# The Case for a High-Redshift Origin of GRB100205A

## TL;DR

This paper argues that GRB100205A is a high-redshift gamma-ray burst, likely originating between redshifts 4 and 8, highlighting the importance of infrared observations for detecting distant GRBs and probing early star formation.

## Contribution

It presents detailed multi-wavelength analysis to classify GRB100205A as a high-redshift event, emphasizing the need for infrared follow-up of dark GRBs to discover more distant bursts.

## Key findings

- GRB100205A likely occurred at redshift 4-8.
- Infrared observations are crucial for identifying high-redshift GRBs.
- High-redshift GRBs are underrepresented due to observational biases.

## Abstract

The number of long gamma-ray bursts (GRBs) known to have occurred in the distant Universe (z greater than 5) is small (approx 15), however these events provide a powerful way of probing star formation at the onset of galaxy evolution. In this paper, we present the case for GRB100205A being a largely overlooked high-redshift event. While initially noted as a high-z candidate, this event and its host galaxy have not been explored in detail. By combining optical and near-infrared Gemini afterglow imaging (at t less than 1.3 days since burst) with deep late-time limits on host emission from the Hubble Space Telescope, we show that the most likely scenario is that GRB100205A arose in the redshift range 4-8. GRB100205A is an example of a burst whose afterglow, even at 1 hour post-burst, could only be identified by 8m class IR observations, and suggests that such observations of all optically dark bursts may be necessary to significantly enhance the number of high-redshift GRBs known.