Search Publications
The Search for Active Marsquakes Using Subpixel Coregistration and Correlation: Best Practice and First Results
Grindrod, Peter M.; Hollingsworth, James; Ayoub, Francois +1 more
The state of seismic activity on Mars is currently unknown. On Earth, coseismic displacement has been observed using visible wavelength images and subpixel coregistration and correlation techniques. We apply this method to Mars with the COSI-Corr (Co-registration of Optically Sensed Images and Correlation) software package using High-Resolution Im…
A multi-wavelength analysis of the diffuse H II region G25.8700+0.1350
Reynoso, E. M.; Dorda, R.; Cichowolski, S. +2 more
We present a multi-wavelength investigation of the H II region G25.8700+0.1350, located in the inner part of the Galaxy. In radio continuum emission, the region is seen as a bright arc-shaped structure. An analysis of the H I line suggests that G25.8700+0.1350 lies at a distance of 6.5 kpc. The ionized gas is bordered by a photodissociation region…
Effects of a caustic ring of dark matter on the distribution of stars and interstellar gas
Chakrabarty, Sankha S.; Sikivie, Pierre
Caustic rings of dark matter with tricusp cross section were predicted to lie in the galactic disk. Their radii increase on cosmological time scales at a rate of order 1 kpc /Gyr . When a caustic ring passes through the orbit of a star, the orbit is strongly perturbed. We find that a star moving in a nearly circular orbit is first attracted toward…
Measuring size evolution of distant, faint galaxies in the radio regime
Muxlow, T. W. B.; Wrigley, N.; Knudsen, K. K. +5 more
We measure the evolution of sizes for star-forming galaxies as seen in 1.4 GHz continuum radio for z = 0-3. The measurements are based on combined VLA+MERLIN data of the Hubble Deep Field, and using a uv-stacking algorithm combined with model fitting to estimate the average sizes of galaxies. A sample of ∼1000 star-forming galaxies is selected fro…
Morphometric and rheological study of lunar domes of Marius Hills volcanic complex region using Chandrayaan-1 and recent datasets
Suresh, K.; Arya, A. S.; Rajasekhar, R. P. +10 more
Marius Hills volcanic complex is one of the most important regions on the lunar surface having an abundant number of volcanic features like domes and cones. Systematic mapping of 106 domes/cones in the Marius Hills region was carried out in this study using high-resolution orthoimage and digital elevation models of Chandrayaan-1 and Kaguya mission…
The global sphere reconstruction (GSR). Demonstrating an independent implementation of the astrometric core solution for Gaia
Lattanzi, M. G.; Messineo, R.; Abbas, U. +6 more
Context. The Gaia ESA mission will estimate the astrometric and physical data of more than one billion objects, providing the largest and most precise catalog of absolute astrometry in the history of astronomy. The core of this process, the so-called global sphere reconstruction, is represented by the reduction of a subset of these objects which w…
Effect of Upstream ULF Waves on the Energetic Ion Diffusion at the Earth’s Foreshock. II. Observations
Dandouras, Iannis; Matsukiyo, Shuichi; Kis, Arpad +5 more
This study reports observations of energetic ions upstream of the Earth’s quasi-parallel bow shock by Cluster at times when interspacecraft separation distances were large. We analyze two individual upstream ion events during high solar wind velocity conditions to compare the spatial evolution of partial energetic ion densities in front of the Ear…
From non-trivial geometries to power spectra and vice versa
Brooker, D. J.; Tsamis, N. C.; Woodard, R. P.
We review a recent formalism which derives the functional forms of the primordial—tensor and scalar—power spectra of scalar potential inflationary models. The formalism incorporates the case of geometries with non-constant first slow-roll parameter. Analytic expressions for the power spectra are given that explicitly display the dependence on the …
The HP2 Survey. IV. The Pipe nebula: Effective dust temperatures in dense cores
Alves, João; Forbrich, Jan; Lada, Charles J. +3 more
Multi-wavelength observations in the sub-millimeter regime provide information on the distribution of both the dust column density and the effective dust temperature in molecular clouds. In this study, we created high-resolution and high-dynamic-range maps of the Pipe nebula region and explored the value of dust-temperature measurements in particu…
O2 signature in thin and thick O2-H2O ices⋆
Caselli, P.; Vasyunin, A. I.; Bizzocchi, L. +2 more
Aims: In this paper we investigate the detectability of the molecular oxygen in icy dust grain mantles towards astronomical objects.
Methods: We present a systematic set of experiments with O2-H2O ice mixtures designed to disentangle how the molecular ratio affects the O2 signature in the mid- and near-in…