J/A+A/629/A67 T Tauri in NGC 2264 cluster (Sousa+, 2019)
A study of accretion and disk diagnostics in the NGC 2264 cluster.
Sousa A.P., Alencar S.H.P., Rebull L.M., Espaillat C.C., Calvet N.,
Teixeira P.S.
<Astron. Astrophys. 629, A67 (2019)>
=2019A&A...629A..67S 2019A&A...629A..67S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; Equivalent widths ;
Effective temperatures
Keywords: stars: pre-main sequence - stars: variables: T Tauri - Herbig Ae/Be -
accretion - accretion disks - protoplanetary disks
Abstract:
Understanding disk dissipation is essential for studying how planets
form. Disk gaps and holes, which almost correspond to dust-free
regions, are inferred from infrared observations of T Tauri stars
(TTS), indicating the existence of a transitional phase between thick
accreting disks and debris disks. Transition disks are usually
referred to as candidates for newly formed planets.
We searched for transition disk candidates belonging to NGC 2264.
Using stellar and disk parameters obtained in the observational
multiwavelength campaign CSI 2264, we characterized accretion, disk,
and stellar properties of transition disk candidates and compared them
to systems with a full disk and diskless stars.
We modeled the spectral energy distribution (SED) of a sample of 401
TTS, observed with both CFHT equipped with MegaCam and IRAC instrument
on the Spitzer, with Hyperion SED fitting code using photometric data
from the U band (0.3um) to the Spitzer/MIPS 24um band. We used the SED
modeling to distinguish transition disk candidates, full disk systems,
and diskless stars.
We classified ∼52% of the sample as full disk systems, ∼41% as
diskless stars, and ∼7% of the systems as transition disk candidates,
among which seven systems are new transition disk candidates belonging
to the NGC 2264 cluster. The sample of transition disk candidates
present dust in the inner disk similar to anemic disks, according to
the αIRAC classification, which shows that anemic disk systems
can be candidate transition disks. We show that the presence of a dust
hole in the inner disk does not stop the accretion process since 82%
of transition disk candidates accrete and show Hα, UV excess,
and mass accretion rates at the same level as full disk systems. We
estimate the inner hole sizes, ranging from 0.1 to 78AU, for the
sample of transition disk candidates. In only ∼18% of the transition
disk candidates, the hole size could be explained by X-ray
photoevaporation from stellar radiation.
Description:
We present the stellar parameters for T Tauri stars with full disk
(Table2) and diskless (Table3). The tables contain spectroscopy
(Halpha equivalent width ...) and photometric (UV excess ...) data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 141 209 Observational parameters of our sample of
full disk systems
table3.dat 127 164 Observational parameters of our sample of
diskless stars
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/123/1528 : UBV(RI)C and JHK photometry in NGC 2264 (Rebull+, 2002)
J/AJ/129/829 : Hα emission stars in NGC 2264 (Dahm+, 2005)
J/A+A/570/A82 : Mapping accretion variability in NGC 2264 (Venuti+, 2014)
J/A+A/586/A47 : Accretion process in NGC 2264 (Sousa+, 2016)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [Mon-]
5- 10 I06 --- Mon Internal identification of the CSI 2264
campaign (CSIMon-NNNNNN in Simbad)
14- 29 A16 --- 2Mass 2MASS identification
33- 37 A5 --- SpType Spectral type (G1)
41- 45 F5.1 0.1nm EWHaS16 ? Hα equivalent width from
Sousa et al., 2016, Cat. J/A+A/586/A47 (G2)
49- 51 I3 km/s W10 ? Hα width at 10% of maximum intensity
from Sousa et al., 2016, Cat. J/A+A/586/A47
55- 59 F5.1 0.1nm EWHaD05 ? Hα equivalent width obtained by
Dahm et al., 2005, Cat. J/AJ/129/829
63 A1 --- Class [cw] Classification as CTTS (c) and WTTS (w)
by Sousa et al., 2016, Cat. J/A+A/586/A47
and Venuti et al., 2014, Cat. J/A+A/570/A82
67- 71 F5.2 --- alphaIRAC Slope of the spectral energy distribution
between 3.6 and 8 micrometer obtained by
Teixeira et al., 2012A&A...540A..83T 2012A&A...540A..83T
77- 80 F4.2 Rsun R* ? Stellar radius from Venuti et al., 2014,
Cat. J/A+A/570/A82
86- 89 I4 K Teff Effective temperature from Venuti et al.,
2014, Cat. J/A+A/570/A82
98-103 F6.3 mag UVexc UV excess from Venuti et al., 2014
Cat. J/A+A/570/A82
111-117 E7.1 Msun/yr dM/dtUV ? UV excess mass accretion rate from
Venuti et al., 2014, Cat. J/A+A/570/A82
125-131 E7.1 Msun/yr dM/dtHa ? Hα mass accretion rate from
Sousa et al., 2016, Cat. J/A+A/586/A47
136-141 F6.1 pc Dist ? Distance from the Sun which was obtained
from the Gaia parallax data
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [Mon-]
5- 10 I06 --- Mon Internal identification of the CSI 2264
campaign (CSIMon-NNNNNN in Simbad)
14- 29 A16 --- 2Mass 2MASS identification
33- 37 A5 --- SpType Spectral type (G1)
42- 45 F4.1 0.1nm EWHaS16 ? Hα equivalent width from
Sousa et al., 2016, Cat. J/A+A/586/A47 (G2)
49- 51 I3 km/s W10 ? Hα width at 10% of maximum intensity
from Sousa et al., 2016, Cat. J/A+A/586/A47
56- 59 F4.1 0.1nm EWHaD05 ? Hα equivalent width obtained by
Dahm et al., 2005, Cat. J/AJ/129/829
63 A1 --- Class [cw] Classification as CTTS (c) and WTTS (w)
by Sousa et al., 2016, Cat. J/A+A/586/A47
and Venuti et al., 2014, Cat. J/A+A/570/A82
67- 71 F5.2 --- alphaIRAC Slope of the spectral energy distribution
between 3.6 and 8 micrometer obtained by
Teixeira et al., 2012A&A...540A..83T 2012A&A...540A..83T
77- 80 F4.2 Rsun R* Stellar radius from Venuti et al., 2014,
Cat. J/A+A/570/A82
86- 89 I4 K Teff Effective temperature Venuti et al.,
2014, Cat. J/A+A/570/A82
98-103 F6.3 mag UVexc UV excess from Venuti et al., 2014
Cat. J/A+A/570/A82
111-117 E7.1 Msun/yr dM/dtHa ? Hα mass accretion rate from
Sousa et al., 2016, Cat. J/A+A/586/A4
123-127 F5.1 pc Dist ? Distance from the Sun which was obtained
from the Gaia parallax data
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Global notes:
Note (G1): Spectral type from Venuti et al, 2014, Cat. J/A+A/570/82,
Dahm et al, 2005, Cat. J/AJ/129/829, Rebull et al., 2002, Cat. J/AJ/123/1528,
Walker, 1956ApJS....2..365W 1956ApJS....2..365W.
Note (G2): We used the convention that positive Hα equivalent width
indicates Hα in emission, and negative values indicate Hα
in absorption.
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Acknowledgements:
Alana Sousa, alana(at)fisica.ufmg.br
(End) Patricia Vannier [CDS] 09-Aug-2019