# New Chandra observations of PG 1116+215 to investigate an extragalactic OVIII WHIM absorption line

## TL;DR

This paper analyzes new Chandra observations of PG 1116+215 to assess the consistency of an OVIII WHIM absorption line detection, finding no significant line due to lower signal-to-noise in the new data.

## Contribution

It provides a comparative analysis of new and previous Chandra data, highlighting the challenges in detecting faint WHIM absorption lines under varying observational conditions.

## Key findings

- New observations are consistent with previous data at the OVIII line wavelength.
- Lower signal-to-noise prevented a significant detection of the WHIM line.
- The WHIM line detection remains inconclusive due to observational limitations.

## Abstract

This is a short AAS Research Note on the analysis of new Chandra observations of PG 1116+215, for which an extragalactic OVIII WHIM line was reported by Bonamente et al. (2016). The new observations occurred at a time when the source flux was three times lower, and the background was three times higher, than in the earlier observations. The analysis described in this research note show that the new observations are consistent with the old one at the wavelengths of the OVIII WHIM line, and the lower signal-to-noise of the new data did not permit a significant detection of the line in the new data.