Search Publications
Evidence for Water in the Rocky Debris of a Disrupted Extrasolar Minor Planet
Gänsicke, B. T.; Koester, D.; Farihi, J.
The existence of water in extrasolar planetary systems is of great interest because it constrains the potential for habitable planets and life. We have identified a circumstellar disk that resulted from the destruction of a water-rich and rocky extrasolar minor planet. The parent body formed and evolved around a star somewhat more massive than the…
Detection of a Noble Gas Molecular Ion, 36ArH+, in the Crab Nebula
Ivison, R. J.; Olofsson, G.; Krause, O. +9 more
Noble gas molecules have not hitherto been detected in space. From spectra obtained with the Herschel Space Observatory, we report the detection of emission in the 617.5- and 1234.6-gigahertz J = 1-0 and 2-1 rotational lines of 36ArH+ at several positions in the Crab Nebula, a supernova remnant known to contain both molecular…
Synchronous X-ray and Radio Mode Switches: A Rapid Global Transformation of the Pulsar Magnetosphere
de Plaa, J.; McKean, J. P.; Eislöffel, J. +86 more
Pulsars emit from low-frequency radio waves up to high-energy gamma-rays, generated anywhere from the stellar surface out to the edge of the magnetosphere. Detecting correlated mode changes across the electromagnetic spectrum is therefore key to understanding the physical relationship among the emission sites. Through simultaneous observations, we…
Decades-Long Changes of the Interstellar Wind Through Our Solar System
McComas, D. J.; Frisch, P. C.; Schwadron, N. A. +8 more
The journey of the Sun through the dynamically active local interstellar medium creates an evolving heliosphere environment. This motion drives a wind of interstellar material through the heliosphere that has been measured with Earth-orbiting and interplanetary spacecraft for 40 years. Recent results obtained by NASA's Interstellar Boundary Explor…
An Integral View of Fast Shocks Around Supernova 1006
Hughes, John P.; van de Ven, Glenn; Raymond, John C. +5 more
Supernova remnants are among the most spectacular examples of astrophysical pistons in our cosmic neighborhood. The gas expelled by the supernova explosion is launched with velocities ∼1000 kilometers per second into the ambient, tenuous interstellar medium, producing shocks that excite hydrogen lines. We have used an optical integral-field spectr…
Linear Structures in the Core of the Coma Cluster of Galaxies
Simionescu, A.; Churazov, E.; Fabian, A. C. +4 more
The hot x-ray-emitting plasma in galaxy clusters is predicted to have turbulent motion, which can contribute around 10% of the cluster’s central energy density. We report deep Chandra X-ray Observatory observations of the Coma cluster core, showing the presence of quasi-linear high-density arms spanning 150 kiloparsecs, consisting of low-entropy m…
Observations of Ejecta Clouds Produced by Impacts onto Saturn’s Rings
Porco, Carolyn C.; Hedman, Matthew M.; Burns, Joseph A. +8 more
We report observations of dusty clouds in Saturn’s rings, which we interpret as resulting from impacts onto the rings that occurred between 1 and 50 hours before the clouds were observed. The largest of these clouds was observed twice; its brightness and cant angle evolved in a manner consistent with this hypothesis. Several arguments suggest that…
More Support for an Ocean in Enceladus
Kerr, Richard A.