Search Publications
Missions
Journals
Publication Years
DRAFTS: A Deep, Rapid Archival Flare Transient Search in the Galactic Bulge
Hawley, Suzanne L.; Osten, Rachel A.; Sahu, Kailash +1 more
We utilize the Sagittarius Window Eclipsing Extrasolar Planet Search Hubble Space Telescope/Advanced Camera for Surveys data set for a Deep Rapid Archival Flare Transient Search to constrain the flare rate toward the older stellar population in the Galactic bulge. During seven days of monitoring 229,293 stars brighter than V = 29.5, we find eviden…
Double Horizontal Branches in NGC 6440 and NGC 6569 Unveiled by the VVV Survey
Minniti, Dante; Geisler, Doug; Moni Bidin, Christian +5 more
We report the discovery of a peculiar horizontal branch (HB) in NGC 6440 and NGC 6569, two massive and metal-rich Galactic globular clusters (GGCs) located in the Galactic bulge, within 4 kpc from the Galactic center. In both clusters, two distinct clumps are detected at the level of the cluster HB, separated by only ~0.1 mag in the K s…
Saturn’s high degree magnetic moments: Evidence for a unique planetary dynamo
Cao, Hao; Dougherty, Michele K.; Russell, Christopher T. +2 more
Saturn’s intrinsic magnetic field has long been known to be highly axisymmetric. None of the existing field models goes beyond spherical harmonic degree 3. In this paper, we assume that the axisymmetry extends to higher degrees. This allows us to derive the degree 4 and 5 axial moments by searching their parameter space based on the Cassini Saturn…
Estimation of the galactic spiral pattern speed from Cepheids
Bobylev, V. V.; Bajkova, A. T.
To study the peculiarities of the Galactic spiral density wave, we have analyzed the space velocities of Galactic Cepheids with propermotions from the Hipparcos catalog and line-of-sight velocities from various sources. First, based on the entire sample of 185 stars and taking R 0 = 8 kpc, we have found the components of the peculiar so…
Seasonal variations in Saturn's plasma between the main rings and Enceladus
Wilson, R. J.; Johnson, R. E.; Elrod, M. K. +1 more
With the discovery by the Cassini spacecraft of an oxygen atmosphere over Saturn's main rings, and a strong source of water products from the plumes of Saturn's moon Enceladus, our picture of the physics of Saturn's magnetosphere from the main rings to inside the orbit of Enceladus has changed dramatically. This region contains oxygen ions from th…
Thermal to Nonthermal Energy Partition at the Early Rise Phase of Solar Flares
Fleishman, Gregory D.; Altyntsev, Alexander A.; Lesovoi, Sergey V. +1 more
In some flares, the thermal component appears much earlier than the nonthermal component in the X-ray range. Using sensitive microwave observations, we revisit this finding made by Battaglia et al. based on a thorough analysis of RHESSI data. We have found that nonthermal microwave emission produced by accelerated electrons with energy of at least…
High-velocity stars in the cores of globular clusters: the illustrative case of NGC 2808
Kruijssen, J. M. D.; Kissler-Patig, M.; de Zeeuw, P. T. +7 more
Context. We report the detection of five high-velocity stars in the core of the globular cluster NGC 2808. The stars lie on the red giant branch and show total velocities between 40 and 45 km s-1. For a core velocity dispersion σc = 13.4 km s-1, this corresponds to up to 3.4σc. These velocities are close…
Control of ion loss from Mars during solar minimum
Brecht, Stephen H.; Ledvina, Stephen A.
A hybrid particle code has been used to examine the interaction of the solar wind with Mars during solar minimum. The results were surprising as they produced ion loss rates from Mars far in excess of what is estimated from MEX. The results are analyzed and found to be consistent with the competition between photochemical rates and advection of th…
The Central Engine Structure of 3C120: Evidence for a Retrograde Black Hole or a Refilling Accretion Disk
Reynolds, Christopher S.; Cowperthwaite, Philip S.
The broad-line radio galaxy 3C120 is a powerful source of both X-ray and radio emission including superluminal jet outflows. We report on our reanalysis of 160 ks of Suzaku data taken in 2006, previously examined by Kataoka et al. Spectral fits to the X-ray Imaging Spectrometer and Hard X-ray Detector/positive intrinsic negative data over a range …
The properties of the brightest Lyα emitters at z=5.7
Schaerer, D.; Meisenheimer, K.; Lidman, C. +5 more
We use deep Very Large Telescope (VLT) optical and near-infrared spectroscopy and deep Spitzer/IRAC imaging to examine the properties of two of the most luminous Lyα emitters at z= 5.7. The continuum redward of the Lyα line is clearly detected in both objects, thus facilitating a relatively accurate measurement (10-20 per cent uncertainties) of th…