NGC 602 is a young, low-metallicity star cluster in the "Wing" of the Small Magellanic Cloud. We reveal the recent evolutionary past of the cluster through analysis of high-resolution (~0.4pc) Atacama Large Millimeter/submillimeter Array observations of molecular gas in the associated HII region N90. We identify 110 molecular clumps (R<0.8pc) traced by CO emission, and study the relationship between the clumps and associated young stellar objects (YSOs) and pre-main-sequence (PMS) stars. The clumps have high virial parameters (typical {alpha}vir=4-11) and may retain signatures of a collision in the last <~8Myr between HI components of the adjacent supergiant shell SMC-SGS 1. We obtain a CO-bright-to-H2 gas conversion factor of X_CO,B_=(3.4+/-0.2)x10^20^cm^-2^ (K.km/s)^-1^, and correct observed clump properties for CO-dark H_2_ gas to derive a total molecular gas mass in N90 of 16600+/-2400M_{sun}. We derive a recent (<~1Myr) star formation rate of 130+/-30M{sun}_/Myr with an efficiency of 8%+/-3% assessed through comparing total YSO mass to total molecular gas mass. Very few significant radial trends exist between clump properties or PMS star ages and distance from NGC 602. We do not find evidence for a triggered star formation scenario among the youngest (<~2Myr) stellar generations, and instead conclude that a sequential star formation process in which NGC 602 did not directly cause recent star formation in the region is likely.
Cone search capability for table J/ApJ/938/82/tablea1 (Clump properties)
Cone search capability for table J/ApJ/938/82/tablea2 (YSO properties)
