Search Publications
Iron Kα echoes from the circumnuclear disk orbiting Sgr A⋆
Haardt, Francesco; Ponti, Gabriele; Stel, Giovanni
Context. Molecular clouds in the Galactic center (GC) reprocess radiation from past outbursts of nearby high-energy sources, generating a bright Fe Kα fluorescence at 6.4 keV. The closest clouds to the GC are only ≃1.5 pc from Sgr A⋆, forming a torus-like structure known as the circumnuclear disk (CND). The study of fluorescence emissio…
Linear and nonlinear kinetic Alfvén waves at Venus
Fichtner, H.; Lazar, M.; Moslem, W. M. +1 more
Space observations show that Venus suffers significant atmospheric erosion caused by the solar wind forcing. Plasma acceleration is found to be one of the main mechanisms contributing to the global atmospheric loss at Venus through its magnetotail. Motivated by these observations, we propose that kinetic Alfvén waves (KAW) may be a possible candid…
[C I] and [C II] emission in the circumstellar envelope of IRC +10216. I. Observational data and NLTE modelling of the [C I] emission
Menten, K. M.; Wyrowski, F.; Wiesemeyer, H. +1 more
Context. The envelopes of evolved late-type stars on the asymptotic giant branch are characterised by a complex chemistry that is close to thermochemical equilibrium near the stellar surface; however, in the outer envelope, it is dominated by radical reactions, assisted by a photo-chemistry driven by the interstellar radiation field.
Aims: Th…
Magnetic holes between Earth and Mercury: BepiColombo cruise phase
Glassmeier, K. -H.; Karlsson, T.; Nakamura, R. +14 more
Context. Magnetic holes are ubiquitous structures in the solar wind and in planetary magnetosheaths. They consist of a strong depression of the magnetic field strength, most likely in pressure balance through increased plasma pressure, which is convected with the plasma flow. These structures are created through a plasma temperature anisotropy, wh…
Multiwavelength and astrometric study of the DBS 89−90−91 embedded clusters region
Orellana, R. B.; Suad, L. A.; Corti, M. A. +1 more
Aims: Our main aims are to improve our understanding of the main properties of the radio source G316.8−0.1 (IRAS 14416−5937) where the DBS 89−90−91 embedded clusters are located, to identify the stellar population present in this region, and to study the interaction of these stars with the interstellar medium.
Methods: We analyzed some c…
Origin of the diffuse 4-8 keV emission in M 82
Gilli, R.; Iwasawa, K.; Gandhi, P. +2 more
We present the first spatially resolved, X-ray spectroscopic study of the 4−8 keV diffuse emission found in the central part of the nearby starburst galaxy M 82 on a few arcsecond scales. The new details that we see allow a number of important conclusions to be drawn on the nature of the hot gas and its origin as well as feedback on the interstell…
Rotational radial shear in the low solar photosphere
Corbard, T.; Faurobert, M.; Gelly, B. +2 more
Context. Radial differential rotation is an important physical ingredient in stellar dynamo theory. In the case of the Sun, heliosismology techniques have revealed the existence of a near-surface shear layer covering 15-20% of the upper convection zone. It was recently shown that the rotation velocity gradient is not uniform in this layer and that…
RXCJ1111.6+4050 galaxy cluster: Observational evidence of a transitional fossil group
Böhringer, H.; Chon, G.; Barrena, R. +2 more
We present a detailed kinematical and dynamical study of the galaxy cluster RXCJ1111.6+4050 (RXCJ1111), at z = 0.0756 using 104 new spectroscopic redshifts of galaxies observed at the Telescopio Nazionale Galileo and SDSS DR16 public archive. Our analysis is performed in a multiwavelength context in order to study and compare mainly optical and X-…
Coronal voids and their magnetic nature
Schmidt, W.; Woch, J.; Barczynski, K. +68 more
Context. Extreme ultraviolet (EUV) observations of the quiet solar atmosphere reveal extended regions of weak emission compared to the ambient quiescent corona. The magnetic nature of these coronal features is not well understood.
Aims: We study the magnetic properties of the weakly emitting extended regions, which we name coronal voids. In p…
No random transits in CHEOPS observations of HD 139139
Guterman, P.; Alonso, R.; Deleuil, M. +77 more
Context. The star HD 139139 (a.k.a. `the Random Transiter') is a star that exhibited enigmatic transit-like features with no apparent periodicity in K2 data. The shallow depth of the events (~200 ppm - equivalent to transiting objects with radii of ~1.5 R⊕ in front of a Sun-like star) and their non-periodicity constitute a challenge for…