Search Publications
SOHO/SUMER observations of prominence oscillation before eruption
Solanki, S. K.; Innes, D. E.; Chen, P. F.
Context: Coronal mass ejections (CMEs), as a large-scale eruptive phenomenon, often reveal some precursors in the initiation phase, e.g., X-ray brightening, filament darkening, etc., which are useful for CME modelling and space weather forecasting.
Aims: With the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectroscopic observa…
Cluster observations of an ion-scale current sheet in the magnetotail under the presence of a guide field
RèMe, H.; Fazakerley, A. N.; Klecker, B. +9 more
We report on Cluster observations of a thin current sheet interval under the presence of a strong ∣BY∣ during a fast earthward flow interval between 1655 UT and 1703 UT on 17 August 2003. The strong ∣BY∣ in the tail could be associated with a strong IMF ∣BY∣, but the large fluctuations in BY, not seen in…
Prevalence of High X-Ray Obscuring Columns among AGNs that Host H2O Masers
Tilak, Avanti; Greenhill, Lincoln J.; Madejski, Grzegorz
Of 104 AGNs known to exhibit H2O maser emission, X-ray data that enable estimation of column densities, or lower limits, are available for 42. Contributing to this, we report analysis of new and archival X-ray data for eight galaxies and collation of values for three more. Maser emission is indicative of large columns of cold gas, and i…
The Hα Luminosity Function and Star Formation Rate at z ≈ 0.24 in the COSMOS 2 Square Degree Field
Kneib, J. -P.; Aussel, H.; Sanders, D. B. +25 more
To derive a new Hα luminosity function and to understand the clustering properties of star-forming galaxies at z ≈ 0.24, we have made a narrowband imaging survey for Hα-emitting galaxies in the Hubble Space Telescope (HST) COSMOS 2 square degree field. We used the narrowband filter NB816 (λc = 8150 Å, Δ λ = 120 Å) and sampled Hα emitter…
A New Comptonization Model for Weakly Magnetized, Accreting Neutron Stars in Low-Mass X-Ray Binaries
Titarchuk, Lev; Farinelli, Ruben; Paizis, Ada +1 more
We have developed a new model for the X-ray spectral fitting package XSPEC that takes into account the effects of both thermal and dynamical (i.e., bulk) Comptonization. The model consists of two components: one is the direct blackbody-like emission due to seed photons that are not subjected to effective Compton scattering, while the other is a co…
Variability of Disk Emission in Pre-Main-Sequence and Related Stars. I. HD 31648 and HD 163296: Isolated Herbig Ae Stars Driving Herbig-Haro Flows
Polomski, Elisha F.; Russell, Ray W.; Sitko, Michael L. +13 more
Infrared photometry and spectroscopy covering a time span of a quarter-century are presented for HD 31648 (MWC 480) and HD 163296 (MWC 275). Both are isolated Herbig Ae stars that exhibit signs of active accretion, including driving bipolar flows with embedded Herbig-Haro (HH) objects. HD 163296 was found to be relatively quiescent photometrically…
Structure and dynamics of the solar wind/ionosphere interface on Mars: MEX-ASPERA-3 and MEX-MARSIS observations
Barabash, S.; Lundin, R.; Woch, J. +8 more
The measurements of the local plasma parameters of the ionospheric and solar wind plasmas and the magnetic field strength carried out by the ASPERA-3 and MARSIS experiments onboard Mars Express (MEX) in the subsolar region of the induced Martian magnetosphere provide us with a first test of the pressure balance across the solar wind/ionosphere int…
The Slow X-Ray Expansion of the Northwestern Rim of the Supernova Remnant RX J0852.0-4622
Mori, K.; Katsuda, S.; Tsunemi, H.
The detection of the radioactive decay line of 44Ti provides unique evidence that the γ-ray source is a young (<1000 yr) supernova remnant because of the short 44Ti lifetime of ~90 yr. Only two Galactic remnants, Cassiopeia A and RX J0852.0-4622, have hitherto been reported as 44Ti line emitters, although the de…
Multi-wavelength spatially resolved analysis of quasi-periodic pulsations in a solar flare
Melnikov, V. F.; Nakariakov, V. M.; Inglis, A. R.
Aims: We aim to perform a spatially resolved analysis of a quasi-periodic pulsation event from 8th May 1998 using microwave data from the Nobeyama Radioheliograph and Radiopolarimeter, and X-ray data from the Yohkoh satellite.
Methods: Time spectra of the signals integrated over the emission source are constructed with the use of the Lomb-Scar…
Evidence for Polar Jets as Precursors of Polar Plume Formation
Solanki, S. K.; Henney, C. J.; Raouafi, N. -E. +2 more
Observations from the Hinode/XRT telescope and STEREO/SECCHI/EUVI are utilized to study polar coronal jets and plumes. The study focuses on the temporal evolution of both structures and their relationship. The data sample, spanning 2007 April 7-8, shows that over 90% of the 28 observed jet events are associated with polar plumes. EUV images (STERE…