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We have used Chandra observations of eight bulge-less disk galaxies toidentify new ultraluminous X-ray source (ULX) candidates, study their high massX-ray binary (HMXB) population, and search for low-luminosity active galacticnuclei (AGN). We report the discovery of 16 new ULX candidates in our sample ofgalaxies. Eight of these are found in the star forming galaxy NGC 337, none ofwhich are expected to be background contaminants. The HMXB luminosity functionof NGC 337 implies a star formation rate (SFR) of 6.8$^{+4.4}_{-3.5}$ \msun\yr$^{-1}$, consistent at 1.5$\sigma$ with a recent state of the art SFRdetermination. We also report the discovery of a bright ULX candidate (X-1) inESO 501-23. X-1's spectrum is well fit by an absorbed power law with $\Gamma =1.18^{+0.19}_{-0.11}$ and N$\rm{_H}$ = 1.13$^{+7.07}_{-1.13} \times 10^{20}$cm$^{-2}$, implying a 0.3-8 keV flux of $1.08^{+0.05}_{-0.07} \times 10^{-12}$\esc. Its X-ray luminosity (L$_X$) is poorly constrained due to uncertaintiesin the host galaxy's distance, but we argue that its spectrum implies L$_X >10^{40}$ \es. An optical counterpart to this object may be present in HSTimaging. We also identify ULX candidates in IC 1291, PGC 3853, NGC 5964 and NGC2805. We find no evidence of nuclear activity in the galaxies in our sample,placing a flux upper limit of $4 \times 10^{-15}$ \esc\ on putative AGN.Additionally, the type II-P supernova SN 2011DQ in NGC 337, which exploded 2months before our X-ray observation, is undetected.

Discovery of a Large Population of Ultraluminous X-ray Sources in the Bulge-less Galaxies NGC 337 and ESO 501-23