Search Publications
The Solar Neighborhood. XXI. Parallax Results from the CTIOPI 0.9 m Program: 20 New Members of the 25 Parsec White Dwarf Sample
Henry, Todd J.; Bergeron, P.; Dufour, P. +5 more
We present accurate trigonometric parallaxes for 20 new members of the 25 pc white dwarf (WD) sample as part of the Discovery and Evalution of Nearby Stellar Embers (DENSE) project.7 http://www.DenseProject.com Previously, there were a total of 112 WD systems with trigonometric parallaxes placin…
Galaxy Clusters in the Swift/Burst Alert Telescope Era: Hard X-rays in the Intracluster Medium
Böhringer, H.; Greiner, J.; Moretti, A. +6 more
We report the detection of 10 clusters of galaxies in the ongoing Swift/Burst Alert Telescope (BAT) all-sky survey. This sample, which mostly comprises merging clusters, was serendipitously detected in the 15-55 keV band. We use the BAT sample to investigate the presence of excess hard X-rays above the thermal emission. The BAT clusters do not sho…
Evidence of Widespread Hot Plasma in a Nonflaring Coronal Active Region from Hinode/X-Ray Telescope
Testa, Paola; Reale, Fabio; Parenti, Susanna +1 more
Nanoflares, short and intense heat pulses within spatially unresolved magnetic strands, are now considered a leading candidate to solve the coronal heating problem. However, the frequent occurrence of nanoflares requires that flare-hot plasma be present in the corona at all times. Its detection has proved elusive until now, in part because the int…
The End of Nucleosynthesis: Production of Lead and Thorium in the Early Galaxy
Roederer, Ian U.; Frebel, Anna; Christlieb, Norbert +4 more
We examine the Pb and Th abundances in 27 metal-poor stars (-3.1< [Fe/H] <-1.4) whose very heavy metal (Z > 56) enrichment was produced only by the rapid (r-) nucleosynthesis process. New abundances are derived from Hubble Space Telescope/Space Telescope Imaging Spectrograph, Keck/High Resolution Echelle Spectrograph, and Very Large Teles…
Hinode X-Ray Telescope Detection of Hot Emission from Quiescent Active Regions: A Nanoflare Signature?
Klimchuk, J. A.; Golub, L.; Schmelz, J. T. +4 more
The X-Ray Telescope (XRT) on the Japanese/USA/UK Hinode (Solar-B) spacecraft has detected emission from a quiescent active region core that is consistent with nanoflare heating. The fluxes from 10 broadband X-ray filters and filter combinations were used to construct differential emission measure (DEM) curves. In addition to the expected active re…
Imaging The Molecular Gas in a z = 3.9 Quasar Host Galaxy at 0farcs3 Resolution: A Central, Sub-Kiloparsec Scale Star Formation Reservoir in APM 08279+5255
Lewis, Geraint F.; Walter, Fabian; Carilli, Christopher L. +1 more
We have mapped the molecular gas content in the host galaxy of the strongly lensed high-redshift quasar APM 08279+5255 (z = 3.911) with the Very Large Array at 0farcs3 resolution. The CO(J = 1 → 0) emission is clearly resolved in our maps. The CO(J = 1 → 0) line luminosity derived from these maps is in good agreement with a previous single-dish me…
Solar-like oscillations in HD 181420: data analysis of 156 days of CoRoT data
Auvergne, M.; Baudin, F.; García, R. A. +18 more
Context: The estimate of solar-like oscillation properties, such as their frequencies, amplitudes and lifetimes, is challenging because of their low amplitudes and will benefit from long and uninterrupted observing runs. The space telescope CoRoT allows us to obtain high-performance photometric data over a long and quasi continuous period. Among i…
Solar infrared occultation observations by SPICAM experiment on Mars-Express: Simultaneous measurements of the vertical distributions of H 2O, CO 2 and aerosol
Reberac, A.; Montmessin, F.; Bertaux, J. -L. +4 more
The infrared AOTF spectrometer is a part of the SPICAM experiment onboard the Mars-Express ESA mission. The instrument has a capability of solar occultations and operates in the spectral range of 1-1.7 µm with a spectral resolution of ∼3.5 cm -1. We report results from 24 orbits obtained during MY28 at L 130°-160°, and the latitud…
Tracers of Chromospheric Structure. I. Observations of Ca II K and Hα in M Dwarfs
Hawley, Suzanne L.; Walkowicz, Lucianne M.
We report on our observing program4This paper is based on observations obtained with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the Ca…
Calibration Of [O IV] 26 µm as a Measure of Intrinsic Active Galactic Nucleus Luminosity
Rigby, J. R.; Aniano, G.; Diamond-Stanic, A. M.
We compare [O IV] 25.89 µm emission line luminosities with very hard (10-200 keV) X-rays from Swift, INTEGRAL, and BeppoSAX for a complete sample of 89 Seyferts from the Revised Shapley-Ames sample. Using Seyfert 1s, we calibrate [O IV] as a measure of active galactic nucleus (AGN) intrinsic luminosity, for particular use in high-obscuration…