Search Publications
Multiband photometry and spectroscopy of an all-sky sample of bright white dwarfs
Geier, S.; Hermes, J. J.; Gänsicke, B. T. +11 more
The upcoming NASA Transiting Exoplanet Survey Satellite (TESS) will obtain space-based uninterrupted light curves for a large sample of bright white dwarfs distributed across the entire sky, providing a very rich resource for asteroseismological studies and the search for transits from planetary debris. We have compiled an all-sky catalogue of ult…
The ALMA Frontier Fields Survey. II. Multiwavelength Photometric analysis of 1.1 mm continuum sources in Abell 2744, MACSJ0416.1-2403 and MACSJ1149.5+2223
Kneissl, R.; Demarco, R.; Treister, E. +32 more
Context. The Hubble and Spitzer Space Telescope surveys of the Frontier Fields provide extremely deep images around six massive, strong-lensing clusters of galaxies. The ALMA Frontier Fields survey aims to cover the same fields at 1.1 mm, with maps reaching (unlensed) sensitivities of <70 µJy, in order to explore the properties of backgro…
Neutral ISM, Lyα, and Lyman-continuum in the Nearby Starburst Haro11
Hayes, Matthew; Östlin, Göran; Rivera-Thorsen, T. Emil +1 more
Star-forming galaxies are believed to be a major source of Lyman continuum (LyC) radiation responsible for reionizing the early universe. Direct observations of escaping ionizing radiation have however been sparse and with low escape fractions. In the local universe, only 10 emitters have been observed, with typical escape fractions of a few perce…
Mirror Instability in the Turbulent Solar Wind
Franci, Luca; Landi, Simone; Hellinger, Petr +2 more
The relationship between a decaying strong turbulence and the mirror instability in a slowly expanding plasma is investigated using two-dimensional hybrid expanding box simulations. We impose an initial ambient magnetic field perpendicular to the simulation box, and we start with a spectrum of large-scale, linearly polarized, random-phase Alfvénic…
Rotating Magnetic Structures Associated with a Quasi-circular Ribbon Flare
Yang, Bo; Yang, Jiayan; Bi, Yi +4 more
We present the detection of a small eruption and the associated quasi-circular ribbon flare during the emergence of a bipole occurring on 2015 February 3. Under a fan dome, a sigmoid was rooted in a single magnetic bipole, which was encircled by negative polarity. The nonlinear force-free field extrapolation shows the presence of twisted field lin…
The Frequency-dependent Damping of Slow Magnetoacoustic Waves in a Sunspot Umbral Atmosphere
Erdélyi, R.; Christian, D. J.; Krishna Prasad, S. +5 more
High spatial and temporal resolution images of a sunspot, obtained simultaneously in multiple optical and UV wavelengths, are employed to study the propagation and damping characteristics of slow magnetoacoustic waves up to transition region heights. Power spectra are generated from intensity oscillations in sunspot umbra, across multiple atmosphe…
Study on Precursor Activity of the X1.6 Flare in the Great AR 12192 with SDO, IRIS, and Hinode
Lee, Kyoung-Sun; Kusano, Kanya; Bamba, Yumi +1 more
The physical properties and their contribution to the onset of a solar flare are still uncleare even though chromospheric brightening is considered a precursor phenomenon of a flare. Many studies suggested that photospheric magnetic field changes cause destabilization of large-scale coronal structure. We aim to understand how a small photospheric …
The Surface Brightness-color Relations Based on Eclipsing Binary Stars: Toward Precision Better than 1% in Angular Diameter Predictions
Gieren, Wolfgang; Pietrzyński, Grzegorz; Maxted, Pierre F. L. +7 more
In this study we investigate the calibration of surface brightness-color (SBC) relations based solely on eclipsing binary stars. We selected a sample of 35 detached eclipsing binaries with trigonometric parallaxes from Gaia DR1 or Hipparcos whose absolute dimensions are known with an accuracy better than 3% and that lie within 0.3 kpc from the Sun…
Simultaneous Mass Determination for Gravitationally Coupled Asteroids
Chesley, Steven R.; Baer, James
The conventional least-squares asteroid mass determination algorithm allows us to solve for the mass of a large subject asteroid that is perturbing the trajectory of a smaller test asteroid. However, this algorithm is necessarily a first approximation, ignoring the possibility that the subject asteroid may itself be perturbed by the test asteroid,…
The Optical/UV Excess of X-Ray-dim Isolated Neutron Stars. I. Bremsstrahlung Emission from a Strangeon Star Atmosphere
Ge, Mingyu; Li, Zhaosheng; Xu, Renxin +4 more
X-ray-dim isolated neutron stars (XDINSs) are characterized by Planckian spectra in X-ray bands, but show optical/ultraviolet (UV) excesses: the factors by which the measured photometry exceeds those extrapolated from X-ray spectra. To solve this problem, a radiative model of bremsstrahlung emission from a plasma atmosphere is established in the r…