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arXiv · 2409.13850

Predicting the Number of Radio Sources Seen by Both VLASS and LSST

Alex Tellez·Yjan Gordon·Keith Bechtol
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Abstract

Radio surveys typically sample extragalactic sources in higher redshift regimes than is typical for optical surveys, resulting in many radio sources not having a detected optical counterpart. Over the next decade the Legacy Survey of Space and Time (LSST) will be performing the deepest ($i < 26.4\,$mag) wide-area optical survey to date increasing the fraction of radio sources for which we have optical data. In this Research Note we use the Hyper Suprime-Cam survey to analyse how the fraction of radio sources in the Very Large Array Sky Survey (VLASS) with optical detections varies as a function of $i$-band magnitude and extrapolate to predict the number of optical counterparts we expect LSST to detect. Assuming a final VLASS point source depth of $S_{3\,\text{GHz}}\lesssim350\,\mu$Jy, we expect LSST to identify optical counterparts to $\sim 10^6$ radio sources in VLASS.

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Alex Tellez, Yjan Gordon, Keith Bechtol. 2024-09-20. Predicting the Number of Radio Sources Seen by Both VLASS and LSST. https://arxiv.org/abs/2409.13850

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