Can we reveal the core-chemical composition of ultra-massive white dwarfs through their magnetic fields?
| Autor: | Maria E Camisassa, Roberto Raddi, Leandro G Althaus, Jordi Isern, Alberto Rebassa-Mansergas, Santiago Torres, Alejandro H Córsico, Lydia Korre |
|---|---|
| Přispěvatelé: | Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. GAA - Grup d'Astronomia i Astrofísica, National Aeronautics and Space Administration (US), Consejo Nacional de Ciencia y Tecnología (México), Universidad Nacional de La Plata, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Stars: magnetic field Stars -- interiors Stars -- magnetic fields FOS: Physical sciences White dwarfs Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Estels nans Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Física::Astronomia i astrofísica [Àrees temàtiques de la UPC] Stars: interiors Astrophysics::Solar and Stellar Astrophysics Stars--Magnetic fields Astrophysics::Earth and Planetary Astrophysics Astrophysics - High Energy Astrophysical Phenomena White dwarf stars Astrophysics::Galaxy Astrophysics Solar and Stellar Astrophysics (astro-ph.SR) |
| Popis: | Ultra-massive white dwarfs (1.05M⊙≲MWD) are particularly interesting objects that allow us to study extreme astrophysical phenomena such as type Ia supernovae explosions and merger events. Traditionally, ultra-massive white dwarfs are thought to harbour oxygen–neon (ONe) cores. However, recent theoretical studies and new observations suggest that some ultra-massive white dwarfs could harbour carbon–oxygen (CO) cores. Although several studies have attempted to elucidate the core composition of ultra-massive white dwarfs, to date, it has not been possible to distinguish them through their observed properties. Here, we present a new method for revealing the core-chemical composition in ultra-massive white dwarfs that is based on the study of magnetic fields generated by convective mixing induced by the crystallization process. ONe white dwarfs crystallize at higher luminosities than their CO counterparts. Therefore, the study of magnetic ultra-massive white dwarfs in the particular domain where ONe cores have reached the crystallization conditions but CO cores have not, may provide valuable support to their ONe core-chemical composition, since ONe white dwarfs would display signs of magnetic fields and CO would not. We apply our method to eight white dwarfs with magnetic field measurements and we suggest that these stars are candidate ONe white dwarfs. This work was supported by the NASA grants 80NSSC17K0008, 80NSSC20K0193, and 80NSSC21K0455, the postdoctoral fellowship programme Beatriu de Pinós agreement no. 801370, by AGENCIA through the Programa de Modernización Tecnológica BID 1728/OC-AR, by the PIP 112200801-00940 grant from CONICET, by grant G149 from National University of La Plata, by the MINECO grant PID2020-117252GB-I00, by the ESP 2017-82674-R, by grant RYC-2016-20254 funded by MCIN/AEI/10.13039/501100011033 and by ESF Investing in your future. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|