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 (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; 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:
FileName Lrecl Records Explanations
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
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
Bytes Format Units Label Explanations
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)
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); D13 = Daemgen et al. (2013A&A...554A..43D); KH07 = Kraus and Hillenbrand 2007, J/ApJ/662/413; La08 = Lafreniere et al. (2008ApJ...683..844L); L07 = Luhman 2007, J/ApJS/173/104; M14 = Manara et al. (2014A&A...568A..18M); M16a = Manara et al. (2016A&A...585A.136M); M16b = Manara et al. (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.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
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)
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.
Byte-by-byte Description of file: figure8.dat
Bytes Format Units Label Explanations
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)
Note (1): Location code as follows: 1 = Taurus; 2 = Lupus; 3 = ChamaeleonI; 4 = Upper Sco. Note (2): Assuming a fixed dust temperature of 20K.
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Feb-2017
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