Search Publications
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 …
Characterization and Subtraction of Well-Exposed HST/NICMOS Camera 2 Point-Spread Functions for a Survey of Very Low Mass Companions to Nearby Stars
Krist, John E.; Golimowski, David A.; Schroeder, Daniel J. +1 more
We are conducting a search for very low mass (M<0.2 M_solar) companions of stars within 10 pc of the Sun using the NICMOS infrared camera on the Hubble Space Telescope. The highly exposed images of each target star are subtracted from the NICMOS Camera 2 (NIC2) field using previously observed stars so that faint companions may be detected. We h…
The Goddard High Resolution Spectrograph: Post-COSTAR Characteristics
Savage, B. D.; Ebbets, D. C.; Carpenter, K. G. +16 more
We review changes to the characteristics of the Goddard High Resolution Spectrograph (GHRS) which resulted from the installation of the Corrective Optics Space Telescope Axial Replacement (COSTAR) on the Hubble Space Telescope. The introduction of two new optical elements into the light path altered the spectral distribution of the light, decreasi…
Hubble Space Telescope/Faint Object Spectrograph Imaging of Wolf 424 AB: Is This Binary a Double Brown Dwarf System?
Benedict, G. F.; Franz, O. G.; Bruhweiler, F. C. +9 more
The low-mass binary system Wolf 424 AB (GJ 473 AB) was spatially resolved in an image obtained on 1996 April 16 with the imaging mode of the Hubble Space Telescope Faint Object Spectrograph. The separation was measured to be 0.42"+/-0.03" at a position angle of 353.2d+/-2.5d. The new measurement was combined with previously published orbital posit…
Duplicity in Hubble Space Telescope Guide Stars: Fine Guidance Sensor Serendipitous Survey Results
Schneider, Glenn; Hershey, John L.; Wenz, Michael T.
Data from the Hubble Space Telescope (HST) Fine Guidance Sensor (FGS) interferometers, covering 22 months of guide-star acquisition operations, have been analyzed for evidence of stellar duplicity. The data comprise a survey of observed guide stars, all of which are taken from the HST Guide Star Catalog, ranging in magnitude from 9 to 14. The surv…
STIS Signal-to-Noise Capabilities in the Ultraviolet
Kaiser, Mary Elizabeth; Kimble, Randy A.; Gilliland, Ronald L. +3 more
The Space Telescope Imaging Spectrograph (STIS) was designed as a versatile spectrograph for the Hubble Space Telescope (HST) capable of maintaining or exceeding the spectroscopic capabilities of both the Goddard High Resolution Spectrograph (GHRS) and the Faint Object Spectrograph (FOS) over the broad bandpass extending from the ultraviolet (115 …
Separate Spectra of the Components of the Low-Mass BinariesRoss 614A,B and L722-22A,B
Hershey, John L.; Chance, Don R.
The Hubble Space Telescope Faint Object Spectrograph has been used to acquire separate spectra of each of the component stars in the binaries Ross 614A,B (Gl 234A,B) and L722-22A,B (GJ 1005). Spectral types have been determined for each: M4.0 V, M5.5 V, M3.5 V, and M5.0 V, respectively, relative to a series of ground-based CCD spectra, in the 6500…
Rotationally Broadened Synthetic Spectra for HST and IUE Observations of Exposed White Dwarfs in Cataclysmic Variables
Sion, E. M.; Nguyen, Quyen; Fabian, Dirk +2 more
In many dwarf novae during quiescence, the underlying white dwarf dominates the flux in the far ultraviolet. By observing these exposed degenerate stars with the Hubble Space Telescope Goddard High Resolution Spectrograph and Faint Object Spectrograph (HST GHRS and FOS), the white-dwarf rotation rates can be determined or constrained by fitting sy…