Search Publications
Heterogeneous evolution of the Galaxy and the origin of the short-lived nuclides in the early solar system
Kaur, Tejpreet; Sahijpal, Sandeep
We present Galactic chemical evolution (GCE) models of the short-lived radionuclides (SLRs), 26Al, 36Cl, 41Ca, 53Mn, and 60Fe, across the entire Milky Way galaxy. The objective is to understand the spatial and temporal distribution of the SLRs in the galaxy. The gamma-ray observations infer wi…
Vertical and horizontal heterogeneity of atmospheric dust loading in northern Gale Crater, Mars
Lemmon, Mark T.; Newman, Claire E.; Moore, Casey A. +3 more
This paper updates the record of atmospheric dust loading within northern Gale Crater, Mars, by providing line-of-sight extinction (LOS-Ext) measurements of the intervening dust between the rover and the crater rim. These measurements are derived from images taken with the Navigation Cameras (Navcam) onboard the Mars Science Laboratory (MSL) rover…
Characteristics of the Solar Coronal Line Profiles from Fabry-Perot Interferometric Observations
Chandrasekhar, T.; Raju, K. P.; Prabhakar, Maya
This article reports the analysis of a set of Fabry-Perot interferograms that were studied to probe the physical parameters of the inner solar corona. The observations were carried out in the coronal green line, Fe XIV 5302.86 Å, during the total solar eclipse of 21 June 2001 that occurred in Lusaka, Zambia. The study was performed in the radial r…
The Enhancement of the Energetic Particle Intensities in ICMEs
Li, Gang; Wang, Yuming; Shen, Chenglong +5 more
The behavior of energetic particles in interplanetary coronal mass ejections (ICMEs) is of great interest. In general, due to the relatively closed magnetic structures of ICMEs, the energetic-particle intensities are usually depressed in them. However, previous studies have found some counterexamples. In this work, using protons with energies form…
Analysis of a long-lived, two-cell lightning storm on Saturn
Gurnett, D. A.; Kurth, W. S.; Delcroix, M. +4 more
Lightning storms in Saturn's atmosphere can last for a few days up to several months. In this paper we analyze a lightning storm that raged for seven and a half months at a planetocentric latitude of 35° south from the end of November 2007 until mid-July 2008. Thunderstorms observed by the Cassini spacecraft before this time were characterized by …
Dwarf Spheroidal Galaxies in the M101 Group and Behind it
Karachentsev, I. D.; Makarova, L. N.
We use images from the Hubble Space Telescope to determine the distances to a dozen objects with low surface brightness recently observed around the bright nearby spiral M101. Only two dwarf galaxies, M101-DwA and M101-Dw9, turn out to be actual satellites of M101 at distances of about 7 Mpc. The other objects are probably members of a distant gro…
Principal component analysis of up-the-ramp sampled infrared array data
Rauscher, Bernard J.; Arendt, Richard G.; Fixsen, Dale J. +3 more
We describe the results of principal component analysis (PCA) of up-the-ramp sampled infrared (IR) array data from the Hubble Space Telescope wide field camera 3 (WFC3 IR), James Webb Space Telescope NIRSpec, and prototype Wide Field Infrared Survey Telescope's wide field instrument detectors. These systems use, respectively, Teledyne H1R, H2RG, a…
Search for multiwavelength emission from the binary millisecond pulsar PSR J1836-2354A in the globular cluster M22
de Martino, D.; Di Salvo, T.; Iaria, R. +5 more
We present a multiband search for X-ray, optical, and γ-ray emission of the radio binary millisecond pulsar J1836-2354A, hosted in the globular cluster M22. X-ray emission is significantly detected in two Chandra observations, performed in 2005 and 2014, at a luminosity of ∼2-3 × 1030 erg s-1, in the 0.5-8 keV energy range. T…
Monitoring of the D doublet of neutral sodium during transits of two `evaporating' planets
Hirano, T.; Ansdell, M.; Gaidos, E.
Spectroscopic transit detection of constituents in winds from `evaporating' planets on close-in transiting orbits could provide desperately needed information on the composition, formation, and orbital evolution of such objects. We obtained high-resolution optical spectra of the host stars during a single transit of Kepler-1520b and two transits o…
Understanding the Plasma and Magnetic Field Evolution of a Filament Using Observations and Nonlinear Force-free Field Modeling
Savcheva, Antonia; van Driel-Gesztelyi, Lidia; Green, Lucie M. +4 more
We present observations and magnetic field models of an intermediate filament present on the Sun in 2012 August, associated with a polarity inversion line that extends from AR 11541 in the east into the quiet Sun at its western end. A combination of Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly, SDO/Helioseismic and Magnetic Imager…