We predict the sensitivity of the Vera C. Rubin Observatory Legacy Survey of
Space and Time (LSST) to faint, resolved Milky Way satellite galaxies and
outer-halo star clusters. We characterize the expected sensitivity using
simulated LSST data from the LSST Dark Energy Science Collaboration (DESC) Data
Challenge 2 (DC2) accessed and analyzed with the Rubin Science Platform as part
of the Rubin Early Science Program. We simulate resolved stellar populations of
Milky Way satellite galaxies and outer-halo star clusters over a wide range of
sizes, luminosities, and heliocentric distances, which are broadly consistent
with expectations for the Milky Way satellite system. We inject simulated stars
into the DC2 catalog with realistic photometric uncertainties and star/galaxy
separation derived from the DC2 data itself. We assess the probability that
each simulated system would be detected by LSST using a conventional isochrone
matched-filter technique. We find that assuming perfect star/galaxy separation
enables the detection of resolved stellar systems with $M_V$ = 0 mag and
$r_{1/2}$ = 10 pc with >50% efficiency out to a heliocentric distance of ~250
kpc. Similar detection efficiency is possible with a simple star/galaxy
separation criterion based on measured quantities, although the false positive
rate is higher due to leakage of background galaxies into the stellar sample.
When assuming perfect star/galaxy classification and a model for the
galaxy-halo connection fit to current data, we predict that 89 +/- 20 Milky Way
satellite galaxies will be detectable with a simple matched-filter algorithm
applied to the LSST wide-fast-deep data set. Different assumptions about the
performance of star/galaxy classification efficiency can decrease this estimate
by ~75-25%, which emphasizes the importance of high-quality star/galaxy
separation for studies of the Milky Way satellite population with LSST.

Este artículo explora los viajes en el tiempo y sus implicaciones.

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