Search Publications
Cold Ion Outflow Modulated by the Solar Wind Energy Input and Tilt of the Geomagnetic Dipole
Wei, Y.; Nilsson, H.; André, M. +7 more
The solar wind energy input into the Earth's magnetosphere-ionosphere system drives ionospheric outflow, which plays an important role in both the magnetospheric dynamics and evolution of the atmosphere. However, little is known about the cold ion outflow with energies lower than a few tens of eV, as the direct measurement of cold ions is difficul…
The Stickney Crater ejecta secondary impact crater spike on Phobos: Implications for the age of Stickney and the surface of Phobos
Head, James W.; Ramsley, Kenneth R.
A global and uniformly distributed spike of secondary impact craters on Phobos with diameters (D) <0.6 km and a portion of craters up to D 2 km were produced by Stickney Crater ejecta, including secondary craters within the surface area of Stickney Crater. The global exposure of Phobos to Stickney secondary impacts was facilitated by the desync…
The nova-like nebular optical spectrum of V404 Cygni at the beginning of the 2015 outburst decay
Gandhi, P.; Tomsick, J. A.; Rossi, A. +7 more
We report on FORS2 optical spectroscopy of the black hole X-ray binary V404 Cygni, performed at the very beginning of its 2015 outburst decay, complemented by quasi-simultaneous Swift X-ray and ultraviolet as well as Rapid Eye Mountain near-infrared observations. Its peculiar spectrum is dominated by a wealth of emission signatures of H I, He I, a…
Automated detection of coronal mass ejections in three-dimensions using multi-viewpoint observations
Morgan, H.; Hutton, J.
A new, automated method of detecting coronal mass ejections (CMEs) in three dimensions for the LASCO C2 and STEREO COR2 coronagraphs is presented. By triangulating isolated CME signal from the three coronagraphs over a sliding window of five hours, the most likely region through which CMEs pass at 5 R⊙ is identified. The centre and size…
Insights from Synthetic Star-forming Regions. I. Reliable Mock Observations from SPH Simulations
Dale, James E.; Robitaille, Thomas P.; Koepferl, Christine M. +1 more
Through synthetic observations of a hydrodynamical simulation of an evolving star-forming region, we assess how the choice of observational techniques affects the measurements of properties that trace star formation. Testing and calibrating observational measurements requires synthetic observations that are as realistic as possible. In this part o…
Influence of the crustal magnetic field on the Mars aurora electron flux and UV brightness
Gérard, J. -C.; Hubert, B.; Shematovich, V. I. +1 more
Observations with the SPICAM instrument on board Mars Express have shown the occasional presence of localized ultraviolet nightside emissions associated with enhanced energetic electron fluxes. These features generally occur in regions with significant radial crustal magnetic field. We use a Monte-Carlo electron transport model to investigate the …
Constraining dynamical neutrino mass generation with cosmological data
Koksbang, S. M.; Hannestad, S.
We study models in which neutrino masses are generated dynamically at cosmologically late times. Our study is purely phenomenological and parameterized in terms of three effective parameters characterizing the redshift of mass generation, the width of the transition region, and the present day neutrino mass. We also study the possibility that neut…
CSI 2264: Simultaneous optical and X-ray variability in pre-main sequence stars. I. Time resolved X-ray spectral analysis during optical dips and accretion bursts in stars with disks
Micela, G.; Stauffer, J.; Sciortino, S. +6 more
Context. Pre-main sequence stars are variable sources. The main mechanisms responsible for their variability are variable extinction, unsteady accretion, and rotational modulation of both hot and dark photospheric spots and X-ray-active regions. In stars with disks, this variability is related to the morphology of the inner circumstellar region (≤…
Bars as seen by Herschel and Sloan
Consolandi, Guido; Gavazzi, Giuseppe; Dotti, Massimo +2 more
We present an observational study of the effect of bars on the gas component and on the star formation properties of their host galaxies in a statistically significant sample of resolved objects, the Herschel Reference Sample. The analysis of optical and far-infrared images allows us to identify a clear spatial correlation between stellar bars and…
The X-ray continuum time-lags and intrinsic coherence in AGN
Papadakis, I. E.; Epitropakis, A.
We present the results from a systematic analysis of the X-ray continuum ('hard') time-lags and intrinsic coherence between the 2-4 keV and various energy bands in the 0.3-10 keV range, for 10 X-ray bright and highly variable active galactic nuclei (AGN). We used all available archival XMM-Newton data, and estimated the time-lags following Epitrop…