Search Publications
Evolution of X-ray emission from young massive star clusters
Oskinova, L. M.
The evolution of X-ray emission from young massive star clusters is modelled, taking into account the emission from the stars as well as from the cluster wind. It is shown that the level and character of the soft (0.2-10 keV) X-ray emission change drastically with cluster age and are tightly linked with stellar evolution. Using the modern X-ray ob…
The Planetary Fourier Spectrometer (PFS) onboard the European Mars Express mission
Grigoriev, A.; Rodrigo, R.; Rodriguez, J. +44 more
The Planetary Fourier Spectrometer (PFS) for the Mars Express mission is an infrared spectrometer optimised for atmospheric studies. This instrument has a short wave (SW) channel that covers the spectral range from 1700 to 8200.0cm-1 (1.2- 5.5µm) and a long-wave (LW) channel that covers 250- 1700cm-1 (5.5- 45µm). …
On the nature of nearby GRB/SN host galaxies
Sollerman, J.; Östlin, G.; Fynbo, J. P. U. +3 more
We present and discuss optical diagnostics of the low redshift ( z < 0.2) galaxies that are known to have hosted supernovae associated with γ-ray bursts (GRBs). The three galaxies are all actively star forming sub-luminous ( L < L⋆) galaxies with relatively low metallicities ( Z ≲ Z⊙). We find no evidence for substantia…
On the Nature of Dark Extreme Ultraviolet Structures Seen by SOHO/EIT and TRACE
Heinzel, P.; Anzer, U.
Spectral lines in the extreme ultraviolet (EUV) observed on the Sun can originate either from the hot corona or the cooler chromosphere to corona transition region. In the present paper we concentrate on coronal lines and in particular on iron lines at 171, 195, and 284 Å, which have been frequently observed by the Solar and Heliospheric Observato…
Rest-Frame Ultraviolet-to-Optical Properties of Galaxies at z ~ 6 and z ~ 5 in the Hubble Ultra Deep Field: From Hubble to Spitzer
Ouchi, Masami; Papovich, Casey; Dickinson, Mark +11 more
We use data from the first epoch of observations with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope for the Great Observatories Origins Deep Survey (GOODS) to detect and study a collection of Lyman break galaxies at z~6-5 in the Hubble Ultra Deep Field (HUDF), six of which have spectroscopic confirmation. At these redshifts, IRAC…
Possibilities for methanogenic life in liquid methane on the surface of Titan
McKay, C. P.; Smith, H. D.
Photochemically produced compounds on Titan, principally acetylene, ethane and organic solids, would release energy when consumed with atmospheric hydrogen, at levels of 334, 57, and 54 kJ mol -1, respectively. On Earth methanogenic bacteria can survive on this energy level. Here we speculate on the possibility of widespread methanogeni…
Hubble Space Telescope Observations of Heavy Elements in Metal-Poor Galactic Halo Stars
Beers, Timothy C.; Truran, James W.; Burles, Scott +6 more
We present new abundance determinations of neutron-capture elements Ge, Zr, Os, Ir, and Pt in a sample of 11 metal-poor (-3.1<=[Fe/H]<=-1.6) Galactic halo giant stars, based on Hubble Space Telescope UV and Keck I optical high-resolution spectroscopy. The stellar sample is dominated by r-process-rich stars such as the well-studied CS 22892-0…
Black Hole Masses and Host Galaxy Evolution of Radio-Loud Active Galactic Nuclei
van der Marel, Roeland P.; Urry, C. Megan; Lira, Paulina +2 more
We report stellar velocity dispersion measurements for a sample of 28 active galactic nucleus (AGN) host galaxies, including our previous work. Using the mass-dispersion (M•-σ) and the fundamental plane relations, we estimate the black hole mass for a sample of 66 BL Lac objects and investigate the role of black hole mass in the energet…
The Cassini UVIS Stellar Probe of the Titan Atmosphere
West, Robert A.; Esposito, Larry W.; Shemansky, Donald E. +3 more
The Cassini Ultraviolet Imaging Spectrometer (UVIS) observed the extinction of photons from two stars by the atmosphere of Titan during the Titan flyby. Six species were identified and measured: methane, acetylene, ethylene, ethane, diacetylene, and hydrogen cyanide. The observations cover altitudes from 450 to 1600 kilometers above the surface. A…
Energy deposition by Alfvén waves into the dayside auroral oval: Cluster and FAST observations
Balogh, A.; Dandouras, I.; Fazakerley, A. N. +16 more
We report in situ observations from the Cluster and FAST spacecraft showing the deposition of energy into the auroral ionosphere from broadband ULF waves in the cusp and low-latitude boundary layer. A comparison of the wave Poynting flux with particle energy and flux at both satellites indicates that energy transfer from the broadband waves to the…