Search Publications
Three-Dimensional Structure and Energy Balance of a Coronal Mass Ejection
Raymond, J. C.; Ko, Y. -K.; Lee, J. -Y. +1 more
The Ultraviolet Coronagraph Spectrometer (UVCS) observed Doppler-shifted material of a partial halo coronal mass ejection (CME) on 2001 December 13. The observed ratio of [O V]/O V] is a reliable density diagnostic important for assessing the state of the plasma. Earlier UVCS observations of CMEs found evidence that the ejected plasma is heated lo…
Simultaneous Multiwavelength Observation of Mkn 501 in a Low State in 2006
Maraschi, L.; Covino, S.; Antonelli, L. A. +147 more
We present results of the multiwavelength campaign on the TeV blazar Mkn 501 performed in 2006 July, including MAGIC for the very-high-energy (VHE) γ-ray band and Suzaku for the X-ray band. A VHE γ-ray signal was clearly detected with an average flux above 200 GeV of ~20% of the Crab Nebula flux, which indicates a low state of source activity in t…
Steep, transient density gradients in the Martian ionosphere similar to the ionopause at Venus
Gurnett, D. A.; Winningham, J. D.; Frahm, R. A. +3 more
With the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) on the Mars Express (MEX) spacecraft, the electron density can be measured by two methods: from the excitation of local plasma oscillations and from remote sounding. A study of the local electron density versus time for 1664 orbits revealed that in 132 orbits very sharp …
Timing of the 2008 outburst of SAX J1808.4-3658 with XMM-Newton: a stable orbital-period derivative over ten years
Papitto, A.; Burderi, L.; D'Aì, A. +4 more
We report on a timing analysis performed on a 62-ks long XMM-Newton observation of the accreting millisecond pulsar SAX J1808.4-3658 during the latest X-ray outburst that started on September 21, 2008. By connecting the time of arrivals of the pulses observed during the XMM-Newton observation, we derived the best-fit orbital solution and a best-fi…
Radio and X-ray study of two multi-shell supernova remnants: Kes 79 and G352.7-0.1
Giacani, E.; Paron, S.; Smith, M. J. S. +3 more
Aims: We investigate two multi-shell galactic supernova remnants (SNRs), Kes 79, and G352.7-0.1, to understand the causes of this morphology.
Methods: The research was carried out based on new and reprocessed archival VLA observations and XMM-Newton archival data. The surrounding gas was investigated based on data extracted from the HI Canadia…
Absorption line indices in the UV. I. Empirical and theoretical stellar population models
Thomas, D.; Bender, R.; Maraston, C. +1 more
Aims: Stellar absorption lines in the optical (e.g. the Lick system) have been extensively studied and constitute an important stellar population diagnostic for galaxies in the local universe and up to moderate redshifts. Proceeding towards higher look-back times, galaxies are younger and the ultraviolet becomes the relevant spectral region where …
X-ray Monitoring of Ultraluminous X-ray Sources
Feng, Hua; Kaaret, Philip
X-ray monitoring observations were performed with the Swift observatory of the ultraluminous X-ray sources Holmberg IX X-1, NGC 5408 X-1, and NGC 4395 X-2 and also of the nuclear X-ray source in NGC 4395. Holmberg IX X-1 remains in the hard X-ray spectral state as its flux varies by a factor of 7 up to a (isotropic) luminosity of 2.8 × 1040
The colors of cometary nuclei—Comparison with other primitive bodies of the Solar System and implications for their origin
Lamy, P.; Toth, I.
We present new color results of cometary nuclei obtained with the Hubble Space Telescope (HST) whose superior resolution enables us to accurately isolate the nucleus signals from the surrounding comae. By combining with scrutinized available data obtained with ground-based telescopes, we accumulated a sample of 51 cometary nuclei, 44 ecliptic come…
Laboratory Experiments, Numerical Simulations, and Astronomical Observations of Deflected Supersonic Jets: Application to HH 110
Williams, R. J. R.; Hartigan, P.; Frank, A. +7 more
Collimated supersonic flows in laboratory experiments behave in a similar manner to astrophysical jets provided that radiation, viscosity, and thermal conductivity are unimportant in the laboratory jets and that the experimental and astrophysical jets share similar dimensionless parameters such as the Mach number and the ratio of the density betwe…
A Spectroscopically Confirmed Excess of 24 µm Sources in a Super Galaxy Group at z = 0.37: Enhanced Dusty Star Formation Relative to the Cluster and Field Environment
Saintonge, Amélie; Tran, Kim-Vy H.; Moustakas, John +5 more
To trace how dust-obscured star formation varies with environment, we compare the fraction of 24 µm sources in a super galaxy group to the field and a rich galaxy cluster at z ~ 0.35. We draw on multi-wavelength observations9Based on observations made with (1) The ESO telescopes at Paranal Observatories under program IDs 072.A-036…