J/A+A/626/A11 Corona Australis ALMA and X-Shooter data (Cazzoletti+, 2019)
ALMA survey of Class II protoplanetary disks in Corona Australis:
a young region with low disk masses.
Cazzoletti P., Manara C.F., van Dishoeck E.F., Facchini S., Alcala J.M.,
Ansdell M., Testi L., Williams J.P., Carrasco-Gonzalez C., Dong R.,
Forbrich J., Fukagawa M., Galvan-Madrid R., Hirano N., Hogerheijde M.,
Hasegawa Y., Muto T., Pinilla P., Takami M., Tamura M., Tazzari M.,
Wisniewski J.P.
<Astron. Astrophys. 626, A11 (2019)>
=2019A&A...626A..11C 2019A&A...626A..11C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; YSOs ; Photometry, millimetric/submm ;
Morphology
Keywords: protoplanetary disks - submillimeter: ISM -
planets and satellites: formation - stars: pre-main sequence -
stars: variables: T Tauri, Herbig Ae/Be - stars: formation
Abstract:
In recent years, the disk populations in a number of young
star-forming regions have been surveyed with the Atacama Large
Millimeter/submillimeter Array (ALMA). Understanding the disk
properties and their correlation with the properties of the central
star is critical to understanding planet formation. In particular, a
decrease of the average measured disk dust mass with the age of the
region has been observed, consistent with grain growth and disk
dissipation.
We aim to compare the general properties of disks and their host stars
in the nearby (d=160pc) Corona Australis (CrA) star forming region
to those of the disks and stars in other regions.
We conducted high-sensitivity continuum ALMA observations of 43 Class
II young stellar objects in CrA at 1.3mm (230GHz). The typical
spatial resolution is 0.3''. The continuum fluxes ar e used to
estimate the dust masses of the disks, and a survival analysis is
performed to estimate the average dust mass. We also obtained new
VLT/X-Shooter spectra for 12 of the objects in our sample for which
spectral type (SpT) information was missing.
Twenty-four disks were detected, and stringent limits have been put on
the average dust mass of the nondetections. Taking into account the
upper limits, the average disk mass in CrA is 6±3M☉. This
value is significantly lower than that of disks in other young
(1-3Myr) star forming regions (Lupus, Taurus, Chamaeleon I, and
Ophiuchus) and appears to be consistent with the average disk mass of
the 5-10Myr-old Upper Sco. The position of the stars in our sample on
the Herzsprung-Russel diagram however seems to confirm that CrA has an
age similar to Lupus. Neither external photoevaporation nor a
lower-than-usual stellar mass distribution can explain the low disk
masses. On the other hand, a low-mass disk population could be
explained if the disks were small, which could happen if the parent
cloud had a low temperature or intrinsic angular momentum, or if the
angular momentum of the cloud were removed by some physical mechanism
such as magnetic braking. Even in detected disks, none show clear
substructures or cavities.
Our results suggest that in order to fully explain and understand the
dust mass distribution of protoplanetary disks and their evolution, it
may also be necessary to take into consideration the initial
conditions of star- and disk-formation process. These conditions at
the very beginning may potentially vary from region to region, and
could play a crucial role in planet formation and evolution.
Description:
Continuum ALMA data at 1.9mm (Band 4) and 2.8mm (Band 3) of the HD
135344B disk. These data are part of three different projects. The
Band 4 data have been observed in C40-8 configuration during ALMA
Cycle 4 in two execution blocks on September 14th, 2017 and September
28th, 2017 as part of program 2016.1.00340.S with 41 and 42 antennas.
Additional Band 4 observations were carried out during Cycle 5 in
C43-5 configuration, on January 17th, 2018 as part of the program
2017.A.00025.S using 44 antennas. The Band 3 data were observed in
Cycle 5 in the C43- 8 configuration on November 11th, 2017
(2017.1.00884.S) using 44 antennas, and in the C43-5 configuration on
January 17th, 2018 (2017.A.00025.S) with 46 antennas. More details as
well as the correlator setup are described in the paper.
Our Band 6 ALMA Cycle 4 observations (Project ID: ) were obtained on
2016 August 1 and 2 as part of project 2015.1.01058.S. The spectral
setup consists of six spectral windows, of which the central frequency
[GHz], total bandwidth [MHz], and frequency channel width [kHz] are
(216.797, 1875,488), (219.552, 59, 61), (219.941, 59, 61), (220.390,
117, 61), (230.531, 117, 31), and (231.484, 1875, 488), respectively.
Our X-Shooter data were carried out in Pr.Id. 299.C-5048 and Pr.Id.
0101.C-0893 with the VLT/X-Shooter spectrograph. This instrument
covers the wavelength range from ∼300nm to ∼2500nm simultaneously,
dividing the spectrum in three arms: the UVB
(λλ∼300-550nm), the VIS (λλ∼500-1050nm),
and the NIR(λλ∼1000-2500nm). All targets were observed
both with a narrow slit - 1.000 in the UVB, 0.900 in the VIS, and NIR
arms - leading to R∼9000 and ∼10000, respectively, and a wide slit of
5.000 used to obtain an accurate flux calibration of the spectra.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 61 43 Stellar properties
table3.dat 88 43 mm continuum properties
tablea1.dat 44 37 Additional stellar properties from
X-Shooter Spectra
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See also:
J/ApJ/397/520 : IRAS observations in Cr A (Wilking+, 1992)
J/A+AS/116/21 : Extinction toward CrA and Lup (Andreazza+, 1996)
J/A+A/488/987 : Near-infrared survey of R CrA cloud (Haas+, 2008)
J/ApJS/194/43 : YSOs candidates and knots in CrA cloud (Peterson+, 2011)
J/A+A/548/A24 : 1.3mm observations of CrA cluster (Lindberg+, 2012)
J/A+A/551/A34 : SED information for CrA members (Sicilia-Aguilar+, 2013)
J/A+A/615/A125 : Molecular cloud in Corona Australis (Bresnahan+, 2018)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- ID 2MASS source identifier
19- 29 A11 --- Name Name of the target
31- 32 I2 h RAh Right ascension (J2000)
34- 35 I2 min RAm Right ascension (J2000)
37- 41 F5.2 s RAs Right ascension (J2000)
43 A1 --- DE- Declination sign (J2000)
44- 45 I2 deg DEd Declination (J2000)
47- 48 I2 arcmin DEm Declination (J2000)
50- 53 F4.1 arcsec DEs Declination (J2000)
55- 58 A4 --- SpType Spectral type
60- 61 I2 --- r_SpType ? Reference for SpType (1)
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Note (1): Reference as follows:
1 = This work
2 = Bouy et al., 2004A&A...424..213B 2004A&A...424..213B
3 = Romero et al., 2012ApJ...749...79R 2012ApJ...749...79R, Cat. J/ApJ/749/79
4 = Lopez Marti et al., 2005A&A...444..175L 2005A&A...444..175L
5 = Sicilia-aguilar et al., 2011ApJ...736..137S 2011ApJ...736..137S
6 = Forbrich & Preibisch, 2007A&A...475..959F 2007A&A...475..959F, Cat, J/A+A/475/959
7 = Sicilia-aguilar et al., 2008ApJ...687.1145S 2008ApJ...687.1145S
8 = Currie & Sicilia-aguilar, 2011ApJ...732...24C 2011ApJ...732...24C
9 = Meyer & Wilking, 2009PASP..121..350M 2009PASP..121..350M
10 = Walter et al., 1997AJ....114.1544W 1997AJ....114.1544W
11 = Herczeg & Hillenbrand, 2014ApJ...786...97H 2014ApJ...786...97H, Cat. J/ApJ/786/97
12 = Patten, 1998ASPC..154.1755P 1998ASPC..154.1755P
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Name of the target
13- 17 F5.2 arcsec dRA ? Right ascension offset with respect to
the Spitzer position
19- 23 F5.2 arcsec dDE ? Declination offset with respect to the
Spitzer position
25- 30 F6.2 mJy F1300 ? ALMA 1.3mm continuum flux density
32- 35 F4.2 mJy e_F1300 ? Uncertainty in F1300
37- 41 F5.2 mJy/beam rms Root mean square
43- 47 F5.3 arcsec amaj ? Semimajor axis
49- 53 F5.3 arcsec e_amaj ? Uncertainty in amaj
55- 58 F4.2 arcsec amin ? Semiminor axis
60- 64 F5.3 arcsec e_amin ? Uncertainty in amin
66- 71 F6.2 deg PA ? Position angle
73- 76 F4.1 deg e_PA ? Uncertainty in PA
78- 83 F6.2 Mgeo Mdust ? Dust mass
85- 88 F4.2 Mgeo e_Mdust ? Uncertainty in Mdust
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Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Name of the target
13- 17 F5.2 mag Jmag J magnitude
19- 23 F5.2 mag AV Absorption in V band
25 I1 --- r_AV Reference for AV (1)
27- 31 I5 K Teff Effective temperature
33- 37 F5.2 [Lsun] logL* Stellar luminosity
39- 42 F4.2 Msun M* Stellar mass
44 A1 --- evtrack [sb] Evolutionary track used to calculate
M* (2)
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Note (1): Reference as follows:
1 = This work
2 = Dunham et al., 2015ApJS..220...11D 2015ApJS..220...11D, Cat. J/ApJS/220/11
3 = Sicilia-aguilar et al., 2011ApJ...736..137S 2011ApJ...736..137S
4 = Patten, 1998ASPC..154.1755P 1998ASPC..154.1755P
5 = 2005A&A...444..175L 2005A&A...444..175L
Note (2): Reference as follows:
s = Siess et al., 2000A&A...358..593S 2000A&A...358..593S
b = Baraffe et al., 2015A&A...577A..42B 2015A&A...577A..42B
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Acknowledgements:
Paolo Cazzoletti, pcazzoletti(at)mpe.mpg.de
(End) Paolo Cazzoletti [MPE], Patricia Vannier [CDS] 19-May-2019