Search Publications
Winds and Accretion in delta Sagittae
Mason, Brian D.; McAlister, Harold A.; Eaton, Joel A. +1 more
The ten-year binary delta Sge (M2 Ib-II+B9.5 V) is a zeta Aur binary containing an abnormally cool component. Combining our analysis of the system as a visual binary with Batten's radial-velocity solution leads to the following properties: i = 40 deg, a = 51 mas = 8.83 A.U. = 1893 solar radius, hence d = 173 pc; MB = 2.9 solar mass and …
The Cooling of the White Dwarf in U Geminorum Following Hearing By Two Different Outbursts
Szkody, Paula; Sion, Edward M.; Huang, Min
We present the analysis of 13 orbital phase-resolved IUE (large and small aperture) SWP spectra, sampling the quiescent intervals of the prototype dwarf nova U Geminorum following two individual outbursts, the outburst of 1992, 29 August-14 September, and the outburst of 1993, 19 March-5 April. The quiescent interval following the outburst 29 Augu…
Hubble Space Telescope Photometry of the Central Regions of Virgo Cluster Elliptical Galaxies. III. Brightness Profiles
Jaffe, W.; Ford, H. C.; O'Connell, R. W. +2 more
We have used the Planetary Camera on the Hubble Space Telescope to study the morphology and surface brightness parameters of a luminosity-limited sample of fourteen elliptical galaxies in the Virgo cluster. The total apparent blue magnitudes of the galaxies range between 9.4 and 13.4. In this paper, the core brightness profiles are presented, whil…
Hubble Space Telescope Photometry of the Central Regions of Virgo Cluster Elliptical Galaxies. I. Observations, Discussion, and Conclusion
Jaffe, W.; Ford, H. C.; O'Connell, R. W. +2 more
Using the Hubble Space Telescope we have observed at 10 pc resolution the nuclei of a luminosity-limited sample of 14 E and E/S0 galaxies in the Virgo Cluster with magnitudes B_T_ = 9.4 to 13.4. In this paper we present the images, and discuss the results of the detailed analysis of the surface photometry given in two companion papers. We find tha…
UBV Stellar Photometry of the 30 Doradus Region of the Large Magellanic Cloud With the Hubble Space Telescope
Heap, Sara R.; Malumuth, Eliot M.
We report on Planetary Camera observations of the central region of 30 Doradus in the Large Magellanic Cloud. These images of 30 Doradus are the first "deep" HST exposures that have appropriate photometric calibration. The B band (F439W) image, which shows RI 36a at the center of the PC6 CCD chip, reveals over 200 stars within 3" of the center of …
Imaging of Two Damped Lyman Alpha Absorbers at Intermediate Redshifts
Dickinson, Mark; Pettini, Max; Steidel, Charles C. +1 more
By observing the fields of the QSOs 3C 286 and PKS 1229-021 in the I and K_s_ bands under good seeing conditions, we have resolved faint galaxy images close to the QSO sight lines. The sizes, magnitudes, and colors of these objects suggest that they are the galaxies producing 21 cm absorption at z_abs_ = 0.6922 and 0.3950 in the spectra of 3C 286 …
Hubble Space Telescope Photometry of the Central Regions of Virgo Cluster Elliptical Galaxies. II. Isophote Shapes
van den Bosch, Frank C.; O'Connell, Robert W.; Ferrarese, Laura +2 more
The isophotal shapes of a magnitude limited sample of Virgo ellipticals are presented. These are derived from high resolution HST photometry. The absence of atmospheric seeing and accurate knowledge of the PSF allows us to perform an accurate deconvolution. Model galaxies were constructed to test the deconvolution algorithms used, and showed that …
Hubble Space Telescope Images of the Central Star-Forming Region in NGC 1140
O'Connell, Robert W.; Gallagher, John S., III; Hunter, Deidre A.
We present broadband images taken with the Hubble Space Telescope's Planetary Camera of the central supergiant H II region in the amorphous galaxy NGC 1140. These images allow observations to a resolution of about 13 pc at the galaxy, and they reveal that its central 1/2 kpc contains 6- 7 blue, luminous, compact super star clusters, many of which …
Globular Cluster Photometry With The Hubble Space Telescope. II. U,V, And I Measurements of M15
Schneider, Donald P.; Yanny, Brian; Bahcall, John N. +1 more
The projected density distribution of resolved stars near the center of M15 is shown to be consistent with either a power-law cusp N(r) approximately ralpha, with alpha approximately -0.85 +/- 0.2, or with a King model with a core of radius approximately less than 2 sec. The inferred slope is in agreement with the theoretical value, alp…
Absolute Flux Calibration of Optical Spectrophotometric Standard Stars
Colina, L.; Bohlin, R. C.
A method based on Landolt photometry in B and V is developed to correct for a wavelength independent offset of the absolute flux level of optical spectrophotometric standards. The method is based on synthetic photometry techniques in B and V and is accurate to approximately 1%. The correction method is verified by Hubble Space Telescope Faint Obje…