The SMASH data have already produced some exciting results.
In Martin et al. (2015), we presented the
discovery of a compact and faint Milky Way satellite, Hydra II (in Field169), with morphological and
stellar population properties consistent with being a dwarf galaxy (also see
Kirby et al. 2015).
Interestingly, comparison with simulations suggests that at Hydra II's position in the sky and distance
of 134 kpc (from blue horizontal branch stars) it could be associated with the Leading Arm of the
Magellanic Stream, although proper motion information is needed to confirm. We obtained follow-up
time-series data on Hydra II to study its variable stars. This work yielded one RR Lyrae star in Hydra II
that gave a slightly larger distance of 151 kpc as well as the discovery of dozens of short period variables
in the field (Vivas et al. 2016).
Further sensitive searching for overdensities in the SMASH data yielded the discovery of a compact and
very faint (MV=-1.0) stellar system (SMASH 1) ~11 degrees away from the LMC. SMASH 1 is consistent
with being an old globular cluster in the LMC periphery likely associated with the LMC disk and potentially
on the verge of tidally disrupting (Martin et al. 2016).
Extended LMC stellar populations
One of the on-going SMASH projects is to map out the extended stellar populations of the LMC. An analysis
of the Hess diagrams indicates that LMC stellar populations can be detected in SMASH data out to 21.1 degrees
from the LMC center, or ~18.4 kpc, and to surface brightness levels of ~33.3 mag/arcsec2
(D. Nidever et al. 2017, in preparation).
Star Formation Histories
One of the main goals of SMASH is to use the data in the central LMC/SMC fields to derive spatially-resolved
star formation histories. The Hess diagram of Field55 in Figure X (upper left) is an example of the wealth
of information in the data. This field, and other nearby ones, in particular, show two subgiant branches
which indicates two periods of peak star formation. This was previously only seen in star formation rate
diagrams from detailed star formation history modeling
(Meschin et al. 2014), but now is visually clear just
in the Hess diagrams. Full star formation history modeling still await computationally intensive artificial
star tests for the SMASH data, which will be a focus of on-going SMASH processing efforts in the near future.
Citizen Science Cluster Detection
The deep and multi-band data in the main bodies of the Magellanic Clouds are also very useful for
detecting faint star clusters. We have developed a citizen science project (led by L .Cliff Johnson)
based on the SMASH data under the Zooniverse platform which
currently has roughly one million users and hosts many citizen science projects in multiple scientific
disciplines. The project is called "Local Group Cluster Search"
The citizen scientists will inspect our deep co-add ugriz images
and visually identify (a) star clusters (open and globular), (b) galaxies behind the LMC/SMC main bodies,
(c) and new dwarf galaxies of MW or the MCs. The SMC portion was completed in early-mid 2019 and the LMC
portion will start in late 2019.