The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Eric R Coughlin - One of the best experts on this subject based on the ideXlab platform.
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post Periapsis pancakes sustenance for self gravity in tidal disruption events
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Eric R Coughlin, Chris Nixon, Mitchell C Begelman, Philip J Armitage, Daniel J PriceAbstract:A tidal disruption event, which occurs when a star is destroyed by the gravitational field of a supermassive black hole, produces a stream of debris, the evolution of which ultimately determines the observational properties of the event. Here, we show that a post-Periapsis caustic – a location where the locus of gas parcels comprising the stream would collapse into a two-dimensional surface if they evolved solely in the gravitational field of the hole – occurs when the pericentre distance of the star is of the order of the tidal radius of the hole. It is demonstrated that this ‘pancake’ induces significant density perturbations in the debris stream, and, for stiffer equations of state (adiabatic index γ 5/3), these fluctuations are sufficient to gravitationally destabilize the stream, resulting in its fragmentation into bound clumps. The results of our findings are discussed in the context of the observational properties of tidal disruption events.
W Magnes - One of the best experts on this subject based on the ideXlab platform.
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electromagnetic waves observed by venus express at Periapsis detection and analysis techniques
Advances in Space Research, 2008Co-Authors: C T Russell, T L Zhang, R J Strangeway, M Delva, W MagnesAbstract:The magnetometer on Venus Express was designed to be able to obtain 128 Hz samples of the magnetic field from two sensors in a gradiometer configuration. This mode is used around Periapsis to determine whether the signals reported at low altitudes near 100 Hz, had the properties of electromagnetic waves generated by electric discharges in the Venus atmosphere. The lack of a magnetic cleanliness program and the shortness of the magnetometer boom make this a challenging measurement. Fortunately the signals are sufficiently strong that they can be easily resolved with rather straightforward analysis techniques.
Daniel J Price - One of the best experts on this subject based on the ideXlab platform.
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post Periapsis pancakes sustenance for self gravity in tidal disruption events
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Eric R Coughlin, Chris Nixon, Mitchell C Begelman, Philip J Armitage, Daniel J PriceAbstract:A tidal disruption event, which occurs when a star is destroyed by the gravitational field of a supermassive black hole, produces a stream of debris, the evolution of which ultimately determines the observational properties of the event. Here, we show that a post-Periapsis caustic – a location where the locus of gas parcels comprising the stream would collapse into a two-dimensional surface if they evolved solely in the gravitational field of the hole – occurs when the pericentre distance of the star is of the order of the tidal radius of the hole. It is demonstrated that this ‘pancake’ induces significant density perturbations in the debris stream, and, for stiffer equations of state (adiabatic index γ 5/3), these fluctuations are sufficient to gravitationally destabilize the stream, resulting in its fragmentation into bound clumps. The results of our findings are discussed in the context of the observational properties of tidal disruption events.
Chris Nixon - One of the best experts on this subject based on the ideXlab platform.
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post Periapsis pancakes sustenance for self gravity in tidal disruption events
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Eric R Coughlin, Chris Nixon, Mitchell C Begelman, Philip J Armitage, Daniel J PriceAbstract:A tidal disruption event, which occurs when a star is destroyed by the gravitational field of a supermassive black hole, produces a stream of debris, the evolution of which ultimately determines the observational properties of the event. Here, we show that a post-Periapsis caustic – a location where the locus of gas parcels comprising the stream would collapse into a two-dimensional surface if they evolved solely in the gravitational field of the hole – occurs when the pericentre distance of the star is of the order of the tidal radius of the hole. It is demonstrated that this ‘pancake’ induces significant density perturbations in the debris stream, and, for stiffer equations of state (adiabatic index γ 5/3), these fluctuations are sufficient to gravitationally destabilize the stream, resulting in its fragmentation into bound clumps. The results of our findings are discussed in the context of the observational properties of tidal disruption events.
Mitchell C Begelman - One of the best experts on this subject based on the ideXlab platform.
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post Periapsis pancakes sustenance for self gravity in tidal disruption events
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Eric R Coughlin, Chris Nixon, Mitchell C Begelman, Philip J Armitage, Daniel J PriceAbstract:A tidal disruption event, which occurs when a star is destroyed by the gravitational field of a supermassive black hole, produces a stream of debris, the evolution of which ultimately determines the observational properties of the event. Here, we show that a post-Periapsis caustic – a location where the locus of gas parcels comprising the stream would collapse into a two-dimensional surface if they evolved solely in the gravitational field of the hole – occurs when the pericentre distance of the star is of the order of the tidal radius of the hole. It is demonstrated that this ‘pancake’ induces significant density perturbations in the debris stream, and, for stiffer equations of state (adiabatic index γ 5/3), these fluctuations are sufficient to gravitationally destabilize the stream, resulting in its fragmentation into bound clumps. The results of our findings are discussed in the context of the observational properties of tidal disruption events.