J/ApJ/831/125 ALMA 887µm obs. of ChaI star-forming region (Pascucci+, 2016)
A steeper than linear disk mass-stellar mass scaling relation.
Pascucci I., Testi L., Herczeg G.J., Long F., Manara C.F., Hendler N.,
Mulders G.D., Krijt S., Ciesla F., Henning T., Mohanty S.,
Drabek-Maunder E., Apai D., Szucs L., Sacco G., Olofsson J.
<Astrophys. J., 831, 125-125 (2016)>
=2016ApJ...831..125P 2016ApJ...831..125P (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, millimetric/submm ; Spectral types ; Stars, masses ;
YSOs
Keywords: brown dwarfs; protoplanetary disks; stars: pre-main sequence;
submillimeter: planetary systems
Abstract:
The disk mass is among the most important input parameter for every
planet formation model to determine the number and masses of the
planets that can form. We present an ALMA 887µm survey of the disk
population around objects from ∼2 to 0.03M☉ in the nearby ∼2Myr
old Chamaeleon I star-forming region. We detect thermal dust emission
from 66 out of 93 disks, spatially resolve 34 of them, and identify
two disks with large dust cavities of about 45 au in radius. Assuming
isothermal and optically thin emission, we convert the 887µm flux
densities into dust disk masses, hereafter Mdust. We find that the
Mdust-M* relation is steeper than linear and of the form
Mdust∝(M*)1.3-1.9, where the range in the power-law index
reflects two extremes of the possible relation between the average
dust temperature and stellar luminosity. By reanalyzing all millimeter
data available for nearby regions in a self-consistent way, we show
that the 1-3 Myr old regions of Taurus, Lupus, and Chamaeleon I share
the same Mdust-M* relation, while the 10 Myr old Upper Sco
association has a steeper relation. Theoretical models of grain
growth, drift, and fragmentation reproduce this trend and suggest that
disks are in the fragmentation-limited regime. In this regime
millimeter grains will be located closer in around lower-mass stars, a
prediction that can be tested with deeper and higher spatial
resolution ALMA observations.
Description:
Our observations were carried out as part of the Atacama Large
Millimeter Array (ALMA) Cycle 2 campaign on 2014 May 1-3 UTC (54
sources) and on 2015 May 18-19 UTC (39 sources). The 2014 observations
included all stars with spectral type from Luhman (2008hsf2.book..169L 2008hsf2.book..169L;
2007, J/ApJS/173/104) equal to or earlier than M3 (hot sample), while
in 2015 we observed the remaining later spectral type sources (cool
sample). All observations were obtained in Band 7 (275-373GHz) with a
spatial resolution of 0.7"x0.5".
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 93 Source properties
table3.dat 71 93 Measured continuum flux densities
figure8.dat 42 446 The Mdust-M* relation
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See also:
J/ApJ/828/46 : ALMA survey of Lupus protoplanetary disks. I. (Ansdell+, 2016)
J/ApJ/827/142 : ALMA observations of GKM stars in Upper Sco (Barenfeld+, 2016)
J/ApJ/826/16 : ALMA and GeMS observations of the OMC1 region (Eisner+, 2016)
J/ApJ/825/19 : Mass-radius relationship for planets (Rp<4) (Wolfgang+, 2016)
J/ApJ/814/130 : Planet occurrence rates calculated for KOIs (Mulders+, 2015)
J/A+A/561/A2 : 36 accreting YSOs emission lines (Alcala+, 2014)
J/ApJ/773/168 : Submm fluxes of very low-mass stars and BDs (Mohanty+, 2013)
J/ApJ/771/129 : Submillimetric Class II sources of Taurus (Andrews+, 2013)
J/ApJ/767/95 : Improved parameters of smallest KIC stars (Dressing+, 2013)
J/A+A/549/A109 : HARPS XXXI. The M-dwarf sample (Bonfils+, 2013)
J/ApJ/751/115 : Millimeter emission from Taurus binary systems (Harris+, 2012)
J/ApJ/746/154 : Kinematic parallaxes for Sco-Cen members (Pecaut+, 2012)
J/ApJ/745/19 : Binary systems in Taurus-Auriga (Kraus+, 2012)
J/A+A/527/A145 : Chamaeleon I 870um sources (Belloche+, 2011)
J/ApJ/688/377 : Low-mass objects in Upper Scorpius. II. (Slesnick+, 2008)
J/ApJ/684/654 : Low-mass members of Chamaeleon I (Luhman+, 2008)
J/ApJ/675/1375 : IRAC/MIPS photometry in Cha I (Luhman+, 2008)
J/ApJS/173/104 : Stellar population in Chamaeleon I (Luhman, 2007)
J/ApJ/651/L49 : Upper Sco OB association IRAC observations (Carpenter+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS 2MASS identifier (JHHMMSSss+DDMMSSs)
18 A1 --- f_2MASS [*] Flag on 2MASS (1)
20- 29 A10 --- Name Other identifier
31- 36 F6.3 arcsec Multi [0/29]?=0 Multiplicity information from lit.
38- 41 A4 --- r_Multi Reference for Multi (2)
43- 47 A5 --- SpT Luhman+ 2007, J/ApJS/173/104;
2008, J/ApJ/675/1375 MK spectral type
49- 52 A4 --- SED SED type ("FS" (flat spectrum),
Class "II" (82 instances), or "II/T")
54- 57 A4 --- ALMA ALMA sample type ("Cool" or "Hot")
59- 63 A5 --- ASpT Adopted MK spectral type
65- 68 A4 --- r_ASpT Reference for ASpType (2)
70- 74 F5.2 [Lsun] logM* [-1.6/0.3] Log stellar mass
76- 80 F5.2 [Lsun] b_logM* [-1.8/0.3]? Lower boundary in logM* (3)
82- 86 F5.2 [Lsun] B_logM* [-1.1/0.6]? Upper boundary in logM* (3)
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Note (1):
* = T30 is the secondary of T31 at a separation of 16.52". ISO 138 is
the secondary of ISO 143 at 18.16". T53 is the secondary of T52
at 11.18". Hn18 is the secondary of CHXR60 (not included in our
ALMA survey) at a separation of 28.28".
Note (2): Reference as follows:
A15 = Anthonioz et al. (2015A&A...574A..41A 2015A&A...574A..41A);
D13 = Daemgen et al. (2013A&A...554A..43D 2013A&A...554A..43D);
KH07 = Kraus and Hillenbrand 2007, J/ApJ/662/413;
La08 = Lafreniere et al. (2008ApJ...683..844L 2008ApJ...683..844L);
L07 = Luhman 2007, J/ApJS/173/104;
M14 = Manara et al. (2014A&A...568A..18M 2014A&A...568A..18M);
M16a = Manara et al. (2016A&A...585A.136M 2016A&A...585A.136M);
M16b = Manara et al. (2016A&A...591L...3M 2016A&A...591L...3M);
N12 = Nguyen et al. 2012, J/ApJ/745/119.
Note (3): When we fixed the isochrone there are no uncertainties associated
with the estimated stellar mass, see Section 2.1.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS 2MASS identifier (JHHMMSSss+DDMMSSs)
18 A1 --- n_2MASS [d*] Flag on 2MASS (4)
20- 26 F7.2 mJy Fnu [-0.7/1364] Integrated flux density at 887um
28- 31 F4.2 mJy e_Fnu [0.1/2] Uncertainty in Fnu
33- 39 F7.4 arcsec DelRA [-0.6/1.1] Offsets from the phase center
in RA (5)
41- 46 F6.4 arcsec e_DelRA [0/0.2] Uncertainty in DelRA (5)
48- 54 F7.4 arcsec DelDE [-0.4/0.5] Offsets from the phase center
in DE (5)
56- 61 F6.4 arcsec e_DelDE [0/0.2] Uncertainty in DelDE (5)
63- 66 F4.2 arcsec MajAxis [0/0.8] FWHM of major axis (5)
68- 71 F4.2 arcsec MinAxis [0/0.5] FWHM of minor axis (5)
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Note (4): Flag as follows:
d = Sources with rings. Integrated flux density measured on image
within the 3σ contour.
* = Sources that have additional mm detections in their exposures:
J11044258-7741571 (ISO 52) at ∼6", coordinates
(11:04:40.59;-77:41:56.9); J11082238-7730277 (ISO 143) at ∼10",
coordinates (11:08:21.11;-77:30:18.9); and J11123092-7644241 (T53)
at ∼11", coordinates (11:12:27.7;-76:44:22.3). In the first two cases
there is no object in the SIMBAD Astronomical Database associated with
the mm emission. In the case of T53 we detect the disk from the
companion T52. Fluxes from these additional detections are not
reported in the table.
Note (5): Sources with a FWHM reported in the last column of the table are
those that were fitted with an elliptical gaussian. Undetected
sources have values of 0.0 in all columns following the Fnu columns.
For these sources flux densities are measured assuming a point source
model and fixed DelRA and DelDE to the median values of the detected
sources.
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Byte-by-byte Description of file: figure8.dat
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Bytes Format Units Label Explanations
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1 I1 --- Loc [1/4] Location code (1)
3- 19 A17 --- ID Source identifier
21 I1 --- Det? Detection code; 1=yes, 0=3σ upper limit
23- 28 F6.3 [Msun] logM* [-1.8/0.6] Log stellar mass
30- 35 F6.3 [Mgeo] logdust [-0.9/2.5] Log dust mass in Earth units
37- 42 F6.3 [Mgeo] logd20 [-1.1/2.7] Log dust mass in Earth units (2)
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Note (1): Location code as follows:
1 = Taurus;
2 = Lupus;
3 = ChamaeleonI;
4 = Upper Sco.
Note (2): Assuming a fixed dust temperature of 20K.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Feb-2017