Search Publications
Solar wind entry into the high-latitude terrestrial magnetosphere during geomagnetically quiet times
Wei, Y.; Zhang, H.; Zong, Q. -G. +14 more
An understanding of the transport of solar wind plasma into and throughout the terrestrial magnetosphere is crucial to space science and space weather. For non-active periods, there is little agreement on where and how plasma entry into the magnetosphere might occur. Moreover, behaviour in the high-latitude region behind the magnetospheric cusps, …
Massive Clumps in Local Galaxies: Comparisons with High-redshift Clumps
Elmegreen, Bruce G.; Elmegreen, Debra Meloy; Muñoz-Tuñón, C. +5 more
Local UV-bright galaxies in the Kiso survey include clumpy systems with kiloparsec-size star complexes that resemble clumpy young galaxies in surveys at high redshift. We compare clump masses and underlying disks in several dozen galaxies from each of these surveys to the star complexes and disks of normal spirals. Photometry and spectroscopy for …
Cosmological constraints from baryon acoustic oscillations and clustering of large-scale structure
Halpern, M.; Hinshaw, G.; Addison, G. E.
We constrain cosmological parameters using combined measurements of the baryon acoustic oscillation (BAO) feature in the correlation function of galaxies and Lyα absorbers that together cover 0.1 < z < 2.4. The BAO position measurements alone - without fixing the absolute sound horizon `standard ruler' length with cosmic microwave background…
Swift heavy ion irradiation of water ice from MeV to GeV energies. Approaching true cosmic ray compaction
Dartois, E.; Chabot, M.; Brunetto, R. +11 more
Context. Cosmic ray ion irradiation affects the chemical composition of and triggers physical changes in interstellar ice mantles in space. One of the primary structural changes induced is the loss of porosity, and the mantles evolve toward a more compact amorphous state. Previously, ice compaction was monitored at low to moderate ion energies. Th…
Solar flares at submillimeter wavelengths
Krucker, Säm; Kretzschmar, M.; Klein, K. -L. +10 more
We discuss the implications of the first systematic observations of solar flares at submillimeter wavelengths, defined here as observing wavelengths shorter than 3 mm (frequencies higher than 0.1 THz). The events observed thus far show that this wave band requires a new understanding of high-energy processes in solar flares. Several events, includ…
Water Vapor in nearby Infrared Galaxies as Probed by Herschel
Omont, A.; Isaak, K. G.; Liu, Daizhong +5 more
We report the first systematic study of the submillimeter water vapor rotational emission lines in infrared (IR) galaxies based on the Fourier Transform Spectrometer (FTS) data of Herschel SPIRE. Among the 176 galaxies with publicly available FTS data, 45 have at least one H2O emission line detected. The H2O line luminosities…
Stellar Populations and Evolution of Early-type Cluster Galaxies: Constraints from Optical Imaging and Spectroscopy of z = 0.5-0.9 Galaxy Clusters
Jørgensen, Inger; Chiboucas, Kristin
We present an analysis of stellar populations and evolutionary history of galaxies in three similarly rich galaxy clusters MS0451.6-0305 (z = 0.54), RXJ0152.7-1357 (z = 0.83), and RXJ1226.9+3332 (z = 0.89). Our analysis is based on high signal-to-noise ground-based optical spectroscopy and Hubble Space Telescope imaging for a total of 17-34 member…
A Soft X-Ray Reverberation Lag in the AGN ESO 113-G010
Fabian, A. C.; Uttley, P.; Cackett, E. M. +3 more
Reverberation lags have recently been discovered in a handful of nearby, variable active galactic nuclei (AGNs). Here, we analyze a ~100 ks archival XMM-Newton observation of the highly variable AGN, ESO 113-G010, in order to search for lags between hard, 1.5-4.5 keV, and soft, 0.3-0.9 keV, energy X-ray bands. At the lowest frequencies available i…
The XMM deep survey in the CDF-S. IV. Compton-thick AGN candidates
Elbaz, D.; Fritz, J.; Vignali, C. +15 more
The Chandra Deep Field is the region of the sky with the highest concentration of X-ray data available: 4 Ms of Chandra and 3 Ms of XMM-Newton data, allowing excellent quality spectra to be extracted even for faint sources. We took advantage of this to compile a sample of heavily obscured active galactic nuclei (AGN) using X-ray spectroscopy. We s…
Is There a Metallicity Ceiling to Form Carbon Stars?—A Novel Technique Reveals a Scarcity of C stars in the Inner M31 Disk
Dalcanton, J. J.; Girardi, L.; Boyer, M. L. +10 more
We use medium-band near-infrared (NIR) Hubble Space Telescope WFC3 photometry with model NIR spectra of asymptotic giant branch (AGB) stars to develop a new tool for efficiently distinguishing carbon-rich (C-type) AGB stars from oxygen-rich (M-type) AGB stars in galaxies at the edge of and outside the Local Group. We present the results of a test …