Search Publications
Discovery of Optical Emission in the Hot Spots of Three 3CR Quasars: High-Energy Particle Acceleration in Powerful Radio Hot Spots
Cheung, C. C.; Wardle, J. F. C.; Chen, Tingdong
Archival Hubble Space Telescope WFPC2 images were used to search for optical emission associated with the radio jets of a number of luminous quasars. From this search, we report new optical hot spot detections in the well-known blazar 3C 454.3 and the lobe-dominated quasars 3C 275.1 and 3C 336. We also find optical emission in the vicinity of the …
Simultaneous XMM-Newton and ESO VLT observations of supernova 1995N: probing the wind-ejecta interaction
Turatto, M.; Cappellaro, E.; Benetti, S. +3 more
We present the results of the first XMM-Newton observation of the interacting Type IIn supernova 1995N, performed in 2003 July. We find that the 0.2-10.0 keV unabsorbed flux dropped to a value of ~=1.8 × 10-13ergcm-2s-1, almost one order of magnitude lower than that of a previous ASCA observation of 1998 January. F…
The symmetric dust shell and the central star of the bipolar planetary nebula NGC6537*†
Waters, L. B. F. M.; Zijlstra, A. A.; Gray, M. D. +2 more
We present high-resolution images of the strongly bipolar planetary nebula NGC6537, obtained with the Hubble Space Telescope (HST) and with the infrared adaptive optics system on the Very Large Telescope. The central star is detected for the first time. Using the multiband photometry and constraints from the dynamical age of the nebula, we derive …
Fourier-Resolved Spectroscopy of the XMM-Newton Observations of MCG -06-30-15
Papadakis, I. E.; Akylas, A.; Kazanas, Demosthenes
We study the frequency-resolved spectra of the Seyfert galaxy MCG -06-30-15 obtained during two recent XMM-Newton observations. Splitting the Fourier spectra in soft (E<~2 keV) and hard (E>~2 keV) bands, we find that the soft band has a variability amplitude larger than the hard one on timescales longer than 10 ks, while the opposite is true…
INTEGRAL and XMM-Newton observations of GRB 040106
Tiengo, A.; Götz, D.; McGlynn, S. +10 more
On January 6th 2004, the IBAS burst alert system triggered the 8th gamma-ray burst (GRB) to be located by the INTEGRAL satellite. The position was determined and publicly distributed within 12 s, prompting ESA's XMM-Newton to execute a ToO observation just 5 h later, during which an X-ray afterglow was detected. The GRB had a duration ~52 s with t…
Influence of random magnetic field on solar global oscillations: The incompressible f-mode
Erdélyi, R.; Kerekes, A.; Mole, N.
The discrepancies between theoretically predicted and observed frequencies of solar global oscillations (e.g. p- and f-modes) have attracted major attention in the past decades. The f-mode is essentially a surface wave hence the mode frequencies are less likely to be influenced by the solar stratification. Most probably then the discrepancies are …
Density irregularities in the plasmasphere boundary layer: Cluster observations in the dusk sector
André, M.; Décréau, P. M. E.; Canu, P. +7 more
We present observations of plasma density structures crossed by the CLUSTER spacecraft constellation near orbit perigee, with the spacecraft located in the vicinity of the plasmapause boundary. Although the constellation is not arranged as a perfect tetrahedron, the four-point measurements reveal interesting properties of density structures, unkno…
A large spin-up rate measured with INTEGRAL in the high mass X-ray binary pulsar SAX J2103.5+4545
Mereghetti, S.; Santangelo, A.; Sidoli, L. +7 more
The High Mass X-ray Binary Pulsar SAX J2103.5+4545 has been observed with INTEGRAL several times during the last outburst in 2002-2004. We report a comprehensive study of all INTEGRAL observations, allowing a study of the pulse period evolution during the recent outburst. We measured a very rapid spin-up episode, lasting 130 days, which decreased …
Kinematics of nearby subdwarf stars
Wielen, R.; Jahreiß, H.; Fuchs, B. +1 more
We present an analysis of the space motions of 742 subdwarf stars based on the sample of Carney et al. (1994, AJ, 107, 22 40). Hipparcos parallaxes, TYC2+HIP proper motions and Tycho 2 proper motions were combined with radial velocities and metallicities from CLLA. The kinematical behavior is discussed in particular in relation to their metallicit…
X-Rays from Cepheus A East and West
Tsuboi, Yohko; Pravdo, Steven H.
We report the discovery of X-rays from both components of Cepheus A, East and West, with the XMM-Newton observatory. HH 168 joins the ranks of other energetic Herbig-Haro objects that are sources of T>=106 K X-ray emission. The effective temperature of HH 168 is T=5.8+3.5-2.3×106 K, and its unabsorbed…