The Experts below are selected from a list of 4362 Experts worldwide ranked by ideXlab platform
Robert Fisher - One of the best experts on this subject based on the ideXlab platform.
-
near chandrasekhar mass type ia supernovae from the double Degenerate Channel
arXiv: High Energy Astrophysical Phenomena, 2021Co-Authors: Sudarshan Neopane, Robert Fisher, Khanak Bhargava, Mckenzie Ferrari, Shinichirou Yoshida, Silvia Toonen, E BravoAbstract:Recent observational evidence has demonstrated that white dwarf (WD) mergers are a highly efficient mechanism for mass accretion onto WDs in the galaxy. In this paper, we show that WD mergers naturally produce highly-magnetized, uniformly-rotating WDs, including a substantial population within a narrow mass range close to the Chandrasekhar mass ($M_{\rm Ch}$). These near-$M_{\rm Ch}$ WD mergers subsequently undergo rapid spin up and compression on a $\sim 10^2$ yr timescale, either leading to central ignition and a normal SN Ia via the DDT mechanism, or alternatively to a failed detonation and SN Iax through pure deflagration. The resulting SNe Ia and SNe Iax will have spectra, light curves, polarimetry, and nucleosynthetic yields similar to those predicted to arise through the canonical near-$M_{\rm Ch}$ single Degenerate (SD) Channel, but with a $t^{-1}$ delay time distribution characteristic of the double-Degenerate (DD) Channel. Furthermore, in contrast to the SD Channel, WD merger near-$M_{\rm Ch}$ SNe Ia and SNe Iax will not produce observable companion signatures. We discuss a range of implications of these findings, from SNe Ia explosion mechanisms, to galactic nucleosynthesis of iron peak elements including manganese.
-
the intrinsic stochasticity of the 56ni distribution of single Degenerate near chandrasekhar mass sn ia
The Astrophysical Journal, 2019Co-Authors: Chris Byrohl, Robert Fisher, Dean M TownsleyAbstract:Binary Chandrasekhar-mass white dwarfs accreting mass from non-Degenerate stellar companions through the single-Degenerate Channel have reigned for decades as the leading explanation of Type Ia supernovae. Yet, a comprehensive theoretical explanation has not yet emerged to explain the expected properties of the canonical near-Chandrasekhar-mass white dwarf model. A simmering phase within the convective core of the white dwarf leads to the ignition of one or more flame bubbles scattered across the core. Consequently, near-Chandrasekhar-mass single-Degenerate SNe Ia are inherently stochastic, and are expected to lead to a range of outcomes, from subluminous SN 2002cx-like events, to overluminous SN 1991T-like events. However, all prior simulations of the single-Degenerate Channel carried through the detonation phase have set the ignition points as free parameters. In this work, for the first time, we place ignition points as predicted by {\it ab initio} models of the convective phase leading up to ignition, and follow through the detonation phase in fully three-dimensional simulations. Single-Degenerates in this framework are characteristically overluminous. Using a statistical approach, we determine the $^{56}$Ni mass distribution arising from stochastic ignition. While there is a total spread of $\gtrsim 0.2 M_{\odot}$ for detonating models, the distribution is strongly left-skewed, and with a narrow standard deviation of $\simeq 0.03 M_{\odot}$. Conversely, if single-Degenerates are not overluminous but primarily yield normal or failed events, then the models require fine-tuning of the ignition parameters, or otherwise require revised physics or progenitor models. We discuss implications of our findings for the modeling of single-Degenerate SNe Ia.
-
double Degenerate carbon oxygen and oxygen neon white dwarf mergers a new mechanism for faint and rapid type ia supernovae
The Astrophysical Journal, 2018Co-Authors: Robert Fisher, R Kashyap, E Garciaberro, P Lorenaguilar, Tazkera HaqueAbstract:Type Ia supernovae (SNe Ia) originate from the thermonuclear explosion of carbon-oxygen white dwarfs (CO WDs), giving rise to luminous optical transients. A relatively common variety of subluminous SNe Ia events, referred to as SNe Iax, are believed to arise from the failed detonation of a CO WD. In this paper, we explore failed detonation SNe Ia in the context of the double-Degenerate Channel of merging WDs. In particular, we have carried out the first fully three-dimensional simulation of the merger of a ONe WD with a CO WD. While the hot, tidally disrupted carbon-rich disk material originating from the CO WD secondary is readily susceptible to detonation in such a merger, the ONe WD primary core is not. This merger yields a failed detonation, resulting in the ejection of a small amount of mass, and leaving behind a kicked, super-Chandrasekhar ONe WD remnant enriched by the fallback of the products of nuclear burning. The resulting outburst is a rapidly fading optical transient with a small amount of radioactive 56Ni powering the light curve. Consequently, the ONe-CO WD merger naturally produces a very faint and rapidly fading transient, fainter even than the faintest Type Iax events observed to date, such as SN 2008 ha and SN 2010ae. More massive ONe primaries than considered here may produce brighter and longer-duration transients.
-
double Degenerate carbon oxygen and oxygen neon white dwarf mergers a new mechanism for faint and rapid type ia supernovae
arXiv: Solar and Stellar Astrophysics, 2018Co-Authors: Robert Fisher, R Kashyap, E Garciaberro, P Lorenaguilar, Tazkera HaqueAbstract:Type Ia supernovae (SNe Ia) originate from the thermonuclear explosion of carbon-oxygen white dwarfs (CO WDs), giving rise to luminous optical transients. A relatively common variety of subluminous SNe Ia events, referred to as SNe Iax, are believed to arise from the failed detonation of a CO WD. In this paper, we explore failed detonation SNe Ia in the context of the double-Degenerate Channel of merging white dwarfs. In particular, we have carried out the first fully three-dimensional simulation of the merger of a ONe WD with a CO WD. While the hot, tidally-disrupted carbon-rich disk material originating from the CO WD secondary is readily susceptible to detonation in such a merger, the ONe WD primary core is not. This merger yields a failed detonation, resulting in the ejection of a small amount of mass, and leaving behind a kicked, super-Chandrasekhar ONe WD remnant enriched by the fallback of the products of nuclear burning. The resulting outburst is a rapidly-fading optical transient with a small amount of radioactive $^{56}$Ni powering the light curve. Consequently, the ONe-CO WD merger naturally produces a very faint and rapidly-fading transient, fainter even than the faintest Type Iax events observed to date, such as SN $2008$ha and SN 2010ae. More massive ONe primaries than considered here may produce brighter and longer-duration transients.
-
constraining the single Degenerate Channel of type ia supernovae with stable iron group elements in snr 3c 397
The Astrophysical Journal, 2017Co-Authors: Pranav Dave, Robert Fisher, R Kashyap, F X Timmes, Dean M Townsley, Chris ByrohlAbstract:Recent Suzaku X-ray spectra of SNR 3C 397 indicate enhanced stable iron-group element abundances of Ni, Mn, Cr, and Fe. Seeking to address key questions about the progenitor and explosion mechanism of 3C 397, we compute nucleosynthetic yields from a suite of multidimensional hydrodynamics models in the near-Chandrasekhar mass, single-Degenerate paradigm for supernova Type Ia. Varying the progenitor white dwarf internal structure, composition, ignition, and explosion mechanism, we find the best match to the observed iron-peak elements of 3C 397 are dense (central density $\ge$ 6$\times$10$^{9}$ g cm$^{-3}$), low-carbon white dwarfs that undergo a weak, centrally-ignited deflagration, followed by a subsequent detonation. The amount of $^{56}$Ni produced is consistent with a normal or bright normal supernova Type Ia. A pure deflagration of a centrally-ignited, low central density ($\simeq$ 2$\times$10$^{9}$ g cm$^{-3}$) progenitor white dwarf, frequently considered in the literature, is also found to produce good agreement with 3C 397 nucleosynthetic yields, but leads to a subluminous SN Ia event, in conflict with X-ray linewidth data. Additionally, in contrast to prior work which suggested a large super-solar metallicity for the white dwarf progenitor for SNR 3C 397, we find satisfactory agreement for solar and sub-solar metallicity progenitors. We discuss a range of implications our results have for the single-Degenerate Channel.
Benjamin Dilday - One of the best experts on this subject based on the ideXlab platform.
-
single or double Degenerate progenitors searching for shock emission in the sdss ii type ia supernovae
The Astrophysical Journal, 2010Co-Authors: Brian Hayden, P M Garnavich, Daniel Kasen, Benjamin Dilday, J Frieman, Saurabh W JhaAbstract:From the set of nearly 500 spectroscopically confirmed Type Ia supernovae (SNe) and around 10,000 unconfirmed candidates from SDSS-II, we select a subset of 108 confirmed SNe Ia with well-observed early-time light curves to search for signatures from shock interaction of the SN with a companion star. No evidence for shock emission is seen; however, the cadence and photometric noise could hide a weak shock signal. We simulate shocked light curves using SN Ia templates and a simple Gaussian shock model to emulate the noise properties of the SDSS-II sample and estimate the detectability of the shock interaction signal as a function of shock amplitude, shock width, and shock fraction. We find no direct evidence for shock interaction in the rest-frame B-band, but place an upper limit on the shock amplitude at 9% of SN peak flux (MB > - 16.6 mag). If the single Degenerate Channel dominates type Ia progenitors, this result constrains the companion stars to be less than about 6 M sun on the main sequence and strongly disfavors red giant companions.
-
single or double Degenerate progenitors searching for shock emission in the sdss ii type ia supernovae
arXiv: Cosmology and Nongalactic Astrophysics, 2010Co-Authors: Brian Hayden, P M Garnavich, Daniel Kasen, Benjamin Dilday, J Frieman, Saurabh W JhaAbstract:From the set of nearly 500 spectroscopically confirmed type~Ia supernovae and around 10,000 unconfirmed candidates from SDSS-II, we select a subset of 108 confirmed SNe Ia with well-observed early-time light curves to search for signatures from shock interaction of the supernova with a companion star. No evidence for shock emission is seen; however, the cadence and photometric noise could hide a weak shock signal. We simulate shocked light curves using SN Ia templates and a simple, Gaussian shock model to emulate the noise properties of the SDSS-II sample and estimate the detectability of the shock interaction signal as a function of shock amplitude, shock width, and shock fraction. We find no direct evidence for shock interaction in the rest-frame $B$-band, but place an upper limit on the shock amplitude at 9% of supernova peak flux ($M_B > -16.6$ mag). If the single Degenerate Channel dominates type~Ia progenitors, this result constrains the companion stars to be less than about 6 $M_{\odot}$ on the main sequence, and strongly disfavors red giant companions.
R Kashyap - One of the best experts on this subject based on the ideXlab platform.
-
double Degenerate carbon oxygen and oxygen neon white dwarf mergers a new mechanism for faint and rapid type ia supernovae
The Astrophysical Journal, 2018Co-Authors: Robert Fisher, R Kashyap, E Garciaberro, P Lorenaguilar, Tazkera HaqueAbstract:Type Ia supernovae (SNe Ia) originate from the thermonuclear explosion of carbon-oxygen white dwarfs (CO WDs), giving rise to luminous optical transients. A relatively common variety of subluminous SNe Ia events, referred to as SNe Iax, are believed to arise from the failed detonation of a CO WD. In this paper, we explore failed detonation SNe Ia in the context of the double-Degenerate Channel of merging WDs. In particular, we have carried out the first fully three-dimensional simulation of the merger of a ONe WD with a CO WD. While the hot, tidally disrupted carbon-rich disk material originating from the CO WD secondary is readily susceptible to detonation in such a merger, the ONe WD primary core is not. This merger yields a failed detonation, resulting in the ejection of a small amount of mass, and leaving behind a kicked, super-Chandrasekhar ONe WD remnant enriched by the fallback of the products of nuclear burning. The resulting outburst is a rapidly fading optical transient with a small amount of radioactive 56Ni powering the light curve. Consequently, the ONe-CO WD merger naturally produces a very faint and rapidly fading transient, fainter even than the faintest Type Iax events observed to date, such as SN 2008 ha and SN 2010ae. More massive ONe primaries than considered here may produce brighter and longer-duration transients.
-
double Degenerate carbon oxygen and oxygen neon white dwarf mergers a new mechanism for faint and rapid type ia supernovae
arXiv: Solar and Stellar Astrophysics, 2018Co-Authors: Robert Fisher, R Kashyap, E Garciaberro, P Lorenaguilar, Tazkera HaqueAbstract:Type Ia supernovae (SNe Ia) originate from the thermonuclear explosion of carbon-oxygen white dwarfs (CO WDs), giving rise to luminous optical transients. A relatively common variety of subluminous SNe Ia events, referred to as SNe Iax, are believed to arise from the failed detonation of a CO WD. In this paper, we explore failed detonation SNe Ia in the context of the double-Degenerate Channel of merging white dwarfs. In particular, we have carried out the first fully three-dimensional simulation of the merger of a ONe WD with a CO WD. While the hot, tidally-disrupted carbon-rich disk material originating from the CO WD secondary is readily susceptible to detonation in such a merger, the ONe WD primary core is not. This merger yields a failed detonation, resulting in the ejection of a small amount of mass, and leaving behind a kicked, super-Chandrasekhar ONe WD remnant enriched by the fallback of the products of nuclear burning. The resulting outburst is a rapidly-fading optical transient with a small amount of radioactive $^{56}$Ni powering the light curve. Consequently, the ONe-CO WD merger naturally produces a very faint and rapidly-fading transient, fainter even than the faintest Type Iax events observed to date, such as SN $2008$ha and SN 2010ae. More massive ONe primaries than considered here may produce brighter and longer-duration transients.
-
constraining the single Degenerate Channel of type ia supernovae with stable iron group elements in snr 3c 397
The Astrophysical Journal, 2017Co-Authors: Pranav Dave, Robert Fisher, R Kashyap, F X Timmes, Dean M Townsley, Chris ByrohlAbstract:Recent Suzaku X-ray spectra of SNR 3C 397 indicate enhanced stable iron-group element abundances of Ni, Mn, Cr, and Fe. Seeking to address key questions about the progenitor and explosion mechanism of 3C 397, we compute nucleosynthetic yields from a suite of multidimensional hydrodynamics models in the near-Chandrasekhar mass, single-Degenerate paradigm for supernova Type Ia. Varying the progenitor white dwarf internal structure, composition, ignition, and explosion mechanism, we find the best match to the observed iron-peak elements of 3C 397 are dense (central density $\ge$ 6$\times$10$^{9}$ g cm$^{-3}$), low-carbon white dwarfs that undergo a weak, centrally-ignited deflagration, followed by a subsequent detonation. The amount of $^{56}$Ni produced is consistent with a normal or bright normal supernova Type Ia. A pure deflagration of a centrally-ignited, low central density ($\simeq$ 2$\times$10$^{9}$ g cm$^{-3}$) progenitor white dwarf, frequently considered in the literature, is also found to produce good agreement with 3C 397 nucleosynthetic yields, but leads to a subluminous SN Ia event, in conflict with X-ray linewidth data. Additionally, in contrast to prior work which suggested a large super-solar metallicity for the white dwarf progenitor for SNR 3C 397, we find satisfactory agreement for solar and sub-solar metallicity progenitors. We discuss a range of implications our results have for the single-Degenerate Channel.
E Garciaberro - One of the best experts on this subject based on the ideXlab platform.
-
double Degenerate carbon oxygen and oxygen neon white dwarf mergers a new mechanism for faint and rapid type ia supernovae
The Astrophysical Journal, 2018Co-Authors: Robert Fisher, R Kashyap, E Garciaberro, P Lorenaguilar, Tazkera HaqueAbstract:Type Ia supernovae (SNe Ia) originate from the thermonuclear explosion of carbon-oxygen white dwarfs (CO WDs), giving rise to luminous optical transients. A relatively common variety of subluminous SNe Ia events, referred to as SNe Iax, are believed to arise from the failed detonation of a CO WD. In this paper, we explore failed detonation SNe Ia in the context of the double-Degenerate Channel of merging WDs. In particular, we have carried out the first fully three-dimensional simulation of the merger of a ONe WD with a CO WD. While the hot, tidally disrupted carbon-rich disk material originating from the CO WD secondary is readily susceptible to detonation in such a merger, the ONe WD primary core is not. This merger yields a failed detonation, resulting in the ejection of a small amount of mass, and leaving behind a kicked, super-Chandrasekhar ONe WD remnant enriched by the fallback of the products of nuclear burning. The resulting outburst is a rapidly fading optical transient with a small amount of radioactive 56Ni powering the light curve. Consequently, the ONe-CO WD merger naturally produces a very faint and rapidly fading transient, fainter even than the faintest Type Iax events observed to date, such as SN 2008 ha and SN 2010ae. More massive ONe primaries than considered here may produce brighter and longer-duration transients.
-
double Degenerate carbon oxygen and oxygen neon white dwarf mergers a new mechanism for faint and rapid type ia supernovae
arXiv: Solar and Stellar Astrophysics, 2018Co-Authors: Robert Fisher, R Kashyap, E Garciaberro, P Lorenaguilar, Tazkera HaqueAbstract:Type Ia supernovae (SNe Ia) originate from the thermonuclear explosion of carbon-oxygen white dwarfs (CO WDs), giving rise to luminous optical transients. A relatively common variety of subluminous SNe Ia events, referred to as SNe Iax, are believed to arise from the failed detonation of a CO WD. In this paper, we explore failed detonation SNe Ia in the context of the double-Degenerate Channel of merging white dwarfs. In particular, we have carried out the first fully three-dimensional simulation of the merger of a ONe WD with a CO WD. While the hot, tidally-disrupted carbon-rich disk material originating from the CO WD secondary is readily susceptible to detonation in such a merger, the ONe WD primary core is not. This merger yields a failed detonation, resulting in the ejection of a small amount of mass, and leaving behind a kicked, super-Chandrasekhar ONe WD remnant enriched by the fallback of the products of nuclear burning. The resulting outburst is a rapidly-fading optical transient with a small amount of radioactive $^{56}$Ni powering the light curve. Consequently, the ONe-CO WD merger naturally produces a very faint and rapidly-fading transient, fainter even than the faintest Type Iax events observed to date, such as SN $2008$ha and SN 2010ae. More massive ONe primaries than considered here may produce brighter and longer-duration transients.
-
the post merger magnetized evolution of white dwarf binaries the double Degenerate Channel of sub chandrasekhar type ia supernovae and the formation of magnetized white dwarfs
The Astrophysical Journal, 2013Co-Authors: Robert Fisher, E Garciaberro, Petros Tzeferacos, George C Jordan, Dongwook Lee, P Lorenaguilar, Pascal Cremer, Jan BehrendsAbstract:Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-Degenerate Channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly rotating white dwarf merger surrounded by a hot corona and a thick, differentially rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths ~2 × 108 G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.
-
the post merger magnetized evolution of white dwarf binaries the double Degenerate Channel of sub chandrasekhar type ia supernovae and the formation of magnetized white dwarfs
arXiv: Solar and Stellar Astrophysics, 2013Co-Authors: Robert Fisher, E Garciaberro, Petros Tzeferacos, George C Jordan, Dongwook Lee, P Lorenaguilar, Pascal Cremer, Jan BehrendsAbstract:Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-Degenerate Channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly-rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly-rotating white dwarf merger surrounded by a hot corona and a thick, differentially-rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths $\sim 2 \times 10^8$ G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.
P Lorenaguilar - One of the best experts on this subject based on the ideXlab platform.
-
double Degenerate carbon oxygen and oxygen neon white dwarf mergers a new mechanism for faint and rapid type ia supernovae
The Astrophysical Journal, 2018Co-Authors: Robert Fisher, R Kashyap, E Garciaberro, P Lorenaguilar, Tazkera HaqueAbstract:Type Ia supernovae (SNe Ia) originate from the thermonuclear explosion of carbon-oxygen white dwarfs (CO WDs), giving rise to luminous optical transients. A relatively common variety of subluminous SNe Ia events, referred to as SNe Iax, are believed to arise from the failed detonation of a CO WD. In this paper, we explore failed detonation SNe Ia in the context of the double-Degenerate Channel of merging WDs. In particular, we have carried out the first fully three-dimensional simulation of the merger of a ONe WD with a CO WD. While the hot, tidally disrupted carbon-rich disk material originating from the CO WD secondary is readily susceptible to detonation in such a merger, the ONe WD primary core is not. This merger yields a failed detonation, resulting in the ejection of a small amount of mass, and leaving behind a kicked, super-Chandrasekhar ONe WD remnant enriched by the fallback of the products of nuclear burning. The resulting outburst is a rapidly fading optical transient with a small amount of radioactive 56Ni powering the light curve. Consequently, the ONe-CO WD merger naturally produces a very faint and rapidly fading transient, fainter even than the faintest Type Iax events observed to date, such as SN 2008 ha and SN 2010ae. More massive ONe primaries than considered here may produce brighter and longer-duration transients.
-
double Degenerate carbon oxygen and oxygen neon white dwarf mergers a new mechanism for faint and rapid type ia supernovae
arXiv: Solar and Stellar Astrophysics, 2018Co-Authors: Robert Fisher, R Kashyap, E Garciaberro, P Lorenaguilar, Tazkera HaqueAbstract:Type Ia supernovae (SNe Ia) originate from the thermonuclear explosion of carbon-oxygen white dwarfs (CO WDs), giving rise to luminous optical transients. A relatively common variety of subluminous SNe Ia events, referred to as SNe Iax, are believed to arise from the failed detonation of a CO WD. In this paper, we explore failed detonation SNe Ia in the context of the double-Degenerate Channel of merging white dwarfs. In particular, we have carried out the first fully three-dimensional simulation of the merger of a ONe WD with a CO WD. While the hot, tidally-disrupted carbon-rich disk material originating from the CO WD secondary is readily susceptible to detonation in such a merger, the ONe WD primary core is not. This merger yields a failed detonation, resulting in the ejection of a small amount of mass, and leaving behind a kicked, super-Chandrasekhar ONe WD remnant enriched by the fallback of the products of nuclear burning. The resulting outburst is a rapidly-fading optical transient with a small amount of radioactive $^{56}$Ni powering the light curve. Consequently, the ONe-CO WD merger naturally produces a very faint and rapidly-fading transient, fainter even than the faintest Type Iax events observed to date, such as SN $2008$ha and SN 2010ae. More massive ONe primaries than considered here may produce brighter and longer-duration transients.
-
the post merger magnetized evolution of white dwarf binaries the double Degenerate Channel of sub chandrasekhar type ia supernovae and the formation of magnetized white dwarfs
The Astrophysical Journal, 2013Co-Authors: Robert Fisher, E Garciaberro, Petros Tzeferacos, George C Jordan, Dongwook Lee, P Lorenaguilar, Pascal Cremer, Jan BehrendsAbstract:Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-Degenerate Channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly rotating white dwarf merger surrounded by a hot corona and a thick, differentially rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths ~2 × 108 G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.
-
the post merger magnetized evolution of white dwarf binaries the double Degenerate Channel of sub chandrasekhar type ia supernovae and the formation of magnetized white dwarfs
arXiv: Solar and Stellar Astrophysics, 2013Co-Authors: Robert Fisher, E Garciaberro, Petros Tzeferacos, George C Jordan, Dongwook Lee, P Lorenaguilar, Pascal Cremer, Jan BehrendsAbstract:Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-Degenerate Channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly-rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly-rotating white dwarf merger surrounded by a hot corona and a thick, differentially-rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths $\sim 2 \times 10^8$ G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.