Search Publications
Cassini UVIS observations of Titan nightglow spectra
West, Robert A.; Esposito, Larry W.; Gustin, Jacques +6 more
In this paper we present the first nightside EUV and FUV airglow limb spectra of Titan showing molecular emissions. The Cassini Ultraviolet Imaging Spectrograph (UVIS) observed photon emissions of Titan's day and night limb-airglow and disk-airglow on multiple occasions, including during an eclipse observation. The 71 airglow observations analyzed…
Off-limb (Spicule) DEM Distribution from SoHO/SUMER Observations
Doyle, J. G.; Madjarska, M. S.; Vanninathan, K. +1 more
In the present work we derive a Differential Emission Measure (DEM) distribution from a region dominated by spicules. We use spectral data from the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on-board the Solar Heliospheric Observatory (SoHO) covering the entire SUMER wavelength range taken off-limb in the Northern pol…
X-Ray, UV and Optical Observations of Classical Cepheids: New Insights into Cepheid Evolution, and the Heating and Dynamics of Their Atmospheres
Guinan, Edward F.; Engle, Scott G.
To broaden the understanding of classical Cepheid structure, evolution and atmospheres, we have extended our continuing secret lives of Cepheids program by obtaining XMM/Chandra X-ray observations, and Hubble space telescope (HST) / cosmic origins spectrograph (COS) FUV-UV spectra of the bright, nearby Cepheids Polaris, δ Cep and β Dor. Previous s…
Characterizing the nature of fossil groups with XMM
Paolillo, M.; La Barbera, F.; De Filippis, E. +1 more
We present an X-ray follow-up, based on XMM plus Chandra, of six fossil group (FG) candidates identified in our previous work using Sloan Digital Sky Survey (SDSS) and ROSAT All-Sky Survey (RASS) data. Four candidates (out of six) exhibit extended X-ray emission, confirming them as true FGs. For the other two groups, the RASS emission has its orig…
More about arc-polarized structures in the solar wind
Haaland, S.; Paschmann, G.; Sonnerup, B.
We report results from a Cluster-based study of the properties of 28 arc-polarized magnetic structures (also called rotational discontinuities) in the solar wind. These Alfvénic events were selected from the database created and analyzed by Knetter (2005) by use of criteria chosen to eliminate ambiguous cases. His studies showed that standard, fou…
A deep X-ray observation of the supernova remnant G304.6+0.1 (Kes 17) using Suzaku
Sezer, A.; Gök, F.
In this paper, we present the analysis of a deep (99.6 ks) observation of G304.6+0.1 with the X-ray Imaging Spectrometer on board the Suzaku satellite. The X-ray spectral data are well fitted with a plasma model consisting of a thermal component, in collisional ionization equilibrium, and a non-thermal component. The thermal emission is well fitte…
Dark energy in six nearby galaxy flows: Synthetic phase diagrams and self-similarity
Valtonen, M. J.; Chernin, A. D.; Teerikorpi, P. +4 more
Outward flows of galaxies are observed around groups of galaxies on spatial scales of about 1 Mpc, and around galaxy clusters on scales of 10 Mpc. Using recent data from the Hubble Space Telescope (HST), we have constructed two synthetic velocity-distance phase diagrams: one for four flows on galaxy-group scales and the other for two flows on clus…
Thermal anomalies on pit craters and sinuous rilles of Arsia Mons: Possible signatures of atmospheric gas circulation in the volcano
d'Uston, L.; Lopez, T.; Antoine, R. +3 more
Seven circular depressions named as pit craters were found in northern flank of Arsia Mons, and we report 76 new ones in the southern flank of the volcano. Their diameters range from 100 m to 1300 m and depths range from 22 to 500 m. THEMIS-IR data reveal that some of these pit craters are 10 K warmer than the surrounding surface during night and …
Suzaku Observation of Nearby On-Going Merger Cluster Abell 3627
Fukazawa, Yasushi; Nishino, Sho; Hayashi, Katsuhiro
We present the results of the Suzaku observation of a nearby (z = 0.016), on-going merger cluster, Abell 3627. The overall temperature of the ICM is around 7 keV, and we found a cool region with kT ∼ 4-5 keV at the position corresponding to the brightness excess from a spherically symmetrical β-model found by ROSAT. This structure seems to be a su…
Flat-spectrum radio sources as likely counterparts of unidentified INTEGRAL sources
Gehrels, N.; Bird, A. J.; Landi, R. +5 more
Many sources in the fourth INTEGRAL/IBIS catalogue are still unidentified since they lack an optical counterpart. An important tool that can help in identifying and classifying these sources is the cross-correlation with radio catalogues, which are very sensitive and positionally accurate. Moreover, the radio properties of a source, such as the sp…