Search Publications
Discovery of accretion-driven pulsations in the prolonged low X-ray luminosity state of the Be/X-ray transient GX 304-1
Wijnands, R.; van den Eijnden, J.; Rouco Escorial, A.
We present our Swift monitoring campaign of the slowly rotating neutron star Be/X-ray transient GX 304-1 (spin period of ∼275 s) when the source was not in outburst. We found that between its type I outbursts, the source recurrently exhibits a slowly decaying low-luminosity state (with luminosities of 1034 - 35 erg s-1). This…
Magnetic Fluctuations and Turbulence in the Venusian Magnetosheath Downstream of Different Types of Bow Shock
Zhang, T. L.; Vörös, Z.; Xiao, S. D.
We statistically examine the characteristic scaling features of fluctuations in the dayside Venusian magnetosheath downstream of different types, quasi-parallel (Q∥) and quasi-perpendicular (Q⊥), of bow shock based on Venus Express data. We found that magnetic fluctuations have different characteristic scaling features downst…
Observational Study of an Earth-affecting Problematic ICME from STEREO
Hess, Phillip; Wang, Yuming; Shen, Chenglong +4 more
We present a study of the origin of one interplanetary coronal mass ejection (ICME) that lacked an easily identifiable signature of an associated progenitor coronal mass ejection (CME) near the Sun in the observations of SOHO/LASCO at the L1 point. We consider these kinds of ICMEs as problematic, as they pose the difficulty of understanding the Su…
In-orbit operation of the soft x-ray spectrometer onboard the Hitomi satellite
Tsujimoto, Masahiro; Okajima, Takashi; Eckart, Megan E. +35 more
We summarize all of the in-orbit operations of the soft x-ray spectrometer (SXS) onboard the ASTRO-H (Hitomi) satellite. The satellite was launched on February 17, 2016, and the communication with the satellite ceased on March 26, 2016. The SXS was still in the commissioning phase, in which the set-ups were progressively changed. This paper is int…
Response of Earth's Neutral Sheet to Reversals in the IMF By Component
Haaland, S.; Case, N. A.; Nagai, T. +2 more
The By component of the interplanetary magnetic field (IMF) plays an integral part in the coupling of the solar wind-magnetosphere-ionosphere system. In this study, we use a suite of magnetospheric spacecraft, with data spanning nearly 25 years, to statistically investigate the control of the IMF By component on the neutral s…
Plasma density structures at comet 67P/Churyumov-Gerasimenko
Nilsson, H.; Goetz, C.; Henri, P. +7 more
We present a Rosetta Plasma Consortium (RPC) case study based on four events in 2015 autumn at various radial distances, phase angles and local times, just after the perihelion of comet 67P/Churyumov-Gerasimenko. Pulse-like (high-amplitude, up to minutes in time) signatures are seen with several RPC instruments in the plasma density (with the LAng…
The impact of ELT distortions and instabilities on future astrometric observations
Massari, D.; Rodeghiero, G.; Pott, J. -U. +4 more
The paper discusses an assessment study about the impact of the distortions on the astrometric observations with the Extremely Large Telescope originated from the optics positioning errors and telescope instabilities. Optical simulations combined with Monte Carlo approach reproducing typical inferred opto-mechanical and dynamical instabilities sho…
Evolution of the UV upturn in cluster galaxies: Abell 1689
Bremer, M. N.; De Propris, R.; Phillipps, S. +1 more
We have measured the strength of the UV upturn for red sequence galaxies in the Abell 1689 cluster at z = 0.18, reaching to or below the L* level and therefore probing the general evolution of the upturn phenomenon. We find that the range of UV upturn strengths in the population as a whole has not declined over the past 2.2 Gyr. This is consistent…
Stringent upper limit of CH4 on Mars based on SOFIA/EXES observations
Aoki, S.; Vandaele, A. C.; Sindoni, G. +13 more
Discovery of CH4 in the Martian atmosphere has led to much discussion since it could be a signature of biological and/or geological activities on Mars. However, the presence of CH4 and its temporal and spatial variations are still under discussion because of the large uncertainties embedded in the previous observations. We pe…
A VLT/MUSE galaxy survey towards QSO Q1410: looking for a WHIM traced by BLAs in inter-cluster filaments
Prochaska, J. Xavier; Tejos, Nicolas; Barrientos, L. Felipe +7 more
Cosmological simulations predict that a significant fraction of the low-z baryon budget resides in large-scale filaments in the form of a diffuse plasma at temperatures T ∼ 105 - 107 K. However, direct observation of this so-called warm-hot intergalactic medium (WHIM) has been elusive. In the Λcold dark matter paradigm, galax…