Search Publications
Missions
Journals
Publication Years
High-redshift galaxy populations
Cowie, Lennox L.; Hu, Esther M.
We now see many galaxies as they were only 800 million years after the Big Bang, and that limit may soon be exceeded when wide-field infrared detectors are widely available. Multi-wavelength studies show that there was relatively little star formation at very early times and that star formation was at its maximum at about half the age of the Unive…
Role of the Sun's Nonaxisymmetric Open Flux in Cosmic-Ray Modulation
Rouillard, A. P.; Sheeley, N. R., Jr.; Wang, Y. -M.
We reexamine the empirical relationship between the Sun's open magnetic flux and the cosmic-ray (CR) intensity over the solar cycle. The single parameter that correlates best with the inverted CR rate is found to be the nonaxisymmetric or longitudinally varying component of the total open flux, rather than the sunspot number or the rate of coronal…
Image-Subtraction Photometry of Variable Stars in the Globular Clusters NGC 6388 and NGC 6441
Catelan, M.; Stetson, Peter B.; Pritzl, Barton J. +4 more
We have applied Alard's image-subtraction method (ISIS ver. 2.1) to the observations of the globular clusters NGC 6388 and NGC 6441 previously analyzed using standard photometric techniques (DAOPHOT and ALLFRAME). In this reanalysis of observations obtained at the Cerro Tololo Inter-American Observatory, besides recovering the variables previously…
SCUBA observations of the Horsehead nebula - what did the horse swallow?
Bontemps, S.; Ward-Thompson, D.; Nutter, D. +2 more
We present observations taken with the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT) of the Horsehead nebula in Orion (B33), at wavelengths of 450 and 850 µm. We see bright emission from that part of the cloud associated with the photon-dominated region (PDR) at the `top' of the horse's head, w…
Optical Polarimetry of the Jets of Nearby Radio Galaxies. I. The Data
Baum, Stefi A.; O'Dea, Christopher P.; Perlman, Eric S. +11 more
We present an overview of new HST imaging polarimetry of six nearby radio galaxies with optical jets. These observations triple the number of extragalactic jets with subarcsecond-resolution optical polarimetry. We discuss the polarization characteristics and optical morphology of each jet. We find evidence of high optical polarization, averaging 2…
A Comprehensive Search for Gamma-Ray Lines in the First Year of Data from the INTEGRAL Spectrometer
Teegarden, B. J.; Watanabe, K.
We have carried out an extensive search for gamma-ray lines in the first year of public data from the spectrometer (SPI) on the INTEGRAL mission. INTEGRAL has spent a large fraction of its observing time in the Galactic plane with particular concentration in the Galactic center (GC) region (~3 Ms in the first year). Hence the most sensitive search…
Energization of Plasma Species by Intermittent Kinetic Alfvén Waves
Goossens, Marcel; Voitenko, Yuriy
We propose a new phase-mixing sweep model of coronal heating and solar wind acceleration based on dissipative properties of kinetic Alfvén waves (KAWs). The energy reservoir is provided by the intermittent ∼1 Hz MHD Alfvén waves excited at the coronal base by magnetic restructuring. These waves propagate upward along open magnetic field lines, pha…
Flares, Magnetic Fields, and Subsurface Vorticity: A Survey of GONG and MDI Data
Howe, R.; Komm, R.; Hill, F. +3 more
We search for a relation between flows below active regions and flare events occurring in those active regions. For this purpose, we determine the subsurface flows from high-resolution Global Oscillation Network Group (GONG) and Michelson Doppler Imager (MDI) Dynamics Program data using the ring-diagram technique. We then calculate the vorticity o…
Automated analysis of eclipsing binary light curves - II. Statistical analysis of OGLE LMC eclipsing binaries
Mazeh, T.; North, P.; Tamuz, O.
In the first paper of this series, we presented EBAS - Eclipsing Binary Automated Solver, a new fully automated algorithm to analyse the light curves of eclipsing binaries, based on the EBOP code. Here, we apply the new algorithm to the whole sample of 2580 binaries found in the Optical Gravitational Lensing Experiment (OGLE) Large Magellanic Clou…
The Chandra, Hubble Space Telescope, and VLA View of the Circumnuclear Extended Emission in the Narrow Emission Line Galaxy NGC 2110
Gallagher, Sarah C.; Lee, Julia C.; Kraft, Ralph P. +4 more
We present results from new Chandra, archival Hubble Space Telescope (HST), and VLA imaging observations of the circumnuclear extended emission in the nearby Type 2 Seyfert galaxy NGC 2110. We find resolved soft-band X-ray emission ~4" (~160 pc) north of the nucleus, which is spatially coincident with [O III] emission, but lies just beyond the nor…