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287 results on '"Dunn, W R"'

3. Jupiter's X-ray aurora during UV dawn storms and injections as observed by XMM-Newton, Hubble, and Hisaki

Author

Wibisono, A. D., Branduardi-Raymont, G., Dunn, W. R., Kimura, T., Coates, A. J., Grodent, D., Yao, Z. H., Kita, H., Rodriguez, P., Gladstone, G. R., Bonfond, B., and Haythornthwaite, R. P.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Physics - Space Physics
Abstract

We present results from a multiwavelength observation of Jupiter's northern aurorae, carried out simultaneously by XMM-Newton, the Hubble Space Telescope (HST), and the Hisaki satellite in September 2019. HST images captured dawn storms and injection events in the far ultraviolet aurora several times during the observation period. Magnetic reconnection occurring in the middle magnetosphere caused by internal drivers is thought to start the production of those features. The field lines then dipolarize which injects hot magnetospheric plasma from the reconnection site to enter the inner magnetosphere. Hisaki observed an impulsive brightening in the dawnside Io plasma torus (IPT) during the final appearance of the dawn storms and injection events which is evidence that a large-scale plasma injection penetrated the central IPT between 6-9 RJ (Jupiter radii). The extreme ultraviolet aurora brightened and XMM-Newton detected an increase in the hard X-ray aurora count rate, suggesting an increase in electron precipitation. The dawn storms and injections did not change the brightness of the soft X-ray aurora and they did not "switch-on" its commonly observed quasi-periodic pulsations. Spectral analysis of the X-ray aurora suggests that the precipitating ions responsible for the soft X-ray aurora were iogenic and that a powerlaw continuum was needed to fit the hard X-ray part of the spectra. The spectra coincident with the dawn storms and injections required two powerlaw continua to get good fits., Comment: 14 pages, 7 figures in main text, 6 figures in the appendices. Accepted in MNRAS 28 July 2021

Published
2021
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4. Searching for Saturn's X-rays during a rare Jupiter Magnetotail Crossing using Chandra

Author

Weigt, D. M., Dunn, W. R., Jackman, C. M., Kraft, R., Branduardi-Raymont, G., Nichols, J. D., Wibisono, A. D., Vogt, M. F., and Gladstone, G. R.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Physics - Space Physics
Abstract

Every 19 years, Saturn passes through Jupiter's 'flapping' magnetotail. Here, we report Chandra X-ray observations of Saturn planned to coincide with this rare planetary alignment and to analyse Saturn's magnetospheric response when transitioning to this unique parameter space. We analyse three Director's Discretionary Time (DDT) observations from the High Resolution Camera (HRC-I) on-board Chandra, taken on November 19, 21 and 23 2020 with the aim to find auroral and/or disk emissions. We infer the conditions in the kronian system by looking at coincident soft X-ray solar flux data from the Geostationary Operational Environmental Satellite (GOES) and Hubble Space Telescope (HST) observations of Saturn's ultraviolet (UV) auroral emissions. The large Saturn-Sun-Earth angle during this time would mean that most flares from the Earth-facing side of the Sun would not have impacted Saturn. We find no significant detection of Saturn's disk or auroral emissions in any of our observations. We calculate the 3$\sigma$ upper band energy flux of Saturn during this time to be 0.9 - 3.04 $\times$ 10$^{14}$ erg cm$^{-2}$ s$^{-1}$ which agrees with fluxes found from previous modelled spectra of the disk emissions. We conclude by discussing the implications of this non-detection and how it is imperative that the next fleet of X-ray telescope (such as Athena and the Lynx mission concept) continue to observe Saturn with their improved spatial and spectral resolution and very enhanced sensitivity to help us finally solve the mysteries behind Saturn's apparently elusive X-ray aurora., Comment: 8 pages, 3 figures, accepted for publication in MNRAS

Published
2021
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5. Auroral diagnosis of solar wind interaction with Jupiter's magnetosphere

Author

Yao, Z. H., Bonfond, B., Grodent, D., Chané, E., Dunn, W. R., Kurth, W. S., Connerney, J. E. P., Nichols, J. D., Palmaerts, B., Guo, R. L., Hospodarsky, G. B., Mauk, B. H., Kimura, T., and Bolton, S. J.

Subjects
Physics - Space Physics, Physics - Plasma Physics
Abstract

Although mass and energy in Jupiter's magnetosphere mostly come from the innermost Galilean moon Io's volcanic activities, solar wind perturbations can play crucial roles in releasing the magnetospheric energy and powering aurorae in Jupiter's polar regions. The systematic response of aurora to solar wind compression remains poorly understood. Here we report the analysis of a set of auroral images with contemporaneous in situ magnetopause detections. We distinguish two types of auroral enhancements: a transient localized one and a long-lasting global one. We show that only the latter systematically appears under a compressed magnetopause, while the localized auroral expansion could occur during an expanded magnetopause. Moreover, we directly examine previous theories on how solar wind compressions enhance auroral emissions. Our results demonstrate that auroral morphologies can be diagnostic of solar wind conditions at planets when in situ measurements are not possible.

Published
2020
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9. In situ evidence of the magnetospheric cusp of Jupiter from Juno spacecraft measurements

Author

Xu, Y., Arridge, C. S., Yao, Z. H., Zhang, B., Ray, L. C., Badman, S. V., Dunn, W. R., Ebert, R. W., Chen, J. J., Allegrini, F., Kurth, W. S., Qin, T. S., Connerney, J. E. P., McComas, D. J., Bolton, S. J., Wei, Y., Xu, Y., Arridge, C. S., Yao, Z. H., Zhang, B., Ray, L. C., Badman, S. V., Dunn, W. R., Ebert, R. W., Chen, J. J., Allegrini, F., Kurth, W. S., Qin, T. S., Connerney, J. E. P., McComas, D. J., Bolton, S. J., and Wei, Y.

Abstract

The magnetospheric cusp connects the planetary magnetic field to interplanetary space, offering opportunities for charged particles to precipitate to or escape from the planet. Terrestrial cusps are typically found near noon local time, but the characteristics of the Jovian cusp are unknown. Here we show direct evidence of Jovian cusps using datasets from multiple instruments onboard Juno spacecraft. We find that the cusps of Jupiter are in the dusk sector, which is contradicting Earth-based predictions of a near-noon location. Nevertheless, the characteristics of charged particles in the Jovian cusps resemble terrestrial and Saturnian cusps, implying similar cusp microphysics exist across different planets. These results demonstrate that while the basic physical processes may operate similarly to those at Earth, Jupiter’s rapid rotation and its location in the heliosphere can dramatically change the configuration of the cusp. This work provides useful insights into the fundamental consequences of star-planet interactions, highlighting how planetary environments and rotational dynamics influence magnetospheric structures.

Published
2024

11. Identifying the Variety of Jovian X‐Ray Auroral Structures: Tying the Morphology of X‐Ray Emissions to Associated Magnetospheric Dynamics

Author

Weigt, D. M., primary, Jackman, C. M., additional, Moral Pombo, D., additional, Badman, S. V., additional, Louis, C. K., additional, Dunn, W. R., additional, McEntee, S. C., additional, Branduardi‐Raymont, G., additional, Grodent, D., additional, Vogt, M. F., additional, Tao, C., additional, Gladstone, G. R., additional, Kraft, R. P., additional, Kurth, W. S., additional, and Connerney, J. E. P., additional

Published
2023
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13. A Possible Picture for the Connected Recurrent Magnetic Dipolarization, Quasi‐periodic ENA enhancement, SKR low frequency extension and Narrowband Emission at Saturn

Author

Xu, Y., primary, Yao, Z. H., additional, Ye, S.‐Y., additional, Badman, S. V., additional, Dialynas, K., additional, Sergis, N., additional, Ray, L. C., additional, Guo, R. L., additional, Pan, D. X., additional, Dunn, W. R., additional, Zhang, B., additional, Bader, A., additional, Kinrade, J., additional, Wu, Siyuan, additional, Coates, A. J., additional, Mitchell, D. G., additional, and Wei, Y., additional

Published
2023
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14. Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Author

Kollmann, P., primary, Allanson, O., additional, Arruda, L., additional, Berland, G., additional, Blum, L. W., additional, Bortnik, J., additional, Cao, X., additional, Chen, T. Y., additional, Clark, G., additional, Cohen, I., additional, Cooper, J. F., additional, Crary, F., additional, Desai, R. T., additional, Dialynas, K., additional, Drozdov, A., additional, Dudnik, O. V., additional, Dunn, W. R., additional, Hospodarsky, G. B., additional, Huybrighs, H., additional, Jackman, C. M., additional, Jaynes, A. N., additional, Jun, I., additional, Khurana, K. K., additional, Kraft, R., additional, Kronberg, E. A., additional, Lejosne, S., additional, Li, W., additional, Li, X., additional, Liuzzo, L., additional, Ma, Q., additional, Marshall, R., additional, Mauk, B., additional, Nénon, Q., additional, Nordheim, T. A., additional, Paranicas, C., additional, Plainaki, C. C., additional, Regoli, L. H., additional, Roussos, E., additional, Shprits, Y., additional, Siecard, A., additional, Simon, S., additional, Smith, H. T., additional, Sorathia, K., additional, Spence, H. E., additional, Sulaiman, A., additional, Sun, Y., additional, Tu, W., additional, Turner, D. L., additional, Usanova, M. E., additional, Williams, P., additional, Woodfield, E. E., additional, Wu, X., additional, and Yuan, C.-J., additional

Published
2023
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15. On the Relation Between Jupiter's Aurora and the Dawnside Current Sheet

Author

Xu, Y., primary, Yao, Z. H., additional, Zhang, B., additional, Delamere, P. A., additional, Ray, L. C., additional, Dunn, W. R., additional, Badman, S. V., additional, Feng, E. H., additional, Zheng, Z. Q., additional, Bolton, S. J., additional, Grodent, D., additional, Bonfond, B., additional, and Wei, Y., additional

Published
2023
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16. On the Relation Between Jupiter's Aurora and the Dawnside Current Sheet

Author

Xu, Yan, Yao, Z. H., Zhang, B., Delamere, P. A., Ray, Licia C, Dunn, W. R., Badman, Sarah, Feng, E. H., Zheng, Z. Q., Bolton, S. J., Grodent, D. C., Bonfond, B. ., Wei, Y., Xu, Yan, Yao, Z. H., Zhang, B., Delamere, P. A., Ray, Licia C, Dunn, W. R., Badman, Sarah, Feng, E. H., Zheng, Z. Q., Bolton, S. J., Grodent, D. C., Bonfond, B. ., and Wei, Y.

Abstract

Jupiter's auroral emission is a spectacular phenomenon that provides insight into energy release processes related to the coupling of its magnetosphere and ionosphere. This energy release is influenced by solar wind conditions. Using joint observations from Juno and the Hubble Space Telescope (HST), we statistically investigate the relationship between auroral power and current sheet variations under different solar wind conditions. In this study, we reveal that during global main auroral brightening events that are closely connected to solar wind compressions, the dawn side current sheet is substantially thinner than during times when a quiet auroral morphology is present. Furthermore, the total current intensity in the current sheet is found to increase under solar wind compression conditions compared to the quiet period. These findings provide important observational evidence for how magnetospheric dynamics driven by solar wind behavior affect auroral activity, deepening our understanding of the coupling between Jupiter's magnetosphere and ionosphere.

Published
2023

17. A Possible Unified Picture for the Connected Recurrent Magnetic Dipolarization, Quasi‐Periodic ENA Enhancement, SKR Low‐Frequency Extension and Narrowband Emission at Saturn

Author

Xu, Y., Yao, Z. H., Ye, S.‐Y., Badman, S. V., Dialynas, K., Sergis, N., Ray, L. C., Guo, R. L., Pan, D. X., Dunn, W. R., Zhang, B., Bader, A., Kinrade, J., Wu, S. Y., Coates, A. J., Mitchell, D. G., Wei, Y., Xu, Y., Yao, Z. H., Ye, S.‐Y., Badman, S. V., Dialynas, K., Sergis, N., Ray, L. C., Guo, R. L., Pan, D. X., Dunn, W. R., Zhang, B., Bader, A., Kinrade, J., Wu, S. Y., Coates, A. J., Mitchell, D. G., and Wei, Y.

Abstract

Magnetic Dipolarization, a hallmark indicator of the formation of field‐aligned currents, plays a crucial role in the energy dissipative processes that occur within planetary magnetospheres. Saturn's magnetic dipolarization was found to recur after one planetary rotation, suggesting a potential correlation with the corotating current systems. The observation of enhanced Energetic Neutral Atoms (ENA) within Saturn's inner magnetosphere serves as a diagnostic tool, revealing the existence of a rotating, dynamic Partial Ring Current (PRC) system. By utilizing multiple datasets from Cassini, this study advances the understanding of the interrelationship between ENA emission and magnetic dipolarization. Our results suggest the possibility of a coupling between the PRC system revealed by the ENA emission and magnetic dipolarization. Furthermore, a temporal correlation was found between the ENA emissions and two distinct radio emissions. This study discusses potential causal relationships among these phenomena and first time proposes a global unified physical picture.

Published
2023

18. Identifying the Variety of Jovian X-Ray Auroral Structures : Tying the Morphology of X-Ray Emissions to Associated Magnetospheric Dynamics

Author

Weigt, Dale M., Jackman, C. M., Moral Pombo, D., Badman, S. V., Louis, C. K., Dunn, W. R., McEntee, S. C., Branduardi-Raymont, G., Grodent, D., Vogt, M. F., Tao, C., Gladstone, G. R., Kraft, R. P., Kurth, W. S., Connerney, J. E. P., Weigt, Dale M., Jackman, C. M., Moral Pombo, D., Badman, S. V., Louis, C. K., Dunn, W. R., McEntee, S. C., Branduardi-Raymont, G., Grodent, D., Vogt, M. F., Tao, C., Gladstone, G. R., Kraft, R. P., Kurth, W. S., and Connerney, J. E. P.

Abstract

We define the spatial clustering of X-rays within Jupiter's northern auroral regions by classifying their distributions into ?X-ray auroral structures.? Using data from Chandra during Juno's main mission observations (24 May 2016 to 8 September 2019), we define five X-ray structures based on their ionospheric location and calculate the distribution of auroral photons. The morphology and ionospheric location of these structures allow us to explore the possibility of numerous X-ray auroral magnetospheric drivers. We compare these distributions to Hubble Space Telescope (HST) and Juno (Waves and MAG) data, and a 1D solar wind propagation model to infer the state of Jupiter's magnetosphere. Our results suggest that the five sub-classes of ?X-ray structures? fall under two broad morphologies: fully polar and low latitude emissions. Visibility modeling of each structure suggests the non-uniformity of the photon distributions across the Chandra intervals are likely associated with the switching on/off of magnetospheric drivers as opposed to geometrical effects. The combination of ultraviolet (UV) and X-ray morphological structures is a powerful tool to elucidate the behavior of both electrons and ions and their link to solar wind/magnetospheric conditions in the absence of an upstream solar monitor. Although much work is still needed to progress the use of X-ray morphology as a diagnostic tool, we set the foundations for future studies to continue this vital research.

Published
2023

19. A Survey of Magnetic Field Line Curvature in Jovian Dawn Magnetodisc.

Author

Gu, W. D., Yao, Z. H., Wei, Y., Qin, T. S., Zhang, B. Z., Xu, Y., Dunn, W. R., Delamere, P. A., and Chen, Y. N.

Subjects
MAGNETIC fields, SOLAR magnetic fields, SOLAR wind, LARMOR radius, PLANETARY rotation, CURVATURE
Abstract

The Jovian magnetosphere is highly dynamic, influenced by both solar wind and internal processes associated with the rapid planetary rotation and Io's volcanic activities. Accompanying the mass and energy circulations driven by the magnetospheric dynamics, the magnetic configuration also changes dramatically. One of the crucial parameters to characterize the magnetic configuration is magnetic field line curvature (FLC), which generally describes how stretched the field line is. The curvature is pivotal to influence particle behaviors, for example, pitch angle scattering which may lead to auroral particle precipitation. In this work, a method is proposed to investigate the real‐time magnetic FLC in Jovian current sheet using the magnetic field data from the Juno spacecraft. The results indicate that the FLC scattering of ions and relativistic electrons are common in Jovian magnetosphere, providing a crucial insight to understand the particle behaviors. Plain Language Summary: Both the Earth and the Jupiter have intrinsic magnetic field. When the planetary magnetic field interacts with the solar wind, a region called magnetosphere is formed. Particle behaviors in different planetary systems are different, due to the different magnetospheric dynamics. The curvature of magnetic field, describing the stretch level of a magnetic field line, is a basic parameter to describe a planetary space system, and it can significantly influence particle behaviors, for example, to scatter the magnetospheric particles to planetary atmosphere, causing auroral emissions. In this work, we proposed a method to calculate the magnetic field line curvature (FLC) near the equatorial plane inside the Jupiter's magnetosphere using Juno data set, for the first time to provide a global picture on the magnetic FLC. By comparing with the radius of particles' gyration motions, we suggest that ions and electrons can be strongly scattered by the magnetic FLC. We believe that the results in this study provide useful information on the different particle behaviors between the terrestrial system and the Jovian system. Key Points: We proposed a method to investigate the magnetic field line curvature (FLC) in Jupiter's current sheet using data from Juno data set50 events are selected by specific criteria. The magnetic FLC and different particles' Larmor radius are investigatedThe FLC will scatter ions and relativistic electrons as a potential cause of auroral precipitation [ABSTRACT FROM AUTHOR]

Published
2024
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23. Long Exposure Chandra X‐Ray Observation of Jupiter's Auroral Emissions During Juno Plasmasheet Encounters in September 2021.

Author

McEntee, S. C., Jackman, C. M., Weigt, D. M., Louis, C. K., Dunn, W. R., Boudouma, A., Connerney, J. E. P., Kurth, W. S., Kraft, R., Branduardi‐Raymont, G., Gladstone, G. R., and Rutala, M. J.

Subjects
AURORAS, SOLAR wind, JUPITER (Planet), MAGNETIC fields, WAVELET transforms, MAGNETOSPHERE
Abstract

On 15 September 2021, Chandra carried out a 40‐hr (∼4 jovian rotations) observation as part of its longest planetary campaign to study the drivers of jovian X‐ray aurora that may be linked to ultra‐low frequency (ULF) wave activity. During this time, Juno's orbit had taken the spacecraft into Jupiter's dusk magnetosphere. Here is believed to be the most probable location of ULF waves propagating along jovian magnetic field lines that drive the X‐ray auroral emissions. This is the first time that this region has been observed by an orbiter since Galileo >20 years ago, and never before has there been contemporaneous in situ and X‐ray observations. A 1D solar wind propagation model identifies a compression event near the midpoint of the 40‐hr observation window. The influence of a compression is confirmed when comparing the measured magnetic field in the dusk lobes of the magnetotail from Juno MAG data against a baseline lobe field model. Data from the Juno Waves instrument also show activation of broadband kilometric (bKOM) emissions during the arrival of the shock, a feature that has previously been observed during compression events. Therefore this is the first time we can fully analyze the morphological variability during the evolution of a shock. Wavelet transforms and Rayleigh testing are used to search for statistically significant quasi‐periodic pulsations (QPPs) of the X‐ray emissions in the data set, and find significant QPPs with periods of 25–26 min for the northern auroral X‐rays. Key Points: We compare a 40‐hr Chandra observation of Jupiter's X‐ray aurora with in situ Juno measurements and a 1‐D solar wind propagation modelWe find statistically significant quasi‐periodic pulsation with a ∼25 min period likely linked to the arrival of a solar wind compressionUsing Juno MAG data form the dusk tail lobes, we infer the state of compression/loading of the magnetosphere [ABSTRACT FROM AUTHOR]

Published
2023
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25. On the Relation Between Auroral Morphologies and Compression Conditions of Jupiter's Magnetopause: Observations From Juno and the Hubble Space Telescope

Author

Yao, Z. H., primary, Bonfond, B., additional, Grodent, D., additional, Chané, E., additional, Dunn, W. R., additional, Kurth, W. S., additional, Connerney, J. E. P., additional, Nichols, J. D., additional, Palmaerts, B., additional, Guo, R. L., additional, Hospodarsky, G. B., additional, Mauk, B. H., additional, Kimura, T., additional, and Bolton, S. J., additional

Published
2022
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26. Jupiter's X‐Ray and UV Dark Polar Region

Author

Dunn, W. R., Weigt, D. M., Grodent, D., Yao, Z. H., May, D., Feigelman, K., Sipos, B., Fleming, D., McEntee, S., Bonfond, B., Gladstone, G. R., Johnson, R. E., Jackman, C. M., Guo, R. L., Branduardi‐Raymont, G., Wibisono, A. D., Kraft, R. P., Nichols, J. D., Ray, L. C., Dunn, W. R., Weigt, D. M., Grodent, D., Yao, Z. H., May, D., Feigelman, K., Sipos, B., Fleming, D., McEntee, S., Bonfond, B., Gladstone, G. R., Johnson, R. E., Jackman, C. M., Guo, R. L., Branduardi‐Raymont, G., Wibisono, A. D., Kraft, R. P., Nichols, J. D., and Ray, L. C.

Abstract

We present 14 simultaneous Chandra X‐ray Observatory (CXO)‐Hubble Space Telescope (HST) observations of Jupiter's Northern X‐ray and ultraviolet (UV) aurorae from 2016 to 2019. Despite the variety of dynamic UV and X‐ray auroral structures, one region is conspicuous by its persistent absence of emission: the dark polar region (DPR). Previous HST observations have shown that very little UV emission is produced by the DPR. We find that the DPR also produces very few X‐ray photons. For all 14 observations, the low level of X‐ray emission from the DPR is consistent (within 2‐standard deviations) with scattered solar emission and/or photons spread by Chandra's Point Spread Function from known X‐ray‐bright regions. We therefore conclude that for these 14 observations the DPR produced no statistically significant detectable X‐ray signature.

Published
2022

27. Jupiter's X‐Ray and UV Dark Polar Region

Author

Dunn, W. R., primary, Weigt, D. M., additional, Grodent, D., additional, Yao, Z. H., additional, May, D., additional, Feigelman, K., additional, Sipos, B., additional, Fleming, D., additional, McEntee, S., additional, Bonfond, B., additional, Gladstone, G. R., additional, Johnson, R. E., additional, Jackman, C. M., additional, Guo, R. L., additional, Branduardi‐Raymont, G., additional, Wibisono, A. D., additional, Kraft, R. P., additional, Nichols, J. D., additional, and Ray, L. C., additional

Published
2022
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29. A Rotating Azimuthally Distributed Auroral Current System on Saturn Revealed by the Cassini Spacecraft

Author

Guo, R. L., primary, Yao, Z. H., additional, Dunn, W. R., additional, Palmaerts, B., additional, Sergis, N., additional, Grodent, D., additional, Badman, S. V., additional, Ye, S. Y., additional, Pu, Z. Y., additional, Mitchell, D. G., additional, Zhang, B. Z., additional, Achilleos, N., additional, Coates, A. J., additional, Wei, Y., additional, Waite, J. H., additional, Krupp, N., additional, and Dougherty, M. K., additional

Published
2021
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35. A Low Signal Detection of X‐Rays From Uranus

Author

Dunn, W. R., primary, Ness, J.‐U., additional, Lamy, L., additional, Tremblay, G. R., additional, Branduardi‐Raymont, G., additional, Snios, B., additional, Kraft, R. P., additional, Yao, Z., additional, and Wibisono, A. D., additional

Published
2021
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38. Jupiter's X‐ray Emission During the 2007 Solar Minimum

Author

Dunn, W. R., primary, Branduardi‐Raymont, G., additional, Carter‐Cortez, V., additional, Campbell, A., additional, Elsner, R., additional, Ness, J.‐U., additional, Gladstone, G. R., additional, Ford, P., additional, Yao, Z., additional, Rodriguez, P., additional, Clark, G., additional, Paranicas, C., additional, Foster, A., additional, Baker, D., additional, Gray, R., additional, Badman, S. V., additional, Ray, L. C., additional, Bunce, E. J., additional, Snios, B., additional, Jackman, C. M., additional, Rae, I. J., additional, Kraft, R., additional, Rymer, A., additional, Lathia, S., additional, and Achilleos, N., additional

Published
2020
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39. Comparisons Between Jupiter's X‐ray, UV and Radio Emissions and In‐Situ Solar Wind Measurements During 2007

Author

Dunn, W. R., primary, Gray, R., additional, Wibisono, A. D., additional, Lamy, L., additional, Louis, C., additional, Badman, S. V., additional, Branduardi‐Raymont, G., additional, Elsner, R., additional, Gladstone, G. R., additional, Ebert, R., additional, Ford, P., additional, Foster, A., additional, Tao, C., additional, Ray, L. C., additional, Yao, Z., additional, Rae, I. J., additional, Bunce, E. J., additional, Rodriguez, P., additional, Jackman, C. M., additional, Nicolaou, G., additional, Clarke, J., additional, Nichols, J., additional, Elliott, H., additional, and Kraft, R., additional

Published
2020
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40. Temporal and Spectral Studies by XMM‐Newton of Jupiter's X‐ray Auroras During a Compression Event

Author

Wibisono, A. D., primary, Branduardi‐Raymont, G., additional, Dunn, W. R., additional, Coates, A. J., additional, Weigt, D. M., additional, Jackman, C. M., additional, Yao, Z. H., additional, Tao, C., additional, Allegrini, F., additional, Grodent, D., additional, Chatterton, J., additional, Gerasimova, A., additional, Kloss, L., additional, Milović, J., additional, Orlandiayni, L., additional, Preidl, A.‐K., additional, Radler, C., additional, Summhammer, L., additional, and Fleming, D., additional

Published
2020
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46. Jupiter's X-ray aurora during UV dawn storms and injections as observed by XMM–Newton, Hubble, and Hisaki.

Author

Wibisono, A D, Branduardi-Raymont, G, Dunn, W R, Kimura, T, Coates, A J, Grodent, D, Yao, Z H, Kita, H, Rodriguez, P, Gladstone, G R, Bonfond, B, and Haythornthwaite, R P

Subjects
AURORAS, X-rays, HARD X-rays, SOFT X rays, ULTRAVIOLET spectra
Abstract

We present results from a multiwavelength observation of Jupiter's northern aurorae, carried out simultaneously by XMM–Newton , the Hubble Space Telescope (HST), and the Hisaki satellite in 2019 September. HST images captured dawn storms and injection events in the far-ultraviolet aurora several times during the observation period. Magnetic reconnection occurring in the middle magnetosphere caused by internal drivers is thought to start the production of those features. The field lines then dipolarize, which injects hot magnetospheric plasma from the reconnection site to enter the inner magnetosphere. Hisaki observed an impulsive brightening in the dawnside Io plasma torus (IPT) during the final appearance of the dawn storms and injection events, which is evidence that a large-scale plasma injection penetrated the central IPT between 6 and 9 R J (Jupiter radii). The extreme ultraviolet aurora brightened and XMM–Newton detected an increase in the hard X-ray aurora count rate, suggesting an increase in electron precipitation. The dawn storms and injections did not change the brightness of the soft X-ray aurora and they did not 'switch-on' its commonly observed quasi-periodic pulsations. Spectral analysis of the X-ray aurora suggests that the precipitating ions responsible for the soft X-ray aurora were iogenic and that a power-law continuum was needed to fit the hard X-ray part of the spectra. The spectra coincident with the dawn storms and injections required two power-law continua to get good fits. [ABSTRACT FROM AUTHOR]

Published
2021
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47. Chandra Observations of Jupiter's X‐ray Auroral Emission During Juno Apojove 2017

Author

Weigt, D. M., primary, Jackman, C. M., additional, Dunn, W. R., additional, Gladstone, G. R., additional, Vogt, M. F., additional, Wibisono, A. D., additional, Branduardi‐Raymont, G., additional, Altamirano, D., additional, Allegrini, F., additional, Ebert, R. W., additional, Valek, P. W., additional, Thomsen, M. F., additional, Clark, G., additional, and Kraft, R. P., additional

Published
2020
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49. On the Relation Between Jovian Aurorae and the Loading/Unloading of the Magnetic Flux: Simultaneous Measurements From Juno, Hubble Space Telescope, and Hisaki

Author

Yao, Z. H., primary, Grodent, D., additional, Kurth, W. S., additional, Clark, G., additional, Mauk, B. H., additional, Kimura, T., additional, Bonfond, B., additional, Ye, S.‐Y., additional, Lui, A. T., additional, Radioti, A., additional, Palmaerts, B., additional, Dunn, W. R., additional, Ray, L. C., additional, Bagenal, F., additional, Badman, S. V., additional, Rae, I. J., additional, Guo, R. L., additional, Pu, Z. Y., additional, Gérard, J.‐C., additional, Yoshioka, K., additional, Nichols, J. D., additional, Bolton, S. J., additional, and Levin, S. M., additional

Published
2019
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