CHIMERA: a wide-field, multi-colour, high-speed photometer at the prime focus of the Hale telescope

Abstract

The Caltech HIgh-speed Multi-color camERA (CHIMERA) is a new instrument that has been developed for use at the prime focus of the Hale 200-inch telescope. Simultaneous optical imaging in two bands is enabled by a dichroic beam splitter centered at 567 nm, with Sloan u and g bands available on the blue arm and Sloan r , i and z s bands available on the red arm. Additional narrow-band filters will also become available as required. An Electron Multiplying CCD (EMCCD) detector is employed for both optical channels, each capable of simultaneously delivering sub-electron effective read noise under multiplication gain and frame rates of up to 26 fps full frame (several 1000 fps windowed), over a fully corrected 5 × 5 arcmin field of view. CHIMERA was primarily developed to enable the characterization of the size distribution of sub-km Kuiper Belt Objects via stellar occultation, a science case that motivates the framerate, the simultaneous multi-color imaging and the wide field of view of the instrument. In addition, it also has unique capability in the detection of faint near-Earth asteroids and will be used for the monitoring of short duration transient and periodic sources, particularly those discovered by the intermediate Palomar Transient Factory (iPTF), and the upcoming Zwicky Transient Facility (ZTF).

High-speed photometry of Gaia14aae: an eclipsing AM CVn that challenges formation models

“…Most of the ULTRA-SPEC data were taken using a custom filter, KG5 , which has a broader band to allow for shorter exposure times given the smaller collecting area of this telescope (for more details on the KG5 band, see Hardy et al 2017). A further series of eclipses were observed using CHIMERA (Harding et al 2016), a 2-band photometer which uses frame-transfer, electron-multiplying CCDs to achieve 15 ms dead time, and is mounted on the Hale 200-inch (5.1 m) Telescope.…”

Orbital Decay in a 20 Minute Orbital Period Detached Binary with a Hydrogen-poor Low-mass White Dwarf

“…We used the high speed photometer on 200-inch Hale telescope at Palomar Observatory, CHIMERA (Harding et al 2016), to obtain a well sampled follow-up lightcurve of the object. The instrument consists of a pair of electron multiplying charge-coupled devices (EM CCDs), has a dichroic and dual channels, allowing us to obtain simultaneous observations in g and i .…”

Upper limits to the number of Oort Cloud objects based on serendipitous occultation events search in X-rays

“…On the other hand, it is relatively easier to accumulate a huge data volume in optical bands, see, e.g., the Miosotys (Shih et al 2010), TAOS II (Lehner et al 2014) and CHIMERA (Harding et al 2016) projects. Because of longer wavelength, however, it can probe objects only down to size of 1 km, 10 km and 30 km or so for the Kuiper Belt, inner and outer Oort Cloud, respectively, again due to diffraction limit.…”