Kavli Affiliate: Gregory Herczeg
| Summary:
The metallicity of the star-forming environment is a fundamental parameter shaping the evolution of protoplanetary disks and the formation of planetary systems, yet its influence remains poorly constrained. We present a spectroscopic study of low-mass pre-main sequence (PMS) stars ($M < 1 , M_odot$) in the exceptionally metal-poor cluster Dolidze~25 ($Z approx 0.2 , Z_odot$), using VLT/MUSE observations to probe accretion processes and disk evolution in a subsolar environment. We identify 132 cluster members using a combination of textitGaia astrometry and spectroscopic youth indicators, including lithium absorption and Balmer emission. The stellar parameters are derived using low-metallicity BT-Settl models yielding effective temperatures, extinctions, luminosities enabling robust estimates of stellar masses and ages. Mass accretion rates ($dotM_mathrmacc$) derived from H$α$ emission span $10^-10$–$10^-8 , M_odot,mathrmyr^-1$ with a median value of (8 times 10^-10,M_odot,mathrmyr^-1). These rates are comparable to those in solar-metallicity regions of similar age, such as Lupus and Orion, indicating minimal metallicity dependence in accretion processes. Our analysis shows that using solar-metallicity templates to fit low-metallicity stars leads to systematic overestimations of (T_mathrmeff) (by approximately (300,mathrmK)) and (A_V) (by around (0.5,mathrmmag)), underscoring the importance of employing metallicity-matched models for reliable characterization in low-(Z) environments. We present flux-calibrated, extinction-corrected spectra of these metal-poor PMS stars as a valuable resource for future investigations of disk evolution in subsolar regimes.
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