Search Publications
Black holes and core expansion in massive star clusters
Davies, M. B.; Mackey, A. D.; Wilkinson, M. I. +1 more
In this study we present the results from realistic N-body modelling of massive star clusters in the Magellanic Clouds. We have computed eight simulations with N ~ 105 particles; six of these were evolved for at least a Hubble time. The aim of this modelling is to examine in detail the possibility of large-scale core expansion in massiv…
Slow dust in Enceladus' plume from condensation and wall collisions in tiger stripe fractures
Schmidt, Jürgen; Spahn, Frank; Kempf, Sascha +1 more
One of the spectacular discoveries of the Cassini spacecraft was the plume of water vapour and icy particles (dust) originating near the south pole of Saturn's moon Enceladus. The data imply considerably smaller velocities for the grains than for the vapour, which has been difficult to understand. The gas and dust are too dilute in the plume to in…
An absorption origin for the X-ray spectral variability of MCG-6-30-15
Turner, T. J.; Reeves, J. N.; Miller, L.
Context: The Seyfert I galaxy MCG-6-30-15 shows one of the best examples of a broad “red wing” of emission in its X-ray spectrum at energies 2 < E < 6.4 keV, commonly interpreted as being caused by relativistically-blurred reflection close to the event horizon of the black hole.
Aims: We aim to test an alternative model in which absorpti…
Giant Chromospheric Anemone Jet Observed with Hinode and Comparison with Magnetohydrodynamic Simulations: Evidence of Propagating Alfvén Waves and Magnetic Reconnection
Shibata, K.; Katsukawa, Y.; Okamoto, T. J. +4 more
Hinode discovered a beautiful giant jet with both cool and hot components at the solar limb on 2007 February 9. Simultaneous observations by the Hinode SOT, XRT, and TRACE 195 Å satellites revealed that hot (~5 × 106 K) and cool (~104 K) jets were located side by side and that the hot jet preceded the associated cool jet (~1-…
The Sloan Lens ACS Survey. VI. Discovery and Analysis of a Double Einstein Ring
Treu, Tommaso; Gavazzi, Raphaël; Marshall, Philip J. +4 more
We report the discovery of two concentric Einstein rings around the gravitational lens SDSS J0946+1006. The main lens is at redshift zl = 0.222, while the inner ring (1) is at redshift zs1 = 0.609 (REin 1 = 1.43'' +/- 0.01''). The wider image separation (REin 2 = 2.07''+/- 0.02'') of the outer ring (2) i…
Sixty-five years of solar radioastronomy: flares, coronal mass ejections and Sun Earth connection
Vilmer, Nicole; Pick, Monique
This paper will review the input of 65 years of radio observations to our understanding of solar and solar terrestrial physics. It is focussed on the radio observations of phenomena linked to solar activity in the period going from the first discovery of the radio emissions to present days. We shall present first an overview of solar radio physics…
Solar Surface Emerging Flux Regions: A Comparative Study of Radiative MHD Modeling and Hinode SOT Observations
Cheung, M. C. M.; Tarbell, T. D.; Title, A. M. +1 more
We present results from numerical modeling of emerging flux regions on the solar surface. The modeling was carried out by means of three-dimensional (3D) radiative MHD simulations of the rise of buoyant magnetic flux tubes through the convection zone and into the photosphere. Due to the strong stratification of the convection zone, the rise result…
Speckle interferometry with adaptive optics corrected solar data
Reardon, K.; von der Lühe, O.; Wöger, F.
Context: Adaptive optics systems are used on several advanced solar telescopes to enhance the spatial resolution of the recorded data. In all cases, the correction remains only partial, requiring post-facto image reconstruction techniques such as speckle interferometry to achieve consistent, near-diffraction limited resolution.
Aims: This stud…
Multiple Stellar Populations in Three Rich Large Magellanic Cloud Star Clusters
Mackey, A. D.; Ferguson, A. M. N.; Broby Nielsen, P. +1 more
We present deep color-magnitude diagrams for three rich intermediate-age star clusters in the LMC, constructed from archival ACS F435W and F814W imaging. All three clusters exhibit clear evidence for peculiar main-sequence turnoffs. NGC 1846 and 1806 each possess two distinct turnoff branches, while the turnoff for NGC 1783 shows a much larger spr…
The Subaru/XMM-Newton Deep Survey (SXDS). III. X-Ray Data
Simpson, Chris; Ueda, Yoshihiro; Carrera, Francisco J. +10 more
We present the X-ray source catalog in the Subaru/XMM-Newton deep survey. A continuous area of 1.14 deg2 centered at R .A . = 02h18m and decl . = - 05° is mapped by seven pointings with XMM-Newton covering the 0.2-10 keV band. From the combined images of the EPIC pn and MOS cameras, we detect 866, 1114, 645, and 13…