# Cosmic Ray Removal in Fiber Spectroscopic Image

## TL;DR

This paper introduces a novel method for detecting and removing cosmic rays in single-exposure, multi-fiber spectroscopic images, achieving high detection accuracy and effective correction.

## Contribution

The paper presents a new cosmic ray removal technique specifically designed for single-exposure, multi-fiber spectra using 2D profile fitting and a position-dependent noise model.

## Key findings

- Detects up to 80% of cosmic rays
- Corrects cosmic ray pixels with 97.8% accuracy
- Works effectively on simulated and real data

## Abstract

Single-exposure spectra in large spectral surveys are valuable for time domain studies such as stellar variability, but there is no available method to eliminate cosmic rays for single-exposure, multi-fiber spectral images. In this paper, we describe a new method to detect and remove cosmic rays in multi-fiber spectroscopic single exposures. Through the use of two-dimensional profile fitting and a noise model that considers the position-dependent errors, we successfully detect as many as 80% of the cosmic rays and correct the cosmic ray polluted pixels to an average accuracy of 97.8%. Multiple tests and comparisons with both simulated data and real LAMOST data show that the method works properly in detection rate, false detection rate, and validity of cosmic ray correction.