Low-Metallicity Star Formation Survey of Sh2-284 (LZ-STAR): The Core Mass Function

Journal article, 2026

We present an Atacama Large Millimeter/submillimeter Array 1.3 mm dust continuum study of the dense core mass function (CMF) in Sh2-284, a low-metallicity outer Galaxy star-forming complex with Z similar to 1/3-1/2 Z circle dot. The observations cover six far-infrared bright subregions at similar to 0 .'' 65 (3000 au) resolution. We identify a total of 91 candidate dense cores and define a robust catalog of 68 cores with Gaussian fitting. The high-mass CMF above 2.5 M circle dot is well described by a Salpeter-like slope, with a fiducial forward-modeled value of alpha=1.22-0.22+0.24 for dN/dlogM proportional to M-alpha . Together with existing constraints on the initial mass function (IMF) of Sh2-284, the Salpeter-like CMF is consistent with a resemblance between the CMF and IMF shapes in the outer Galaxy environments, suggesting that moderately low metallicity alone does not strongly reshape the high-mass CMF/IMF slope.