The Experts below are selected from a list of 286026 Experts worldwide ranked by ideXlab platform
Yang Su - One of the best experts on this subject based on the ideXlab platform.
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low altitude reconnection Inflow outflow observations during a 2010 november 3 solar eruption
The Astrophysical Journal, 2012Co-Authors: Sabrina Savage, Gordon D Holman, Katharine K Reeves, Daniel B Seaton, D E Mckenzie, Yang SuAbstract:For a solar flare occurring on 2010 November 3, we present observations using several SDO/AIA extreme-ultraviolet (EUV) passbands of an erupting flux rope followed by Inflows sweeping into a current sheet region. The Inflows are soon followed by outflows appearing to originate from near the termination point of the Inflowing motion-an observation in line with standard magnetic reconnection models. We measure average Inflow plane-of-sky speeds to range from {approx}150 to 690 km s{sup -1} with the initial, high-temperature Inflows being the fastest. Using the Inflow speeds and a range of Alfven speeds, we estimate the Alfvenic Mach number which appears to decrease with time. We also provide Inflow and outflow times with respect to RHESSI count rates and find that the fast, high-temperature Inflows occur simultaneously with a peak in the RHESSI thermal light curve. Five candidate Inflow-outflow pairs are identified with no more than a minute delay between detections. The Inflow speeds of these pairs are measured to be {approx}10{sup 2} km s{sup -1} with outflow speeds ranging from {approx}10{sup 2} to 10{sup 3} km s{sup -1}-indicating acceleration during the reconnection process. The fastest of these outflows are in the form of apparently traveling density enhancements along the legsmore » of the loops rather than the loop apexes themselves. These flows could possibly either be accelerated plasma, shocks, or waves prompted by reconnection. The measurements presented here show an order of magnitude difference between the retraction speeds of the loops and the speed of the density enhancements within the loops-presumably exiting the reconnection site.« less
Markus Weiler - One of the best experts on this subject based on the ideXlab platform.
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quantification of localized groundwater Inflow into streams using ground based infrared thermography
Geophysical Research Letters, 2011Co-Authors: Tobias Schuetz, Markus WeilerAbstract:[1] Due to temperature differences of groundwater and streamwater, localized groundwater Inflows into small streams can directly be detected with ground-based thermographic systems in summer or winter. Infrared radiation temperatures of surface water were used to determine mixing length and to calculate the relative fraction of groundwater Inflow to downstream discharge. These fractions were comparable to groundwater Inflow fractions derived from electrical conductivity, kinetic water temperatures and discharge measurements. This approach advances the immediate detection and quantification of localized groundwater Inflow for hydrology, geology and ecology.
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Quantification of localized groundwater Inflow into streams using ground‐based infrared thermography
Geophysical Research Letters, 2011Co-Authors: Tobias Schuetz, Markus WeilerAbstract:[1] Due to temperature differences of groundwater and streamwater, localized groundwater Inflows into small streams can directly be detected with ground-based thermographic systems in summer or winter. Infrared radiation temperatures of surface water were used to determine mixing length and to calculate the relative fraction of groundwater Inflow to downstream discharge. These fractions were comparable to groundwater Inflow fractions derived from electrical conductivity, kinetic water temperatures and discharge measurements. This approach advances the immediate detection and quantification of localized groundwater Inflow for hydrology, geology and ecology.
Benjamin D Oppenheimer - One of the best experts on this subject based on the ideXlab platform.
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galaxy evolution in cosmological simulations with outflows ii metallicities and gas fractions
Monthly Notices of the Royal Astronomical Society, 2011Co-Authors: Romeel Dave, Kristian Finlator, Benjamin D OppenheimerAbstract:We use cosmological hydrodynamic simulations to investigate how Inflows, star formation, and outflows govern the the gaseous and metal content of galaxies within a hierarchical structure formation context. In our simulations, galaxy metallicities are established by a balance between Inflows and outflows as governed by the mass outflow rate, implying that the mass-metallicity relation reflects how the outflow rate varies with stellar mass. Gas content, meanwhile, is set by a competition between Inflow into and gas consumption within the interstellar medium, the latter being governed by the star formation law, while the former is impacted by both wind recycling and preventive feedback. Stochastic variations in the Inflow rate move galaxies off the equilibrium mass-metallicity and mass-gas fraction relations in a manner correlated with star formation rate, and the scatter is set by the timescale to re-equilibrate. The evolution of both relations from z = 3 ! 0 is slow, as individual galaxies tend to evolve mostly along the relations. Gas fractions at a given stellar mass slowly decrease with time because the cosmic Inflow rate diminishes faster than the consumption rate, while metallicities slowly increase as infalling gas becomes more enriched. Observations from z � 3 ! 0 are better matched by simulations employing momentum-driven wind scalings rather than constant wind speeds, but all models predict too low gas fractions at low masses and too high metallicities at high masses. All our models reproduce observed second-parameter trends of the mass-metallicity relation with star formation rate and environment, indicating that these are a consequence of equilibrium and not feedback. Overall, the analytical framework of our equilibrium scenario broadly captures the relevant physics establishing the galaxy gas and metal content in simulations, which suggests that the cycle of baryonic Inflows and outflows centrally governs the cosmic evolution of these properties in typical star-forming galaxies.
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Galaxy evolution in cosmological simulations with outflows - II. Metallicities and gas fractions
Monthly Notices of the Royal Astronomical Society, 2011Co-Authors: Romeel Dave, Kristian Finlator, Benjamin D OppenheimerAbstract:We use cosmological hydrodynamic simulations to investigate how Inflows, star formation, and outflows govern the the gaseous and metal content of galaxies. In our simulations, galaxy metallicities are established by a balance between Inflows and outflows as governed by the mass outflow rate, implying that the mass-metallicity relation reflects how the outflow rate varies with stellar mass (M*). Gas content is set by a competition between Inflow into and gas consumption within the ISM, the latter being governed by the SF law, while the former is impacted by both wind recycling and preventive feedback. Stochastic variations in the Inflow rate move galaxies off the equilibrium M*-Z and Z*-fgas relations in a manner correlated with star formation rate, and the scatter is set by the timescale to re-equilibrate. The evolution of both relations from z=3-0 is slow, as individual galaxies tend to evolve mostly along the relations. Gas fractions at a given M* slowly decrease with time because the cosmic Inflow rate diminishes faster than the consumption rate, while metallicities slowly increase as infalling gas becomes more enriched. Observations from z~3-0 are better matched by simulations employing momentum-driven wind scalings rather than constant wind speeds, but all models predict too low gas fractions at low masses and too high metallicities at high M*. All our models reproduce observed second-parameter trends of the mass-metallicity relation with star formation rate and environment, indicating that these are a consequence of equilibrium and not feedback. Overall, the analytical framework of our equilibrium scenario broadly captures the relevant physics establishing the galaxy gas and metal content in simulations, which suggests that the cycle of baryonic Inflows and outflows centrally governs the cosmic evolution of these properties in typical star-forming galaxies.
Tobias Schuetz - One of the best experts on this subject based on the ideXlab platform.
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quantification of localized groundwater Inflow into streams using ground based infrared thermography
Geophysical Research Letters, 2011Co-Authors: Tobias Schuetz, Markus WeilerAbstract:[1] Due to temperature differences of groundwater and streamwater, localized groundwater Inflows into small streams can directly be detected with ground-based thermographic systems in summer or winter. Infrared radiation temperatures of surface water were used to determine mixing length and to calculate the relative fraction of groundwater Inflow to downstream discharge. These fractions were comparable to groundwater Inflow fractions derived from electrical conductivity, kinetic water temperatures and discharge measurements. This approach advances the immediate detection and quantification of localized groundwater Inflow for hydrology, geology and ecology.
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Quantification of localized groundwater Inflow into streams using ground‐based infrared thermography
Geophysical Research Letters, 2011Co-Authors: Tobias Schuetz, Markus WeilerAbstract:[1] Due to temperature differences of groundwater and streamwater, localized groundwater Inflows into small streams can directly be detected with ground-based thermographic systems in summer or winter. Infrared radiation temperatures of surface water were used to determine mixing length and to calculate the relative fraction of groundwater Inflow to downstream discharge. These fractions were comparable to groundwater Inflow fractions derived from electrical conductivity, kinetic water temperatures and discharge measurements. This approach advances the immediate detection and quantification of localized groundwater Inflow for hydrology, geology and ecology.
Romeel Dave - One of the best experts on this subject based on the ideXlab platform.
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galaxy evolution in cosmological simulations with outflows ii metallicities and gas fractions
Monthly Notices of the Royal Astronomical Society, 2011Co-Authors: Romeel Dave, Kristian Finlator, Benjamin D OppenheimerAbstract:We use cosmological hydrodynamic simulations to investigate how Inflows, star formation, and outflows govern the the gaseous and metal content of galaxies within a hierarchical structure formation context. In our simulations, galaxy metallicities are established by a balance between Inflows and outflows as governed by the mass outflow rate, implying that the mass-metallicity relation reflects how the outflow rate varies with stellar mass. Gas content, meanwhile, is set by a competition between Inflow into and gas consumption within the interstellar medium, the latter being governed by the star formation law, while the former is impacted by both wind recycling and preventive feedback. Stochastic variations in the Inflow rate move galaxies off the equilibrium mass-metallicity and mass-gas fraction relations in a manner correlated with star formation rate, and the scatter is set by the timescale to re-equilibrate. The evolution of both relations from z = 3 ! 0 is slow, as individual galaxies tend to evolve mostly along the relations. Gas fractions at a given stellar mass slowly decrease with time because the cosmic Inflow rate diminishes faster than the consumption rate, while metallicities slowly increase as infalling gas becomes more enriched. Observations from z � 3 ! 0 are better matched by simulations employing momentum-driven wind scalings rather than constant wind speeds, but all models predict too low gas fractions at low masses and too high metallicities at high masses. All our models reproduce observed second-parameter trends of the mass-metallicity relation with star formation rate and environment, indicating that these are a consequence of equilibrium and not feedback. Overall, the analytical framework of our equilibrium scenario broadly captures the relevant physics establishing the galaxy gas and metal content in simulations, which suggests that the cycle of baryonic Inflows and outflows centrally governs the cosmic evolution of these properties in typical star-forming galaxies.
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Galaxy evolution in cosmological simulations with outflows - II. Metallicities and gas fractions
Monthly Notices of the Royal Astronomical Society, 2011Co-Authors: Romeel Dave, Kristian Finlator, Benjamin D OppenheimerAbstract:We use cosmological hydrodynamic simulations to investigate how Inflows, star formation, and outflows govern the the gaseous and metal content of galaxies. In our simulations, galaxy metallicities are established by a balance between Inflows and outflows as governed by the mass outflow rate, implying that the mass-metallicity relation reflects how the outflow rate varies with stellar mass (M*). Gas content is set by a competition between Inflow into and gas consumption within the ISM, the latter being governed by the SF law, while the former is impacted by both wind recycling and preventive feedback. Stochastic variations in the Inflow rate move galaxies off the equilibrium M*-Z and Z*-fgas relations in a manner correlated with star formation rate, and the scatter is set by the timescale to re-equilibrate. The evolution of both relations from z=3-0 is slow, as individual galaxies tend to evolve mostly along the relations. Gas fractions at a given M* slowly decrease with time because the cosmic Inflow rate diminishes faster than the consumption rate, while metallicities slowly increase as infalling gas becomes more enriched. Observations from z~3-0 are better matched by simulations employing momentum-driven wind scalings rather than constant wind speeds, but all models predict too low gas fractions at low masses and too high metallicities at high M*. All our models reproduce observed second-parameter trends of the mass-metallicity relation with star formation rate and environment, indicating that these are a consequence of equilibrium and not feedback. Overall, the analytical framework of our equilibrium scenario broadly captures the relevant physics establishing the galaxy gas and metal content in simulations, which suggests that the cycle of baryonic Inflows and outflows centrally governs the cosmic evolution of these properties in typical star-forming galaxies.
