# OGLE-ing the Magellanic System: RR Lyrae Stars in the Bridge

**Authors:** Anna M. Jacyszyn-Dobrzeniecka, P. Mr\'oz, K. Kruszy\'nska, I., Soszy\'nski, D. Skowron, A. Udalski, M. K. Szyma\'nski, P. Iwanek, J., Skowron, P. Pietrukowicz, R. Poleski, S. Koz{\l}owski, K. Ulaczyk, K., Rybicki, M. Wrona

arXiv: 1904.07888 · 2020-02-05

## TL;DR

This study analyzes RR Lyrae stars in the Magellanic Bridge using OGLE and Gaia data, revealing a complex, overlapping structure rather than a direct stellar bridge, and highlights challenges in identifying true connections with current data.

## Contribution

It provides a detailed distribution analysis of RR Lyrae stars in the Magellanic Bridge using OGLE and Gaia data, and evaluates the limitations of current datasets in confirming a stellar bridge.

## Key findings

- RR Lyrae stars are present between the Magellanic Clouds.
- The distribution resembles overlapping structures rather than a clear bridge.
- Gaia DR2 data supports the OGLE findings, but the connection remains inconclusive.

## Abstract

We use the extended and updated OGLE Collection of Variable Stars to thoroughly analyze distribution of RR Lyrae stars in the Magellanic Bridge. We use photometric metallicities to derive absolute Wesenheit magnitude and then individual distance of each RR Lyr star. We confirm results from our earlier study showing that RR Lyr stars are present in between the Magellanic Clouds, though their three-dimensional distribution rather resembles two extended overlapping structures than a strict bridge-like connection. The contours do connect in the southern parts of the Bridge, albeit on a too low level to state that there exists an evident connection. To test the sample numerically, we use multi-Gaussian fitting and conclude that there is no additional population or overdensity located in the Bridge. We also try to reproduce results on putative RR Lyr Magellanic Bridge stream by selecting RR Lyr candidates from Gaia Data Release 1. We show that we are not able to obtain the evident connection of the Clouds without many spurious sources in the sample, as the cuts are not able to remove artifacts and not eliminate the evident connection at the same time. Moreover, for the first time we present the Gaia Data Release 2 RR Lyr stars in the Magellanic Bridge area and show that their distribution matches our results.

## Full text

_Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/1904.07888/full.md

## Figures

21 figures with captions in the complete paper: https://tomesphere.com/paper/1904.07888/full.md

## References

66 references — full list in the complete paper: https://tomesphere.com/paper/1904.07888/full.md

---
Source: https://tomesphere.com/paper/1904.07888