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Improved SOT (Hinode mission) high resolution solar imaging observations: 2—Photometric properties of sunspot umbral dots
Koutchmy, S.; Adjabshirizadeh, A.; Goodarzi, H.
The origin and evolution of solar sunspots in deep photospheric layers are not yet well understood. The case of a quasi-symmetric single mature sunspot near the solar centre is selected for analysis. We use the best available observations of the partial Sun free of turbulent Earth atmospheric effects from the Solar Optical Telescope (SOT) onboard …
A possible mechanism for the formation of magnetic field dropouts in the coma of 67P/Churyumov-Gerasimenko
Altwegg, K.; Huang, Z.; Jia, X. +10 more
The Rosetta Plasma Consortium MAGnetometer (RPC-MAG) has detected signatures of diamagnetic regions associated with comet 67P/Churyumov-Gerasimenko at distances from 30 to 400 km at different heliocentric distances, which is larger than what has been predicted by numerical simulations of the cometary plasam environment. The physical mechanism behi…
Spectral components in black hole X-ray binaries
Malzac, J.
This paper summarises our current understanding of the spectral continuum components observed in black hole X-ray binaries. The consequences for theoretical models are discussed with an emphasis on the constraints set by observations on the nature of the X-ray corona in different spectral states.
The CONSERT operations planning process for the Rosetta mission
Altobelli, Nicolas; Vallat, Claire; Hubault, Armelle +28 more
The COmet Nucleus Sounding Experiment by Radio wave Transmission (CONSERT / Rosetta) has been designed to sound the interior of the comet 67P/Churyumov-Gerasimenko. This instrument consists of two parts: one onboard Rosetta and the other one onboard Philae. A good CONSERT science measurement sequence requires joint operations of both spacecrafts i…
Multi-wavelength landscape of the young galaxy cluster RXJ 1257.2+4738 at z = 0.866. II. Morphological properties
Altieri, B.; Cepa, J.; Pérez García, A. M. +11 more
Studying the evolution of the morphological distribution of galaxies in different environments can provide important information about the effects of the environment and the physical mechanisms responsible for the morphological transformations. As part of a complete analysis of the young cluster RXJ 1257+4738 at z ~ 0.9, in this work we study the …
Fractality of Isotherms of the Cosmic Microwave Background Based on Data from the Planck Spacecraft
Mylläri, A. A.; Raikov, A. A.; Orlov, V. V. +3 more
A system of isophotes of the cosmic microwave background (CMB) is constructed for several regions on the celestial sphere using data from the Planck spacecraft. The fractal dimensionality of the isotherms is estimated to be Dc ≈ 1.78 ± 0.03. Our results agree with earlier work based on the ILC charts with WMAP data. Our simulations conf…
Estimation of the flux tube diameters outside sunspots using Hinode observations. Preliminary results
Lozitsky, V. G.; Botygina, O. O.; Gordovskyy, M. Yu.
Indirect estimations of diameters of the smallest flux tubes outside sunspots are made using SOT/Hinode observations of Fe I 6301.5 and 6302.5 lines. These estimations are based on the comparison of measured effective magnetic field strength B_{eff} in named lines. It is shown that B_{eff}(6301.5)/B_{eff}(6302.5)≈ 1.3 in the range B_{eff}=40-300 G…
Generation of auroral kilometric radiation by a finite-size source in a dipole magnetic field
Burinskaya, T. M.; Shevelev, M. M.
Generation, amplification, and propagation of auroral kilometric radiation in a narrow three-dimensional plasma cavity in which a weakly relativistic electron beam propagates is studied in the geometrical optics approximation. It is shown that the waves that start with a group velocity directed earthward and have optimal relation between the wave …
Decontaminating Swift UVOT Grism Observations of Transient Sources
Suntzeff, Nicholas B.; Kuin, Paul; Brown, Peter J. +1 more
We present a new technique of decontaminating Swift Ultraviolet/Optical Telescope grism spectra for transient objects. We describe the template image requirements and image processing steps necessary to successfully implement the empirical decontamination technique. We demonstrate the accuracy of the flux and wavelength calibrations for decontamin…
The featureless and non-variable optical spectral energy distribution of AXP 4U 0142+61
Muñoz-Darias, T.; Casares, J.; de Ugarte Postigo, A.
We present GTC-10.4 m spectroscopy and multiband photometry of the faint (r ∼ 26) optical counterpart of the anomalous X-ray pulsar 4U 0142+61. The 5000-9000 Å spectrum - the first obtained for a magnetar - is featureless, allowing us to set an equivalent width upper limit EW < 25 Å to the presence of emission lines in the H α region. Multiband…