Search Publications
Creating Habitable Zones, at all Scales, from Planets to Mud Micro-Habitats, on Earth and on Mars
Jaumann, Ralf; Zahnle, Kevin; Westall, Frances +5 more
The factors that create a habitable planet are considered at all scales, from planetary inventories to micro-habitats in soft sediments and intangibles such as habitat linkage. The possibility of habitability first comes about during accretion, as a product of the processes of impact and volatile inventory history. To create habitability water is …
Iron lines from transient and persisting hot spots on AGN accretion disks
Dovčiak, M.; Karas, V.; Mouchet, M. +4 more
Aims:We model the X-ray reprocessing from a strong co-rotating flare above an accretion disk in active galactic nuclei. By performing detailed radiative transfer computations we explore the horizontal structure and evolution of the underlying hot spot. The main goal is to study how the resulting spectral features manifest themselves in short expos…
Reconstruction of solar irradiance using the Group sunspot number
Solanki, S. K.; Krivova, N. A.; Balmaceda, L.
We present a reconstruction of total solar irradiance since 1610 to the present based on variations of the surface distribution of the solar magnetic field. The latter is calculated from the historical record of the Group sunspot number using a simple but consistent physical model. Our model successfully reproduces three independent data sets: tot…
The Temperature and Density Structure of an Active Region Observed with the Extreme-Ultraviolet Imaging Spectrometer on Hinode
Warren, Harry P.; Doschek, George A.; Young, Peter R. +5 more
The Extreme-Ultraviolet Imaging Spectrometer (EIS) on Hinode produces high resolution spectra that can be combined via rasters into monochromatic images of solar structures, such as active regions. Electron temperature and density maps of the structures can be obtained by imaging the structures in different spectral lines with ratios sensitive to …
Filtration of Interstellar Atoms through the Heliospheric Interface
Izmodenov, V. V.
Interstellar atoms penetrate deep into the heliosphere after passing through the heliospheric interface—the region of the interaction of the solar wind with the interstellar medium. The heliospheric interface serves as a filter for the interstellar atoms of hydrogen and oxygen, and, to a lesser extent, nitrogen, due to their coupling with interste…
Micro-Type III Radio Bursts
Morioka, Akira; Miyoshi, Yoshizumi; Masuda, Satoshi +5 more
We present a detailed description of the features of solar ``micro-type III'' radio bursts, which are elements of the so-called type III storms, using long-term observations made by the Geotail and Akebono satellites. Micro-type III bursts are characterized by short-lived, continuous, and weak emission. Their average power is estimated to be well …
Signatures of Enceladus in Saturn's E ring
Morfill, Gregor E.; Horányi, Mihály; Juhász, Antal
Dust production from Enceladus has long been suggested as the main source of dust in Saturn's E ring. This was supported by the observation that the ring's optical depth peaks close to the orbit of this moon. However, both HST and Keck observations indicated that the peak of the optical depth distribution in fact lies outside the orbit of Enceladu…
Speed of sound measurements and the methane abundance in Titan's atmosphere
Lorenz, R. D.; Hagermann, A.; Leese, M. R. +6 more
Aboard the Huygens probe, which descended through Titan's atmosphere in January 2005, was the Surface Science Package (SSP), a set of 9 sensors, including a speed-of-sound sensor. We present the first detailed description of the SSP speed of sound measurements and report constraints on the methane content in Titan's lower atmosphere based on these…
Ulysses observations of Jovian relativistic electrons in the interplanetary space near Jupiter: Determination of perpendicular particle transport coefficients and their energy dependence
Qin, Gang; Heber, Bernd; Zhang, Ming +3 more
Intensities of ∼1-10 MeV relativistic electrons in several energy channels of the high-energy telescope (HET) on Ulysses increase dramatically during its flybys of Jupiter in 1992 and 2004. Perpendicular diffusion coefficients of these particles are derived by fitting the spatial profile of Jovian electron intensity to a diffusion-convection model…
Discovery of a single faint AGN in a large sample of z > 5 Lyman break galaxies
Lehnert, Matthew D.; Stanway, Elizabeth R.; Bremer, Malcolm N. +1 more
As part of a large spectroscopic survey of z > 5 Lyman break galaxies (LBGs), we have identified a single source which is clearly hosting an active galactic nucleus (AGN). Out of a sample of more than 50 spectroscopically confirmed R-band dropout galaxies at z ~ 5 and above, only J104048.6-115550.2 at z = 5.44 shows evidence for a high ionizati…