Search Publications
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…
Neon and [C II] 158 µm Emission Line Profiles in Dusty Starbursts and Active Galactic Nuclei
Lebouteiller, Vianney; Samsonyan, Anahit; Weedman, Daniel +2 more
A sample of 379 extragalactic sources is presented that has mid-infrared, high-resolution spectroscopy from the Spitzer Infrared Spectrograph (IRS) and also spectroscopy of the [C II] 158 µm line from the Herschel Photodetector Array Camera and Spectrometer (PACS). The emission line profiles of [Ne II] 12.81 µm, [Ne III] 15.55 µm…
Dust Impact Monitor (SESAME-DIM) on board Rosetta/Philae: Millimetric particle flux at comet 67P/Churyumov-Gerasimenko
Flandes, Alberto; Krüger, Harald; Loose, Alexander +7 more
Context. The Philae lander of the Rosetta mission, aimed at the in situ investigation of comet 67P/Churyumov-Gerasimenko, was deployed to the surface of the comet nucleus on 12 November 2014 at 2.99 AU heliocentric distance. The Dust Impact Monitor (DIM) as part of the Surface Electric Sounding and Acoustic Monitoring Experiment (SESAME) on the la…
X-ray narrow emission lines from the nuclear region of NGC 1365
Page, M. J.; Branduardi-Raymont, G.; Whewell, M.
Context. NGC 1365 is a Seyfert 2 galaxy with a starburst ring in its nuclear region. In this work we look at the XMM-Newton Reflection Grating Spectrometer (RGS) data from four 2012-13, three 2007 and two 2004 observations of NGC 1365, in order to analyse and characterise in a uniform way the soft X-ray narrow-line emitting gas in the nucleus.
Ultraviolet emission lines of Si II in cool star and solar spectra
Ayres, Thomas R.; Laha, Sibasish; Ferland, Gary J. +6 more
Recent atomic physics calculations for Si II are employed within the CLOUDY modelling code to analyse Hubble Space Telescope (HST) STIS ultraviolet spectra of three cool stars, β Geminorum, α Centauri A and B, as well as previously published HST/GHRS observations of α Tau, plus solar quiet Sun data from the High Resolution Telescope and Spectrogra…