Search Publications
Cluster Multi-Probing of the Aurora During Two Decades
Lindqvist, Per-Arne; Marklund, Göran
The Cluster spacecraft, launched in the year 2000, were pioneers using multi-point measurements to explore the dynamic space plasma environment of Earth. This capability offered a new, powerful approach to study in situ fundamental space plasma processes of the solar-terrestrial interaction. Although not a major science objective of the mission, t…
Does Phobos Reflect Solar Wind Protons? Mars Express Special Flyby Operations With and Without the Presence of Phobos
Barabash, Stas; Holmström, Mats; Futaana, Yoshifumi +1 more
We characterize the solar wind proton reflection (backscattering) from Phobos using a series of Mars Express operations. The plasma data obtained during the Phobos flyby of Mars Express in January 2016 showed a non-solar wind signal possibly reflected from the Phobos surface. Similar signatures were previously reported during an earlier Phobos fly…
Fine structure in the luminosity function in young stellar populations with Gaia DR2
Brown, Anthony G. A.; Kaper, Lex; de Bruijne, Jos H. J. +2 more
Context. A pioneering study showed that the fine structure in the luminosity function (LF) of young star clusters contains information about the evolutionary stage (age) and composition of the stellar population. The notable features include the H-peak, which is the result of the onset of hydrogen burning turning pre-main sequence stars into main …
HADES RV programme with HARPS-N at TNG. XIV. A candidate super-Earth orbiting the M-dwarf GJ 9689 with a period close to half the stellar rotation period
Rebolo, R.; Ribas, I.; Morales, J. C. +27 more
Context. It is now well-established that small, rocky planets are common around low-mass stars. However, the detection of such planets is challenged by the short-term activity of host stars.
Aims: The HARPS-N red Dwarf Exoplanet Survey programme is a long-term project at the Telescopio Nazionale Galileo aimed at monitoring nearby, early-type,…
Spectroscopic Observations of Obscured Populations in the Inner Galaxy: 2MASS-GC02, Terzan 4, and the 200 km s-1 stellar peak
Kunder, Andrea; Debattista, Victor P.; Koch-Hansen, Andreas J. +2 more
The interpretation of potentially new and already known stellar structures located at low latitudes is hindered by the presence of dense gas and dust, as observations toward these sight lines are limited. We have identified Apache Point Observatory Galaxy Evolution Experiment (APOGEE) stars belonging to the low-latitude globular clusters 2MASS-GC0…
First detection of VHE gamma-ray emission from TXS 1515-273, study of its X-ray variability and spectral energy distribution
Maraschi, L.; Covino, S.; Antonelli, L. A. +196 more
We report here on the first multiwavelength (MWL) campaign on the blazar TXS 1515-273, undertaken in 2019 and extending from radio to very-high-energy gamma-rays (VHE). Up until now, this blazar had not been the subject of any detailed MWL observations. It has a rather hard photon index at GeV energies and was considered a candidate extreme high-s…
Thermodynamic evolution of a sigmoidal active region with associated flares
Mulay, Sargam M.; Tripathi, Durgesh; Mason, Helen
Active regions often show S-shaped structures in the corona called sigmoids. These are highly sheared and twisted loops formed along the polarity inversion line. They are considered to be one of the best pre-eruption signatures for CMEs. Here, we investigate the thermodynamic evolution of an on-disc sigmoid observed during 2015 December 24-28. For…
Quasi-periodic ripples in the heliosphere from 1 to 40 AU
Birch, M. J.; Hargreaves, J. K.
This study extends the investigation of the ripples in the solar wind and the interplanetary magnetic field at L1 reported by Birch and Hargreaves (2020) to cover heliospheric distances from 1 to 40 AU, using data from the Voyager 2, Ulysses, Juno, Cassini, Themis and Apollo-12 spacecraft. The ripples were extracted from the source data using a ba…
Testing and Validating Two Morphological Flare Predictors by Logistic Regression Machine Learning
Erdélyi, R.; Korsós, M. B.; Morgan, H. +1 more
Whilst the most dynamic solar active regions (ARs) are known to flare frequently, predicting the occurrence of individual flares and their magnitude, is very much a developing field with strong potentials for machine learning applications. The present work is based on a method which is developed to define numerical measures of the mixed states of …
Molecular Gas in a Gravitationally Lensed Galaxy Group at z = 2.9
Richard, Johan; Brammer, Gabriel; Whitaker, Katherine E. +5 more
Most molecular gas studies of z > 2.5 galaxies are of intrinsically bright objects, despite the galaxy population being primarily normal galaxies with less extreme star formation rates. Observations of normal galaxies at high redshift provide a more representative view of galaxy evolution and star formation, but such observations are challengin…