# Supermassive Black Hole Binary Candidates from the Pan-STARRS1 Medium Deep Survey

## TL;DR

This study systematically searches for supermassive black hole binary candidates in the Pan-STARRS1 survey, identifying one statistically significant candidate and evaluating detection prospects with future surveys like LSST.

## Contribution

It introduces a rigorous method for identifying SMBHB candidates in large quasar samples and assesses detection capabilities of upcoming surveys.

## Key findings

- Identified one significant SMBHB candidate.
- Extended observation baseline improved candidate evaluation.
- Provided insights into SMBHB detection prospects with LSST.

## Abstract

We present a systematic search for periodically varying quasar and supermassive black hole binary (SMBHB) candidates in the Pan-STARRS1 Medium Deep Survey. From $\sim9,000$ color-selected quasars in a $\sim50$ deg$^{2}$ sky area, we initially identify $26$ candidates with more than $1.5$ cycles of variation. We extend the baseline of observations via our imaging campaign with the Discovery Channel Telescope and the Las Cumbres Observatory network and reevaluate the candidates using a more rigorous, maximum likelihood method. Using a range of statistical criteria and assuming the Damped Random Walk model for normal quasar variability, we identify one statistically significant periodic candidate. We also investigate the capabilities of detecting SMBHBs by the Large Synoptic Survey Telescope using our study with MDS as a benchmark and explore any complementary, multiwavelength evidence for SMBHBs in our sample.