J/ApJ/875/L9 ODISEA: Disk dust mass distributions (Williams+, 2019)
The Ophiuchus DIsk Survey Employing ALMA (ODISEA): disk dust mass distributions
across protostellar evolutionary classes.
Williams J.P., Cieza L., Hales A., Ansdell M., Ruiz-Rodriguez D.,
Casassus S., Perez S., Zurlo A.
<Astrophys. J., 875, L9 (2019)>
=2019ApJ...875L...9W 2019ApJ...875L...9W
ADC_Keywords: Stars, pre-main sequence; Millimetric/submm sources;
Stars, distances; Radio continuum
Keywords: protoplanetary disks ; stars: pre-main sequence ;
submillimeter: general
Abstract:
As protostars evolve from optically faint/infrared-bright (Class I)
sources to optically bright/infrared-faint (Class II) the solid
material in their surrounding disks accumulates into planetesimals and
protoplanets. The nearby, young Ophiuchus star-forming region contains
hundreds of protostars in a range of evolutionary states. Using the
Atacama Large Millimeter Array to observe their millimeter continuum
emission, we have measured masses of, or placed strong upper limits
on, the dust content of 279 disks. The masses follow a log-normal
distribution with a clear trend of decreasing mass from less to more
evolved protostellar infrared class. The (logarithmic) mean Class I
disk mass, M=3.8M⊕, is about 5 times greater than the mean
Class II disk mass, but the dispersion in each class is so high,
σlogM∼0.8-1, that there is a large overlap between the two
distributions. The disk mass distribution of flat-spectrum protostars
lies in between Classes I and II. In addition, three Class III sources
with little to no infrared excess are detected with low disk masses,
M∼0.3M⊕. Despite the clear trend of decreasing disk mass with
protostellar evolutionary state in this region, a comparison with
surveys of Class II disks in other regions shows that masses do not
decrease monotonically with age. This suggests that the cloud-scale
environment may determine the initial disk mass scale or that there is
substantial dust regeneration after 1Myr.
Description:
The full set of 289 sources in the Ophiuchus DIsk Survey Employing
ALMA (ODISEA) sample was observed in two samples, A and B, with 147
and 142 sources each. Paper I (Cieza+ 2019, J/MNRAS/482/698) describes
the full sample selection and the observations of sample A, consisting
of Class I, Flat Spectrum, and bright (K≤10mag) Class II sources.
Here, we augment those data with the observations of sample B,
consisting of the fainter (K>10mag) Class II and Class III sources in
the same Cycle 4 ALMA program 2016.1.00545.S.
The observations of sample B were carried out in ALMA Band 6 with 40
antennas in the C40-3 array configuration (15 to 500m baselines) on
2018 May 2, and August 20 and 21.
The correlator was configured in the same way as for sample A, with a
total continuum bandwidth of 7.3GHz centered at 225.4GHz
(λ=1.33mm). There were also three higher spectral resolution
windows centered on the J=2-1 transition of CO, 13CO, and C18O.
The ALMA measurements and GAIA distances for the final sample of 265
sources (279 disks after allowing for 12 binaries and one triple
system) is listed in Table 1.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 65 279 Disk distances and flux densities
--------------------------------------------------------------------------------
See also:
II/332 : c2d Spitzer final data release (DR4) (Evans+, 2003)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJ/771/129 : Submillimetric Class II sources of Taurus (Andrews+, 2013)
J/ApJ/827/142 : ALMA obs. of GKM stars in Upper Sco (Barenfeld+, 2016)
J/AJ/153/240 : Protoplanetary disks in sigma Ori with ALMA (Ansdell+, 2017)
J/ApJ/869/L41 : DSHARP I. Sample, ALMA obs. log and overview (Andrews+, 2018)
J/ApJ/859/21 : Lupus protoplanetary disks with ALMA. II. (Ansdell+, 2018)
J/ApJS/238/19 : VANDAM IV. Free-free emissions (Tychoniec+, 2018)
J/MNRAS/482/698 : Ophiuchus DIsc Survey Employing ALMA. I. (Cieza+, 2019)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- SSTc2d Spitzer source name (JHHMMSS.s+DDMMSS)
19- 21 A3 --- Class Protostellar classification (1)
24- 29 F6.2 pc Dist [81.99/216.43] Distance to source (d) (2)
32- 37 F6.2 mJy F225GHz [-0.31/361.2] Flux density at 225GHz
39- 43 F5.2 mJy e_F225GHz [0.1/1.22] RMS of F225GHz
46- 54 F9.5 deg RAdeg [245/250]? Right Ascension of ALMA source (J2000)
57- 65 F9.5 deg DEdeg [-25.5/-22.9]? Declination of ALMA source (J2000)
--------------------------------------------------------------------------------
Note (1): Derived from the infrared spectral index:
I/II/III = Class I/II/III,
F = Flat Spectrum.
Note (2): For the 14 sources with large fractional errors and the 106 with
no measurement in Gaia DR2 (I/345), we used a mean distance d=139.4pc.
See Section 2.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Cieza et al. Paper I. 2019MNRAS.482..698C 2019MNRAS.482..698C Cat. J/MNRAS/482/698
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Sep-2020