A self-consistent, absolute isochronal age scale for young moving groups in the solar neighbourhood

By C. Bell, Eric Mamajek, Tim Naylor University of Rochester, U. Exeter. 2015

361 citations recorded by the source corpus.

We present a self-consistent, absolute isochronal age scale for young (< 200 Myr), nearby (< 100 pc) moving groups in the solar neighbourhood based on homogeneous fitting of semi-empirical pre-main-sequence model isochrones using the tau^2 maximum-likelihood fitting statistic of Naylor & Jeffries in the M_V, V-J colour-magnitude diagram. The final adopted ages for the groups are: 149+51-19 Myr for the AB Dor moving group, 24+/-3 Myr for the {\beta} Pic moving group (BPMG), 45+11-7 Myr for the Carina association, 42+6-4 Myr for the Columba association, 11+/-3 Myr for the {\eta} Cha cluster, 45+/-4 Myr for the Tucana-Horologium moving group (Tuc-Hor), 10+/-3 Myr for the TW Hya association, and 22+4-3 Myr for the 32 Ori group. At this stage we are uncomfortable assigning a final, unambiguous age to the Argus association as our membership list for the association appears to suffer from a high level of contamination, and therefore it remains unclear whether these stars represent a single population of coeval stars. Our isochronal ages for both the BPMG and Tuc-Hor are consistent with recent lithium depletion boundary (LDB) ages, which unlike isochronal ages, are relatively insensitive to the choice of low-mass evolutionary models. This consistency between the isochronal and LDB ages instills confidence that our self-consistent, absolute age scale for young, nearby moving groups is robust, and hence we suggest that these ages be adopted for future studies of these groups. Software implementing the methods described in this study is available from http: //www.astro.ex.ac.uk/people/timn/tau-squared/.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/ca63e7853778640ee88a3a72b10db8c6e22a4b3e

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In Astronomy and Astrophysics

1. B. Bowler
2. Michael C. Liu
3. T. Dupuy
4. Jon Fortney
5. M. Marley
6. Adam Burrows
7. A. Kraus
8. N. Madhusudhan

In Instrumentation

1. B. Bowler
2. Michael C. Liu
3. Jon Fortney
4. T. Dupuy
5. M. Marley
6. K. Allers
7. Adam Burrows
8. A. Kraus

Citations in the corpus

• Untangling the Galaxy. I. Local Structure and Star Formation History of the Milky Way (2019, background): “They include regions such as TW Hya, TucHor, AB Dor, Ursa Major, and several others (e.g., Bannister & Jameson 2005; Bell et al. 2015; Faherty et al. 2018; Lee & Song 2018).”
• How to Constrain Your M Dwarf. II. The Mass–Luminosity–Metallicity Relation from 0.075 to 0.70 Solar Masses (2018, methodology): “DSEP uses PHOENIX Hauschildt et al. (1999a,b) models, and have been used widely for studies of late-type dwarfs (e.g., Boyajian et al. 2012; Bell et al. 2015; Kesseli et al. 2018a).”
• BANYAN. XI. The BANYAN Σ Multivariate Bayesian Algorithm to Identify Members of Young Associations with 150 pc (2018, methodology): “Since its UVW position is at 0.7 ± 0.7 km s−1 from the core of CAR and at 5.5± 2.1 km s−1 from that of THA, here it was included in the list of CAR members (see also the discussions of Bell et al. 2015, Section B2.”
• Imaging Extrasolar Giant Planets (2016, background): “…star-forming regions and young moving groups in particular have been systematically adjusted to older ages over the past few years, which has propagated to the ages and masses of planets in those 10 associations (Pecaut et al. 2012; Binks & Jeffries 2014; Kraus et al. 2014b; Bell et al. 2015).”
• THE HAWAII INFRARED PARALLAX PROGRAM. II. YOUNG ULTRACOOL FIELD DWARFS (2016, background): “…members that are currently unidentified, which would alter the triaxial gaussians used by BANYAN II, (2) uncertainties in the reality of all seven adopted YMGs, e.g., the exact nature of Argus is disputed (Bell et al. 2015), and (3) new YMGs in the solar neighborhood that remain to be discovered.”
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics from 10 to 100 au (2019, background): “…19.1 Note. a System mass. References(1) Houk & Swift (1999), (2) Gaia Collaboration et al. (2018), (3) This study (SED fitting), (4) Torres et al. (2006), (5) Bell et al. (2015), (6) Nielsen et al. (2016), (7) Zuckerman et al. (2006), (8) Keenan & McNeil (1989), (9) This study (activity), (10)…”