Listed are all scientific papers resulting from an ISSI activity written or co-authored by ISSI Team members, Working Group members, Workshop participants, visitors or staff members.
The nuclear gamma-ray (γ-ray) lines in the MeV range of the electromagnetic spectrum hold a vast variety of astrophysical, particle-physical, and fundamental physical information that is otherwise extreme difficult to access. MeV γ-ray line observations provide the most direct evidence for ongoing nucleosynthesis in galaxies by measuring freshly produced radioactive isotopes from massive stars, supernovae (SNe), classical novae (CNe), or binary neutron star mergers (BNSMs).
We present JWST NIRSpec and NIRCam observations of 457P/Lemmon-PANSTARRS, a main-belt comet that displayed activity around its 2020 perihelion and that was observed to regain activity during its 2024 perihelion by a ground-based observing campaign. The previous successful measurements of water production from two main-belt comets by the JWST NIRSpec instrument confirmed the hypothesis that H2O reservoirs are responsible for activity in dynamically stable main-belt comets.
The Lower Thermosphere–Ionosphere (LTI) is the interface region between the Earth’s atmosphere and space. It is modulated by the energy and momentum deposition from the magnetosphere above and by the impacting waves from the lower atmosphere. The LTI region is defined by the co-existence and interaction of neutral and ionized species within the region’s electric and magnetic fields.
This study aims to improve the uncertainty estimates of soil moisture datasets produced by merging various satellite products via inverse-variance weighting. In this scheme, the weight of each sensor depends on its specific uncertainty derived from Triple Collocation Analysis (TCA). However, the TCA-derived uncertainties are themselves uncertain due to finite sample sizes, introducing a second-order uncertainty we denote the ‘uncertainty of the uncertainty’.
Despite early theoretical expectations that large-scale, massive outflows would be triggered by accretion onto black holes and neutron stars, their presence was not firmly established until the 2000s. Since then, these accretion disc winds have been recognised as a common, perhaps ubiquitous, feature of accretion discs in X-ray binaries.
Solar–terrestrial physics, the science of interactions between the Sun and the Earth’s environment, is increasingly envisioned as a complex system consisting of regions of very different nature but strongly coupled to each other via multiple physical processes. Over time, a tremendous amount of observational data have been collected on the various solar–terrestrial physics subsystems: the Sun, the solar wind, Earth’s magnetosphere, ionosphere, and neutral atmosphere.
Ion-driven plasma instability thresholds, derived from linear theory, constrain the distribution of solar observations in parameter space, defining boundaries of stable plasma parameters. Excursions beyond these thresholds result in the emission of energy, transferred from particles to coherent electromagnetic waves, acting to adjust the system toward a more stable configuration.
Using deep JWST/NIRSpec spectra from the Blue Jay survey, we performed the first systematic investigation of neutral gas content in massive galaxies at Cosmic Noon based on the Ca II H, K absorption lines. We analyzed a sample of nine galaxies at 1.8 < z < 2.8 with log M*/M⊙ > 10.6, for which we detected neutral gas absorption both in Ca II and in Na I.
The heliospheric current sheet (HCS) is an important large-scale structure of the heliosphere, and, for the first time, the Parker Solar Probe (PSP) mission enables us to study its properties statistically, close to the Sun.
Potential field source surface (PFSS) models are widely used to study the solar corona and form the basis for solar wind forecasting, yet they often fail to reproduce observed properties of coronal holes. We analyze 702 observed coronal holes between 2010 and 2019 and compute corresponding PFSS magnetic field extrapolations to examine their magnetic topology and loop statistics, comparing them with quiet-Sun regions.
