Search Publications
Structure and Dynamics of Candidate O Star Bubbles in N44
Oey, M. S.; Nazé, Yaël; Guerrero, Martín A. +3 more
Dynamical studies of superbubbles and Wolf-Rayet ring nebulae show discrepancies from the standard adiabatic model for windblown bubbles. We therefore study the physical properties and kinematics of three candidate bubbles blown by single O stars to evaluate whether these discrepancies are also found in these simpler objects. Our sample candidates…
Star Formation in the Infrared Space Observatory Atlas of Bright Spiral Galaxies
Bendo, George J.; Leech, Kieron; Metcalfe, Leo +11 more
We investigate star formation along the Hubble sequence using the Infrared Space Observatory Atlas of Bright Spiral Galaxies. Using mid-infrared and far-infrared flux densities normalized by K-band flux densities as indicators of recent star formation, we find several trends. First, star formation activity is stronger in late-type (Sc-Scd) spirals…
Active Nuclei and Star-forming Objects at z>2: Metallicities, Winds, and Formation Histories
Keel, William C.; Windhorst, Rogier A.; Pascarelle, Sebastian M. +2 more
We present near-infrared observations of the active galactic nuclei (AGNs) and star-forming objects in the field of the radio galaxy 53W002 at z=2.39. The star-forming objects are of special interest as candidate protogalactic objects. The 1.1-2.2 µm passbands sample the emitted-optical range at this redshift, providing new diagnostics of th…
Far-Infrared Spectroscopy of the HH 1/2 Outflow
Molinari, Sergio; Noriega-Crespo, Alberto
The HH 1/2 system has been observed with the two spectrometers on board the Infrared Space Observatory. Diffuse [C II] 158 µm emission indicates the presence of a photodissociation region (PDR), which is only in part due to the external far-UV (FUV) irradiation from the nearby Orion Nebula. Additional irradiation must originate locally, and …
Astrometry and Near-Infrared Photometry of Neptune's Inner Satellites and Ring Arcs
Schneider, Glenn; Dumas, Christophe; Terrile, Richard J. +1 more
We report 1.87 µm photometry and astrometry of the inner satellites (Proteus, Larissa, Galatea, and Despina) and ring arcs of Neptune, obtained with the Hubble Space Telescope and its near-infrared camera NICMOS. From comparison with the Voyager data obtained at visible wavelengths, the small bodies orbiting within the ring region of Neptune…
Hubble Space Telescope Observations of the Windblown Nebula NGC 7635
Hester, J. Jeff; Dufour, Reginald J.; Scowen, Paul A. +3 more
We present Hubble Space Telescope observations of the northern part of NGC 7635, a circular shell around the O6.5 IIIf star BD +60°2522. The nebula, which lies within the large emission-line region S162, is notable not only for its symmetric shell, but also for a complex of ``cometary'' knots close to the central star. Our observations include spe…
Far Ultraviolet Spectroscopic Explorer 900-1200 Å Spectroscopy of AM Herculis
Hutchings, J. B.; Fullerton, A. W.; Cowley, A. P. +1 more
Spectra of the magnetic white dwarf binary AM Herculis were obtained with the Far Ultraviolet Spectroscopic Explorer during three consecutive spacecraft orbits. These observations were split into 19 spectra of about 5 minutes' duration (0.025P binary phase) partially covering the binary orbit. We report the phase-related changes in the far-ultravi…
Observations of Galaxies with the Midcourse Space Experiment
Carey, Sean J.; Kraemer, Kathleen E.; Price, Stephan D. +1 more
We have imaged eight nearby spiral galaxies with the SPIRIT III infrared telescope on the Midcourse Space Experiment (MSX) satellite in the mid-infrared at 18" resolution at 8.3, 12.1, 14.7, and 21.3 µm. Each of the eight shows interesting structure not previously detected with older, lower resolution infrared data sets, such as a resolved n…
Narrow Lines in Type II Supernovae: Probing the Circumstellar Nebulae of the Progenitors
Van Dyk, Schuyler D.; Chu, You-Hua; Gruendl, Robert A. +1 more
We have carried out a high-dispersion (R~30,000) echelle spectroscopic survey of 16 Type II supernovae (SNe) to search for narrow emission lines from circumstellar nebulae ejected by their massive progenitors. Circumstellar nebulae, if detected, provide invaluable opportunities to probe SN progenitors. Of the 16 SNe observed, SN ejecta are clearly…
Hubble Space Telescope Survey of Clusters in Nearby Galaxies. II. Statistical Analysis of Cluster Populations
Dolphin, Andrew E.; Kennicutt, Robert C., Jr.
We present a statistical system that can be used in the study of cluster populations. The basis of our approach is the construction of synthetic cluster color-magnitude-radius diagrams (CMRDs), which we compare with the observed data using a maximum likelihood calculation. This approach permits a relatively easy incorporation of incompleteness (a …