2001A&A...373..597P


C.D.S. - SIMBAD4 rel 1.7 - 2020.09.30CEST18:55:58

2001A&A...373..597P - Astronomy and Astrophysics, volume 373, 597-607 (2001/7-2)

Subphotospheric convection and magnetic activity dependence on metallicity and age: Models and tests.

PIZZOLATO N., VENTURA P., D'ANTONA F., MAGGIO A., MICELA G. and SCIORTINO S.

Abstract (from CDS):

We present an extensive study on the dependence of the convective turnover time (τconv) on the stellar metallicity and age for main-sequence stars of masses 0.6-1.6M. To this aim we have used and compared predictions by stellar models based on the classical Mixing Length Theory and models incorporating a Full Spectrum of Turbulence treatment of subphotospheric convection. We show that the metallicity effect is relevant for dG stars but negligible for dK stars, while stellar age is important when computing the turnover times for red dwarfs younger than logt ∼8.5yr. A scatter by up to a factor 3 could be spuriously introduced in the activity vs. Rossby number relationships if such effects are neglected. We have tested our model predictions on the metallicity effect by comparison with the observed median X-ray luminosities for dG and dK stars in the open clusters NGC 2516, the Pleiades, and Blanco 1, having similar age but likely different metal contents. We show that our model predictions, taking into account also the dependence of the coronal plasma emissivity on the metal abundance, are in agreement with the observations in all cases except for the dK stars in the metal-rich cluster Blanco 1, where our assumption of a rotation period distribution similar to those of the other cluster need to be confirmed by future observations.

Abstract Copyright:

Journal keyword(s): convection - stars: abundances - stars: coronae - X-rays: stars

Simbad objects: 3

goto Full paper

goto View the reference in ADS

Number of rows : 3

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 Cl Blanco 1 OpC 00 04 07 -29 50.0           ~ 238 0
2 Cl Melotte 22 OpC 03 47 00 +24 07.0           ~ 3010 0
3 NGC 2516 OpC 07 58 04 -60 45.2           ~ 593 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2001A&A...373..597P and select 'bookmark this link' or equivalent in the popup menu


2020.09.30-18:55:58

© Université de Strasbourg/CNRS

    • Contact