2014A&A...570A..66S


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.13CEST07:38:31

2014A&A...570A..66S - Astronomy and Astrophysics, volume 570A, 66-66 (2014/10-1)

BONNSAI : a Bayesian tool for comparing stars with stellar evolution models.

SCHNEIDER F.R.N., LANGER N., DE KOTER A., BROTT I., IZZARD R.G. and LAU H.H.B.

Abstract (from CDS):

Powerful telescopes equipped with multi-fibre or integral field spectrographs combined with detailed models of stellar atmospheres and automated fitting techniques allow for the analysis of large number of stars. These datasets contain a wealth of information that require new analysis techniques to bridge the gap between observations and stellar evolution models. To that end, we develop Bonnsai (BONN Stellar Astrophysics Interface), a Bayesian statistical method, that is capable of comparing all available observables simultaneously to stellar models while taking observed uncertainties and prior knowledge such as initial mass functions and distributions of stellar rotational velocities into account. Bonnsai can be used to (1) determine probability distributions of fundamental stellar parameters such as initial masses and stellar ages from complex datasets; (2) predict stellar parameters that were not yet observationally determined; and (3) test stellar models to further advance our understanding of stellar evolution. An important aspect of Bonnsai is that it singles out stars that cannot be reproduced by stellar models through χ2 hypothesis tests and posterior predictive checks. Bonnsai can be used with any set of stellar models and currently supports massive main-sequence single star models of Milky Way and Large and Small Magellanic Cloud composition. We apply our new method to mock stars to demonstrate its functionality and capabilities. In a first application, we use Bonnsai to test the stellar models of Brott et al. (2011A&A...530A.115B) by comparing the stellar ages inferred for the primary and secondary stars of eclipsing Milky Way binaries of which the components range in mass between 4.5 and 28M. Ages are determined from dynamical masses and radii that are known to better than 3%. We show that the stellar models must include rotation because stellar radii can be increased by several percent via centrifugal forces. We find that the average age difference between the primary and secondary stars of the binaries is 0.9±2.3Myr (95% CI), i.e. that the stellar models reproduce the Milky Way binaries well. The predicted effective temperatures are in agreement for observed effective temperatures for stars cooler than 25000K. In hotter stars, i.e. stars earlier than B1-2V and more massive than about 10M, we find that the observed effective temperatures are on average hotter by 1.1±0.3kK (95% CI) and the bolometric luminosities are consequently larger by 0.06±0.02dex (95% CI) than predicted by the stellar models.

Abstract Copyright:

Journal keyword(s): methods: data analysis - methods: statistical - stars: general - stars: fundamental parameters - stars: rotation - binaries: general

Simbad objects: 22

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Number of rows : 22

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 V* MU Cas bL* 00 15 51.5602447232 +60 25 53.641656065   11.12 10.80     A0 42 0
2 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 9446 1
3 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 5669 1
4 V* AG Per A SB* 04 06 55.828400 +33 26 46.92224   6.83 6.87     ~ 255 0
5 V* AG Per Al* 04 06 55.8351101323 +33 26 47.009585515       7.71   B3Vn 258 0
6 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 14832 1
7 V* V1388 Ori Al* 06 10 59.1665079565 +11 59 41.490382447 6.67 7.44 7.50     B2V 49 0
8 V* V578 Mon EB* 06 32 00.6080933581 +04 52 40.879145861 8.01 8.72 8.55 8.09 8.28 B0V+B1V 94 0
9 V* CV Vel Al* 09 00 37.9908050285 -51 33 20.064841471 5.88 6.55 6.69     B2V 130 0
10 * 163 Car Al* 09 54 33.8842290875 -58 25 16.572216816 5.6 6.47 6.64     B2V 103 0
11 V* DW Car Al* 10 43 10.0816952047 -60 02 11.743736924 9.02 9.83 9.85 10.03 9.59 B1III 63 0
12 V* EM Car Al* 11 12 04.5059542892 -61 05 42.941349454 8.06 8.80 8.54 9.25   O7.5V((f))+O7.5V((f)) 147 0
13 V* V760 Sco Al* 16 24 43.7186408435 -34 53 37.535017356   7.16 7.05     B4V 142 0
14 CD-41 11042 Al* 16 54 19.8364088142 -41 50 09.384765116 7.733 9.02 8.80 9.23 7.859 O9.5IV 92 0
15 V* U Oph Al* 17 16 31.7132736201 +01 12 37.996480495   5.941 5.921     B3V 360 1
16 V* V539 Ara Al* 17 50 28.3923147204 -53 36 44.664519556   5.60 5.71     B2/3Vnn 163 0
17 * 11 Sgr Or* 18 09 17.7002679002 -23 59 18.232366605 6.65 7.45 7.31 8.36   O7V(n)z+B0:V: 125 2
18 V* DI Her Al* 18 53 26.2400114975 +24 16 40.792385926   8.46 8.47     B5III 234 0
19 V* V453 Cyg Al* 20 06 34.9662773363 +35 44 26.267177168 7.83 8.52 8.40     B1III 181 0
20 V* V478 Cyg Al* 20 19 38.7475966004 +38 20 09.193010946   9.16 8.767     B0Vp 173 0
21 V* AH Cep bL* 22 47 52.9411821102 +65 03 43.797787196 6.53 7.10 6.88     B0.2V+B2V 202 0
22 HD 218066 Be* 23 04 02.2015433256 +63 23 48.645418835 7.50 7.97 7.6     B1.5Vn 261 0

    Equat.    Gal    SGal    Ecl

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2020.07.13-07:38:31

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