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An Extendable Galaxy Number Count Model
Gardner, Jonathan P.
I review galaxy number count models and present ncmod, an extendable and general purpose model for comparing and interpreting the results of field galaxy survey data. I develop techniques and software for converting the results of a survey done in one filter into another filter for direct comparison with other surveys. Comparison of the data from …
Compact Lyalpha-emitting Candidates at Z ~= 2.4 in Deep Medium-Band Hubble Space Telescope WFPC2 Images
Keel, William C.; Windhorst, Rogier A.; Pascarelle, Sebastian M.
Medium-band imaging with Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) in the F410M filter has previously revealed a population of compact Lyalpha emission objects around the radio galaxy 53W002 at z ~= 2.4. We report detections of similar objects at z ~= 2.4 in random, high-latitude HST parallel observations of three addition…
The Hubble Space Telescope Extragalactic Distance Scale Key Project. X. The Cepheid Distance to NGC 7331
Illingworth, Garth D.; Madore, Barry F.; Freedman, Wendy L. +17 more
The distance to NGC 7331 has been derived from Cepheid variables observed with the Hubble Space Telescope (HST) WFPC2, as part of the Extragalactic Distance Scale Key Project. Multiepoch exposures in F555W (~V) and F814W (~I), with photometry derived independently from DoPHOT and DAOPHOT/ALLFRAME programs, were used to detect a total of 13 reliabl…
Keck Spectroscopy of Candidate 97Proto-Globular Clusters in NGC 1275
Forbes, Duncan A.; Brodie, Jean P.; Huchra, John P. +3 more
Keck spectroscopy of five proto-globular cluster candidates in NGC 1275 has been combined with Hubble Space Telescope Wide Field Planetary Camera 2 photometry to explore the nature and origin of these objects and discriminate between merger and cooling-flow scenarios for globular cluster formation. The objects we have studied are not H ii regions,…
H i 21 Centimeter Absorption in Two Low-Redshift Damped Lyalpha Systems
Turnshek, D.; Meylan, G.; Smette, A. +3 more
We report the discovery of two low-redshift H i 21 cm absorbers, one at z = 0.2212 toward the z_em = 0.630 quasar OI 363 (B0738+313), and the other at z = 0.3127 toward PKS B1127-145 (z_em = 1.187). Both were found during a survey of Mg ii-selected systems at redshifts 0.2 < z < 1 using the new UHF-high system at the Westerbork Synthesis Rad…
Molecular Gas and Star Formation in the Host Galaxy of the QSO I ZW 1
Tacconi, L. J.; Schinnerer, E.; Eckart, A.
We have investigated the ISM of the I Zw 1 QSO host galaxy with Plateau de Bure millimeter interferometry and high angular resolution near-infrared imaging spectroscopy. We have detected a circumnuclear gas ring of diameter ~1.5" (1.8 kpc) in its millimetric CO line emission and have mapped the disk and the spiral arms of the host galaxy in the
A sample of planetary nebulae observed by HIPPARCOS
Pottasch, S. R.; Jasniewicz, G.; Acker, A. +1 more
By using HIPPARCOS data (magnitudes, parallaxes, proper motions), (1) we determine new values of the apparent luminosity of the central stars of 19 planetary nebulae, (2) we discuss their distance and position on the T/L diagram. By comparison with the distances determined by individual or statistical methods, we see that most of these ``ground" d…
Red Clump Morphology as Evidence against a New Intervening Stellar Population as the Primary Source of Microlensing toward the Large Magellanic Cloud
Beaulieu, Jean-Philippe; Sackett, Penny D.
We examine the morphology of the color-magnitude diagram (CMD) for core helium burning (red clump) stars to test the recent suggestion by Zaritsky & Lin that an extension of the red clump in the Large Magellanic Cloud (LMC) toward brighter magnitudes is the result of an intervening population of stars that is responsible for a significant frac…
FIP Effect in the Solar Upper Atmosphere: Spectroscopic Results
Feldman, U.
Recent spectroscopic measurements from instruments on the Solar and Heliospheric Observatory (SOHO) find that the coronal composition above a polar coronal hole is nearly photospheric. However, similar SOHO observations show that in coronal plasmas above quiet equatorial regions low-FIP elements are enhanced by a factor of ≈ 4. In addition, the pr…
The Mass Distribution in the Elliptical Galaxy NGC 3377: Evidence for a 2 X 10^8 M_⊙ Black Hole
Richstone, Douglas; Kormendy, John; Bender, Ralf +1 more
This paper is a study of the mass distribution in the central 35" ~= 1.7 kpc of the E5 galaxy NGC 3377. Stellar rotation velocity and velocity dispersion profiles (seeing sigma_* = 0.20"-0.56") and V-band surface photometry (sigma_* = 0.20"-0.26") have been obtained with the Canada-France-Hawaii Telescope. NGC 3377 is kinematically similar to M32:…