Search Publications
Solar Micro-Type III Burst Storms and Long Dipolar Magnetic Field in the Outer Corona
Misawa, H.; Kasaba, Y.; Miyoshi, Y. +4 more
Solar micro-type III radio bursts are elements of the so-called type III storms and are characterized by short-lived, continuous, and weak emissions. Their frequency of occurrence with respect to radiation power is quite different from that of ordinary type III bursts, suggesting that the generation process is not flare-related, but due to some re…
Observations and Numerical Modeling of the Jovian Ribbon
Sayanagi, K. M.; Simon, A.; Cosentino, R. G. +1 more
Multiple wavelength observations made by the Hubble Space Telescope in early 2007 show the presence of a wavy, high-contrast feature in Jupiter’s atmosphere near 30°N. The “Jovian Ribbon,” best seen at 410 nm, irregularly undulates in latitude and is time-variable in appearance. A meridional intensity gradient algorithm was applied to the observat…
Mapping possible non-Gaussianity in the Planck maps
Bernui, A.; Rebouças, M. J.
Context. The study of the non-Gaussianity of the temperature fluctuations of cosmic background radiation (CMB) can be used to break the degeneracy between the inflationary models and to test alternative scenarios of the early universe. However, there are several sources of non-Gaussian contaminants in the CMB data, which make a convincing extracti…
A Study of the Coronal Non-thermal Velocity in Polar Regions During the Rise from Solar Minimum to Solar Maximum in Cycle 24
van Driel-Gesztelyi, L.; Howe, R.; Harra, L. +3 more
We explore the changes in coronal non-thermal velocity (Vnt) measurements at the poles from solar minimum to solar maximum using Hinode EUV Imaging Spectrometer data. We find that although the intensity in the corona at the poles does tend to increase with the cycle, there are no significant changes in the Vnt values. The loc…
New geometric representations of the CMB two-point correlation function
Starkman, Glenn D.; Froes, Andre L. D.; Pereira, Thiago S. +1 more
When searching for deviations of statistical isotropy in the cosmic microwave background, a popular strategy is to write the two-point correlation function (2pcf) as the most general function of four spherical angles (i.e., two unit vectors) in the celestial sphere. Then, using a basis of bipolar spherical harmonics, statistical anisotropy will sh…
Optical counterparts of ROSAT X-ray sources in two selected fields at low vs. high Galactic latitudes
Greiner, J.; Richter, G. A.
Context. The optical identification of large number of X-ray sources such as those from the ROSAT All-Sky Survey is challenging with conventional spectroscopic follow-up observations.
Aims: We investigate two ROSAT All-Sky Survey fields of size 10°× 10° each, one at galactic latitude b = 83° (26 Com), the other at b = -5° (γ Sge), in order to…
HD 207651: a Composite Spectrum Triple System
Fekel, Francis C.
From numerous radial velocities obtained at KPNO and Fairborn Observatory, we have determined the orbital elements of the composite spectrum triple system HD 207651. This system consists of a broad-lined A8 V star and an unseen M dwarf companion in a 1.470739 days orbit. Variations of the center-of-mass velocity of this short-period system and vel…
Hα and EUV Observations of a Partial CME
Antolin, Patrick; Christian, Damian J.; Jess, David B. +1 more
We have obtained Hα high spatial and time resolution observations of the upper solar chromosphere and supplemented these with multi-wavelength observations from the Solar Dynamics Observatory (SDO) and the Hinode Extreme-ultraviolet Imaging Spectrometer. The Hα observations were conducted on 2012 February 11 with the Hydrogen-Alpha Rapid Dynamics …
Exploring the potential X-ray counterpart of the puzzling TeV gamma-ray source HESS J1507-622 with new Suzaku observations
Eger, P.; Hahn, J.; Domainko, W. F.
The unidentified very high energy (VHE, E > 100 GeV) gamma-ray source HESS J1507-622 seems to not fit into standard models for sources related to young supernova remnants, pulsar wind nebulae, or young stellar populations in general. This is due to its intrinsically extended, but yet compact morphology, coupled with a relative large offset (∼3.…
Study of X-ray emission from the old open cluster, M67
Singh, K. P.; Mooley, K. P.
We present an X-ray analysis of a 4 Gyr old open cluster, M67, using archival XMM-Newton data. The aim of this study was to find new X-ray members of M67, and to use the updated member list for studying X-ray variability, and derive the X-ray luminosity functions (XLFs) of different stellar types and compare them with other star clusters of simila…