J/ApJ/898/27 Bayesian Ages For Field LowEr-mass Stars (Stanford-Moore+, 2020)
BAFFLES: Bayesian Ages For Field LowEr-mass Stars.
Stanford-Moore S.A., Nielsen E.L., De Rosa R.J., Macintosh B., Czekala I.
<Astrophys. J., 898, 27 (2020)>
=2020ApJ...898...27S 2020ApJ...898...27S
ADC_Keywords: Stars, ages; Spectral types; Stars, nearby; Optical
Keywords: Stellar activity ; Stellar ages ; Field stars ; Bayesian statistics
Abstract:
Age is a fundamental parameter of stars, yet in many cases, ages of
individual stars are presented without robust estimates of the
uncertainty. We have developed a Bayesian framework, BAFFLES, to
produce the age posterior for a star from its calcium emission
strength (log(RHK')) or lithium abundance (Li EW) and B-V color.
We empirically determine the likelihood functions for calcium and
lithium as functions of age from literature measurements of stars in
benchmark clusters with well-determined ages. We use a uniform prior
on age, which reflects a uniform star formation rate. The age
posteriors we derive for several test cases are consistent with
literature ages found from other methods. BAFFLES represents a robust
method to determine the age posterior probability distribution for any
field star with 0.45≤B-V0.9 and a measurement of RHK' and/or
0.35≤B-V≤1.9 and measured Li EW. We compile colors, RHK', and Li
EW from over 2630 nearby field stars from the literature, and present
the derived BAFFLES age posterior for each star.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 203 2630 BAFFLES ages for nearby stars
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See also:
II/122 : UBV Photoelectric Catalog: data 1953-1985 (Mermilliod 1987)
III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)
III/159 : Ca II H and K Measurements Made at MWO (Duncan+ 1991)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
J/AJ/106/1059 : Lithium in the Pleiades (Soderblom+, 1993)
J/AJ/111/439 : Chromospheric emission in late-type stars. (Henry+ 1996)
J/AJ/117/354 : OB associations from Hipparcos (de Zeeuw+, 1999)
J/A+A/348/897 : Ages of main-sequence stars (Lachaume+, 1999)
J/MNRAS/306/361 : UBVI CCD photometry of M35 (NGC 2168) (Sung+ 1999)
J/AJ/124/1670 : Post-T Tauri Stars in Sco-Cen Association (Mamajek+, 2002)
J/ApJS/152/261 : Chromospheric Ca II emission in nearby stars (Wright+, 2004)
J/AJ/132/161 : NStars project: The southern sample. I. (Gray+, 2006)
J/MNRAS/372/163 : Activity indices for southern stars (Jenkins+, 2006)
J/AJ/131/2967 : α Persei open cluster members (Makarov+, 2006)
J/AJ/132/866 : New M dwarfs in solar neighborhood (Riaz+, 2006)
J/A+A/460/695 : Associations Containing Young stars (Torres+, 2006)
J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)
J/A+A/504/829 : Spec. survey of youngest field stars (Guillout+, 2009)
J/AJ/138/312 : Activity of bright solar analogs (Hall+, 2009)
J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010)
J/MNRAS/403/1949 : UBV(RcIc)JHK photometry of HIP nearby stars (Koen+, 2010)
J/A+A/520/A15 : RACE-OC project: YSOs within 100pc (Messina+, 2010)
J/ApJ/734/70 : Chromospheric activity of Southern stars (Arriagada, 2011)
J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)
J/ApJ/733/115 : Rotation periods and membership in M34 (Meibom+, 2011)
J/AcA/62/67 : ASAS photometry of ROSAT sources (Kiraga, 2012)
J/A+A/549/A109 : HARPS XXXI. The M-dwarf sample (Bonfils+, 2013)
J/A+A/551/L8 : Chromospheric activity of field stars (Pace, 2013)
J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)
J/ApJ/794/159 : Statistical analysis of exoplanet surveys (Brandt+, 2014)
J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/ApJ/804/146 : Atmospheric parameters for nearby B-F stars (David+, 2015)
J/AJ/149/119 : Radial velocities of stars in NGC 2264 (Tobin+, 2015)
J/MNRAS/461/794 : Scorpius-Centaurus K-Type Stars (Pecaut+, 2016)
J/AJ/154/69 : ACRONYM II. β Pictoris Moving Group (Shkolnik+, 2017)
J/AJ/156/37 : Li abund. of cool dwarfs in M35 (Anthony-Twarog+, 2018)
J/A+A/616/A108 : Cool stars chromospheric activity (Boro Saikia+, 2018)
J/A+A/612/A99 : Gaia-ESO Survey in open star cluster fields (Randich+, 2018)
J/AJ/158/13 : The first 300 stars observed by the GPIES (Nielsen+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- ID Source identifier
20- 21 I2 h RAh Hour of Right Ascension (J2000)
23- 24 I2 min RAm Minute of Right Ascension (J2000)
26- 30 F5.2 s RAs Second of Right Ascension (J2000)
32 A1 --- DE- Sign of the Declination (J2000)
33- 34 I2 deg DEd Degree of Declination (J2000)
36- 37 I2 arcmin DEm Arcminute of Declination (J2000)
39- 43 F5.2 arcsec DEs Arcsecond of Declination (J2000)
45- 59 A15 --- SpType Spectral type
61- 65 F5.3 mag B-V [0.45/1.74] The (B-V) color index
67- 72 F6.3 [-] logRHK [-5/-3.7]? log calcium emission strength index;
logR'HK
74- 80 F7.3 10-13m EW [-3.3/570]? Lithum equivalent width;
in milli-Angstrom units
82- 88 A7 --- Ref Reference code(s) (1)
90- 96 F7.2 Myr 2.5Age1 [1.8/2850]? R'HK age 2.5% posterior CDF value
98-104 F7.2 Myr 16Age1 [8.8/5730]? R'HK age 16% posterior CDF value
106-111 F6.1 Myr 50Age1 [69.2/8980]? R'HK age 50% posterior CDF value
113-117 I5 Myr 84Age1 [443/11700]? R'HK age 84% posterior CDF value
119-123 I5 Myr 97.5Age1 [1660/12800]? R'HK age 97.5% posterior
CDF value
125-131 F7.2 Myr 2.5Age2 [1.2/1510]? Li EW age 2.5% posterior CDF value
133-139 F7.2 Myr 16Age2 [2.47/4300]? Li EW age 16% posterior CDF value
141-147 F7.2 Myr 50Age2 [5.6/8380]? Li EW age 50% posterior CDF value
149-155 F7.1 Myr 84Age2 [10/11600]? Li EW age 84% posterior CDF value
157-163 F7.1 Myr 97.5Age2 [29/12800]? Li EW age 97.5% posterior CDF value
165-171 F7.2 Myr 2.5AgeF [1.2/2850] Final age 2.5% posterior CDF value
173-179 F7.2 Myr 16AgeF [2.47/5730] Final age 16% posterior CDF value
181-187 F7.2 Myr 50AgeF [5.6/8980] Final age 50% posterior CDF value
189-195 F7.1 Myr 84AgeF [10/11700] Final age 84% posterior CDF value
197-203 F7.1 Myr 97.5AgeF [29/12800] Final age 97.5% posterior CDF value
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Note (1): Reference code as follows:
1 = Nielsen & Close (2010ApJ...717..878N 2010ApJ...717..878N);
2 = Brandt et al. (2014, J/ApJ/794/159);
3 = Boro Saikia et al. (2018, J/A+A/616/A108);
4 = Guillout et al. (2009, J/A+A/504/829).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-Nov-2021