J/A+A/657/A70 Linking high- and low-mass star formation (Pitts+, 2022)
Linking high- and low-mass star formation:
Observation-based continuum modelling and physical conditions.
Pitts R.L., Kristensen L.E., Jorgensen J.K., van der Walt S.J.
<Astron. Astrophys. 657, A70 (2022)>
=2022A&A...657A..70P 2022A&A...657A..70P (SIMBAD/NED BibCode)
ADC_Keywords: Infrared sources ; Photometry, millimetric/submm ; Protostars
Keywords: stars: formation - circumstellar matter - dust, extinction -
submillimeter: stars - submillimeter: ISM - stars: protostars
Abstract:
Astronomers have yet to establish whether high-mass protostars form
from high-mass prestellar cores, similar to their lower-mass
counterparts, or from lower-mass fragments at the heart of a
pre-protostellar cluster undergoing large-scale collapse. Part of
the uncertainty is due to a shortage of envelope structure data on
protostars of a few tens of solar masses, where we expect to see a
transition from intermediate-mass star formation to the high-mass
process. We sought to derive the masses, luminosities, and envelope
density profiles for eight sources in Cygnus-X, whose mass estimates
in the literature placed them in the sampling gap. Combining these
sources with similarly evolved sources in the literature enabled us to
perform a meta-analysis of protostellar envelope parameters over six
decades in source luminosity. We performed spectral energy
distribution (SED) fitting on archival broadband photometric continuum
data from 1.2 to 850 microns, to derive bolometric luminosities for
our eight sources plus initial mass and radius estimates for modelling
density and temperature profiles with the radiative transfer package
Transphere. The envelope masses, densities at 1000AU, outer envelope
radii, and density power law indices as functions of bolometric
luminosity all follow established trends in the literature spanning
six decades in luminosity. Most of our sources occupy an intermediate
to moderately high range of masses and luminosities, which helps more
firmly establish the continuity between low- and high-mass star
formation mechanisms. Our density power law indices are consistent
with observed values in literature, which show no discernible trends
with luminosity. Finally, we show that the trends in all of the
envelope parameters for high-mass protostars are statistically
indistinguishable from trends in the same variables for low- and
intermediate-mass protostars.
Description:
Photometric data on 10 protostars in Cygnus-X, and envelope parameters
for these sources plus as many other resolved sources of a similar
evolutionary stage as we could find in the literature.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 53 10 List of stars with data in table A1
tablea1.dat 282 21 Broadband fluxes, errors, and quality flags for
10 protostars in 21 bands
fig6data.dat 177 287 Envelope parameters for 284 protostars in the
literature, plus our sources
list.dat 124 10 List of fits images
fits/* . 10 Individual fits images
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Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Name Source name (1)
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 15 F5.2 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 27 F4.1 arcsec DEs Declination (J2000)
29- 53 A25 --- AName Associated object
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Note (1): Names from Motte et al., 2007A&A...476.1243M 2007A&A...476.1243M, Cat. J/A+A/476/1243.
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Band Instrument & (broadband) filter used for
flux measurement
10- 15 F6.2 um lambda Wavelength of observations
17- 26 E10.3 --- FN12 ?=-9.999 N12 integrated continuum flux (1)
29- 40 E12.2 --- e_FN12 ?=-9 N12 flux uncertainty
41- 42 I2 --- q_FN12 [-1/5] Quality flag for FN12 (2)
44- 53 E10.3 --- FN30 ?=-9.999 N30 integrated continuum flux (1)
56- 67 E12.2 --- e_FN30 ?=-9 N30 flux uncertainty
68- 69 I2 --- q_FN30 [-1/5] Quality flag for FN30 (2)
71- 80 E10.3 --- FN38 ?=-9.999 N38 integrated continuum flux (1)
83- 94 E12.2 --- e_FN38 ?=-9 N38 flux uncertainty
95- 96 I2 --- q_FN38 [-1/5] Quality flag for FN38 (2)
98-107 E10.3 --- FN48 ?=-9.999 N48 integrated continuum flux (1)
110-121 E12.2 --- e_FN48 ?=-9 N48 flux uncertainty
122-123 I2 --- q_FN48 [-1/5] Quality flag for FN48 (2)
125-134 E10.3 --- FN51 ?=-9.999 N51 integrated continuum flux (1)
137-148 E12.2 --- e_FN51 ?=-9 N51 flux uncertainty
149-150 I2 --- q_FN51 [-1/5] Quality flag for FN51 (2)
152-161 E10.3 --- FN53 ?=-9.999 N53 integrated continuum flux (1)
164-175 E12.2 --- e_FN53 ?=-9 N53 flux uncertainty
176-177 I2 --- q_FN53 [-1/5] Quality flag for FN53 (2)
179-188 E10.3 --- FN54 ?=-9.999 N54 integrated continuum flux (1)
191-202 E12.2 --- e_FN54 ?=-9 N53 flux uncertainty
203-204 I2 --- q_FN54 [-1/5] Quality flag for FN54 (2)
206-215 E10.3 --- FN63 ?=-9.999 N63 integrated continuum flux (1)
218-229 E12.2 --- e_FN63 ?=-9 N63 flux uncertainty
230-231 I2 --- q_FN63 [-1/5] Quality flag for FN63 (2)
234-241 E8.2 --- FS8 ?=-9.999 S8 integrated continuum flux (1)
244-255 E12.2 --- e_FS8 ?=-9 S8 flux uncertainty
256 I1 --- q_FS8 [-1/5] Quality flag for FS8 (2)
258-266 E9.2 --- FS26 ?=-9.999 S26 integrated continuum flux (1)
269-280 E12.2 --- e_FS26 ?=-9 S26 flux uncertainty
281-282 I2 --- q_FS26 [-1/5] Quality flag for FS26 (2)
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Note (1): We made all flux measurements via aperture photometry and/or Gaussian
deconvolution EXCEPT for data from IRAS (1984ApJ...278L...1N 1984ApJ...278L...1N) and MSX
(2003yCat.5114....0E 2003yCat.5114....0E). We looked up IRAS and MSX catalogue values for these
sources only to fill gaps where data in Spitzer bands were lacking or
severely affected by imaging artefacts.
Note (2): Quality flag as follows:
-1= unsalvageable/no data
0 = good (no serious caveats)
1 = lower limit (saturated)
2 = upper limit (blended/contaminated with diffraction artefacts)
3 = poorly-constrained errors (missing error maps or poorly deconvolved)
4 = range (flux & error columns = lower & upper flux limits respectively)
5 = poorly aligned with catalogue entry (mistaken ID possible)
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Byte-by-byte Description of file: fig6data.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Protostar name (1)
17- 24 E8.2 Lsun LBol Bolometric luminosity
27- 34 E8.2 Lsun E_LBol Upper error margin on LBol
37- 44 E8.2 Lsun e_LBol Lower error margin on LBol
46- 54 E9.2 Msun MEnv ?=-9.99E+99 Envelope mass
56- 64 E9.2 Msun E_MEnv ?=-9.99E+99 Upper error margin on MEnv
66- 74 E9.2 Msun e_MEnv ?=-9.99E+99 Lower error margin on MEnv
76- 84 E9.2 AU ROut ?=-9.99E+99 Outer envelope radius
86- 94 E9.2 AU E_ROut ?=-9.99E+99 Upper error margin on ROut
96-104 E9.2 AU e_ROut ?=-9.99E+99 Lower error margin on ROut
107-110 F4.2 --- prho ?=0.00 Density power-law index (2)
115-118 F4.2 --- E_prho ?=0.00 Upper error margin on prho
123-126 F4.2 --- e_prho ?=0.00 Upper error margin on prho
128-136 E9.2 cm-3 nkAU ?=-9.99E+99 Density at 1000 AU (3)
138-146 E9.2 cm-3 E_nkAU ?=-9.99E+99 Upper error margin on nkAU
148-156 E9.2 cm-3 e_nkAU ?=-9.99E+99 Lower error margin on nkAU
159-177 A19 --- BibCode BibCode of object reference (4)
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Note (1): objects in the literature from
van der Tak et al. (2000ApJ...537..283V 2000ApJ...537..283V),
Jorgensen et al. (2002A&A...389..908J 2002A&A...389..908J),
Mueller et al. (2002ApJS..143..469M 2002ApJS..143..469M),
Shirley et al. (2002ApJ...575..337S 2002ApJ...575..337S),
Hatchell & van der Tak (2003A&A...409..589H 2003A&A...409..589H),
Williams et al. (2005A&A...434..257W 2005A&A...434..257W),
Crimier et al. (2009A&A...506.1229C 2009A&A...506.1229C, 2010A&A...516A.102C 2010A&A...516A.102C, 2010A&A...519A..65C 2010A&A...519A..65C),
Kristensen et al. (2012A&A...542A...8K 2012A&A...542A...8K),
van der Tak et al. (2013A&A...554A..83V 2013A&A...554A..83V), and
Cao et al. (2019ApJS..241....1C 2019ApJS..241....1C)
Note (2): If power-law index was not given, we assumed the statistical average
and standard deviation of available power-law indices (1.4±0.4).
Note (3): nkAU and its uncertainties were often calculated using ROut and prho,
assuming RIn∼20AU (adjusting RIn to available values changed nkAU by much
less than a margin of error).
Note (4): Many sources were covered by multiple references in the list. We only
include the latest, most complete data set for any given protostar; sources
associated with any given reference should not be interpreted as a complete
list of the sources covered by that reference.
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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- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 53 A26 "datime" Obs.date Observation date
55- 61 F7.3 GHz Freq Observed frequency
63- 66 I4 Kibyte size Size of FITS file
68- 90 A23 --- FileName Name of FITS file, in subdirectory fits
92-124 A33 --- Title Title of the FITS file
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Acknowledgements:
Rebecca L. Pitts, rebecca.pitts(at)nbi.ku.dk
(End) Rebecca L. Pitts [NBI/UCPH], Patricia Vannier [CDS] 29-Oct-2021