimate of source size (FWHM)
along minor axis at 70µm
115- 117 I3 deg PA70 [] Position angle of source major axis,
east of north at 70µm
119- 127 F9.3 --- Sig160 ?=0 Detection significance from
monochromatic single scales in the
image at 160µm
129- 137 E9.3 Jy/beam I160p Peak intensity at 160µm estimated
by getsources
139- 145 E7.2 Jy/beam e_I160p Error on I160p
147- 151 F5.2 --- I160p/Ibg Ratio of the background-subtracted peak
intensity to the local background
intensity at 160µm
153- 161 E9.3 Jy/beam I160cv500 Peak intensity at 160µm after
smoothing to a resolution
corresponding to the 500 micron beam
163- 171 E9.3 Jy S160 Integrated flux density at 160µm as
estimated by getsources
173- 179 E7.2 Jy e_S160 Error on S160
181- 183 I3 arcsec a160 ?=-1 Estimate of source size (FWHM)
along major axis at 160µm
185- 187 I3 arcsec b160 ?=-1 Estimate of source size (FWHM)
along minor axis at 160µm
189- 191 I3 deg PA160 [] Position angle of source major axis,
east of north at 160µm
193- 200 F8.3 --- Sig250 ?=0 Detection significance from
monochromatic single scales in the
image at 250µm
202- 210 E9.3 Jy/beam I250p Peak intensity at 250µm estimated by
getsources
212- 218 E7.2 Jy/beam e_I250p Error on I250p
220- 224 F5.2 --- I250p/Ibg Ratio of the background-subtracted peak
intensity to the local background
intensity at 250µm
226- 234 E9.3 Jy/beam I250cv500 Peak intensity at 250µm after
smoothing to a resolution
corresponding to the 500 micron beam
236- 244 E9.3 Jy S250 Integrated flux density at 250µm as
estimated by getsources
246- 252 E7.2 Jy e_S250 Error on S250
254- 256 I3 arcsec a250 ?=-1 Estimate of source size (FWHM)
along major axis at 250µm
258- 260 I3 arcsec b250 ?=-1 Estimate of source size (FWHM)
along minor axis at 250µm
262- 264 I3 deg PA250 [] Position angle of source major axis,
east of north at 250µm
266- 273 F8.3 --- Sig350 ?=0 Detection significance from
monochromatic single scales in the
image at 350µm
275- 283 E9.3 Jy/beam I350p Peak intensity at 350µm estimated by
getsources
285- 291 E7.2 Jy/beam e_I350p Error on I350p
293- 297 F5.2 --- I350p/Ibg Ratio of the background-subtracted peak
intensity to the local background
intensity at 350µm
299- 307 E9.3 Jy/beam I350cv500 Peak intensity at 350µm after
smoothing to a resolution
corresponding to the 500 micron beam
309- 317 E9.3 Jy S350 Integrated flux density at 350µm as
estimated by getsources
319- 325 E7.2 Jy e_S350 Error on S350
327- 329 I3 arcsec a350 ?=-1 Estimate of source size (FWHM)
along major axis at 350µm
331- 333 I3 arcsec b350 ?=-1 Estimate of source size (FWHM)
along minor axis at 350µm
335- 337 I3 deg PA350 [] Position angle of source major axis,
east of north at 350µm
339- 346 F8.3 --- Sig500 ?=0 Detection significance from
monochromatic single scales in the
image at 500µm
348- 356 E9.3 Jy/beam I500p Peak intensity at 500µm estimated by
getsources
358- 364 E7.2 Jy/beam e_I500p Error on I500p
366- 370 F5.2 --- I500p/Ibg Ratio of the background-subtracted peak
intensity to the local background
intensity at 500µm
372- 380 E9.3 Jy S500 Integrated flux density at 500µm as
estimated by getsources
382- 388 E7.2 Jy e_S500 Error on S500
390- 392 I3 arcsec a500 ?=-1 Estimate of source size (FWHM)
along major axis at 500µm
394- 396 I3 arcsec b500 ?=-1 Estimate of source size (FWHM)
along minor axis at 500µm
398- 400 I3 deg PA500 [] Position angle of source major axis,
east of north at 500µm
402- 409 F8.3 --- SigNH2 Detection significance from single
scales on high-resolution column
density map
411- 417 F7.3 10+21/cm2 NH2p Peak column density at 18.2arcsec
resolution, estimated by getsources
419- 423 F5.2 --- NH2p/NH2bg Contrast of peak column density over
the local background
425- 430 F6.3 10+21/cm2 NH2cv500 Peak column density estimated by
getsources after smoothing to a
resolution corresponding to the 500
micron beam
432- 437 F6.3 10+21/cm2 NH2bg Column density of local background
439- 441 I3 arcsec aNH2 Estimate of source size (FWHM) along
major axis in column density map
443- 445 I3 arcsec bNH2 Estimate of source size (FWHM) along
minor axis in column density map
447- 449 I3 deg PANH2 [] Position angle of source major axis
in column density map
451 I1 --- NSED Number of bands in which the source is
significant (Sigλ>5)
453 A1 --- CuTex CuTex flag (1)
455- 466 A12 --- Core Core type
(starless, prestellar or protostellar)
468- 606 A139 --- Simbad Simbad associated IDs within 1 arcmin
of Herschel position
608- 622 A15 --- Comments Comments
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Note (1): Flag as follows:
1 = source found independently by CuTex
0 = otherwise
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [1/833] Core running number
5- 19 A15 --- Name Core name HBBS J (HHMMSS.s+DDMMSS)
21- 22 I2 h RAh Right ascension (J2000)
24- 25 I2 min RAm Right ascension (J2000)
27- 31 F5.2 s RAs Right ascension (J2000)
33 A1 --- DE- Declination sign (J2000)
34- 35 I2 deg DEd Declination (J2000)
37- 38 I2 arcmin DEm Declination (J2000)
40- 43 F4.1 arcsec DEs Declination (J2000)
45- 52 E8.3 pc Rcobs Core radius as observed
54- 61 E8.3 pc Rcdec Core radius with 18.2arcsec beam
deconvolved
63- 68 F6.3 Msun Mcore Core mass assuming the dust opacity law
by Roy et al. (2014A&A...562A.138R 2014A&A...562A.138R)
70- 75 F6.3 Msun e_Mcore Error on Mcore
77- 80 F4.1 K Tdust Dust temperature
82- 85 F4.1 K e_Tdust Error on Tdust
87- 93 F7.3 10+21/cm2 NH2p Peak H2 column density at the
resolution of the 500 micron data
95- 101 F7.2 10+21/cm2 NH2aobs Average column density derived using
observed radius (1)
103- 108 F6.2 10+21/cm2 NH2adec Average column density derived using
deconvolved radius (1)
110- 116 F7.3 10+4/cm3 nH2p Beam-averaged peak volume density (2)
118- 124 F7.2 10+4/cm3 nH2aobs Average volume density derived using
observed radius (3)
126- 131 F6.2 10+4/cm3 nH2adec Average volume density derived using
deconvolved radius (3)
133- 139 F7.3 --- alphaBE Bonnor-Ebert mass ratio
αBE=MBE/Mcore
141- 152 A12 --- Core Core type
(starless, prestellar or protostellar)
154- 168 A15 --- Comments Comments
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Note (1): The average column density is calculated as:
NaveH2=Mcore/(πR2coreµmH), where Mcore is the
estimated core mass, Rcore the core radius and µ=2.8
Note (2): Beam-averaged peak volume density is derived from the peak column
density assuming a Gaussian spherical distribution:
npeakH2=sqrt(4ln2/π)NpeakH2/FWHM500
Note (3): The average volume density is calculated as:
naveH2=Mcore/(4/3πR3coreµmH), where Mcore is the
estimated core mass, Rcore the core radius and µ=2.8
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 10-Oct-2023