Search Publications
Fully stripped? The dynamics of dark and luminous matter in the massive cluster collision MACSJ0553.4-3342
Richard, J.; Ebeling, H.; Qi, J.
We present the results of a multiwavelength investigation of the very X-ray luminous galaxy cluster MACSJ0553.4-3342 (z = 0.4270; hereafter MACSJ0553). Combining high-resolution data obtained with the Hubble Space Telescope and the Chandra X-ray Observatory with ground-based galaxy spectroscopy, our analysis establishes the system unambiguously as…
The evolution of Saturn's radiation belts modulated by changes in radial diffusion
Krupp, N.; Roussos, E.; Paranicas, C. +2 more
Globally magnetized planets, such as the Earth1 and Saturn2, are surrounded by radiation belts of protons and electrons with kinetic energies well into the million electronvolt range. The Earth's proton belt is supplied locally from galactic cosmic rays interacting with the atmosphere3, as well as from slow inward …
Tail reconnection in the global magnetospheric context: Vlasiator first results
Pulkkinen, Tuija I.; Vainio, Rami; Juusola, Liisa +7 more
The key dynamics of the magnetotail have been researched for decades and have been associated with either three-dimensional (3-D) plasma instabilities and/or magnetic reconnection. We apply a global hybrid-Vlasov code, Vlasiator, to simulate reconnection self-consistently in the ion kinetic scales in the noon-midnight meridional plane, including b…
The Late-Type Extension to MoVeRS (LaTE-MoVeRS): Proper Motion Verified Low-mass Stars and Brown Dwarfs from SDSS, 2MASS, and WISE
Burgasser, Adam J.; Schmidt, Sarah J.; Theissen, Christopher A. +2 more
We present the Late-Type Extension to the Motion Verified Red Stars (LaTE-MoVeRS) catalog, containing 46,463 photometric late-type (>M5) dwarfs within the Sloan Digital Sky Survey (SDSS) footprint. Proper motions were computed for objects combining astrometry from the SDSS Data Release 12 (DR12), the Two-micron All-Sky Survey (2MASS) Point Sour…
Multiwavelength variability study and search for periodicity of PKS 1510-089
Tagliaferri, G.; Ghisellini, G.; Pian, E. +14 more
Context. Blazars are the most luminous and variable active galactic nuclei (AGNs). They are thus excellent probes of accretion and emission processes close to the central engine.
Aims: We concentrate here on PKS 1510-089 (z = 0.36), a blazar belonging to the flat-spectrum radio quasar subclass, an extremely powerful gamma-ray source and one o…
Morphology and the Color-mass Diagram as Clues to Galaxy Evolution at z&approx1
Schawinski, Kevin; Urry, C. Megan; Simmons, Brooke D. +4 more
We study the significance of mergers in the quenching of star formation in galaxies at z∼ 1 by examining their color-mass distributions for different morphology types. We perform two-dimensional light profile fits to GOODS iz images of ∼5000 galaxies and X-ray selected active galactic nucleus (AGN) hosts in the CANDELS/GOODS-north and south fields…
Observational Evidence Linking Interstellar UV Absorption to PAH Molecules
Behar, Ehud; Brosch, Noah; Tielens, Alexander G. G. M. +2 more
The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, …
Particle Radiation Sources, Propagation and Interactions in Deep Space, at Earth, the Moon, Mars, and Beyond: Examples of Radiation Interactions and Effects
Downs, Cooper; Riley, Pete; Kozarev, Kamen +13 more
Particle radiation has significant effects for astronauts, satellites and planetary bodies throughout the Solar System. Acute space radiation hazards pose risks to human and robotic exploration. This radiation also naturally weathers the exposed surface regolith of the Moon, the two moons of Mars, and other airless bodies, and contributes to chemi…
Identification of Faint Chandra X-Ray Sources in the Core-collapsed Globular Cluster NGC 6752
Anderson, Jay; Heinke, Craig O.; Cool, Adrienne M. +2 more
We have searched for optical identifications for 39 Chandra X-ray sources that lie within the 1.‧9 half-mass radius of the nearby (d=4.0 {kpc}), core-collapsed globular cluster, NGC 6752, using deep Hubble Space Telescope ACS/WFC imaging in B 435, {R}625, and Hα. Photometry of these images allows us to classify candidate coun…
Transit probabilities in secularly evolving planetary systems
Triaud, Amaury H. M. J.; Wyatt, Mark C.; Read, Matthew J.
This paper considers whether the population of known transiting exoplanets provides evidence for additional outer planets on inclined orbits, due to the perturbing effect of such planets on the orbits of inner planets. As such, we develop a semi-analytical method for calculating the probability that two mutually inclined planets are observed to tr…