Search Publications
Solar Energetic Particle Events in the 23rd Solar Cycle: Interplanetary Magnetic Field Configuration and Statistical Relationship with Flares and CMEs
Klein, K. -L.; Malandraki, O.; Miteva, R. +1 more
We study the influence of the large-scale interplanetary magnetic field configuration on the solar energetic particles (SEPs) as detected at different satellites near Earth and on the correlation of their peak intensities with the parent solar activity. We selected SEP events associated with X- and M-class flares at western longitudes, in order to…
Auroral counterpart of magnetic field dipolarizations in Saturn's tail
Dougherty, Michele K.; Cowley, Stanley W. H.; Bunce, Emma J. +6 more
Following magnetic reconnection in a planetary magnetotail, newly closed field lines can be rapidly accelerated back towards the planet, becoming "dipolarized" in the process. At Saturn, dipolarizations are initially identified in magnetometer data by looking for a southward turning of the magnetic field, indicating the transition from a radially …
Blind Extraction of an Exoplanetary Spectrum through Independent Component Analysis
Waldmann, I. P.; Tinetti, G.; Yurchenko, S. N. +3 more
Blind-source separation techniques are used to extract the transmission spectrum of the hot-Jupiter HD189733b recorded by the Hubble/NICMOS instrument. Such a "blind" analysis of the data is based on the concept of independent component analysis. The detrending of Hubble/NICMOS data using the sole assumption that nongaussian systematic noise is st…
GOODS-Herschel: Separating High-redshift Active Galactic Nuclei and Star-forming Galaxies Using Infrared Color Diagnostics
Dickinson, Mark; Kirkpatrick, Allison; Valtchanov, Ivan +17 more
We have compiled a large sample of 151 high-redshift (z = 0.5-4) galaxies selected at 24 µm (S 24 > 100 µJy) in the GOODS-N and ECDFS fields for which we have deep Spitzer IRS spectroscopy, allowing us to decompose the mid-infrared spectrum into contributions from star formation and activity in the galactic nuclei. In add…
The Millennium Run Observatory: first light
White, S. D. M.; Bertin, E.; Overzier, R. +5 more
Simulations of galaxy evolution aim to capture our current understanding as well as to make predictions for testing by future experiments. Simulations and observations are often compared in an indirect fashion: physical quantities are estimated from the observational data and compared to models. However, many applications can benefit from a more d…
The dusty aftermath of the V1309 Sco binary merger.
Udalski, A.; Pietrukowicz, P.; Poleski, R. +9 more
We present mid-IR photometry and spectra of the merged binary V1309 Sco taken between 18 and 23 months after outburst. Strong mid-IR emission and a solid-state absorption feature indicate the presence of a significant amount of dust in the circumstellar environment. The absence of detectable mid-IR emission before the outburst suggests that this d…
The Optical Counterpart to the X-Ray Transient IGR J1824-24525 in the Globular Cluster M28
Dalessandro, E.; Beccari, G.; Ferraro, F. R. +2 more
We report on the identification of the optical counterpart to the recently detected INTEGRAL transient IGR J1824-24525 in the Galactic globular cluster M28. From analysis of a multi-epoch Hubble Space Telescope data set, we have identified a strongly variable star positionally coincident with the radio and Chandra X-ray sources associated with the…
Decay-phase Cooling and Inferred Heating of M- and X-class Solar Flares
Ryan, Daniel F.; Chamberlin, Phillip C.; Milligan, Ryan O. +1 more
In this paper, the cooling of 72 M- and X-class flares is examined using GOES/XRS and SDO/EVE. The observed cooling rates are quantified and the observed total cooling times are compared with the predictions of an analytical zero-dimensional hydrodynamic model. We find that the model does not fit the observations well, but does provide a well-defi…
Observations of D/H ratios in H2O, HCl, and HF on Venus and new DCl and DF line strengths
Li, G.; Belyaev, D. A.; Krasnopolsky, V. A. +2 more
Intensities of the spectral lines in the fundamental bands of D35Cl and DF were calculated using the semi-empirical dipole moment functions derived from the most accurate and precise measurements of intensities of the ro-vibrational lines of H35Cl and HF. Values obtained in this way for the deuterated species are superior to …
Methods for Characterising Microphysical Processes in Plasmas
Alexandrova, O.; Dudok de Wit, T.; Sorriso-Valvo, L. +2 more
Advanced spectral and statistical data analysis techniques have greatly contributed to shaping our understanding of microphysical processes in plasmas. We review some of the main techniques that allow for characterising fluctuation phenomena in geospace and in laboratory plasma observations. Special emphasis is given to the commonalities between d…