J/ApJ/827/142 ALMA observations of GKM stars in Upper Sco (Barenfeld+, 2016)
ALMA observations of circumstellar disks in the Upper Scorpius OB association.
Barenfeld S.A., Carpenter J.M., Ricci L., Isella A.
<Astrophys. J., 827, 142-142 (2016)>
=2016ApJ...827..142B 2016ApJ...827..142B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, masses ; Spectral types ; Effective temperatures ;
Millimetric/submm sources ; Extinction
Keywords: open clusters and associations: individual: Upper Scorpius OB1;
protoplanetary disks; stars: pre-main sequence
Abstract:
We present ALMA observations of 106 G-, K-, and M-type stars in the
Upper Scorpius OB Association hosting circumstellar disks. With these
data, we measure the 0.88mm continuum and 12CO J=3-2 line fluxes of
disks around low-mass (0.14-1.66M☉) stars at an age of 5-11Myr.
Of the 75 primordial disks in the sample, 53 are detected in the dust
continuum and 26 in CO. Of the 31 disks classified as debris/evolved
transitional disks, five are detected in the continuum and none in CO.
The lack of CO emission in approximately half of the disks with
detected continuum emission can be explained if CO is optically thick
but has a compact emitting area (≲40au), or if the CO is heavily
depleted by a factor of at least ∼1000 relative to interstellar medium
abundances and is optically thin. The continuum measurements are used
to estimate the dust mass of the disks. We find a correlation between
disk dust mass and stellar host mass consistent with a power-law
relation of Mdust∝M*1.67±0.37. Disk dust masses in
Upper Sco are compared to those measured in the younger Taurus
star-forming region to constrain the evolution of disk dust mass. We
find that the difference in the mean of log(Mdust/M*) between Taurus
and Upper Sco is 0.64±0.09, such that Mdust/M* is lower in Upper
Sco by a factor of ∼4.5.
Description:
ALMA observations were obtained in Cycle 0 and Cycle 2 using the 12m
array. Twenty sources were observed in Cycle 0 between 2012 August and
2012 December. Eighty-seven sources were observed in 2014 June and
2014 July.
All observations used band 7 with the correlator configured to record
dual polarization. Spectral windows for Cycle 2 were centered at
334.2, 336.1, 346.2, and 348.1GHz for a mean frequency of 341.1GHz
(0.88mm). The bandwidth of each window is 1.875GHz.
Cycle 0 observations used between 17 and 28 antennas with maximum
baselines of ∼400m, for an angular resolution of ∼0.55". Cycle 2
observations used between 34 and 36 antennas with baselines extending
out to 650m, corresponding to an angular resolution of 0.34".
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 95 106 Stellar properties
table4.dat 98 106 Continuum and CO J=3-2 flux measurements
table5.dat 37 106 Derived dust masses
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See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/MNRAS/448/2737 : New PMS K/M Stars in Upper Scorpius (Rizzuto+, 2015)
J/MNRAS/431/3222 : UKIDSS GCS Upper Sco members (Lodieu, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/ApJ/758/31 : IR photometry for members of Upper Sco (Luhman+, 2012)
J/ApJ/746/154 : Improved parallaxes for Sco-Cen members (Pecaut+, 2012)
J/ApJ/745/56 : Upper Sco members rotational velocities (Dahm+, 2012)
J/ApJ/738/122 : ScoCen debris disks Around F- and G-type stars (Chen+, 2011)
J/A+A/533/A109 : Pisa pre-main sequence tracks and isochrones (Tognelli+, 2011)
J/A+A/527/A24 : Spectra of low-mass stars in Upper Sco (Lodieu+, 2011)
J/A+A/504/981 : Proper motions of cool stars in Upper Sco OB (Bouy+, 2009)
J/ApJ/705/1646 : Debris disks in Upper Sco (Carpenter+, 2009)
J/ApJ/688/377 : Low-mass objects in Upper Scorpius. II. (Slesnick+, 2008)
J/ApJ/651/L49 : Upper Sco OB association IRAC observations (Carpenter+, 2006)
J/AJ/131/3016 : Low-mass objects in Upper Scorpius (Slesnick+, 2006)
J/AJ/124/404 : Upper Scorpius OB association Li survey. II. (Preibisch, 2002)
J/AJ/120/479 : Low-mass stars in the Upper Sco association (Ardila+, 2000)
J/AJ/117/354 : OB associations from Hipparcos (de Zeeuw+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS ID (JHHMMSSss+DDMMSSs)
25- 29 A5 --- SpT MK spectral type (G2 to M5) from
Luhman & Mamajek (2012, J/ApJ/758/31)
31- 47 A17 --- Type Disk type (1)
49- 53 F5.2 mag Av [-0.6/4.3] Visual extinction
55- 58 F4.2 mag e_Av [0.2/0.5] Uncertainty in Av
60- 63 F4.2 [K] logTeff [3.4/3.8] Log effective temperature
65- 68 F4.2 [K] e_logTeff [0/0.02] Uncertainty in logTeff
70- 74 F5.2 [Lsun] logL [-1.9/0.8] Log luminosity (estimated using
2MASS J-band; see section 2)
76- 79 F4.2 [Lsun] e_logL [0.1/0.2] Uncertainty in logL
81- 85 F5.2 [Msun] logM [-0.9/0.3] Log stellar mass
87- 90 F4.2 [Msun] e_logM [0.04/0.2] Lower uncertainty in logM
92- 95 F4.2 [Msun] E_logM [0.02/0.2] Upper uncertainty in logM
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Note (1): Disk type as defined by Luhman & Mamajek (2012, J/ApJ/758/31):
Full = optically thick in the infrared with an SED that shows
no evidence of disk clearing (53 sources).
Transitional = with an SED showing evidence for gaps and holes (5 sources)
Evolved = becoming optically thin in the infrared, but no evidence
of clearing (17 sources)
Debris/Ev. Trans. = "Debris/Evolved Transitional": either young debris disks
composed of second-generation dust originating from the
collisional destruction of planetesimals, or the final
phase of primordial disk evolution (31 sources).
See section 2 for further details.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS ID (JHHMMSSss+DDMMSSs)
25- 25 I1 --- f_Aper ? Continuum flux density photometry flag:
1=aperture
27- 32 F6.2 mJy Snu [-0.4/904] ALMA 0.88mm continuum flux density
34- 37 F4.2 mJy e_Snu [0.1/1] Uncertainty in Snu
39- 43 F5.2 arcsec dRA [-0.6/0.5]? ALMA continuum offset from
stellar source, RA (1)
45- 48 F4.2 arcsec e_dRA [0.04/0.3]? Uncertainty in dRA
50- 54 F5.2 arcsec dDE [-0.6/0.6]? ALMA continuum offset from
stellar source, Dec (1)
56- 59 F4.2 arcsec e_dDE [0.04/0.3]? Uncertainty in dDE
61- 65 F5.3 arcsec FWHM [0.1/0.5]? Full width at half maximum (2)
67- 71 F5.3 arcsec e_FWHM [0.001/0.07]? Uncertainty in FWHM
73- 77 I5 mJy.km/s COFlux [-86/22748] ALMA CO J=3-2 flux
79- 81 I3 mJy.km/s e_COFlux [16/158] Uncertainty in COFlux
83- 87 F5.1 km/s Vmin [-17/3.5] Velocity range of the CO, minimum
91- 94 F4.1 km/s Vmax [6/24] Velocity range of the CO, maximum
96- 98 F3.1 arcsec Aper [0.3/2.1] Aperture Radius
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Note (1): Continuum offsets from the expected stellar position. Blank values
indicate a non-detection, for which the fit position is held fix at
the expected stellar position.
Note (2): Full width at half maximum for sources fitted with an elliptical
Gaussian. Blank values indicate point sources and sources measured
with aperture photometry.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS ID (JHHMMSSss+DDMMSSs)
25 A1 --- l_Mdust Upper limit flag on Mdust, in Earth Masses
26- 31 F6.2 Mgeo Mdust [0.05/128] Disk dust mass
33- 37 F5.2 Mgeo e_Mdust [0.03/32]? Uncertainty in Mdust, in Earth Masses
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-Nov-2016