Search Publications
Missions
Journals
Publication Years
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 …
Strong jet and a new thermal wave in Saturn's equatorial stratosphere
Fletcher, Leigh N.; Achterberg, Richard K.; Flasar, F. Michael +7 more
The strong jet, with a speed between 500 and 600 m/s, is inferred in the equatorial region of Saturn by combining the nadir and limb observations of Composite Infrared Spectrometer (CIRS) aboard the Cassini spacecraft. A similar jet was discovered on Jupiter (F. M. Flasar et al., 2004a). These discoveries raise the possibility that intense jets ar…
Evolution in the discs and bulges of group galaxies since z = 0.4
Mulchaey, John S.; Balogh, Michael L.; Oemler, Augustus, Jr. +4 more
We present quantitative morphology measurements of a sample of optically selected group galaxies at 0.3 < z < 0.55 using the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) and the GIM2D surface brightness fitting software package. The group sample is derived from the Canadian Network for Observational Cosmology Field Galaxy R…
The Symbiotic System SS73 17 Seen with Suzaku
Mukai, Koji; Kallman, Tim; Smith, Randall K. +3 more
We observed with Suzaku the symbiotic star SS73 17, motivated by the discovery by the INTEGRAL satellite and the Swift BAT survey that it emits hard X-rays. Our observations showed a highly-absorbed X-ray spectrum with NH > 1023cm-2, equivalent to AV > 26, although the source has B magnitude 11.3 a…