Scientific Benefits of the One-Meter Telescope: Galaxy Imaging and Spectroscopy at Low and Intermediate Redshift: We plan to perform a deep galaxy imaging survey of over 4000 galaxies in a large volume surrounding the Milky Way galaxy using both the proposed 4-H, and the smaller 0.6-meter Fick Observatory telescope. These data, which will take a few years to collect, will allow us to probe the evolutionary history of a statistically complete sample of galaxies, many of which are as old as the Milky Way. The project will explore the evolutionary dependency of galaxies on their environment, ranging from more isolated galaxies, through loose groups, to nearby rich clusters. We will be particularly interested in studying the past and present star formation rates, the morphology, degree of tidal distortion, especially evidence for past or ongoing mergers, as a function of the local galaxy density or morphological structure. The survey will also study the dwarf-satellite galaxy population as a function of parent galaxy environment. The work will be extended to modest redshift (0 < z < 0.3) for comparison with higher redshift samples. Broad-band imaging of nearby galaxies will be performed on current ISU facilities, but narrow-band images (requiring the 1-meter aperture) would be best performed on the 4-H telescope because of the larger collection area. The imaging will be followed up with spectroscopy of some of the galaxies using the intermediate-dispersion spectrometer to provide radial velocities for those galaxies without redshift information. Because the light is being split-up into its spectral components, then a large telescope is required to obtain spectra of faint galaxies. The 1-meter telescope is idea for this. Images obtained with the 4-H telescope will be stored in the NASA Extragalactic Database (NED) at California Institute of Technology and will be made available over INTERNET. Imaging and Spectroscopy of Embedded Infrared Sources in the Galactic Plane: High quality images and most importantly, spectra, will be obtained of a sample of 1000 infrared sources in the plane of the Milky Way. These sources are currently being imaged with the 0.6-meter telescope at the Fick Observatory as part if ISU's research program. About 30% of the sources have optical counterparts which have never been cataloged before. The purpose of the imaging and spectroscopy will be to determine the nature of these sources. For example, the Fick observatory images often show compact emission at red wavelengths, but spectra of these objects are essential in order to determine whether the sources are Galactic or Extra-galactic. If Galactic, the nature of any extended nebulosity can only be probed with high-quality long-slit spectra. Narrow-band images of these sources are also best performed with a 1-meter class telescope and the 4-H instrument would be ideal in this respect. It is likely that many new discoveries will result from these observations, including the discovery of new and unusual nebulae, to the discovery of nearby galaxies which are hidden from our view by dust in our own galaxy. Participation in Whole Earth Telescope (WET) Observations: The new telescope will have sufficient aperture to become a component of the Whole Earth Telescope (hereafter WET). network. The WET is a global network of meter-class telescopes employed in obtaining 24-hr/day observations of pulsating stars for weeks at a time. The scientific goal is to use the data in astreroseismological analysis of white dwarfs and other pulsating stars. The f/10 focus of the proposed telescope will be ideal for this work, allowing for short dedicated observing runs from Iowa. Typically these observing runs occur about 2 or 3 times a year and last for a few days only, and so participation by the 4-H telescope would be very convenient. Instrumentation: CCD Imaging Camera We plan to place a modern Kodak 2048 x 2048 pixel array CCD chip at the f/10 focus of the telescope. In order to provide a wide field-of-view, we would place in the light path a focal reducer to change the focus from f/10 to f/4. A similar system has been used successfully at the Fick Observatory. Discussions between Dr. Appleton at ISU and Torus Precision Optics Inc., of Iowa City, indicate that such a system is quite feasible. The f/4 camera will have a field-of-view of 16 x 16 arcminutes (about 1/2 the size of the full moon), and each pixel would subtend an angle of 0.45 arcsecs on the sky. We expect that the seeing at the site will blur images on a scale of about 1 arcsec, and so our CCD will nicely oversample the seeing disk. This will be ideal for the imaging of galaxies science requirements. Cooling of the Kodak 2K chip (9 micron pixels) will be performed using new low-cost closed cycle cooling technology. A low-cost device is available now which will easily provide a cold-finger for the CCD without the need for liquid nitrogen cooling. We believe that low temperature operation of the CCD is essential to get the best out of the observations. Very good results have been obtained at the 0.6-meter Fick Observatory with operating temperature of -150 degrees C below ambient, where the CCD has a negligible dark current. The device comes with its own, small compressor which is hooked up to the instrumentation package through small compression lines. This system is preferable to a liquid-nitrogen system because it does not require much maintenance or constant re-filling. The CCD will be placed in a low-vacuum dewar to reduce thermal losses. Autoguiding will be performed with small ST5 CCD chip and a feed-back loop similar to that operating on the current 0.6-meter ISU telescope. The precise method for picking off a guide-star has not yet been fully worked out (this will depend on the final optical design) but it will involve either a single translational mirror that can be moved around the periphery of the imaging camera, or a fixed annular mirror which will cover the peripheral field of the main CCD camera. To allow remote operation, the ST5 will most likely have to be attached to a simple X-Y translation stage that could allow the camera to be positioned on a guide-star of choice. Spectroscopy Light from the f/10 focus will be focused onto a long-slit. The light would then pass through a grating and collimation system, and the spectrum would be imaged by the 2K CCD chip. The grating and collimation spectrograph component is commercially available, and we would simply combine the CCD imaging capability. The Monospec 18 system with replaceable gratings will provide 1.2 Ang/pix resolution at the Kodak chip. This is ideal for extragalactic spectroscopy. Other gratings (for example 0.6 Ang/pix) will be available for higher resolution work if necessary. It should be possible to use the same CCD in this camera as with the imaging system. The CCD, as with the imaging system, will be cooled to -150 C (relative to ambient) to provide high signal-to-noise spectra.     © Copyright 2007 - Samuel J. Wormley   by swormley1@gmail.com