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The non-constant slope of the C IV Baldwin effect in NGC 4151
Wang, R.; Han, J. L.; Wu, X. -B. +2 more
Context: .The relationship between the emission-line equivalent width and the continuum luminosity, called the Baldwin effect, is important for studies of the physics of the broad-line region of AGNs. Some recent studies have revealed the non-constant slope of the intrinsic Baldwin effect for several Seyfert 1 galaxies.
Aims: .Using the archiv…
The colour-magnitude relations of ClJ1226.9+3332, a massive cluster of galaxies at z = 0.89
Ebeling, H.; Jones, L. R.; Donovan, D. +2 more
The colour-magnitude relations (CMRs) of one of the most massive (~1015Msolar), high-redshift (z = 0.89) clusters of galaxies known have been studied. Photometry has been measured in the V, R, I, z, F606W, F814W, J and K bands to a depth of K ~ 20.5 = K* + 2.5 and spectroscopy confirms 27 K-band selected galaxies as members o…
Energetics and Dynamics of an Impulsive Flare on March 10, 2001
Sakao, Taro; Uddin, Wahab; Chandra, Ramesh +5 more
We present Hα observations from ARIES (Nainital) of a compact and impulsive solar flare that occurred on March 10, 2001 and which was associated with a CME. We have also analyzed HXT, SXT/Yohkoh observations as well as radio observations from the Nobeyama Radio Observatory to derive the energetics and dynamics of this impulsive flare. We coalign t…
On the multiwavelength spectrum of the microquasar 1E 1740.7-2942
Bassani, L.; Bazzano, A.; Del Santo, M. +3 more
Context: .The microquasar 1E 1740.7-2942 is a source located in the direction of the Galactic Center. It has been detected at X-rays, soft gamma-rays, and in the radio band, showing an extended radio component in the form of a double-sided jet. Although no optical counterpart has been found so far for 1E 1740.7-2942, its X-ray activity strongly po…
The Evaporation Regime in a Confined Flare
Maltagliati, L.; Teriaca, L.; Falchi, A.
We studied the evolution of a small eruptive flare (GOES class C1) from its onset phase using multi-wavelength observations that sample the flare atmosphere from the chromosphere to the corona. The main instruments involved were the Coronal Diagnostic Spectrometer (CDS) aboard SOHO and facilities at the Dunn Solar Tower of the National Solar Obser…
Mathematical Morphology: Star/Galaxy Differentiation & Galaxy Morphology Classification
Moore, Jason A.; Pimbblet, Kevin A.; Drinkwater, Michael J.
We present an application of Mathematical Morphology (MM) for the classification of astronomical objects, both for star/galaxy differentiation and galaxy morphology classification. We demonstrate that, for CCD images, 99.3+/-3.8% of galaxies can be separated from stars using MM, with 19.4+/-7.9% of the stars being misclassified. We demonstrate tha…
Suzaku Reveals Helium-burning Products in the X-Ray-emitting Planetary Nebula BD +30 3639
Hamaguchi, K.; Matsushita, K.; Hayashida, K. +7 more
BD +30 3639, the brightest planetary nebula at X-ray energies, was observed with Suzaku, an X-ray observatory launched on 2005 July 10. Using the X-ray Imaging Spectrometer, the K lines from C VI, O VII, and O VIII were resolved for the first time, and the C/O, N/O, and Ne/O abundance ratios were determined. The C/O and Ne/O abundance ratios excee…
Chaotic gravitational zones around a regularly shaped complex rotating body
Mysen, E.; Aksnes, K.; Olsen, Ø.
In preparation for the Rosetta mission, the location and widths of gravitational resonances surrounding a regularly shaped and possibly complex rotating body are mapped following the second fundamental model of resonance. It is found that for uniaxial rotation of the central body, the surrounding resonances are widest for prograde orbits. If the f…
Remote sensing of a magnetotail reconnection X-line using polar rain electrons
Lucek, E.; Owen, C. J.; Sergeev, V. +3 more
We report on electron phase space distributions (PSDs) observed near the plasma sheet (PS) boundary layer (PSBL) by the Cluster electron spectrometers when the northern lobe was occupied by significant fluxes of polar rain (PR) electrons. These observations reveal the spatial structure of the electron transition layer (TL) between the polar rain e…
Planetary nebula candidates in extragalactic young star clusters
Larsen, S. S.; Richtler, T.
Context: .During an analysis of optical spectra of 80 young star clusters in several nearby spiral galaxies, [O III] and [N II] emission lines were noted in some cases. Three of these emission line sources are associated with clusters older than 30 Myr, and are identified as likely planetary nebula (PN) candidates.
Aims: .These objects may re…