Continuous gravitational waves from magnetized white dwarfs

Abstract

Recent evidence of super-Chandrasekhar white dwarfs (WDs), from the observations of over-luminous type Ia supernovae (SNeIa), has been a great astrophysical discovery. However, no such massive WDs have so far been observed directly as their luminosities are generally quite low. Hence it immediately raises the question of whether there is any possibility of detecting them directly. The search for super-Chandrasekhar WDs is very important as SNeIa are used as standard candles in cosmology. In this article, we show that continuous gravitational wave can allow us to detect such super-Chandrasekhar WDs directly.

Gravitational wave in f(R) gravity: possible signature of sub- and super-Chandrasekhar limiting mass white dwarfs

“…Starobinsky (1980) first used one of the modified theories of gravity, namely R 2 -gravity with R being the scalar curvature, to explain the cosmology of the very early universe. Eventually, researchers have proposed a large number of modifications to GR, e.g., various f (R) gravity models, to elaborate the physics of the different astronomical systems, such as the massive neutron stars (Astashenok et al 2013(Astashenok et al , 2014, accretion disk around the compact object (Multamäki & Vilja 2006;Pun et al 2008;Pérez et al 2013;Kalita & Mukhopadhyay 2019a) and many more. Our group has also shown that using the suitable forms of f (R) gravity, we can unify the physics of all WDs, including those possessing sub-and super-Chandrasekhar limiting masses (Das & Mukhopadhyay 2015;Kalita & Mukhopadhyay 2018).…”

“…Eventually, researchers have proposed a large number of modifications to GR, e.g., various f (R) gravity models, to elaborate the physics of the different astronomical systems, such as the massive neutron stars (Astashenok et al 2013(Astashenok et al , 2014, accretion disk around the compact object (Multamäki & Vilja 2006;Pun et al 2008;Pérez et al 2013;Kalita & Mukhopadhyay 2019a) and many more. Our group has also shown that using the suitable forms of f (R) gravity, we can unify the physics of all WDs, including those possessing sub-and super-Chandrasekhar limiting masses (Das & Mukhopadhyay 2015;Kalita & Mukhopadhyay 2018). We showed that by fixing the parameters in a viable f (R) gravity model such that it satisfies the solar system test (Guo 2014), one can obtain the sub-Chandrasekhar limiting mass WDs at a relatively low density and super-Chandrasekhar WDs at high density (Kalita & Mukhopadhyay 2018).…”

“…Our group has also shown that using the suitable forms of f (R) gravity, we can unify the physics of all WDs, including those possessing sub-and super-Chandrasekhar limiting masses (Das & Mukhopadhyay 2015;Kalita & Mukhopadhyay 2018). We showed that by fixing the parameters in a viable f (R) gravity model such that it satisfies the solar system test (Guo 2014), one can obtain the sub-Chandrasekhar limiting mass WDs at a relatively low density and super-Chandrasekhar WDs at high density (Kalita & Mukhopadhyay 2018). Of course, the mass-radius relation alters from Chandrasekhar's original mass-radius relation depending on the form of f (R) gravity model.…”

Timescales for Detecting Magnetized White Dwarfs in Gravitational Wave Astronomy

“…Ostriker and Hartwick first showed that rotation could increase a WD's mass up-to ∼ 1.8M [4]. Later, Mukhopadhyay and his collaborators, in a series of papers for about a decade, showed that magnetic field could be one of the prominent physics, which can significantly increase the mass of the WDs [5][6][7][8]. Nevertheless, various other physics such as modified gravity [9], generalized uncertainty principle [10], noncommutative geometry [11], and many more, can also explain these super-Chandrasekhar WD progenitors.…”

Timescales for Detecting Magnetized White Dwarfs in Gravitational Wave Astronomy

“…Ostriker and Hartwick first showed that rotation could increase a WD's mass up-to ∼ 1.8M [4]. Later, Mukhopadhyay and his collaborators, in a series of papers for about a decade, showed that magnetic field could be one of the prominent physics, which can significantly increase the mass of the WDs [5][6][7][8]. Nevertheless, various other physics such as modified gravity [9], generalized uncertainty principle [10], noncommutative geometry [11], and many more, can also explain these super-Chandrasekhar WD progenitors.…”