Search Publications
The Stellar Content of the Bulge of M31
Rich, R. Michael; Jablonka, Pascale; Frogel, Jay A. +6 more
We analyze the stellar populations present in M31 by using nine sets of adjacent Hubble Space Telescope NICMOS camera 1 and 2 fields with galactocentric distances ranging from 2' to 20'. These infrared observations provide some of the highest spatial resolution measurements of M31 to date; our data place tight constraints on the maximum luminositi…
Molecular Hydrogen in the Ring Nebula: Clumpy Photodissociation Regions
Knezek, Patricia M.; Meixner, Margaret; Jacoby, George H. +1 more
We present a 0.65" resolution H2 1-0 S(1) 2.122 µm image of the Ring Nebula (NGC 6720), which was taken with the Near Infrared Imager at the WIYN 3.5 m telescope on Kitt Peak. The high resolution of the H2 observation is sufficient to reveal the finer structure of the molecular material in this nebula. The morphology of…
Space Telescope Imaging Spectrograph Spectroscopy of the Emission-Line Gas in the Nuclei of Nearby FR-I Galaxies
Baum, Stefi A.; O'Dea, Christopher P.; van der Marel, Roeland P. +4 more
We present the results of the analysis of a set of medium-resolution spectra, obtained by the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, of the emission-line gas present in the nuclei of a complete sample of 21 nearby, early-type galaxies with radio jets (the UGC FR-I Sample). For each galaxy nucleus we present spect…
Wide-Field CCD Photometry of the Globular Cluster M92
Lee, Hyung Mok; Lee, Myung Gyoon; Fahlman, Gregory G. +1 more
We present wide-field CCD photometry of the Galactic globular cluster M92 obtained in the V and I bands with the CFH12K mosaic CCD at the Canada-France-Hawaii Telescope. A well-defined color-magnitude diagram is derived down to 5 mag fainter than the cluster main-sequence turnoff. After removing the background contribution, we obtain luminosity an…
Tether-cutting Energetics of a Solar Quiet-Region Prominence Eruption
Moore, Ronald L.; Sterling, Alphonse C.
We study the morphology and energetics of a slowly evolving quiet-region solar prominence eruption occurring on 1999 February 8-9 in the solar north polar crown region, using soft X-ray data from the soft X-ray telescope (SXT) on Yohkoh and Fe XV EUV 284 Å data from the EUV Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO). …
Coronal Mass Ejection (CME)-induced shock formation, propagation and some temporally and spatially developing shock parameters relevant to particle energization
Wu, S. T.; Tsurutani, B.; Dryer, M. +1 more
Interplanetary shocks accelerate solar energetic particles (SEPs) from the point of shock formation in the lower corona, and continuously as the shock propagates outward to 1 AU and beyond. In this study, the formation properties of a CME-induced shock and propagation characteristics are studied from the inner corona to 1 AU. We use a 2D, three-co…
Discontinuity observations with cluster
Balogh, A.; Neubauer, F. M.; Horbury, T. +1 more
Observations of solar wind magnetic field discontinuities using four spacecraft allow their orientation to be estimated by relative timings referred to as triangulation. From February 1st until May 13th 2001 the Cluster orbit traversed the solar wind. During these periods we identified 489 directional discontinuities (DDs) using the Tsurutani-Smit…
A Revised Calibration of the MV-W(O I 7774) Relationship using Hipparcos Data: Its Application to Cepheids and Evolved Stars
Arellano Ferro, A.; Giridhar, S.; Rojo Arellano, E.
A new calibration of the MV-W(O I 7774) relationship has been calculated using better reddening and distance estimates for a sample of 27 calibrator stars of spectral types A to G, based on accurate parallaxes and proper motions from the Hipparcos and Tycho catalogues. The present calibration predicts absolute magnitude with accuracies …
Evidence for Grain Growth in the Protostellar Disks of Orion
Bally, John; Throop, Henry; Shuping, R. Y. +1 more
We present a Brα (λ=4.05 µm) image of the largest silhouette proplyd in Orion (114-426) using the facility near-IR spectrometer NIRSPEC at the Keck Observatory. This is the longest wavelength observation of a silhouette disk to date. The diameter of the disk at 4 µm is only marginally smaller than that observed in the optical with the …
Latitudinal structure and north-south asymmetry of the solar wind from Lyman-alpha remote sensing by SWAN
Bzowski, M.; Quémerais, E.; Summanen, T. +2 more
Based on SWAN/SOHO observations carried out during 1996-2002, we analyze latitudinal profiles of the heliospheric backscatter Lyman-alpha radiation. We use these results to investigate the ionization field of neutral hydrogen in the inner heliosphere and the latitudinal distribution of the solar wind mass flux. The the depth and latitudinal range …