Swift Ultraviolet Survey of the Magellanic Clouds (SUMaC). I. Shape of
  the Ultraviolet Dust Extinction Law and Recent Star Formation History of the
  Small Magellanic Cloud
  We present the first results from the Swift Ultraviolet Survey of the
Magellanic Clouds (SUMaC), the highest resolution ultraviolet (UV) survey of
the Magellanic Clouds yet completed. In this paper, we focus on the Small
Magellanic Cloud (SMC). When combined with multi-wavelength optical and
infrared observations, the three near-UV filters on the Swift
Ultraviolet/Optical Telescope are conducive to measuring the shape of the dust
extinction curve and the strength of the 2175\AA\ dust bump. We divide the SMC
into UV-detected star-forming regions and large 200" (58~pc) pixels and then
model the spectral energy distributions using a Markov Chain Monte Carlo method
to constrain the ages, masses, and dust curve properties. We find that the
majority of the SMC has a 2175\AA\ dust bump, which is larger to the northeast
and smaller to the southwest, and that the extinction curve is universally
steeper than the Galactic curve. We also derive a star formation history and
find evidence for peaks in the star formation rate at 6-10 Myr, 30-80 Myr, and
400 Myr, the latter two of which are consistent with previous work.
