Search Publications
Superluminous X-Rays from a Superluminous Supernova
Read, A. M.; Wheatley, P. J.; Levan, A. J. +2 more
The discovery of a population of superluminous supernovae (SLSNe), with peak luminosities a factor of ~100 brighter than normal supernovae (SNe; typically SLSNe have MV < -21), has shown an unexpected diversity in core-collapse SN properties. Numerous models have been postulated for the nature of these events, including a strong inte…
Ensemble Modeling of CME Propagation
Arge, C. N.; Henney, C. J.; Pizzo, V. +4 more
The current progression toward solar maximum provides a unique opportunity to use multi-perspective spacecraft observations together with numerical models to better understand the evolution and propagation of coronal mass ejections (CMEs). Of interest to both the scientific and forecasting communities are the Earth-directed "halo" CMEs, since they…
Plasma Composition in a Sigmoidal Anemone Active Region
van Driel-Gesztelyi, L.; Démoulin, P.; Baker, D. +4 more
Using spectra obtained by the EUV Imaging Spectrometer (EIS) instrument onboard Hinode, we present a detailed spatially resolved abundance map of an active region (AR)-coronal hole (CH) complex that covers an area of 359'' × 485''. The abundance map provides first ionization potential (FIP) bias levels in various coronal structures within the larg…
Herschel's "Cold Debris Disks": Background Galaxies or Quiescent Rims of Planetary Systems?
Krivov, A. V.; Eiroa, C.; Löhne, T. +24 more
Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around ~100 µm or shorter. However, 6 out of 31 excess sources studied in the Herschel Open Time Key Programme, DUNES, have been seen to show significant—and in some cases extended—excess emission at 160 µm, which is larger than the 100 µ…
A tidal flare candidate in Abell 1795
Ho, L. C.; Maksym, W. P.; Ulmer, M. P. +2 more
As part of our ongoing archival X-ray survey of galaxy clusters for tidal flares, we present evidence of an X-ray transient source within 1 arcmin of the core of Abell 1795. The extreme variability (a factor of nearly 50), luminosity (>2 × 1042 erg s-1), long duration (>5 yr) and supersoft X-ray spectrum (<0.1 keV) a…
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…
Basic parameters and properties of the rapidly rotating magnetic helium-strong B star HR 7355
Štefl, S.; Baade, D.; Kochukhov, O. +4 more
The spectral and magnetic properties and variability of the B2Vnp emission-line magnetosphere star HR 7355 were analysed. The object rotates at almost 90 per cent of the critical value, meaning it is a magnetic star for which oblateness and gravity darkening effects cannot be ignored any longer. A detailed modelling of the photospheric parameters …
Parametric validations of analytical lifetime estimates for radiation belt electron diffusion by whistler waves
Artemyev, A. V.; Agapitov, O. V.; Krasnoselskikh, V. V. +1 more
The lifetimes of electrons trapped in Earth's radiation belts can be calculated from quasi-linear pitch-angle diffusion by whistler-mode waves, provided that their frequency spectrum is broad enough and/or their average amplitude is not too large. Extensive comparisons between improved analytical lifetime estimates and full numerical calculations …
Coronal Hole Influence on the Observed Structure of Interplanetary CMEs
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
We report on the coronal hole (CH) influence on the 54 magnetic cloud (MC) and non-MC associated coronal mass ejections (CMEs) selected for studies during the Coordinated Data Analysis Workshops (CDAWs) focusing on the question if all CMEs are flux ropes. All selected CMEs originated from source regions located between longitudes 15E - 15W. Xie, G…
Sensitive Search for Radio Variables and Transients in the Extended Chandra Deep Field South
Frail, D. A.; Kulkarni, S. R.; Horesh, A. +3 more
We report on an analysis of the Extended Chandra Deep Field South (E-CDFS) region using archival data from the Very Large Array, with the goal of studying radio variability and transients at the sub-milliJansky level. The 49 epochs of E-CDFS observations at 1.4 GHz sample timescales from 1 day to 3 months. We find that only a fraction (1%) of unre…