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Vicky Kalogera - One of the best experts on this subject based on the ideXlab platform.
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angular momentum exchange in white dwarf binaries accreting through direct impact
The Astrophysical Journal, 2014Co-Authors: Jeremy Sepinsky, Vicky KalogeraAbstract:We examine the exchange of angular momentum between the Component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular momentum of the orbit at all times. This includes changes in the orbital angular momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial Component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular momentum is conserved, which requires the donor star spin to vary self-consistently. With these improvements, we calculate the angular momentum change of the orbit and each Binary Component across the entire parameter space of direct impact double white dwarf Binary systems. We find a significant decrease in the amount of angular momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular momentum of the orbit at the expense of the spin angular momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the Binary and that the quantity and sign of the orbital angular momentum transfer depends on the Binary properties, particularly the masses of the double white dwarf Binary Component stars. This stabilization may significantly impact the population synthesis calculations of the expected numbers of events/systems for which double white dwarfs may be a progenitor, e.g., Type Ia supernovae, Type.Ia supernovae, and AM CVn.
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angular momentum exchange in white dwarf binaries accreting through direct impact
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: Jeremy Sepinsky, Vicky KalogeraAbstract:We examine the exchange of angular momentum between the Component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular momentum of the orbit at all times. This includes changes in the orbital angular momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial Component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular momentum is conserved, which requires the donor star spin to vary self-consistently. We calculate the angular momentum change of the orbit and each Binary Component across the entire parameter space of direct impact double white dwarf binaries. We find a significant decrease in the amount of angular momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular momentum of the orbit at the expense of the spin angular momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the Binary and that the quantity and sign of the orbital angular momentum transfer depends on the Binary properties. This stabilization may significantly impact the population synthesis calculations of double white dwarf progenitors.
Ian Harry - One of the best experts on this subject based on the ideXlab platform.
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2 ogc open gravitational wave catalog of Binary mergers from analysis of public advanced ligo and virgo data
The Astrophysical Journal, 2020Co-Authors: A Nitz, T Dent, G Davies, Sumit Kumar, C D Capano, Ian HarryAbstract:We present the second Open Gravitational-wave Catalog (2-OGC) of compact-Binary coalescences, obtained from the complete set of public data from Advanced LIGO's first and second observing runs. For the first time we also search public data from the Virgo observatory. The sensitivity of our search benefits from updated methods of ranking candidate events including the effects of non-stationary detector noise and varying network sensitivity; in a separate targeted Binary black hole merger search we also impose a prior distribution of Binary Component masses. We identify a population of 14 Binary black hole merger events with probability of astrophysical origin $> 0.5$ as well as the Binary neutron star merger GW170817. We confirm the previously reported events GW170121, GW170304, and GW170727 and also report GW151205, a new marginal Binary black hole merger with a primary mass of $67^{+28}_{-17}\,\mathrm{M}_{\odot}$ that may have formed through hierarchical merger. We find no additional significant Binary neutron star merger or neutron star--black hole merger events. To enable deeper follow-up as our understanding of the underlying populations evolves, we make available our comprehensive catalog of events, including the sub-threshold population of candidates and posterior samples from parameter inference of the 30 most significant Binary black hole candidates.
Jeremy Sepinsky - One of the best experts on this subject based on the ideXlab platform.
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angular momentum exchange in white dwarf binaries accreting through direct impact
The Astrophysical Journal, 2014Co-Authors: Jeremy Sepinsky, Vicky KalogeraAbstract:We examine the exchange of angular momentum between the Component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular momentum of the orbit at all times. This includes changes in the orbital angular momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial Component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular momentum is conserved, which requires the donor star spin to vary self-consistently. With these improvements, we calculate the angular momentum change of the orbit and each Binary Component across the entire parameter space of direct impact double white dwarf Binary systems. We find a significant decrease in the amount of angular momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular momentum of the orbit at the expense of the spin angular momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the Binary and that the quantity and sign of the orbital angular momentum transfer depends on the Binary properties, particularly the masses of the double white dwarf Binary Component stars. This stabilization may significantly impact the population synthesis calculations of the expected numbers of events/systems for which double white dwarfs may be a progenitor, e.g., Type Ia supernovae, Type.Ia supernovae, and AM CVn.
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angular momentum exchange in white dwarf binaries accreting through direct impact
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: Jeremy Sepinsky, Vicky KalogeraAbstract:We examine the exchange of angular momentum between the Component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular momentum of the orbit at all times. This includes changes in the orbital angular momentum during the ballistic trajectory of the ejected mass, as well as changes during the ejection/accretion due to the radial Component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular momentum is conserved, which requires the donor star spin to vary self-consistently. We calculate the angular momentum change of the orbit and each Binary Component across the entire parameter space of direct impact double white dwarf binaries. We find a significant decrease in the amount of angular momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular momentum of the orbit at the expense of the spin angular momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the Binary and that the quantity and sign of the orbital angular momentum transfer depends on the Binary properties. This stabilization may significantly impact the population synthesis calculations of double white dwarf progenitors.
A Nitz - One of the best experts on this subject based on the ideXlab platform.
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2 ogc open gravitational wave catalog of Binary mergers from analysis of public advanced ligo and virgo data
The Astrophysical Journal, 2020Co-Authors: A Nitz, T Dent, G Davies, Sumit Kumar, C D Capano, Ian HarryAbstract:We present the second Open Gravitational-wave Catalog (2-OGC) of compact-Binary coalescences, obtained from the complete set of public data from Advanced LIGO's first and second observing runs. For the first time we also search public data from the Virgo observatory. The sensitivity of our search benefits from updated methods of ranking candidate events including the effects of non-stationary detector noise and varying network sensitivity; in a separate targeted Binary black hole merger search we also impose a prior distribution of Binary Component masses. We identify a population of 14 Binary black hole merger events with probability of astrophysical origin $> 0.5$ as well as the Binary neutron star merger GW170817. We confirm the previously reported events GW170121, GW170304, and GW170727 and also report GW151205, a new marginal Binary black hole merger with a primary mass of $67^{+28}_{-17}\,\mathrm{M}_{\odot}$ that may have formed through hierarchical merger. We find no additional significant Binary neutron star merger or neutron star--black hole merger events. To enable deeper follow-up as our understanding of the underlying populations evolves, we make available our comprehensive catalog of events, including the sub-threshold population of candidates and posterior samples from parameter inference of the 30 most significant Binary black hole candidates.
A Ozasik - One of the best experts on this subject based on the ideXlab platform.
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single and Binary Component adsorption of copper ii and cadmium ii from aqueous solutions using tea industry waste
Separation and Purification Technology, 2004Co-Authors: A Uyanik, A OzasikAbstract:Abstract The adsorption ability of Turkish tea waste (fibrous) obtained from various tea-processing factories was investigated for the removal of Cu(II) and Cd(II) from single (non-competitive) and Binary (competitive) aqueous systems. Adsorption of the investigated heavy metal ions by tea waste strongly depends on pH, contact time, initial concentration of the heavy metal ions and adsorbent dosage. The maximum adsorption capacities of Cu(II) and Cd(II) per gram tea waste were calculated as 8.64±0.51 and 11.29±0.48 mg for single and 6.65±0.31 and 2.59±0.28 mg for Binary systems, respectively. The experimental data for single and Binary Cu(II) and Cd(II) systems fitted the Freundlich isotherm model excellently ( r 2 =0.977–0.992). The results show that tea-processing factory waste, which has a very low economical value, may be used effectively in removal of Cu(II) and Cd(II) ions from aqueous systems for environmental cleaning purposes.