Characterization of the C-RED 2: A High Frame Rate Near-Infrared Camera

TL;DR

This paper evaluates the performance of the C-RED 2 camera, a key component of the PARVI instrument, demonstrating its suitability for high-speed, low-noise guiding in near-infrared radial velocity measurements of cool stars.

Contribution

It provides the first detailed characterization of the C-RED 2 camera's performance in a high-frame-rate, low-noise regime for astronomical guiding applications.

Findings

Dark and background current of 493 e^- /s at -40°C

Read noise reduced to 21.2 e^- using up-the-ramp sampling

Guiding capability for targets as faint as 14.6 H magnitude

Abstract

A new wave of precision radial velocity instruments will open the door to exploring the populations of companions of low mass stars. The Palomar Radial Velocity Instrument (PARVI) will be optimized to detect radial velocity signals of cool K and M stars with an instrument precision floor of 30 cm/s. PARVI will operate in the $\lambda = 1.2-1.8$ $\rm{\mu m}$ wavelength range with a spectral resolution of $\lambda/\Delta\lambda$ $\sim$100,000. It will operate on the Palomar 5.1 m Hale telescope and use Palomar's PALM-3000 adaptive optics system, single-mode fibers, and an H band laser frequency comb to probe and characterize the population of planets around cool, red stars. In this work we describe the performance of the PARVI guide camera: a C-RED 2 from First Light Advanced Imagery. The C-RED 2 will be used in a tip-tilt loop which requires fast readout at low noise levels to eliminate any residual guide errors and ensure the target starlight stays centered on the fiber. At -40$^{\circ}$ C and a frame rate of 400 FPS in non-destructive read mode, the C-RED 2 has a combined dark and background current of 493 $e^-$/s. Using up-the-ramp sampling we are able to reduce the read noise to 21.2 e$^-$. With the C-RED 2, PARVI will be able to guide using targets as faint as 14.6 H magnitude.