Search Publications
Wave activity inside hot flow anomaly cavities
Dandouras, I.; Lucek, E. A.; Tjulin, A.
Low-frequency wave properties inside two hot flow anomalies (HFAs) at different stages of evolution are, for the first time, studied applying the k-filtering technique on multipoint measurements from the Cluster satellites. The observed wave activity in an HFA cavity in an early stage of its evolution was interpreted as the combination of inherent…
Multiresolution Analysis of Active Region Magnetic Structure and its Correlation with the Mount Wilson Classification and Flaring Activity
Gallagher, P. T.; Young, C. A.; McAteer, R. T. J. +3 more
Two different multiresolution analyses are used to decompose the structure of active-region magnetic flux into concentrations of different size scales. Lines separating these opposite polarity regions of flux at each size scale are found. These lines are used as a mask on a map of the magnetic field gradient to sample the local gradient between op…
High-Velocity Interstellar Bullets in IRAS 05506+2414: A Very Young Protostar
Sahai, Raghvendra; Sánchez Contreras, Carmen; Morris, Mark +2 more
We have made a serendipitous discovery of an enigmatic outflow source, IRAS 05506+2414 (hereafter IRAS 05506), as part of a multiwavelength survey of pre-planetary nebulae (PPNs). The HST optical and near-infrared images show a bright compact central source with a jetlike extension, and a fanlike spray of high-velocity (with radial velocities up t…
The XMM-Newton survey of the ELAIS-S1 field. II. Optical identifications and multiwavelength catalogue of X-ray sources
Berta, S.; Pozzi, F.; Fiore, F. +13 more
We present the optical identifications and a multi-band catalogue of a sample of 478 X-ray sources detected in the XMM-Newton and Chandra surveys of the central 0.6 deg2 of the ELAIS-S1 field. The most likely optical/infrared counterpart of each X-ray source was identified using the chance coincidence probability in the R and IRAC 3.6 &…
A C-level flare observed in an arch filament system: reconnection between pre-existing and emerging field lines?
Romano, P.; Spadaro, D.; Contarino, L. +3 more
Context: Observations show that solar flares are often caused by the emergence of new magnetic flux from subphotospheric layers and by the interaction of the rising field lines with the ambient magnetic field. In this framework, recent theoretical models of magnetic flux emergence have investigated the effectiveness of magnetic reconnection as a f…
Asymmetry of plasma fluxes at Mars. ASPERA-3 observations and hybrid simulations
Barabash, S.; Lundin, R.; Winningham, J. D. +6 more
The asymmetry of fluxes of solar wind and planetary ions is studied by using the ASPERA-3 observations onboard the Mars Express spacecraft in February 2004 to March 2006. Due to the small scale of the Martian magnetosphere and its induced origin, the flow pattern near Mars is sensitive to the directions of the interplanetary magnetic and electric …
Shear driven waves in the induced magnetosphere of Mars
Fedorov, A.; Barabash, S.; Lundin, R. +12 more
We present measurements of oscillations in the electron density, ion density and ion velocity in the induced magnetosphere of Mars. The fundamental frequency of the oscillations is a few millihertz, but higher harmonics are present in the spectrum. The oscillations are observed in a region where there is a velocity shear in the plasma flow. The fu…
A limit on the number density of bright z ~ 7 galaxies
Lehnert, Matthew D.; Stanway, Elizabeth R.; Bremer, Malcolm N. +2 more
We present a survey of bright optical dropout sources in two deep, multiwavelength surveys comprising 11 widely separated fields, aimed at constraining the galaxy luminosity function at z ~ 7 for sources at 5-10L*(z = 6). Our combined survey area is 225arcmin2 to a depth of JAB = 24.2 (3σ) and 135arcmin2 to J = 25.…
X-ray observations of the Large Magellanic Cloud pulsar PSR B0540-69 and its pulsar wind nebula
de Rosa, A.; Bassani, L.; Dean, A. J. +3 more
PSR B0540-69 is a young pulsar in the Large Magellanic Cloud that has similar properties with respect to the Crab Pulsar, and is embedded in a pulsar wind nebula (PWN). We have analysed the complete archival Rossi X-Ray Timing Explorer (RXTE) data set of observations of this source, together with new Swift/XRT (X-Ray Telescope) and International G…
HE 0515-4414: an unusual sub-damped Ly α system revisited
Reimers, D.; Baade, R.; Quast, R.
Aims:We examine the ionization, abundances, and differential dust depletion of metals, the kinematic structure, and the physical conditions in the molecular hydrogen-bearing sub-damped Ly α system toward HE 0515-4414.
Methods: We used the STIS and VLT UVES spectrographs to obtain high-resolution recordings of the damped Ly α profile and numero…