Search Publications
H I absorption in nearby compact radio galaxies
Sadler, E. M.; Glowacki, M.; Allison, J. R. +6 more
H I absorption studies yield information on both active galactic nucleus (AGN) feeding and feedback processes. This AGN activity interacts with the neutral gas in compact radio sources, which are believed to represent the young or recently re-triggered AGN population. We present the results of a survey for H I absorption in a sample of 66 compact …
Broad-band characteristics of seven new hard X-ray selected cataclysmic variables
Mukai, K.; Israel, G.; de Martino, D. +5 more
We present timing and spectral analysis of a sample of seven hard X-ray selected cataclysmic variable candidates based on simultaneous X-ray and optical observations collected with XMM-Newton, complemented with Swift/BAT and INTEGRAL /IBIS hard X-ray data and ground-based optical photometry. For six sources, X-ray pulsations are detected for the f…
Rosetta photoelectron emission and solar ultraviolet flux at comet 67P
Edberg, N. J. T.; Simon Wedlund, C.; Andersson, L. +10 more
The Langmuir Probe instrument on Rosetta monitored the photoelectron emission current of the probes during the Rosetta mission at comet 67P/Churyumov-Gerasimenko, in essence acting as a photodiode monitoring the solar ultraviolet radiation at wavelengths below 250 nm. We have used three methods of extracting the photoelectron saturation current fr…
Heating of an Erupting Prominence Associated with a Solar Coronal Mass Ejection on 2012 January 27
Moon, Yong-Jae; Reeves, Katharine K.; Raymond, John C. +2 more
We investigate the heating of an erupting prominence and loops associated with a coronal mass ejection and X-class flare. The prominence is seen as absorption in EUV at the beginning of its eruption. Later, the prominence changes to emission, which indicates heating of the erupting plasma. We find the densities of the erupting prominence using the…
Stellar Stream Candidates in the Solar Neighborhood Found in the LAMOST DR3 and TGAS
Oswalt, T. D.; Zhao, G.; Zhang, L. +3 more
We have cross-matched the LAMOST DR3 with the Gaia DR1 TGAS catalogs and obtained a sample of 166,827 stars with reliable kinematics. A technique based on the wavelet transform was applied to detect significant overdensities in velocity space among five subsamples divided by spatial position. In total, 16 significant overdensities of stars with ve…
First detection of hydrogen in the β Pictoris gas disk
Lecavelier des Etangs, A.; Bourrier, V.; Ferlet, R. +6 more
The young and nearby star β Pictoris (β Pic) is surrounded by a debris disk composed of dust and gas known to host a myriad evaporating exocomets, planetesimals and at least one planet. At an edge-on inclination, as seen from Earth, this system is ideal for debris disk studies providing an excellent opportunity to use absorption spectroscopy to st…
Kinematics of coronal rain in a transversely oscillating loop: Ponderomotive force and rain-excited oscillations
Kohutova, P.; Verwichte, E.; Neukirch, T. +2 more
Context. Coronal rain is composed of cool dense blobs that form in solar coronal loops and are a manifestation of catastrophic cooling linked to thermal instability. Once formed, rain falls towards the solar surface at sub-ballistic speeds, which is not well understood. Pressure forces seem to be the prime candidate to explain this. In many observ…
Power spectra based Planck constraints on compensated isocurvature, and forecasts for LiteBIRD and CORE space missions
Väliviita, Jussi
Compensated isocurvature perturbations (CIP), where the primordial baryon and cold dark matter density perturbations cancel, do not cause total matter isocurvature perturbation. Consequently, at the linear order in the baryon density contrast Δ, a mixture of CIP and the adiabatic mode leads to the same CMB spectra as the pure adiabatic mode. Only …
Late-time observations of the relativistic tidal disruption flare candidate Swift J1112.2-8238
Cenko, S. B.; Krühler, T.; Levan, A. J. +6 more
We present late-time follow-up of the relativistic tidal disruption flare (rTDF) candidate Swift J1112.2-8238. We confirm the previously determined redshift of z = 0.8900 ± 0.0005 based on multiple emission line detections. Hubble Space Telescope imaging of the host galaxy indicates a complex and distorted morphology with at least two spatially di…
Sensitivity and fragmentation calibration of the time-of-flight mass spectrometer RTOF on board ESA's Rosetta mission
Mall, Urs; Fiethe, Björn; Wurz, Peter +8 more
The European Space Agency's Rosetta spacecraft, with the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) onboard, has been following and observing comet 67P/Churyumov-Gerasimenko since summer 2014. Prior to this period, and due to a technical failure also during this period, optimization and calibration campaigns have been condu…