Search Publications
Latitudinal Distribution of Dayside Magnetospheric Currents Based on Cluster Observations
Dunlop, Malcolm W.; Liu, Wenlong; Du, Yingshuai +2 more
Based on the curlometer method, we calculate the azimuthal component of the current density from nearly 19 years of Fluxgate Magnetometer (FGM) data of Cluster and investigate its latitudinal distribution in the dayside noon sector (09:00-15:00 magnetic local time, MLT). A crossing event in the noon meridian plane shows an unexpected eastward curr…
Long-term Variation of the Solar Polar Magnetic Fields at Different Latitudes
Hou, Yijun; Li, Ting; Yang, Shuhong +10 more
The polar magnetic fields of the Sun play an important role in governing solar activity and powering fast solar wind. However, because our view of the Sun is limited in the ecliptic plane, the polar regions remain largely uncharted. Using the high spatial resolution and polarimetric precision vector magnetograms observed by Hinode from 2012 to 202…
Extreme magnetic field modulus variability of the Bp star HD 57372
Ilyin, I.; Hubrig, S.; Järvinen, S. P. +2 more
Context. In chemically peculiar Ap/Bp stars with large-scale organised magnetic fields of simple centred dipole configuration, the ratio between the maximum and the minimum of the mean magnetic field modulus is on the order of 1.25. Values of two or more are observed only for very few Ap/Bp stars and are indicative of a very unusual magnetic field…
Longitudinal Extent of 3He-rich Solar Energetic Particle Events Near 1 au
Kouloumvakos, Athanasios; Wimmer-Schweingruber, Robert F.; Allen, Robert C. +3 more
Multispacecraft observations of 3He-rich solar energetic particle (SEP) events are scarce, but much needed in order to understand and properly constrain the source and transport of these remarkably enriched 3He SEP events. In this paper, we report 15 3He-rich SEP events that were detected by the Advanced Compositio…
The disk of the eruptive protostar V900 Mon. A MATISSE/VLTI and MUSE/VLT perspective
Lykou, F.; Ábrahám, P.; Chen, L. +8 more
Aims: In this work, we study the silicate dust content in the disk of one of the youngest eruptive stars, V900 Mon, at the highest angular resolution, probing down to the inner 10 au of said disk, and study the historical evolution of the system, traced in part by a newly discovered emission clump.
Methods: We performed high angular reso…
A multiwavelength study of the most distant gamma-ray detected BL Lacertae object 4FGL J1219.0+3653 (z = 3.59)
Domínguez, A.; Gallego, J.; Cardiel, N. +3 more
BL Lac objects are a class of jetted active galactic nuclei that do not exhibit or have weak emission lines in their optical spectra. Recently, the first γ-ray emitting BL Lac beyond
Dynamical traceback age of the Octans young stellar association
Miret-Roig, N.; Bouy, H.; Barrado, D. +2 more
Context. Octans is one of the most distant (d ∼ 150 pc) young stellar associations of the solar neighbourhood, and it has not yet been sufficiently explored. Its age is still poorly constrained in the literature and requires further investigation.
Aims: We take advantage of the state-of-the-art astrometry delivered by the third data release o…
Modeling the plasma composition of 67P/C-G at different heliocentric distances
Ahmed, Sana; Soni, Vikas
The Rosetta spacecraft accompanied the comet 67P/C-G for nearly 2 years, collecting valuable data on the neutral and ion composition of the coma. The Rosetta Plasma Consortium (RPC) provided continuous measurements of the in situ plasma density while ROSINA-COPS monitored the neutral composition. In this work, we aim to estimate the composition of…
Rapid Dimming Followed by a State Transition: A Study of the Highly Variable Nuclear Transient AT 2019avd over 1000+ Days
Gandhi, Poshak; Miller, Jon M.; Ji, Long +16 more
The tidal disruption of a star around a supermassive black hole (SMBH) offers a unique opportunity to study accretion onto an SMBH on a human timescale. We present results from our 1000+ days monitoring campaign of AT 2019avd, a nuclear transient with tidal-disruption-event-like properties, with NICER, Swift, and Chandra. Our primary finding is th…
No evidence for gamma-ray emission from the Sagittarius dwarf spheroidal galaxy
Calore, Francesca; Eckner, Christopher; Manconi, Silvia
More than a decade ago, the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope unveiled the existence of two gigantic gamma-ray lobes known as the Fermi bubbles. While their origin is still unknown, various studies identified intricate spectral and morphological structures within the bubbles. One peculiar region, the cocoon, has recen…