Search Publications
Missions
Journals
Publication Years
Energetic particle acceleration and transport at coronal mass ejection-driven shocks
Li, Gang; Zank, G. P.; Rice, W. K. M.
Evidence now exists which suggests that in large solar energetic particle (SEP) events, particles are often accelerated to ∼ MeV energies (and perhaps up to GeV energies) at shock waves driven by coronal mass ejections (CMEs). These energetic particles are of considerable importance to space weather studies since they serve as a precursor signal f…
A Spectroscopic Survey of Subarcsecond Binaries in the Taurus-Auriga Dark Cloud with the Hubble Space Telescope
Hartigan, Patrick; Kenyon, Scott J.
We report the results of a spectroscopic survey of 20 close T Tauri binaries in the Taurus-Auriga dark cloud where the separations between primaries and their secondaries are less than the typical size of a circumstellar disk around a young star. Analysis of low- and medium-resolution Space Telescope Imaging Spectrograph spectra yields the stellar…
The iron line in MCG-6-30-15 from XMM-Newton: evidence for gravitational light bending?
Vaughan, S.; Fabian, A. C.
The lack of variability of the broad iron line seen in the Seyfert 1 galaxy MCG-6-30-15 is studied using the EPIC pn data obtained from a 2001 observation of 325 ks, during which the count rate from the source varied by a factor of 5. The spectrum of 80 ks of data from when the source was bright, using the lowest 10 ks as background, is well fitte…
Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group
Adelman, Saul J.; Soderblom, David R.; King, Jeremy R. +2 more
Utilizing Hipparcos parallaxes, original radial velocities and recent literature values, new Ca II H and K emission measurements, literature-based abundance estimates, and updated photometry (including recent resolved measurements of close doubles), we revisit the Ursa Major moving group membership status of some 220 stars to produce a final clean…
The Globular Cluster System of NGC 1399. I. A Wide-Field Photometric Study
Geisler, D.; Dirsch, B.; Richtler, T. +3 more
We present a photometric investigation of the globular cluster population of NGC 1399, the central galaxy in the Fornax cluster, in Washington C and Kron R filters within a field of 36'×36', corresponding to about 200×200 kpc at the Fornax distance. This is the largest area around this galaxy ever studied with CCD photometry. The cluster system of…
OMC: An Optical Monitoring Camera for INTEGRAL. Instrument description and performance
Hanlon, L.; McBreen, B.; Mas-Hesse, J. M. +48 more
The Optical Monitoring Camera (OMC) will observe the optical emission from the prime targets of the gamma-ray instruments onboard the ESA mission INTEGRAL, with the support of the JEM-X monitor in the X-ray domain. This capability will provide invaluable diagnostic information on the nature and the physics of the sources over a broad wavelength ra…
The origin of crystalline silicates in the Herbig Be star HD 100546 and in comet Hale-Bopp
Waters, L. B. F. M.; Dominik, C.; de Koter, A. +1 more
We have investigated the spatial distribution, and the properties and chemical composition of the dust orbiting HD 100546. This system is remarkably different from other isolated Herbig Ae/Be stars in both the strength of the mid-IR excess and the composition of the circumstellar dust. To explain spectral features and the amount of mid-IR dust emi…
Kinematic Masses of Super-Star Clusters in M82 from High-Resolution Near-Infrared Spectroscopy
Graham, James R.; McCrady, Nate; Gilbert, Andrea M.
Using high-resolution (R~22,000) near-infrared (1.51-1.75 µm) spectra from Keck Observatory, we measure the kinematic masses of two super-star clusters in M82. Cross-correlation of the spectra with template spectra of cool evolved stars gives stellar velocity dispersions of σr=15.9+/-0.8 km s-1 for J0955505+694045 (MGG-…
Lyman break galaxies and the star formation rate of the Universe at z~ 6
Bunker, Andrew J.; McMahon, Richard G.; Stanway, Elizabeth R.
We determine the space density of UV-luminous starburst galaxies at z~ 6 using deep HST ACS SDSS-i' (F775W) and SDSS-z' (F850LP) and VLT ISAAC J and Ks band imaging of the Chandra Deep Field South. We find eight galaxies and one star with (i'-z') > 1.5 to a depth of z'AB= 25.6 (an 8σ detection in each of the 3 available AC…
Hot coronal loop oscillations observed with SUMER: Examples and statistics
Solanki, S. K.; Curdt, W.; Innes, D. E. +3 more
We give an extensive overview of Doppler shift oscillations in hot active region loops obtained with SUMER. The oscillations have been detected in loops sampled 50-100 arcsec off the limb of the Sun in ultraviolet lines, mainly Fe Xix and Fe Xxi, with formation temperature greater than 6 MK. The spectra were recorded along a 300 arcsec slit placed…