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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…
Solar wind dynamic pressure and electric field as the main factors controlling Saturn's aurorae
Coates, A. J.; Dougherty, M. K.; Kurth, W. S. +11 more
The interaction of the solar wind with Earth's magnetosphere gives rise to the bright polar aurorae and to geomagnetic storms, but the relation between the solar wind and the dynamics of the outer planets' magnetospheres is poorly understood. Jupiter's magnetospheric dynamics and aurorae are dominated by processes internal to the jovian system, wh…
Seismic Emission from the Solar Flares of 2003 October 28 and 29
Lindsey, C.; Donea, A. -C.
We report the detection of seismic waves emitted from powerful solar flares that occurred in NOAA Active Region 10486 on 2003 October 28 and 29. We used helioseismic holography to image the seismic sources of the waves. This technique was previously used to image the source of seismic emission from the large solar flare of 1996 July 9. Egression p…
The Double Star magnetic field investigation: instrument design, performance and highlights of the first year's observations
Balogh, A.; Zhang, T. L.; Glassmeier, K. -H. +19 more
One of the primary objectives of the Double Star mission is the accurate measurement of the magnetic field vector along the orbits of the two spacecraft. The magnetic field is an essential parameter for the understanding of space plasma processes and is also required for the effective interpretation of data from the other instruments on the spacec…
Cluster encounter of a magnetic reconnection diffusion region in the near-Earth magnetotail on September 19, 2003
Balogh, A.; Rème, H.; Mouikis, C. +7 more
We report a clear encounter by the Cluster spacecraft of a magnetic reconnection diffusion region in the near-Earth magnetotail at XGSM = -17.5 RE on September 19, 2003. In addition to the reversals of the plasma jets and of GSM-z (~normal) component of the magnetic field, clear signatures of Hall quadrupolar (GSM-y) magnetic…