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2XMM J083026+524133: the most X-ray luminous cluster at redshift 1
Schwope, A.; Hoeft, M.; Lamer, G. +2 more
Aims: In the distant universe X-ray luminous clusters of galaxies are rare objects. Large area surveys are therefore needed to probe the high luminosity end of the cluster population at redshifts z ⪆ 1.
Methods: We correlated extended X-ray sources from the second XMM-Newton source catalogue (2XMM) with the SDSS in order to identify new cluste…
Analysis of a Solar Coronal Bright Point Extreme Ultraviolet Spectrum from the EUNIS Sounding Rocket Instrument
Landi, Enrico; Brosius, Jeffrey W.; Thomas, Roger J. +1 more
We present a well-calibrated EUV spectrum of a solar coronal bright point observed with the Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) sounding rocket instrument on 2006 April 12. The coronal bright point brightened around 06:30 UT during a period of emerging magnetic flux and remained bright at least until the rocket flight around …
Origins of Coronal Energy and Helicity in NOAA 10030
Alexander, David; Tian, Lirong; Nightingale, Richard
Exploring the origins of coronal helicity and energy, as well as determining the mechanisms that lead to coronal energy release, is a fundamental topic in solar physics. Using MDI 96 minute line-of-sight and HSOS vector magnetograms in conjunction with TRACE white-light and UV (1600 Å) images and BBSO Hα and SOHO EIT (195 Å) images, we find in act…
Suzaku Observation of the Metallicity in the Hot Interstellar Medium of the Isolated Elliptical Galaxy NGC 720
Fukazawa, Yasushi; Anabuki, Naohisa; Matsushita, Kyoko +3 more
The metal abundances in the interstellar medium of the isolated elliptical galaxy NGC 720 were studied with the CCD X-ray Imaging Spectrometer (XIS) aboard the Suzaku satellite. The high detection efficiency along with the excellent spectral resolution of the XIS allowed the K-shell lines of O and Mg to be clearly resolved, and the abundances of O…
Retrieval of air temperature profiles in the Venusian mesosphere from VIRTIS-M data: Description and validation of algorithms
Irwin, P. G. J.; Drossart, P.; Piccioni, G. +7 more
We present here methods developed for the retrieval of air temperature profiles in the Venusian mesosphere from the absolute radiances measured by the Visual and Infrared Thermal Imaging Spectrometer (VIRTIS) on board the Venus Express satellite. The infrared M channel of the instrument acquires multispectral images between 1000 and 5000 nm. In ni…
GD 552: a cataclysmic variable with a brown dwarf companion?
Gänsicke, B. T.; Dhillon, V. S.; Marsh, T. R. +7 more
GD 552 is a high proper motion star with the strong, double-peaked emission lines characteristic of the dwarf nova class of cataclysmic variable (CV) star, and yet no outburst has been detected during the past 12yr of monitoring. We present spectroscopy taken with the aim of detecting emission from the mass donor in this system. We fail to do so a…
HiRes Deconvolution of Spitzer Infrared Images
Marsh, K. A.; Beichman, C. A.; Velusamy, T. +2 more
Spitzer provides unprecedented sensitivity in the infrared (IR), but the spatial resolution is limited by a relatively small aperture (0.85 m) of the primary mirror. In order to maximize the scientific return it is desirable to use processing techniques which make the optimal use of the spatial information in the observations. We have developed a …
Zeeman-tomography of the solar photosphere. Three-dimensional surface structures retrieved from Hinode observations
Carroll, T. A.; Kopf, M.
Aims:The thermodynamic and magnetic field structure of the solar photosphere is analyzed by means of a novel 3-dimensional spectropolarimetric inversion and reconstruction technique.
Methods: On the basis of high-resolution, mixed-polarity magnetoconvection simulations, we used an artificial neural network (ANN) model to approximate the nonlin…
Reflection-dominated X-ray spectra of narrow-line Seyfert 1 galaxies: Mrk 478 and EXO 1346.2+2645
Fabian, A. C.; Gallo, L. C.; Zoghbi, A.
Multi-epoch XMM-Newton spectra of the two narrow-line Seyfert 1 (NLS1), Mrk 478 and EXO 1346.2+2645, are presented. The data were fitted with different models, including the relativistically blurred reflection model REFLIONX, which was found to give a good description of both spectra in all epochs. The two sources are reflection dominated with the…
A Search for Synchrotron X-Ray Emission in Radio Quasars
Giommi, Paolo; Cheung, Chi C.; Landt, Hermine +2 more
This paper presents XMM-Newton and Chandra X-ray spectroscopy of 10 flat-spectrum radio quasars (FSRQ) that are candidates to have an X-ray spectrum dominated by jet synchrotron emission. In all these FSRQ, which are less strongly relativistically beamed than blazars, a considerable contribution from a power-law component similar to that present i…