Search Publications
High-redshift galaxies in the Hubble Deep Field: colour selection and star formation history to z~4
Ferguson, Henry C.; Giavalisco, Mauro; Dickinson, Mark E. +3 more
The Lyman decrement associated with the cumulative effect of HI in QSO absorption systems along the line of sight provides a distinctive feature for identifying galaxies at z>~2.5. Colour criteria, which are sensitive to the presence of a Lyman continuum break superposed on an otherwise flat UV spectrum, have been shown, through Keck spectrosco…
The Infrared Space Observatory (ISO) mission.
Kessler, M. F.; Clavel, J.; Taylor, B. G. +8 more
ESA's Infrared Space Observatory (ISO) is an astronomical satellite, operating at wavelengths from 2.5-240 µm. Essentially, ISO consists of a large cryostat which contained at launch about 2300 litres of superfluid helium to maintain the Ritchey-Chretien telescope, the scientific instruments and the optical baffles at temperatures of 2-8 K. …
Interstellar Abundances from Absorption-Line Observations with the Hubble Space Telescope
Sembach, Kenneth R.; Savage, Blair D.
The Goddard High-Resolution Spectrograph (GHRS) aboard the Hubble Space Telescope (HST) has yielded precision abundance results for a range of interstellar environments, including gas in the local medium, in the warm neutral medium, in cold diffuse clouds, and in distant halo clouds. Through GHRS studies, investigators have determined the abundanc…
The Hubble Deep Field: Observations, Data Reduction, and Galaxy Photometry
Dickinson, Mark; Ferguson, Henry C.; Giavalisco, Mauro +14 more
The Hubble Deep Field (HDF) is a Director's Discretionary program on HST in Cycle 5 to image an undistinguished field at high Galactic latitude in four passbands as deeply as reasonably possible. These images provide the most detailed view to date of distant field galaxies and are likely to be important for a wide range of studies in galaxy evolut…
Template Ultraviolet to Near-Infrared Spectra of Star-forming Galaxies and Their Application to K-Corrections
Calzetti, Daniela; Storchi-Bergmann, Thaisa; Bohlin, Ralph C. +3 more
Template UV-optical spectra of quiescent and starburst galaxies are presented and used to derive K-corrections as a function of morphological type and redshift. IUE observations and archival data are used for the UV template spectra. The optical spectra are from ground-based observations obtained in apertures that match closely the 200 arcsec^2^ I…
Observing with the ISO Short-Wavelength Spectrometer.
Lutz, D.; Genzel, R.; Heras, A. M. +59 more
The Short-Wavelength Spectrometer (SWS) is one of the four instruments on-board ESA's Infrared Space Observatory (ISO), launched on November 17, 1995. The spectrometer covers the wavelength range of 2.38 to 45.2µm with a spectral resolution ranging from 1000 to 2000. By inserting Fabry-Perot filters the resolution can be enhanced by a factor…
O-star mass-loss and wind momentum rates in the Galaxy and the Magellanic Clouds Observations and theoretical predictions.
Lennon, D. J.; Herrero, A.; Pauldrach, A. W. A. +8 more
A new, very fast approximate method is presented to determine mass-loss rates of O-stars from Halpha_ line profiles. The method uses H and HeII departure coefficients from unified model atmospheres parametrized in a simple way as function of wind velocity together with photospheric NLTE line profiles as the inner boundary condition for …
Galaxy morphology to I=25 mag in the Hubble Deep Field
Santiago, B. X.; Glazebrook, K.; Abraham, R. G. +3 more
The morphological properties of galaxies in the range 21<<e1>I<</e1>25 mag in the Hubble Deep Field are investigated using a quantitative classification system based on measurements of the central concentration and asymmetry of galaxian light. The class distribution of objects in the Hubble Deep Field is strongly skewed towards h…
ISOPHOT - capabilities and performance.
Telesco, C.; Lemke, D.; Schulz, B. +46 more
ISOPHOT covers the largest wavelength range on ISO from 2.5 to 240µm. Its scientific capabilities include multi-filter and multi-aperture photometry, polarimetry, imaging and spectrophotometry. All modes can optionally include a focal plane chopper. The backbone of the photometric calibration are internal standard sources checked against cel…
Spectroscopy of Lyman Break Galaxies in the Hubble Deep Field
Dickinson, Mark; Giavalisco, Mauro; Steidel, Charles C. +1 more
We report on the initial results of a spectroscopic investigation of galaxies in the Hubble Deep Field which exhibit spectral discontinuities between the F450W and F300W passbands, indicative of the presence of the Lyman continuum break in the redshift range 2.4 <~ z <~ 3.4. We have employed color selection criteria similar to those we have …