Search Publications
The detection of ultra-relativistic electrons in low Earth orbit
Dammasch, Ingolf E.; Berghmans, David; Dominique, Marie +6 more
Aims: To better understand the radiation environment in low Earth orbit (LEO), the analysis of in-situ observations of a variety of particles, at different atmospheric heights, and in a wide range of energies, is needed.
Methods: We present an analysis of energetic particles, indirectly detected by the large yield radiometer (LYRA) instr…
Titan's Variable Ionosphere During the T118 and T119 Cassini Flybys
Wahlund, J. -E.; Edberg, N. J. T.; Andrews, D. J. +6 more
We report on unusual dynamics in Titan's ionosphere as a significant difference in ionospheric electron density is observed between the T118 and T119 Cassini nightside flybys. Two distinct nightside electron density peaks were present during T118, at 1,150 and 1,200 km, and the lowest density ever observed in Titan's ionosphere at altitudes 1,000-…
Synthetic photometry of globular clusters: Uncertainties on synthetic colors
Martins, F.
Context. Synthetic photometry is a great tool for studying globular clusters, especially for understanding the nature of their multiple populations.
Aims: Our goal is to quantify the errors on synthetic photometry that are caused by uncertainties on stellar and observational/calibration parameters. These errors can be taken into account when …
Observing Galaxy Mergers at the Epoch of Reionization
Kaurov, Alexander A.; Chaikin, Evgenii A.; Tyulneva, Nadezda V.
The galaxies with photometric redshifts observed in a close angular proximity might be either projection coincidences, strongly lensed images of the same galaxy, or separate galaxies that are in a stage of merging. We search for the groups of galaxies in the Hubble Ultra Deep Field (HUDF09) in z ∼ 7 and z ∼ 8 drop-out samples. We find no close pai…
A Spatially Resolved Study of the GRB 020903 Host Galaxy
Levesque, Emily M.; Thorp, Mallory D.
GRB 020903 is a long-duration gamma-ray burst with a host galaxy close enough and extended enough for spatially resolved observations, making it one of less than a dozen GRBs where such host studies are possible. GRB 020903 lies in a galaxy host complex that appears to consist of four interacting components. Here we present the results of spatiall…
The broad-band SEDs of four `hypervariable' AGN
Done, Chris; Elvis, Martin; Marshall, Philip J. +6 more
We present an optical-to-X-ray spectral analysis of four `hypervariable' AGN (HVAs) discovered by comparing Pan-STARRS data to that from the Sloan Digital Sky Survey over a 10 yr baseline (Lawrence et al.). There is some evidence that these objects are X-ray loud for their corresponding UV luminosities, but given that we measured them in a histori…
Improved model of the triple system V746 Cassiopeiae that has a bipolar magnetic field associated with the tertiary
Harmanec, P.; Zasche, P.; Korčáková, D. +9 more
V746 Cas is known to be a triple system composed of a close binary with an alternatively reported period of either 25.^d4 or 27.^d8 and a distant third component in a 170 yr (62 000 d) orbit. The object was also reported to exhibit multiperiodic light variations with periods from 0.^d83 to 2.^d50, on the basis of which it was classified as a slowl…
Velocity-resolved [O I] 63 µm Emission in the HD 50138 Circumstellar Disk
de Wit, W. -J.; Güsten, R.; Wiesemeyer, H. +5 more
HD 50138 is one of the brightest B[e] stars and is located at a distance of ∼380 pc with strong infrared excess. The star was observed in [O I] 63 µm and [C II] 158 µm with high velocity resolution with upGREAT on SOFIA. The velocity-resolved [O I] emission provides evidence for a large gas disk, ∼760 au in size, around HD 50138. Where…
Spatial distribution of ion polytropic index joint-modulated by temperature anisotropy and MHD disturbances in the southern high latitude magnetosheath
Cao, J. B.; Pang, X. X.; Deng, Z. +1 more
The Albedos, Sizes, Colors, and Satellites of Dwarf Planets Compared with Newly Measured Dwarf Planet 2013 FY27
Sheppard, Scott S.; Fernandez, Yanga R.; Moullet, Arielle
2013 FY27 is the ninth intrinsically brightest Trans-Neptunian Object (TNO). We used ALMA at thermal wavelengths and Magellan in the optical to determine 2013 FY27's size and albedo for the first time and compare it to other dwarf planets. We found 2013 FY27 has a geometric albedo of {p}V={0.17}-0.030+0.045 and eff…