Search Publications
Ion-Scale Sideband Waves and Filament Formation: Alfvénic Impact on Heliospheric Plasma Turbulence
Motschmann, Uwe; Narita, Yasuhito
A mini-review is given about two recent discoveries in the solar wind turbulence research on ion-kinetic scales: the existence of sideband waves (or breakdown of the linear mode wave picture) and the wavevector anisotropy leading to a persistent filament formation in a wide range of plasma beta.
Decay of COSAC and Ptolemy mass spectra at comet 67P/Churyumov-Gerasimenko
Krüger, Harald; McKenna-Lawlor, Susan; Gautier, Thomas +11 more
Context. The Rosetta lander Philae successfully landed on the nucleus of comet 67P/Churyumov-Gerasimenko on 12 November 2014. Philae is equipped with two gas analysers: The Cometary Sampling and Composition experiment (COSAC) and the gas chromatograph and mass spectrometer Ptolemy.
Aims: COSAC is designed for in situ analysis of organic molec…
The formation of superdense plasma sheet in association with the IMF turning from northward to southward
Lavraud, Benoit; Thomsen, Michelle F.; Liang, En-Wei +3 more
We have studied two events in which relatively superdense plasma appeared near geosynchronous orbit after the interplanetary magnetic field (IMF) changed from a long period of northward condition to southward condition. We used the magnetosphere MHD model Open Geospace General Circulation Model to simulate these two events and compared the simulat…
The Luminous Blue Variable RMC 127 as Seen with ALMA and ATCA
Paladini, R.; Umana, G.; Bauer, F. E. +12 more
We present ALMA and ATCA observations of the luminous blue variable RMC 127. The radio maps show for the first time the core of the nebula and evidence that the nebula is strongly asymmetric with a Z-pattern shape. Hints of this morphology are also visible in the archival Hubble Space Telescope {{H}}α image, which overall resembles the radio emiss…
3XMM J181923.7-170616: An X-Ray Binary with a 408 s Pulsar
Qiu, Hao; Zhou, Ping; Xu, Xiaojie +2 more
We carry out a dedicated study of 3XMM J181923.7-170616 with an approximate pulsation period of 400 s using the XMM-Newton and Swift observations spanning across nine years. We have refined the period of the source to 407.904(7) s (at epoch MJD 57142) and constrained the 1σ upper limit on the period derivative \dot{P}≤slant 1.1× {10}-8 …
The lack of X-ray pulsations in the extreme helium star BD+37°442 and its possible stellar wind X-ray emission
Mereghetti, Sandro; Esposito, Paolo; Tiengo, Andrea +1 more
We report the results of a new XMM-Newton observation of the helium-rich hot subdwarf BD+37°442 carried out in 2016 February. The possible periodicity at 19 s seen in a 2011 shorter observation is not confirmed, thus dismissing the evidence for a binary nature. This implies that the observed soft X-ray emission, with a luminosity of a few 103…
Covariance of lucky images: performance analysis
Ginski, C.; Mugrauer, M.; Seeliger, M. +5 more
The covariance of ground-based lucky images is a robust and easy-to-use algorithm that allows us to detect faint companions surrounding a host star. In this paper, we analyse the relevance of the number of processed frames, the frames' quality, the atmosphere conditions and the detection noise on the companion detectability. This analysis has been…
A Molecular-line Study of the Interstellar Bullet Engine IRAS05506+2414
Morris, Mark R.; Lee, Chin-Fei; Patel, Nimesh +3 more
We present interferometric and single-dish molecular line observations of the interstellar bullet-outflow source IRAS 05506+2414, whose wide-angle bullet spray is similar to the Orion BN/KL explosive outflow and likely arises from an entirely different mechanism than the classical accretion-disk-driven bipolar flows in young stellar objects. The b…
Fourier transform spectrometers for remote sensing of planetary atmospheres and surfaces
Korablev, Oleg; Grigoriev, Alexey; Ignatiev, Nikolay +14 more
In planetary research, Fourier transform infrared spectrometers (FTIR) solve a number of important scientific goals related both to the atmosphere and to the surface sounding. For remote orbital measurements, these goals are the thermal sounding of the atmosphere using, in particular, the 15-µm CO2 band, sensitive detections of minor ga…
The study of umbral dots in sunspots based on SOT/Hinode observations
Ebadi, H.; Abbasvand, V.; Pourjavadi, H.
To understand the energy transport in sunspots, it is necessary to investigate the dynamic properties of umbral dots (UDs). In this connection, we used high-resolution SOT/Hinode time-series images. The intensity oscillations of UDs are determined. We conclude that their periods are in the range of 3-5 min, which may be related to the propagation …