Search Publications
Synchrotron intensity gradient revealing magnetic fields in galaxy clusters
Brunetti, G.; Bonafede, A.; Stuardi, C. +3 more
Magnetic fields and their dynamical interplay with matter in galaxy clusters contribute to the physical properties and evolution of the intracluster medium. However, the current understanding of the origin and properties of cluster magnetic fields is still limited by observational challenges. In this article, we map the magnetic fields at hundreds…
Global-scale magnetosphere convection driven by dayside magnetic reconnection
Branduardi-Raymont, Graziella; Wang, Chi; Dai, Lei +8 more
Plasma convection on a global scale is a fundamental feature of planetary magnetosphere. The Dungey cycle explains that steady-state convection within the closed part of the magnetosphere relies on magnetic reconnection in the nightside magnetospheric tail. Nevertheless, time-dependent models of the Dungey cycle suggest an alternative scenario whe…
Cassini spacecraft reveals global energy imbalance of Saturn
West, Robert A.; Nixon, Conor A.; Guillot, Tristan +16 more
The global energy budget is pivotal to understanding planetary evolution and climate behaviors. Assessing the energy budget of giant planets, particularly those with large seasonal cycles, however, remains a challenge without long-term observations. Evolution models of Saturn cannot explain its estimated Bond albedo and internal heat flux, mainly …
A binary system in the S cluster close to the supermassive black hole Sagittarius A*
Eckart, Andreas; Zajaček, Michal; Labadie, Lucas +4 more
High-velocity stars and peculiar G objects orbit the central supermassive black hole (SMBH) Sagittarius A* (Sgr A*). Together, the G objects and high-velocity stars constitute the S cluster. In contrast with theoretical predictions, no binary system near Sgr A* has been identified. Here, we report the detection of a spectroscopic binary system in …
Surface properties of the seas of Titan as revealed by Cassini mission bistatic radar experiments
Soderblom, Jason M.; Lorenz, Ralph D.; Tortora, Paolo +9 more
Saturn's moon Titan was explored by the Cassini spacecraft from 2004 to 2017. While Cassini revealed a lot about this Earth-like world, its radar observations could only provide limited information about Titan's liquid hydrocarbons seas Kraken, Ligeia and Punga Mare. Here, we show the results of the analysis of the Cassini mission bistatic radar e…
Recent collisional history of (65803) Didymos
Lucchetti, Alice; Pajola, Maurizio; Michel, Patrick +7 more
The Double Asteroid Redirection Test (DART, NASA) spacecraft revealed that the primary of the (65803) Didymos near-Earth asteroid (NEA) binary system is not exactly the expected spinning top shape observed for other km-size asteroids. Ground based radar observations predicted that such shape was compatible with the uncertainty along the direction …
Long-term Doppler imaging of the star XX Trianguli indicates chaotic non-periodic dynamo
Strassmeier, K. G.; Weber, M.; Granzer, T. +1 more
Sunspots are the most well-known manifestations of solar magnetic fields and exhibit a range of phenomena related to the interior dynamo. Starspots are the direct analogs of sunspots on other stars but with the big observational restriction that we usually cannot resolve other star's surfaces. In this paper we employ an indirect surface imaging te…
Unexpected major geomagnetic storm caused by faint eruption of a solar trans-equatorial flux rope
Zhang, Qingmin; Ji, Haisheng; Su, Yingna +1 more
Some geomagnetic storms' solar origins are ambiguous, making them hard to predict. On March 23, 2023, a severe geomagnetic storm occurred, however, forecasts based on remote-sensing observations failed to predict it. Here, we show clear evidence that this storm originates from the eruption of a trans-equatorial, longitudinal and low-density magnet…