J/MNRAS/484/5102 NGC 6383 T Tauri accretion rates (Kalari, 2019)
Classical T-Tauri stars with VPHAS+: II: NGC 6383 in Sh 2-012.
Kalari V.M.
<Mon. Not. R. Astron. Soc., 484, 5102-5112 (2019)>
=2019MNRAS.484.5102K 2019MNRAS.484.5102K (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Accretion ;
Photometry, ugriz ; Photometry, H-alpha
Keywords: accretion, accretion discs; stars: pre-main sequence -
stars: variables: T Tauri -
open clusters and associations: individual: Sh 2-012 -
open clusters and associations: individual: NGC 6383
Abstract:
This paper presents optical (ugriHα)-infrared (JHKs, 3.6-8.0um)
photometry and Gaia astrometry of 55 Classical T-Tauri stars (CTTS) in
the star-forming region Sh 2-012 and its central cluster NGC 6383. The
sample was identified based on photometric Hα emission
linewidths, and has a median age of 2.8±1.6Myr, with a mass range
between 0.3 and 1M☉. 94 per cent of CTTS with near-infrared
cross-matches fall on the near-infrared T-Tauri locus, with all stars
having mid-infrared photometry exhibiting evidence for accreting
circumstellar discs. CTTS are found concentrated around the central
cluster NGC 6383, and towards the bright rims located at the edges of
Sh 2-012. Stars across the region have similar ages, suggestive of a
single burst of star formation. Mass accretion rates dMacc/dt)
estimated via Hα and u-band line intensities show a scatter
(0.3dex) similar to spectroscopic studies, indicating the suitability
of Hα photometry to estimate dMacc/dt. Examining the variation
of dMacc/dt with stellar mass (M*), we find a smaller intercept in the
(dMacc/dt)-M* relation than oft-quoted in the literature, providing
evidence to discriminate between competing theories of protoplanetary
disc evolution.
Description:
Based on Hα excess emission, we identified 55 CTTS in the
star-forming region Sh 2-012. The identified CTTS have an age of
2.8Myr, and fall between 0.3 and 0.9M☉. From their Hα and
u-band excess intensities, we measured their mass accretion rates.
Photometry and derived parameters of pre-main sequence stars in
NGC 6383
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 194 55 Estimated results
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/341 : VPHAS+ DR2 survey (Drew+, 2016)
J/MNRAS/453/1026 : Lagoon Nebula M8 T tauri accretion rates (Kalari+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- VPHASDR2 sourceID from VPHAS+ DR2
(Drew et al., 2016, Cat. II/341)
16- 33 F18.14 deg RAdeg Right Ascension (J2000)
35- 53 F19.15 deg DEdeg Declination (J2000)
55- 60 F6.3 mag umag ?=- u magnitude
62- 65 F4.2 mag e_umag ?=- rms uncertainty on umag
67- 72 F6.3 mag gmag g magnitude
74- 77 F4.2 mag e_gmag rms uncertainty on gmag
79- 84 F6.3 mag rmag r magnitude
86- 89 F4.2 mag e_rmag rms uncertainty on rmag
91- 96 F6.3 mag Hamag Hα magnitude
98-101 F4.2 mag e_Hamag rms uncertainty on Hamag
103-108 F6.3 mag imag i magnitude
110-113 F4.2 mag e_imag rms uncertainty on imag
115-119 F5.3 mas/yr pmRA Proper motion in right ascension
direction (pmRA*cosDE)
121-125 F5.3 mas/yr e_pmRA Standard error of proper motion in
right ascension direction
127-132 F6.3 mas/yr pmDE Proper motion in declination direction
134-138 F5.3 mas/yr e_pmDE Standard error of proper motion in
declination direction
140-146 F7.2 0.1nm EWHa Equivalent width of Hα line
148-152 F5.2 0.1nm e_EWHa Standard error on EWHa
154-158 F5.2 Myr Age Age
160-163 F4.2 Myr e_Age Standard error on age
165-168 F4.2 Msun Mass Mass
170-173 F4.2 Msun e_Mass Standard error on mass
175-179 F5.2 Msun/yr (dMac/dt)Ha Accretion rate derived from the
Hα line
181-184 F4.2 Msun/yr e_(dMac/dt)Ha Standard error on (dMac/dt)Ha
186-190 F5.2 Msun/yr (dMac/dt)u ?=- Accretion rate derived from
u photometry
192-194 F3.1 Msun/yr e_(dMac/dt)u ?=- Standard error on (dMac/dt)u
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Acknowledgements:
Venu Kalari, vkalari(at)gemini.edu
References:
Kalari et al., Paper I 2015MNRAS.453.1026K 2015MNRAS.453.1026K, Cat. J/MNRAS/453/1026
(End) Patricia Vannier [CDS] 03-Nov-2021