J/A+A/580/A26 T Tauri star population in Lupus (Galli+, 2015)
Evolution of the T Tauri star population in the Lupus association.
Galli P.A.B., Bertout C., Teixeira R., Ducourant C.
<Astron. Astrophys., 580, A26-26 (2015)>
=2015A&A...580A..26G 2015A&A...580A..26G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; Stars, ages ; Stars, masses
Keywords: stars: pre-main sequence - circumstellar matter - stars: formation
Abstract:
In a recent study, we derived individual distances for 109 pre-main
sequence stars that define the Lupus kinematic association of young
stars. Here, we use these new distances to derive the masses and ages
of Lupus T Tauri stars with the aim of better constraining the
lifetime of their circumstellar disks. Using the photometric and
spectroscopic information available in the literature, we computed the
photospheric luminosity of 92 T Tauri stars in the Lupus association.
Then, we estimated their masses and ages from theoretical evolutionary
models. Based on Monte Carlo simulations and statistical tests, we
compare the mass and age distribution of the classical T Tauri stars
(CTTS) and weak-line T Tauri (WTTS) in our sample. We show that the
CTTSs are on average younger than the WTTSs and that the probability
that both T Tauri subclasses are drawn from the same mass and age
parental distribution is very low. Our results favor the scenario
proposed earlier for the Taurus-Auriga association, where the CTTSs
evolve into WTTSs when their disks are fully accreted by the star.
Based on an empirical disk model, we find that the average disk
lifetime for the T Tauri stars in the Lupus association is
τd=3x106(M*/M☉)0.55yr. We find evidence that the
average lifetime of the circumstellar disks in the Lupus association
is shorter than in the Taurus-Auriga association and discuss the
implications of this result.
Description:
The newly derived individual parallaxes from our previous kinematic
study of the Lupus association have been used in this paper to
determine the photospheric luminosities and refine the masses and ages
of the TTS population in this SFR. We investigated the mass and age
distributions of CTTSs and WTTSs in the Lupus association.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 104 92 Physical properties of the Lupus comoving stars
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Star Star name
24 A1 --- n_Star [*] *: binary (or multiple) systems (see Sect. 2)
26- 30 A5 --- SpType MK spectral type
33- 36 I4 K Teff Effective temperature
38- 43 F6.2 0.1nm EWHa ?=- Hα equivalent width
45- 49 F5.2 mag AV ?=0 Visual extinction
51- 54 F4.2 mag e_AV ? rms uncertainty on AV
55 A1 --- n_AV [:] : denotes a non-physical negative value or
a non-significant result
57- 60 F4.2 Msun Mass Mass derived from the Siess et al.
(2000A&A...358..593S 2000A&A...358..593S) models
62- 65 F4.2 Msun e_Mass rms uncertainty on Mass
67- 70 F4.2 [Myr] logt Age derived from the Siess et al.
(2000A&A...358..593S 2000A&A...358..593S) models
72- 75 F4.2 [Myr] e_logt rms uncertainty on Age
77- 83 A7 --- TTau T Tauri sub-class
85- 88 F4.2 [Myr] logtau Disk lifetime computed from Eq. (5),
tau≃3*106(M*/M_☉)0.55(±0.10)yr
90- 93 F4.2 [Myr] e_logtau rms uncertainty on logtau
95-104 A10 -- Refs Sources of photometric/spectroscopic
information (1)
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Note (1): Reference as follows:
1 = Krautter et al. (1997, Cat. J/A+AS/123/329)
2 = 2MASS (Cutri et al. 2003)
3 = Torres et al. (2006, Cat. J/A+A/460/695)
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5 = Sartori et al. (2003, Cat. J/A+A/404/913)
6 = Hughes et al. (1994AJ....108.1071H 1994AJ....108.1071H)
7 = Neuhauser et al. (2008A&A...484..281N 2008A&A...484..281N)
8 = Wahhaj et al. (2010, Cat. J/ApJ/724/835)
9 = Wichmann et al. (1997, Cat. J/A+A/326/211)
10 = Ghez et al. (1997ApJ...481..378G 1997ApJ...481..378G)
11 = Comeron et al. (2009, Cat.J/A+A/500/1045)
12 = Lopez Marti et al. (2011, Cat. J/A+A/529/A108)
13 = Valenti et al. (2003, Cat. J/ApJS/147/305)
14 = Brandner et al. (1996A&A...307..121B 1996A&A...307..121B)
15 = Merin et al. (2008, Cat. J/ApJS/177/551)
16 = Guenther et al. (2001A&A...366..965G 2001A&A...366..965G)
17 = Alcala et al. (2014, Cat. J/A+A/561/A2)
18 = Comeron et al. (2013A&A...554A..86C 2013A&A...554A..86C)
19 = Cieza et al. (2007, Cat. J/ApJ/667/308)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 02-Nov-2015