Search Publications
A Catalog of Visual Double and Multiple Stars With Eclipsing Components
Wolf, M.; Gazeas, K.; Liakos, A. +4 more
A new catalog of visual double systems containing eclipsing binaries as one component is presented. The main purpose of this catalog is to compile a complete list of all known multiples of this variety, both for current analysis and to highlight those in need of additional observations. All available photometric and astrometric data were analyzed,…
Discovery of C IV Emission Filaments in M87
Sparks, W. B.; Pringle, J. E.; Donahue, M. +4 more
Gas at intermediate temperatures between the hot X-ray-emitting coronal gas in galaxies at the centers of galaxy clusters and the much cooler optical line emitting filaments yields information on transport processes and plausible scenarios for the relationship between X-ray cool cores and other galactic phenomena such as mergers or the onset of an…
An HST/WFPC2 survey of bright young clusters in M31. I. VdB0, a massive star cluster seen at t ≃ 25 Myr
Barmby, P.; Bellazzini, M.; Galleti, S. +12 more
Aims: We introduce our imaging survey of possible young massive globular clusters in M31 performed with the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope (HST). We obtained shallow (to B∼ 25) photometry of individual stars in 20 candidate clusters. We present here details of the data reduction pipeline that is being appli…
Probing the Accretion Disk and Central Engine Structure of NGC 4258 with Suzaku and XMM-Newton Observations
Reynolds, Christopher S.; Young, Andrew J.; Nowak, Michael A. +3 more
We present an X-ray study of the low-luminosity active galactic nucleus (AGN) in NGC 4258 using data from Suzaku, XMM-Newton, and the Swift/Burst Alert Telescope survey. We find that signatures of X-ray reprocessing by cold gas are very weak in the spectrum of this Seyfert-2 galaxy; a weak, narrow fluorescent Kα emission line of cold iron is robus…
Signatures of interchange reconnection: STEREO, ACE and Hinode observations combined
Sauvaud, J. -A.; Luhmann, J. G.; van Driel-Gesztelyi, L. +8 more
Combining STEREO, ACE and Hinode observations has presented an opportunity to follow a filament eruption and coronal mass ejection (CME) on 17 October 2007 from an active region (AR) inside a coronal hole (CH) into the heliosphere. This particular combination of "open" and closed magnetic topologies provides an ideal scenario for interchange recon…
Expansion Speed of Coronal Mass Ejections
Gopalswamy, N.; Michalek, G.; Yashiro, S.
A large set of limb coronal mass ejections (CMEs) are used to determine the accurate relationship between radial (Vrad) and expansion (Vexp) speeds of CMEs. It is demonstrated that this relation is exceptionally well described by the function f(w)=1/2(1+cot w), representing a full cone model for the CME with a half-width, w. …
Reconstruction of solar UV irradiance since 1974
Solanki, S. K.; Krivova, N. A.; Podlipnik, B. +1 more
Variations of the solar UV irradiance are an important driver of chemical and physical processes in the Earth's upper atmosphere and may also influence global climate. Here we reconstruct solar UV irradiance in the range 115-400 nm over the period 1974-2007 by making use of the recently developed empirical extension of the Spectral And Total Irrad…
Shape, rheology and emplacement times of small martian shield volcanoes
Mangold, N.; Pinet, P.; Baratoux, D. +3 more
This paper focuses on the shape of 31 shield volcanoes of small to intermediate size (a few tens of kilometers in diameter) in 5 regions of Mars: Tempe Terra, Syria Planum, Pavonis Mons, Arsia Mons and central Elysium Planitia. A model for the shape of these shield volcanoes is applied, based upon the concept of porous flow of an unconfined aquife…
Dual periodicities in energetic electrons at Saturn
Krupp, N.; Krimigis, S. M.; Mitchell, D. G. +1 more
The fluxes of energetic electrons (110-365 keV) in Saturn's magnetosphere were subjected to Lomb periodogram analyses for 1677 days from late 2004 to the middle of 2009. The electrons generally exhibited strong periodicities at 10.82 hours and 10.60 hours for much of the ∼4.6 year interval. The longer period was generally present all the time, whi…
Detection of Supersonic Horizontal Flows in the Solar Granulation
Bellot Rubio, L. R.
Hydrodynamic simulations of granular convection predict the existence of supersonic flows covering ~3%-4% of the solar surface at any time, but these flows have not been detected unambiguously as yet. Using data from the spectropolarimeter aboard the Hinode satellite, I present direct evidence of fast horizontal plasma motions in quiet-Sun granule…