Tidal Stream Pilot Survey Description and Observational Facilities
his pilot survey was conducted with three privately owned observatories equipped with modest sized telescopes located in the USA and Australia.
- The .5 meter Ritchey-Chretien Telescope of the Blackbird Observatory is situated at 7300 ft.(2225 meters) elevation under spectacularly clear and dark skies in the south central Sacramento Mountains of New Mexico, near Mayhill.
- Photo credit: R. Wodaski
Each observing site features very dark, clear skies with seeing that is routinely at and often below 1.5 arcseconds. These telescopes are manufactured by RC Optical Systems and follow a classic Ritchey-Chretien design.
The observatories are commanded with on-site computers that allow remote operation and control from any global location with highband web accesses. Each observatory uses proven, widely available remote desktop control software. Robotic orchestration of all observatory and instrument functions, including multiple target acquisition and data runs, is performed using available scripting software. Additionally, we also made use of a wide field instrument for those galaxies with an extended angular size. For this purpose, we selected the Astro Physics Starfire 160EDF6, a short focal length (f/7) 16 cm aperture refractor that provides a FOV of 73.7 × 110.6 arcmin.
- The Rancho Del Sol Observatory is located in the foothills of the northern California's Sierra Mountains approximately one hour north of Sacramento. It houses a .5 meter Ritchey-Chretien Telescope.
- Photo credit: Ken Crawford
Each telescope is equipped with a commercially available CCD camera. The primary survey camera of the Black Bird Observatory (BBO)
was the SBIG STL11000, which uses a Kodak KAI-11000M imaging sensor. This sensor consists of a 4008 × 2672 pixel array with 9 × 9 micron pixels. In addition, some telescopes use a 16-megapixel camera manufactured by Apogee Instruments, of Roseville (California).
The Rancho del Sol Observatory (RdS)
uses the Apogee Alta KAFO9000 imaging sensor with 3056 × 3056 pixels at 12 × 12 microns each . The Moorook (MrK) observatory used an Apogee Alta KAF16803 that features a 4096 × 4096 pixel sensor with smaller 9 × 9 micron pixels.
The tidal stream detection strategy, the procedures used for data acquisition and reduction are the same as those described in our previous papers released at an earlier stage of this project (Martinez-Delgado et al. 2008
). In summary, this strategy strives for multiple deep exposures of each target using a wide bandpass, high throughput, clear filter with a near IR cut off, also known as a luminance filter. The typical cumulative exposure times range from 6 to 11 hours. Data reduction followed standard techniques.