Spectral Mapping Reconstruction of Extended Sources

TL;DR

This paper introduces a spectral mapping reconstruction method for extended sources using traditional slit spectrographs, enabling efficient 3D spectral cube creation with reduced instrument complexity, especially suitable for space-based observations.

Contribution

It presents a novel flux-conserving cube reconstruction algorithm and a practical tool, CUBISM, for spectral map analysis from space telescope data, enhancing existing spectral mapping techniques.

Findings

Effective reconstruction of spectral cubes from slit spectrograph data.

Reduced instrument complexity without sacrificing mapping efficiency.

Application to Spitzer Space Telescope data demonstrates practical utility.

Abstract

Three dimensional spectroscopy of extended sources is typically performed with dedicated integral field spectrographs. We describe a method of reconstructing full spectral cubes, with two spatial and one spectral dimension, from rastered spectral mapping observations employing a single slit in a traditional slit spectrograph. When the background and image characteristics are stable, as is often achieved in space, the use of traditional long slits for integral field spectroscopy can substantially reduce instrument complexity over dedicated integral field designs, without loss of mapping efficiency -- particularly compelling when a long slit mode for single unresolved source followup is separately required. We detail a custom flux-conserving cube reconstruction algorithm, discuss issues of extended source flux calibration, and describe CUBISM, a tool which implements these methods for spectral maps obtained with ther Spitzer Space Telescope's Infrared Spectrograph.