%0 Generic %1 citeulike:13700422 %A de Freitas, D. B. %A Cavalcante, F. J. %A Soares, B. B. %A Silva, J. R. P. %D 2015 %K imported %T A nonextensive view of the stellar braking indices %U http://arxiv.org/abs/1508.02237 %X The present work is based on a description for the angular mometum loss rate due to magnetic braking for main-sequence stars on the relationship between stellar rotation and age. In general, this loss rate denoted by \$\mathrm dJ/dt\$ depends on angular velocity \$Ømega\$ in the form \$\mathrm dJ/dt\proptoØmega^q\$, where \$q\$ is a parameter extracted from nonextensive statistical mechanics. Already, in context of stellar rotation, this parameter is greater than unity and it is directly related to the braking index. For \$q\$ equal to unity, the scenario of saturation of the magnetic field is recovered, otherwise \$q\$ indicates an unsaturated field. This new approach have been proposed and investigated by de Freitas & De Medeiros for unsaturated field stars. In present work, we propose a nonextensive approach for the stellar rotational evolution based on the Reiners & Mohanthy model. In this sense, we developed a nonextensive version of Reiners & Mohanthy torque and also compare this generalized version with the model proposed in de Freitas & De Medeiros based on the spin-down Kawaler torque for the main-sequence stars with F and G spectral types. We use the same sample of \$\sim16 000\$ field stars with rotational velocity \$v i\$ limited in age and mass. As a result, we show that the Kawaler and Reiners & Mohanthy models exhibit strong discrepancies, mainly in relation to the domain of validity of the entropic index \$q\$. These discrepancies are mainly due to sensitivity on the stellar radius. Finally, our results showed that modified Kawaler prescription is compatible with a wider mass range, while the Reiners & Mohanty model is restricted to masses less than G6 stars.

@misc{citeulike:13700422, abstract = {The present work is based on a description for the angular mometum loss rate due to magnetic braking for main-sequence stars on the relationship between stellar rotation and age. In general, this loss rate denoted by \$\mathrm dJ/\mathrm dt\$ depends on angular velocity \$\Omega\$ in the form \$\mathrm dJ/\mathrm dt\propto\Omega^{q}\$, where \$q\$ is a parameter extracted from nonextensive statistical mechanics. Already, in context of stellar rotation, this parameter is greater than unity and it is directly related to the braking index. For \$q\$ equal to unity, the scenario of saturation of the magnetic field is recovered, otherwise \$q\$ indicates an unsaturated field. This new approach have been proposed and investigated by de Freitas \& De Medeiros for unsaturated field stars. In present work, we propose a nonextensive approach for the stellar rotational evolution based on the Reiners \& Mohanthy model. In this sense, we developed a nonextensive version of Reiners \& Mohanthy torque and also compare this generalized version with the model proposed in de Freitas \& De Medeiros based on the spin-down Kawaler torque for the main-sequence stars with F and G spectral types. We use the same sample of \$\sim16 000\$ field stars with rotational velocity \$v \sin i\$ limited in age and mass. As a result, we show that the Kawaler and Reiners \& Mohanthy models exhibit strong discrepancies, mainly in relation to the domain of validity of the entropic index \$q\$. These discrepancies are mainly due to sensitivity on the stellar radius. Finally, our results showed that modified Kawaler prescription is compatible with a wider mass range, while the Reiners \& Mohanty model is restricted to masses less than G6 stars.}, added-at = {2019-03-25T08:20:55.000+0100}, archiveprefix = {arXiv}, author = {de Freitas, D. B. and Cavalcante, F. J. and Soares, B. B. and Silva, J. R. P.}, biburl = {https://www.bibsonomy.org/bibtex/2c2b1a69d7374df38bb4f7df5daff618f/ericblackman}, citeulike-article-id = {13700422}, citeulike-linkout-0 = {http://arxiv.org/abs/1508.02237}, citeulike-linkout-1 = {http://arxiv.org/pdf/1508.02237}, day = 10, eprint = {1508.02237}, interhash = {6146b9a12794a594624665adf80b390b}, intrahash = {c2b1a69d7374df38bb4f7df5daff618f}, keywords = {imported}, month = aug, posted-at = {2015-08-12 06:15:30}, priority = {2}, timestamp = {2019-03-25T08:20:55.000+0100}, title = {{A nonextensive view of the stellar braking indices}}, url = {http://arxiv.org/abs/1508.02237}, year = 2015 }