Search Publications
The Atacama Cosmology Telescope: Physical Properties and Purity of a Galaxy Cluster Sample Selected via the Sunyaev-Zel'dovich Effect
Hilton, Matt; Hasselfield, Matthew; Bond, J. Richard +48 more
We present optical and X-ray properties for the first confirmed galaxy cluster sample selected by the Sunyaev-Zel'dovich effect (SZE) from 148 GHz maps over 455 deg2 of sky made with the Atacama Cosmology Telescope (ACT). These maps, coupled with multi-band imaging on 4 m class optical telescopes, have yielded a sample of 23 galaxy clus…
C+ detection of warm dark gas in diffuse clouds
Li, D.; Goldsmith, P. F.; Langer, W. D. +3 more
We present the first results of the Herschel open time key program, Galactic Observations of Terahertz C+ (GOT C+) survey of the [CII] 2P3/2-2P1/2 fine-structure line at 1.9 THz (158 µm) using the HIFI instrument on Herschel. We detected 146 interstellar clouds along sixteen lines-of-sig…
Observation of Plasma Instabilities in Quiescent Prominences
Title, A.; Berger, T.; Frank, Z. +2 more
We study dynamics of quiescent prominences using several data sets taken with the Solar Optical Telescope (SOT) on Hinode. We find a number of processes occurring at different stages of prominence evolution that are common for all of our chosen cases and, having universal character, can be related to fundamental plasma instabilities. We combine th…
Observational Evidence of Back Reaction on the Solar Surface Associated with Coronal Magnetic Restructuring in Solar Eruptions
Liu, Chang; Wang, Haimin
Most models of solar eruptions assume that coronal field lines are anchored in the dense photosphere and thus the photospheric magnetic fields would not have rapid, irreversible changes associated with eruptions resulted from the coronal magnetic reconnection. Motivated by the recent work of Hudson et al. on quantitatively evaluating the back reac…
The role of aerodynamic drag in propagation of interplanetary coronal mass ejections
Möstl, C.; Vršnak, B.; Vennerstrom, S. +3 more
Context. The propagation of interplanetary coronal mass ejections (ICMEs) and the forecast of their arrival on Earth is one of the central issues of space weather studies.
Aims: We investigate to which degree various ICME parameters (mass, size, take-off speed) and the ambient solar-wind parameters (density and velocity) affect the ICME Sun-E…
Halo Gas and Galaxy Disk Kinematics Derived from Observations and ΛCDM Simulations of Mg II Absorption-selected Galaxies at Intermediate Redshift
Kacprzak, Glenn G.; Steidel, Charles C.; Churchill, Christopher W. +3 more
We obtained ESI/Keck rotation curves of 10 Mg II absorption-selected galaxies (0.3 <= z <= 1.0) for which we have WFPC-2/HST images and high-resolution HIRES/Keck and UVES/VLT quasar spectra of the Mg II absorption profiles. We perform a kinematic comparison of these galaxies and their associated halo Mg II absorption. For all 10 galaxies, t…
New Hubble Space Telescope WFC3/UVIS Observations Augment the Stellar-population Complexity of ω Centauri
Milone, A. P.; Marino, A. F.; Bedin, L. R. +3 more
We used archival multi-band Hubble Space Telescope observations obtained with the Wide Field Camera 3 in the UV-optical channel to present important new observational findings on the color-magnitude diagram (CMD) of the Galactic globular cluster ω Centauri. The UV WFC3 data have been coupled with available Wide Field Channel/Advanced Camera for Su…
The Lunar Reconnaissance Orbiter Miniature Radio Frequency (Mini-RF) Technology Demonstration
Nozette, Stewart; Spudis, Paul; Bussey, Ben +8 more
The Miniature Radio Frequency (Mini-RF) system is manifested on the Lunar Reconnaissance Orbiter (LRO) as a technology demonstration and an extended mission science instrument. Mini-RF represents a significant step forward in spaceborne RF technology and architecture. It combines synthetic aperture radar (SAR) at two wavelengths (S-band and X-band…
New Density Profile and Structural Parameters of the Complex Stellar System Terzan 5
Dalessandro, E.; Ransom, S. M.; Valenti, E. +9 more
Terzan 5 is a globular cluster-like stellar system in the Galactic bulge which has been recently found to harbor two stellar populations with different iron content and probably different ages. This discovery suggests that Terzan 5 may be the relic of a primordial building block that contributed to the formation of the Galactic bulge. Here we pres…
FERO: Finding extreme relativistic objects. I. Statistics of relativistic Fe Kα lines in radio-quiet Type 1 AGN
Bianchi, S.; Cappi, M.; Ponti, G. +10 more
Context. Accretion models predict that fluorescence lines broadened by relativistic effects should arise from reflection of X-ray emission onto the inner region of the accretion disc surrounding the central black hole of active galactic nuclei (AGN). The theory behind the origin of relativistic lines is well established, and observational evidence…