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Daniel P. Stark - One of the best experts on this subject based on the ideXlab platform.
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Resolved spectroscopy of gravitationally lensed galaxies: recovering coherent velocity fields in subluminous z ~ 2-3 galaxies
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: T. A. Jones, Johan Richard, A. M. Swinbank, R. S. Ellis, Daniel P. StarkAbstract:We present spatially resolved dynamics for six strongly lensed star-forming galaxies at z = 1.7-3.1, each enlarged by a Linear Magnification factor of ~×8. Using the Keck laser guide star AO system and the OH-Suppressing Infra-Red Imaging Spectrograph integral field unit spectrograph, we resolve kinematic and morphological detail in our sample with an unprecedented fidelity, in some cases achieving spatial resolutions of ~=100pc. With one exception our sources have diameters ranging from 1 to 7 kpc, integrated star formation rates of 2-40Msolaryr-1 (uncorrected for extinction) and dynamical masses of 109.7-10.3Msolar. With this exquisite resolution, we find that four of the six galaxies display coherent velocity fields consistent with a simple rotating disc model. Our model fits imply ratios for the systemic to random motion, Vc sini/σ, ranging from 0.5 to 1.3 and Toomre disc parameters Q < 1. The large fraction of well-ordered velocity fields in our sample is consistent with data analysed for larger, more luminous sources at this redshift. We demonstrate that the apparent contradiction with earlier dynamical results published for unlensed compact sources arises from the considerably improved spatial resolution and sampling uniquely provided by the combination of adaptive optics and strong gravitational lensing. Our high-resolution data further reveal that all six galaxies contain multiple giant star-forming HII regions whose resolved diameters are in the range 300 pc to 1.0 kpc, consistent with the Jeans length expected in the case of dispersion support. From the kinematic data, we calculate that these regions have dynamical masses of 108.8-9.5Msolar, also in agreement with local data. However, the density of star formation in these regions is ~100× higher than observed in local spirals; such high values are only seen in the most luminous local starbursts. The global dynamics and demographics of star formation in these HII regions suggest that vigorous star formation is primarily governed by gravitational instability in primitive rotating discs. The physical insight provided by the combination of adaptive optics and gravitational lensing suggests it will be highly valuable to locate many more strongly lensed distant galaxies with high star formation rates before the era of the next-generation ground-based telescopes when such observations will become routine.
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Resolved Spectroscopy of Gravitationally-Lensed Galaxies: Recovering Coherent Velocity Fields in Sub-Luminous z~2-3 Galaxies
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: Tucker Jones, Mark Swinbank, Richard Ellis, Johan Richard, Daniel P. StarkAbstract:We present spatially-resolved dynamics for six strongly lensed star-forming galaxies at z=1.7-3.1, each enlarged by a Linear Magnification factor ~8. Using the Keck laser guide star AO system and the OSIRIS integral field unit spectrograph we resolve kinematic and morphological detail in our sample with an unprecedented fidelity, in some cases achieving spatial resolutions of ~100 pc. With one exception our sources have diameters ranging from 1-7 kpc, star formation rates of 2-40 Msun/yr (uncorrected for extinction) and dynamical masses of 10^(9.7-10.3) Msun. With this exquisite resolution we find that four of the six galaxies display coherent velocity fields consistent with a simple rotating disk model, which can only be recovered with the considerably improved spatial resolution and sampling from the combination of adaptive optics and strong gravitational lensing. Our model fits imply ratios for the systemic to random motion, V sin(i)/sigma, ranging from 0.5-1.3 and Toomre disk parameters Q
Johan Richard - One of the best experts on this subject based on the ideXlab platform.
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Resolved spectroscopy of gravitationally lensed galaxies: recovering coherent velocity fields in subluminous z ~ 2-3 galaxies
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: T. A. Jones, Johan Richard, A. M. Swinbank, R. S. Ellis, Daniel P. StarkAbstract:We present spatially resolved dynamics for six strongly lensed star-forming galaxies at z = 1.7-3.1, each enlarged by a Linear Magnification factor of ~×8. Using the Keck laser guide star AO system and the OH-Suppressing Infra-Red Imaging Spectrograph integral field unit spectrograph, we resolve kinematic and morphological detail in our sample with an unprecedented fidelity, in some cases achieving spatial resolutions of ~=100pc. With one exception our sources have diameters ranging from 1 to 7 kpc, integrated star formation rates of 2-40Msolaryr-1 (uncorrected for extinction) and dynamical masses of 109.7-10.3Msolar. With this exquisite resolution, we find that four of the six galaxies display coherent velocity fields consistent with a simple rotating disc model. Our model fits imply ratios for the systemic to random motion, Vc sini/σ, ranging from 0.5 to 1.3 and Toomre disc parameters Q < 1. The large fraction of well-ordered velocity fields in our sample is consistent with data analysed for larger, more luminous sources at this redshift. We demonstrate that the apparent contradiction with earlier dynamical results published for unlensed compact sources arises from the considerably improved spatial resolution and sampling uniquely provided by the combination of adaptive optics and strong gravitational lensing. Our high-resolution data further reveal that all six galaxies contain multiple giant star-forming HII regions whose resolved diameters are in the range 300 pc to 1.0 kpc, consistent with the Jeans length expected in the case of dispersion support. From the kinematic data, we calculate that these regions have dynamical masses of 108.8-9.5Msolar, also in agreement with local data. However, the density of star formation in these regions is ~100× higher than observed in local spirals; such high values are only seen in the most luminous local starbursts. The global dynamics and demographics of star formation in these HII regions suggest that vigorous star formation is primarily governed by gravitational instability in primitive rotating discs. The physical insight provided by the combination of adaptive optics and gravitational lensing suggests it will be highly valuable to locate many more strongly lensed distant galaxies with high star formation rates before the era of the next-generation ground-based telescopes when such observations will become routine.
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Resolved Spectroscopy of Gravitationally-Lensed Galaxies: Recovering Coherent Velocity Fields in Sub-Luminous z~2-3 Galaxies
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: Tucker Jones, Mark Swinbank, Richard Ellis, Johan Richard, Daniel P. StarkAbstract:We present spatially-resolved dynamics for six strongly lensed star-forming galaxies at z=1.7-3.1, each enlarged by a Linear Magnification factor ~8. Using the Keck laser guide star AO system and the OSIRIS integral field unit spectrograph we resolve kinematic and morphological detail in our sample with an unprecedented fidelity, in some cases achieving spatial resolutions of ~100 pc. With one exception our sources have diameters ranging from 1-7 kpc, star formation rates of 2-40 Msun/yr (uncorrected for extinction) and dynamical masses of 10^(9.7-10.3) Msun. With this exquisite resolution we find that four of the six galaxies display coherent velocity fields consistent with a simple rotating disk model, which can only be recovered with the considerably improved spatial resolution and sampling from the combination of adaptive optics and strong gravitational lensing. Our model fits imply ratios for the systemic to random motion, V sin(i)/sigma, ranging from 0.5-1.3 and Toomre disk parameters Q
Bernard F. Burke - One of the best experts on this subject based on the ideXlab platform.
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First- and second-epoch VLBI observations of the gravitational lens system 2016 + 112
The Astrophysical Journal, 1991Co-Authors: M. B. Heflin, M. V. Gorenstein, Charles R. Lawrence, Bernard F. BurkeAbstract:The structure of A and B radio components at the milliarcsecond level is examined on the basis of two 18-cm Mark III VLBI observations of the 2016 + 112 gravitational lens system. One hypothesis consistent with all of the numerous models considered is that images A and B are not related by Linear Magnification because the source is evolving on a time scale comparable to or shorter than the time delay between images. Models not required to be consistent with Linear Magnification are not. Models required to be consistent with Linear Magnification either fit the data significantly less well or indicate significantly different matrices for the two epochs.
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First epoch VLBI observations of the gravitational lens system 2016+112
Gravitational Lensing, 1Co-Authors: M. B. Heflin, M. V. Gorenstein, Charles R. Lawrence, Bernard F. Burke, Irwin I. ShapiroAbstract:VLBI data at 18 cm indicate that 2016+112 A and B have milliarcsecond structure. The A and B images can be adequately modeled with a Linear Magnification matrix, although a few features in each hybrid map cannot be explained by such a model. Three lens models by Narasimha, Subramanian, and Chitre (1987) and one by Narasimha and Chitre (1989) predict Magnification matrices. The dark halo model by Narasimha and Chitre (1989) works best. Less than half of the VLA fluxes are seen in the respective VLBI hybrid maps, indicating some extended structures. The C component was too faint to be mapped. The VLBI flux ratio B/C is about 3.8.
Tucker Jones - One of the best experts on this subject based on the ideXlab platform.
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Resolved Spectroscopy of Gravitationally-Lensed Galaxies: Recovering Coherent Velocity Fields in Sub-Luminous z~2-3 Galaxies
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: Tucker Jones, Mark Swinbank, Richard Ellis, Johan Richard, Daniel P. StarkAbstract:We present spatially-resolved dynamics for six strongly lensed star-forming galaxies at z=1.7-3.1, each enlarged by a Linear Magnification factor ~8. Using the Keck laser guide star AO system and the OSIRIS integral field unit spectrograph we resolve kinematic and morphological detail in our sample with an unprecedented fidelity, in some cases achieving spatial resolutions of ~100 pc. With one exception our sources have diameters ranging from 1-7 kpc, star formation rates of 2-40 Msun/yr (uncorrected for extinction) and dynamical masses of 10^(9.7-10.3) Msun. With this exquisite resolution we find that four of the six galaxies display coherent velocity fields consistent with a simple rotating disk model, which can only be recovered with the considerably improved spatial resolution and sampling from the combination of adaptive optics and strong gravitational lensing. Our model fits imply ratios for the systemic to random motion, V sin(i)/sigma, ranging from 0.5-1.3 and Toomre disk parameters Q
T. A. Jones - One of the best experts on this subject based on the ideXlab platform.
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Resolved spectroscopy of gravitationally lensed galaxies: recovering coherent velocity fields in subluminous z ~ 2-3 galaxies
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: T. A. Jones, Johan Richard, A. M. Swinbank, R. S. Ellis, Daniel P. StarkAbstract:We present spatially resolved dynamics for six strongly lensed star-forming galaxies at z = 1.7-3.1, each enlarged by a Linear Magnification factor of ~×8. Using the Keck laser guide star AO system and the OH-Suppressing Infra-Red Imaging Spectrograph integral field unit spectrograph, we resolve kinematic and morphological detail in our sample with an unprecedented fidelity, in some cases achieving spatial resolutions of ~=100pc. With one exception our sources have diameters ranging from 1 to 7 kpc, integrated star formation rates of 2-40Msolaryr-1 (uncorrected for extinction) and dynamical masses of 109.7-10.3Msolar. With this exquisite resolution, we find that four of the six galaxies display coherent velocity fields consistent with a simple rotating disc model. Our model fits imply ratios for the systemic to random motion, Vc sini/σ, ranging from 0.5 to 1.3 and Toomre disc parameters Q < 1. The large fraction of well-ordered velocity fields in our sample is consistent with data analysed for larger, more luminous sources at this redshift. We demonstrate that the apparent contradiction with earlier dynamical results published for unlensed compact sources arises from the considerably improved spatial resolution and sampling uniquely provided by the combination of adaptive optics and strong gravitational lensing. Our high-resolution data further reveal that all six galaxies contain multiple giant star-forming HII regions whose resolved diameters are in the range 300 pc to 1.0 kpc, consistent with the Jeans length expected in the case of dispersion support. From the kinematic data, we calculate that these regions have dynamical masses of 108.8-9.5Msolar, also in agreement with local data. However, the density of star formation in these regions is ~100× higher than observed in local spirals; such high values are only seen in the most luminous local starbursts. The global dynamics and demographics of star formation in these HII regions suggest that vigorous star formation is primarily governed by gravitational instability in primitive rotating discs. The physical insight provided by the combination of adaptive optics and gravitational lensing suggests it will be highly valuable to locate many more strongly lensed distant galaxies with high star formation rates before the era of the next-generation ground-based telescopes when such observations will become routine.