Search Publications
Iron-rich Metal-poor Stars and the Astrophysics of Thermonuclear Events Observationally Classified as Type Ia Supernovae. I. Establishing the Connection
Casey, Andrew R.; Reggiani, Henrique; Schlaufman, Kevin C.
The progenitor systems and explosion mechanisms responsible for the thermonuclear events observationally classified as Type Ia supernovae are uncertain and difficult to uniquely constrain using traditional observations of Type Ia supernova host galaxies, progenitors, light curves, and remnants. For the subset of thermonuclear events that are proli…
Hadronic Processes at Work in 5BZB J0630‑2406
Marchesi, Stefano; Fichet de Clairfontaine, Gaëtan; Buson, Sara +6 more
Recent observations are shedding light on the important role that active galactic nuclei play in the production of high-energy neutrinos. In this study, we focus on one object, 5BZB J0630‑2406, which is among the blazars recently proposed as associated with neutrino emission during the first 7 yr of IceCube observations. Modeling the quasi-simulta…
Recurrent 3He-rich solar energetic particle injections observed by Solar Orbiter at ∼0.5 au
Rodriguez, L.; Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F. +8 more
We report Solar Orbiter observations of six recurrent solar energetic particle injections in 2022 March 3−6 at ∼0.5 au. All but one were associated with jets emanating from a plage near a large sunspot in active region 12 957. We saw large jets in injections with high 3He and Fe enrichments and minor jets in injections with no or lower …
A dynamical mass for GJ 463 b: A massive super-Jupiter companion beyond the snow line of a nearby M dwarf
Sozzetti, A.
We determined the full orbital architecture and true mass of the recently Doppler-detected long-period giant planet GJ 463 b using the HIPPARCOS-Gaia proper motion anomaly in combination with the available radial velocities, constraints from the knowledge of the spectroscopic orbital parameters, and supplementary information from a sensitivity ana…
Sub-mm/mm optical properties of real protoplanetary matter derived from Rosetta/MIRO observations of comet 67P
Blum, Jürgen; Gundlach, Bastian; Wolf, Sebastian +6 more
Optical properties are required for the correct understanding and modelling of protoplanetary and debris discs. By assuming that comets are the most pristine bodies in the Solar system, our goal is to derive optical constants of real protoplanetary material. We determine the complex index of refraction of the near-surface material of comet 67P/Chu…
An investigation of the '10 keV feature' in the spectra of accretion powered X-ray pulsars with NuSTAR
Paul, Biswajit; Rana, Vikram; Manikantan, Hemanth
Some of the accreting X-ray pulsars are reported to exhibit a peculiar spectral feature at ~10 keV, known as the '10 keV feature'. The feature has been characterized as either an emission line or an absorption line, and its origin is unknown. It has been found in multiple observations of the same source by different observatories, but not all the …
On the gamma-ray emission from the core of the Sagittarius dwarf galaxy
Linden, Tim; Pace, Andrew B.; Strigari, Louis E. +5 more
We use Fermi-LAT data to analyse the faint gamma-ray source located at the centre of the Sagittarius (Sgr) dwarf spheroidal galaxy. In the 4FGL-DR3 catalogue, this source is associated with the globular cluster, M54. We investigate the spectral energy distribution and spatial extension of this source, with the goal of testing two hypotheses: (1) t…
Constraints on the multiplicity of the most massive stars known: R136 a1, a2, a3, and c
Crowther, P. A.; Bostroem, K. A.; Sander, A. A. C. +5 more
Context. The upper stellar mass limit is a fundamental parameter for simulations of star formation, galactic chemical evolution, and stellar feedback. An empirical bound on this parameter is therefore highly valuable. The most massive stars known to date are R 136 a1, a2, a3, and c, with reported masses in excess of 150-200 M⊙ and initi…
BASS-XL: X-ray variability properties of unobscured active galactic nuclei
Kawamuro, Taiki; Ricci, Claudio; Bauer, Franz E. +15 more
We investigate the X-ray variability properties of Seyfert 1 Galaxies belonging to the BAT AGN Spectroscopic Survey (BASS). The sample includes 151 unobscured (NH < 1022 cm-2) AGNs observed with XMM-Newton for a total exposure time of ~27 ms, representing the deepest variability study done so far with high signa…
Clustering of magnetic reconnection exhausts in the solar wind: An automated detection study
Rouillard, Alexis P.; Phan, Tai D.; Louarn, Philippe +9 more
Context. Magnetic reconnection is a fundamental process in astrophysical plasmas that enables the dissipation of magnetic energy at kinetic scales. Detecting this process in situ is therefore key to furthering our understanding of energy conversion in space plasmas. However, reconnection jets typically scale from seconds to minutes in situ, and as…