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An Infrared Space Observatory Atlas of Bright Spiral Galaxies
Bendo, George J.; Leech, Kieron; Metcalfe, Leo +11 more
In this first paper in a series we present an atlas of infrared images and photometry from 1.2 to 180 µm for a sample of bright spiral galaxies. The atlas galaxies are an optically selected, magnitude-limited sample of 77 spiral and S0 galaxies chosen from the Revised Shapley-Ames Catalog (RSA). The sample is a representative sample of spira…
The Dwarf Irregular/Wolf-Rayet Galaxy NGC 4214. I. A New Distance, Stellar Content, and Global Parameters
Greggio, Laura; Hopp, Ulrich; Schulte-Ladbeck, Regina E. +2 more
We present the results of a detailed optical and near-IR study of the nearby star-forming dwarf galaxy NGC 4214. We discuss the stellar content, drawing particular attention to the intermediate-age and/or old field stars, which are used as a distance indicator. On images obtained with the Hubble Space Telescope Wide Field Planetary Camera 2 and Ne…
Circumnuclear Star Formation in the Spiral Galaxy NGC 3310
McGrath, Elizabeth J.; Elmegreen, Debra Meloy; Chromey, Frederick R. +1 more
The star-forming properties of the circumnuclear ring in the starburst spiral galaxy NGC 3310 have been studied in B, I, J, H, and K bands using images from KPNO and from the HST archives. The colors and magnitudes of the star-forming regions indicate ages less than 10 Myr and masses of 104 to 105 Msolar for the la…
The Oldest Stars of the Extremely Metal-Poor Local Group Dwarf Irregular Galaxy Leo A
Greggio, Laura; Hopp, Ulrich; Schulte-Ladbeck, Regina E. +2 more
We present deep Hubble Space Telescope (HST) single-star photometry of Leo A in B, V, and I. Our new field of view is offset from the centrally located field observed by Tolstoy et al. in order to expose the halo population of this galaxy. We report the detection of metal-poor red horizontal branch stars, which demonstrate that Leo A is not a youn…
Optical Observations and Orbital Parameters of the Close DA plus dMe Binaries BPM 71214, EUVE J0720-31.7, BPM 6502, and EC 13471-1258
Vennes, Stéphane; Kawka, Adela; Koch, Rolf +1 more
We have obtained photometric and spectroscopic observations of the close DA plus dMe binaries BPM 6502 and EC 13471-1258, and spectroscopic observations of the close binaries BPM 71214 and EUVE J0720-31.7. We have updated the ephemerides of BPM 6502 and EUVE J0720-31.7 with the spectroscopic measurements and obtained periods of 0.20162 and 0.15074…
Spiral Galaxies with HST/NICMOS. II. Isophotal Fits and Nuclear Cusp Slopes
Stiavelli, Massimo; de Zeeuw, P. Tim; Carollo, C. Marcella +2 more
We present surface brightness profiles for 56 of the 78 spiral galaxies observed in the HST/NICMOS2 F160W snapshot survey introduced in Paper I of this series, as well as surface brightness profiles for 23 objects out of the 41 that were also observed in the F110W filter. We fit these surface brightness profiles with the Nuker law of Lauer et al. …
Astrometric and Light-Travel Time Orbits to Detect Low-Mass Companions: A Case Study of the Eclipsing System R Canis Majoris
Guinan, Edward F.; Arenou, Frédéric; Ribas, Ignasi
We discuss a method to determine orbital properties and masses of low-mass bodies orbiting eclipsing binaries. The analysis combines long-term eclipse timing modulations (the light-travel time [LTT] effect) with short-term, high-accuracy astrometry. As an illustration of the method, the results of a comprehensive study of Hipparcos astrometry and …
Deep Hubble Space Telescope WFPC2 Photometry of NGC 288. II. The Main-Sequence Luminosity Function
Fusi Pecci, Flavio; Rood, Robert T.; Messineo, Maria +3 more
The main-sequence luminosity function (LF) of the Galactic globular cluster NGC 288 has been obtained using deep Wide Field Planetary Camera 2 photometry. We have employed a new method to correct for completeness and fully account for bin-to-bin migration due to blending and/or observational scatter. The effect of the presence of binary systems in…
Balmer and He I Absorption in the Nuclear Spectrum of NGC 4151
Gull, T. R.; Kraemer, S. B.; Crenshaw, D. M. +4 more
Spectra taken with the Space Telescope Imaging Spectrograph allow accurate location and extraction of the nuclear spectrum of NGC 4151, with minimal contamination by extended line emission and circumnuclear starlight. Spectra since 1997 show that the P Cygni Balmer and He I absorption seen previously in low nuclear states is present in higher stat…
Using a Hipparcos-derived Hertzsprung-Russell Diagram to Limit the Metallicity Scatter of Stars in the Hyades: Are Stars Polluted?
Quillen, A. C.
Hipparcos parallaxes and proper motions have made it possible to construct Hertzsprung-Russell (H-R) diagrams of nearby clusters with unprecedented accuracy. The standard deviation of high-fidelity, nonbinary, nonvariable stars about a model stellar evolution isochrone in the Hyades cluster is about 0.04 mag. We use this deviation to estimate an u…