Search Publications
XMM-Newton and Chandra observations of the globular cluster NGC 6388
Guainazzi, M.; Nucita, A. A.; Carpano, S. +2 more
Context: By studying the optical brightness surface density of the globular cluster NGC 6388, it has been recently proposed that it harbors a central intermediate-mass black hole with mass ≃ 5.7×103 M⊙.
Aims: We expect that the compact object in the center of NGC 6388 emits radiation in the X-ray band as a consequence of …
Multi-conjugate adaptive optics images of the Trapezium cluster
Martín, E. L.; Huélamo, N.; Bouy, H. +3 more
Context: Multi-conjugate adaptive optics (MCAO) combine the advantages of both standard adaptive optics, which provide high contrast and high spatial resolution, and of wide field imaging (≈1'). Up to recently, MCAO for astronomy was limited to laboratory experiments. In this paper, we present the first scientific results obtained with the first M…
High resolution science with high redshift galaxies
Hathi, N. P.; Jansen, R. A.; Driver, S. P. +4 more
We summarize the high-resolution science that has been done on high redshift galaxies with Adaptive Optics (AO) on the world’s largest ground-based facilities and with the Hubble Space Telescope (HST). These facilities complement each other. Ground-based AO provides better light gathering power and in principle better resolution than HST, giving i…
A coronal explosion on the flare star CN Leonis
Liefke, C.; Schmitt, J. H. M. M.; Reiners, A. +4 more
We present simultaneous high-temporal and high-spectral resolution observations of the nearby flare star CN Leo at optical and soft X-ray wavelengths. During our observing campaign a major flare occurred, raising the star's instantaneous energy output by almost three orders of magnitude. The flare shows the often observed impulsive behavior, with …
The Fundamental Plane of QSOs and the Relationship between Host and Nucleus
Turnshek, David A.; Casertano, Stefano; Hamilton, Timothy S.
We present results from an archival study of 70 medium-redshift QSOs observed with HST's WFPC2. The QSOs have magnitudes MV <= - 23 (total nuclear plus host light) and redshifts 0.06 <= z <= 0.46. The aim of the present study is to investigate the connections between the nuclear and host properties of QSOs, using high-resolutio…
Isotopic Ratios in Titan's Atmosphere from Cassini CIRS Limb Sounding: CO2 at Low and Midlatitudes
Irwin, P. G. J.; Teanby, N. A.; Flasar, F. M. +8 more
This Letter reports on a search for infrared emissions of isotopologues of CO2 in the atmosphere of Titan using spectral data recorded by the Cassini Composite Infrared Spectrometer (CIRS). We have made a successful 6.5 σ detection of 13CO2 at a fraction CO2/13CO2 = 84 ± 17, consist…
Probing Elemental Abundances in SNR 1987A using XMM-Newton
Haberl, Frank; Heng, Kevin; Hasinger, Günther +1 more
We report on the latest (2007 January) observations of supernova remnant (SNR) 1987A from the XMM-Newton mission. Since the 2003 May observations of Haberl et al., 11 emission lines have experienced increases in flux by factors ~3-10, with the 775 eV line of O VIII showing the greatest increase; we have observed six lines of Fe XVII and Fe XVIII p…
Exploring the disc/jet interaction in the radio-loud quasar 4C+74.26 with Suzaku
Larsson, J.; Fabian, A. C.; Miniutti, G. +1 more
We report on a 90 ks Suzaku observation of the radio-loud quasar 4C+74.26. The source was observed in its highest flux state to date, and we find that it brightened by about 20 per cent during the observation. We see evidence of spectral hardening as the count rate increases and also find that the rms variability increases with energy up to about …
Shock propagation in the magnetosphere: Observations and MHD simulations compared
Laitinen, T. V.; Pulkkinen, T. I.; AndréEová, K. +1 more
We examine the propagation of disturbances in the Earth's magnetosphere caused by fast forward shock interaction with the magnetopause. Our statistical study and event analyses show that the propagation speeds are larger in the magnetosphere than in the solar wind and are larger in the nightside magnetosphere than in the dayside magnetosphere. A c…
Titan's surface from reconciled Cassini microwave reflectivity and emissivity observations
Janssen, Michael A.; Cassini Radar Team; Wye, Lauren C. +1 more
The surface of Titan, Saturn's largest moon, appears to consist of solid hydrocarbons or CO 2 with considerable small-scale structure, according to a new electromagnetic scattering model that uses both Cassini radar reflectivity and emissivity measurements. Our model resolves a well-known ambiguity in active and passive observations of …