J/A+A/628/A85 Disk masses in the Orion Molecular Cloud-2 (van Terwisga+, 2019)
Disk masses in the Orion Molecular Cloud-2: distinguishing time and environment.
van Terwisga S.E., Hacar A., van Dishoeck E.F.
<Astron. Astrophys. 628, A85 (2019)>
=2019A&A...628A..85V 2019A&A...628A..85V (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Stars, pre-main sequence ; Stars, masses
Keywords: stars: pre-main sequence - protoplanetary disks -
techniques: interferometric
Abstract:
The mass evolution of protoplanetary disks is driven by internal
processes and by external factors such as photoevaporation.
Disentangling these two effects, however, remains difficult.
We measured the dust masses of a sample of 132 disks in the Orion
Molecular Cloud 2 (OMC-2) region, and compared them to externally
photoevaporated disks in the Trapezium cluster, and to disks in nearby
low-mass star-forming regions (SFRs). This allowed us to test whether
initial disk properties are the same in high- and low-mass SFRs, and
enabled a direct measurement of the effect of external
photoevaporation on disks.
A ∼20'x4'mosaic of 3mm continuum observations from the Atacama
Large Millimeter/submillimeter Array (ALMA) was used to measure the
fluxes of 132 disks and 35 protostars >0.5pc away from the Trapezium.
We identify and characterize a sample of 34 point sources not included
in the Spitzer catalog on which the sample is based.
Of the disks, 37 (28%) are detected, and have masses ranging from
7-270M☉. The detection rate for protostars is higher (69%).
Disks near the Trapezium are found to be less massive by a factor
0.18+0.18_-0.11), implying a mass loss rate of 8x10-8M☉/yr.
Our observations allow us to distinguish the impact of time and
environment on disk evolution in a single SFR. The disk mass
distribution in OMC-2 is statistically indistinguishable from that in
nearby low-mass SFRs like Lupus and Taurus. We conclude that age is
the main factor that determines the evolution of these disks. This
result is robust with respect to assumptions of dust temperature,
sample incompleteness, and biases. The difference between the OMC-2
and Trapezium cluster samples is consistent with mass loss driven by
far-ultraviolet radiation near the Trapezium. Taken together, this
implies that in isolation disk formation and evolution proceed
similarly, regardless of cloud mass.
Description:
From a 3-millimeter continuum ALMA map of the Integral-Shaped Filament
centered on OMC-2, using the catalogue of YSOs published in Megeath et
al. (2012. Cat. J/AJ/144/192), we obtain mm continuum fluxes for disks
and protostars, and infer their masses (assuming a temperature of 20K
for the bulk mm continuum). The resulting tables are provided here as
disks.dat and prtstars.dat. Additionally, we provide a list of
positions, fluxes, and inferred masses for objects detected in the
ALMA data without counterparts in Megeath et al. 2012 (unknown.dat).
Additionally, we flag these objects if they have counterparts in other
surveys.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
disks.dat 131 132 Disks data (table 1)
prtstars.dat 130 39 Protostars data (table A1)
unknown.dat 135 34 Objects detected in the ALMA data without
counterparts in Megeath et al.
(2012, J/AJ/144/192) data (table A2)
list.dat 123 1 Information on fits image
fits/* . 1 fits image
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See also:
J/ApJS/160/353 : Membership of the Orion nebula population (Getman+, 2005)
J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)
J/A+A/587/A153 : VISION I. VISTA Orion A Survey (Meingast+, 2016)
J/A+A/600/A141 : Orion A integral shaped filament image (Kainulainen+, 2017)
Byte-by-byte Description of file: disks.dat prtstars.dat unknown.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- ID Rank (when sorted by flux or S/N) of object
6- 22 F17.14 deg RAdeg Right ascension (J2000.0)
24- 41 F18.15 deg DEdeg Declination (J2000.0)
43- 64 F22.20 Jy F3mm 3mm continuum flux
66- 87 F22.20 Jy e_F3mm 3mm continuum flux error
89-109 F21.16 Mgeo M ? Continuum mass
111-131 F21.16 Mgeo e_M Error on continuum mass
133-135 A3 --- Com Surveys with detections of the object,
for unknown.dat file only (1)
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Note (1): Counterparts code as follows:
- = No counterpart identified in the following catalogues.
a = Source detected in Kainulainen et al. (2017A&A...600A.141K 2017A&A...600A.141K, J/A+A/600/A141)
b = Source detected in Getman et al. (2005ApJS..160..353G 2005ApJS..160..353G, J/ApJS/160/353)
c = Source detected in Meingast et al. (2016A&A...587A.153M 2016A&A...587A.153M, J/A+A/587/A153)
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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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 55 A26 "datime" Obs.date Observation date
57- 63 F7.4 GHz Freq Observed frequency
65- 69 I5 Kibyte size Size of FITS file
71-100 A30 --- FileName Name of FITS file, in subdirectory fits
102-123 A22 --- Title Title of the FITS file
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Acknowledgements:
Sierk van Terwisga, terwisga(at)strw.leidenuniv.nl
(End) Sierk van Terwisga [Leiden Obs.], Patricia Vannier [CDS] 02-Jul-2019