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Observations of free-free and anomalous microwave emission from LDN 1622 with the 100 m Green Bank Telescope
Dickinson, C.; Cleary, K.; Harper, S. E.
LDN 1622 has previously been identified as a possible strong source of dust-correlated anomalous microwave emission (AME). Previous observations were limited by resolution meaning that the radio emission could not be compared with current generation high-resolution infrared data from Herschel, Spitzer or Wide-field Infrared Sky Explorer. This pape…
Determination of parameters of Long-Term variability of the X-ray pulsar LMC X-4
Lutovinov, A. A.; Falanga, M.; Molkov, S. V.
We have investigated the temporal variability of the X-ray flux measured from the high-mass X-ray binary LMCX-4 on time scales from several tens of days to tens of years, i.e., exceeding considerably the orbital period (~1.408 days). In particular, we have investigated the 30-day cycle of modulation of the X-ray emission from the source (superorbi…
Far-infrared signatures and inner hole sizes of protoplanetary discs undergoing inside-out dust dispersal
Robitaille, Thomas; Owen, James; Ercolano, Barbara +1 more
By means of radiative transfer simulation, we study the evolution of the far-infrared colours of protoplanetary discs undergoing inside-out dispersal, often referred to as transition discs. We show that a brightening of the mid- and far-infrared emission from these objects is a natural consequence of the removal of the inner disc. Our results can …
Decameter U-burst Harmonic Pair from a High Loop
Rucker, H. O.; Panchenko, M.; Poedts, S. +6 more
The results of the first observations of solar sporadic radio emission within 10 - 70 MHz by the Giant Ukrainian Radio Telescope (GURT) are presented and discussed. Observations in such a wide range of frequencies considerably facilitate the registration of harmonic pairs. The solar U-burst harmonic pair observed on 8 August 2012 is analyzed. The …
Multiwavelength observations of NaSt1 (WR 122): equatorial mass loss and X-rays from an interacting Wolf-Rayet binary
Van Dyk, Schuyler D.; Smith, Nathan; Close, Laird M. +5 more
NaSt1 (aka Wolf-Rayet 122) is a peculiar emission-line star embedded in an extended nebula of [N II] emission with a compact dusty core. The object was previously characterized as a Wolf-Rayet (WR) star cloaked in an opaque nebula of CNO-processed material, perhaps analogous to η Car and its Homunculus nebula, albeit with a hotter central source. …
Intensity of nightside MARSIS AIS surface reflections and implications for low-altitude ionospheric densities
Gurnett, D. A.; Němec, F.; Morgan, D. D. +1 more
Spacecraft radar sounding signals at frequencies higher than the ionospheric peak plasma frequency are not reflected by the ionosphere. Instead, they make it to the ground where they are reflected by the planetary surface. We analyze the intensity of the surface reflections measured by the Mars Advanced Radar for Subsurface and Ionosphere Sounding…
The Q/U Imaging Experiment: Polarization Measurements of the Galactic Plane at 43 and 95 GHz
Davies, R. D.; Dickinson, C.; Eriksen, H. K. +39 more
We present polarization observations of two Galactic plane fields centered on Galactic coordinates (l, b) = (0°, 0°) and (329°, 0°) at both Q (43 GHz) and W bands (95 GHz), covering between 301 and 539 square degrees depending on frequency and field. These measurements were made with the QUIET instrument between 2008 October and 2010 December, and…
Volcanic terrain and the possible periglacial formation of "excess ice" at the mid-latitudes of Utopia Planitia, Mars
Soare, R. J.; El-Maarry, M. R.; Conway, S. J. +2 more
At the mid-latitudes of Utopia Planitia (UP), Mars, a suite of spatially-associated landforms exhibit geomorphological traits that, on Earth, would be consistent with periglacial processes and the possible freeze-thaw cycling of water. The suite comprises small-sized polygonally-patterned ground, polygon-junction and -margin pits, and scalloped, r…
Corrugations and eccentric spirals in Saturn's D ring: New insights into what happened at Saturn in 1983
Hedman, M. M.; Burns, J. A.; Showalter, M. R.
Previous investigations of Saturn's outer D ring (73,200-74,000 km from Saturn's center) identified periodic brightness variations whose radial wavenumber increased linearly over time. This pattern was attributed to a vertical corrugation, and its temporal variability implied that some event - possibly an impact with interplanetary debris - caused…
Influence of a CME’s Initial Parameters on the Arrival of the Associated Interplanetary Shock at Earth and the Shock Propagational Model Version 3
Feng, X. S.; Zhao, X. H.
Predicting the arrival times of coronal mass ejections (CMEs) and their related waves at Earth is an important aspect of space weather forecasting. The Shock Propagation Model (SPM) and its updated version (SPM2), which use the initial parameters of solar flare-Type II burst events as input, have been developed to predict the shock arrival time. T…