The Cosmic Infrared Background Experiment (CIBER): The Low Resolution Spectrometer

TL;DR

The paper details the design, testing, and calibration of the Low Resolution Spectrometer (LRS) on CIBER, aimed at precise measurements of the near-infrared sky brightness to study cosmic background radiation.

Contribution

It introduces the LRS instrument's design, ground testing procedures, and calibration methods for accurate absolute spectrophotometry in the near-infrared range.

Findings

LRS meets design specifications for optical and sensitivity performance.

Systematic errors in absolute photometry are well understood and controlled.

Instrument calibration ensures reliable measurements of the extragalactic background light.

Abstract

Absolute spectrophotometric measurements of diffuse radiation at 1 \mu m to 2 \mu m are crucial to our understanding of the radiative content of the Universe from nucleosynthesis since the epoch of reionization, the composition and structure of the Zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment (CIBER) is a \lambda / \Delta \lambda \sim 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 \mu m < \lambda < 2.1 \mu m. This paper presents the optical, mechanical and electronic design of the LRS, as well as the ground testing, characterization and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding and control of sources of systematic error for absolute photometry of the near-infrared extragalactic background light.