Search Publications
Multiwavelength constraints on the origin of a nearby repeating fast radio burst source in a globular cluster
Kaspi, Victoria M.; Smith, Kendrick M.; Güver, Tolga +26 more
The precise origins of fast radio bursts (FRBs) remain unknown. Multiwavelength observations of nearby FRB sources can provide important insights into the enigmatic FRB phenomenon. Here we present results from a sensitive, broadband X-ray and radio observational campaign of FRB 20200120E, the closest known extragalactic repeating FRB source (locat…
X-ray eruptions every 22 days from the nucleus of a nearby galaxy
Gendreau, Keith; van Velzen, Sjoert; Gezari, Suvi +15 more
Galactic nuclei showing recurrent phases of activity and quiescence have recently been discovered. Some have recurrence times as short as a few hours to a day and are known as quasi-periodic X-ray eruption (QPE) sources. Others have recurrence times as long as hundreds to a thousand days and are called repeating nuclear transients. Here we present…
Constraints on the dense matter equation of state from young and cold isolated neutron stars
Rea, N.; Marino, A.; Pons, J. A. +3 more
Neutron stars are the dense and highly magnetic relics of supernova explosions of massive stars. The quest to constrain the equation of state (EOS) of ultradense matter and thereby probe the behaviour of matter inside neutron stars is one of the core goals of modern physics and astrophysics. A promising method involves investigating the long-term …
X-ray detection of astrospheres around three main-sequence stars and their mass-loss rates
Güdel, M.; Koutroumpa, D.; Lisse, C. M. +3 more
Stellar winds of cool main-sequence stars are difficult to constrain observationally. One way to measure stellar mass-loss rates is to detect the soft X-ray emission from stellar astrospheres produced by charge exchange between heavy ions of the stellar wind and cold neutrals of the interstellar medium surrounding the stars. Here we report detecti…
The X-ray mysteries of neutron stars and white dwarfs
Rea, Nanda; Schartel, Norbert
These two types of compact objects share several similarities, despite their different compositions. A short workshop in Spain brought communities together to share understanding of dense matter under extreme conditions.
Magnetar spin-down glitch clearing the way for FRB-like bursts and a pulsed radio episode
Lin, L.; Kouveliotou, C.; Baring, M. G. +16 more
Magnetars are a special subset of the isolated neutron star family, with X-ray and radio emission mainly powered by the decay of their immense magnetic fields. Many attributes of magnetars remain poorly understood: spin-down glitches or the sudden reductions in the star's angular momentum, radio bursts reminiscent of extragalactic fast radio burst…
A 5.3-min-period pulsing white dwarf in a binary detected from radio to X-rays
Kepler, S. O.; Heywood, I.; Dhillon, V. S. +19 more
White dwarf stars are the most common stellar fossils. When in binaries, they make up the dominant form of compact object binary within the Galaxy and can offer insight into different aspects of binary formation and evolution. One of the most remarkable white dwarf binary systems identified to date is AR Scorpii (AR Sco). AR Sco is composed of an …
Vertical wind structure in an X-ray binary revealed by a precessing accretion disk
Fabian, A. C.; Reynolds, C. S.; Pinto, C. +11 more
The accretion of matter onto black holes and neutron stars often leads to the launching of outflows that can greatly affect the environments surrounding the compact object. An important means of studying these winds is through X-ray absorption line spectroscopy, which allows us to probe their properties along a single sightline, but usually provid…
A strangely light neutron star within a supernova remnant
Doroshenko, Victor; Santangelo, Andrea; Pühlhofer, Gerd +1 more
To constrain the equation of state of cold dense matter, astrophysical measurements are essential. These are mostly based on observations of neutron stars in the X-ray band, and, more recently, also on gravitational wave observations. Of particular interest are observations of unusually heavy or light neutron stars which extend the range of centra…
Signatures of strong magnetization and a metal-poor atmosphere for a Neptune-sized exoplanet
Mikal-Evans, Thomas; Sing, David K.; López-Morales, Mercedes +10 more
The magnetosphere of an exoplanet has yet to be unambiguously detected. Investigations of star-planet interaction and neutral atomic hydrogen absorption during transit to detect magnetic fields in hot Jupiters have been inconclusive, and interpretations of the transit absorption non-unique. In contrast, ionized species escaping a magnetized exopla…