Search Publications
Plasma injection into a solar coronal loop
Peter, H.; Li, L. P.
Context. The details of the spectral profiles of extreme UV emission lines from solar active regions contain key information for investigating the structure, dynamics, and energetics of the solar upper atmosphere.
Aims: We characterize the line profiles not only through the Doppler shift and intensity of the bulk part of the profile. More imp…
Proton Temperature Anisotropies in the Plasma Environment of Venus
Futaana, Y.; Zhang, T. L.; Nilsson, H. +5 more
Velocity distribution functions (VDFs) are a key to understanding the interplay between particles and waves in a plasma. Any deviation from an isotropic Maxwellian distribution may be unstable and result in wave generation. Using data from the ion mass spectrometer IMA (Ion Mass Analyzer) and the magnetometer (MAG) onboard Venus Express, we study …
SPECTRUM: Synthetic Spectral Calculations for Global Space Plasma Modeling
Gombosi, T. I.; Toth, G.; Landi, E. +3 more
High-resolution spectroscopy is the most accurate tool for measuring the properties of the solar corona. However, interpreting measured line intensities and line profiles emitted by the optically thin solar corona is complicated by line-of-sight (LOS) integration, which leads to measuring weighted averages of the plasma properties along the LOS. L…
Improving statistical sensitivity of X-ray searches for axion-like particles
Conlon, Joseph P.; Rummel, Markus
X-ray observations of bright AGNs in or behind galaxy clusters offer unique capabilities to constrain axion-like particles. Existing analysis technique relies on measurements of the global goodness of fit. We develop a new analysis methodology that improves the statistical sensitivity to ALP-photon oscillations by isolating the characteristic quas…
Revising More Than 20 Years of EPHIN Ion Flux Data—A New Data Product for Space Weather Applications
Heber, B.; Kühl, P.
Solar energetic particle events and galactic cosmic rays are important aspects of space weather. Investigating them requires consistent measurements of electrons and ions over long time periods, that is, over more than a solar cycle. The Electron Proton Helium INstrument onboard the SOlar and Heliospheric Observatory is operational since 1995 and …
V752 Cen - a triple-lined spectroscopic contact binary with sudden and continuous period changes
Zhou, X.; Qian, S. -B.; Fernández Lajús, E. +1 more
V752 Cen is a triple-lined spectroscopic contact binary. Its multicolour light curves were obtained in the years 1971 and 2018, independently. Photometric analyses reveal that the two sets of light curves produce almost consistent results. It contains a W-subtype totally eclipsing binary, and its mass ratio and fill-out factor are q = 3.35(1) and …
XMM-Newton observations of the symbiotic recurrent nova T CrB: evolution of X-ray emission during the active phase
Zhekov, Svetozar A.; Tomov, Toma V.
We present an analysis of the XMM-Newton observations of the symbiotic recurrent nova T CrB, obtained during its active phase which started in 2014-2015. The XMM-Newton spectra of T CrB have two prominent components: a soft one (0.2-0.6 keV), well represented by blackbody emission, and a heavily absorbed hard component (2-10 keV), well matched by …
Does AGN fraction depend on redshift or luminosity? An extinction-free test by 18-band near- to mid-infrared SED fitting in the AKARI NEP wide field
Hashimoto, Tetsuya; Goto, Tomotsugu; Kim, Seong Jin +3 more
Revealing what fraction of galaxies harbor active galactic nuclei (AGNs) is central to understanding the black hole accretion history of the universe. However, optical and soft X-ray surveys miss the most highly obscured AGNs. Infrared (IR), instead, is more robust against absorption. Previous IR photometric surveys, however, only had four or five…
Strong Gravitational Lensing by Wave Dark Matter Halos
Gonzalez-Morales, Alma X.; Herrera-Martín, Antonio; Hendry, Martin +1 more
Wave dark matter (WaveDM) has recently gained attention as a viable candidate to account for the dark matter content of the universe. In this paper we explore the extent to which, and under what conditions, dark matter halos in this model are able to reproduce strong-lensing systems. First, we explore analytically the lensing properties of the mod…
Studying the Evolution of Warm Dust Encircling BD +20 307 Using SOFIA
Stark, Christopher C.; Weinberger, Alycia J.; Thompson, Maggie A. +2 more
The small class of known stars with unusually warm, dusty debris disks is a key sample to probe in order to understand cascade models and the extreme collisions that likely lead to the final configurations of planetary systems. Because of its extreme dustiness and small radius, the disk of BD +20 307 has a short predicted collision time and is the…