Characterizing the Low-mass Pre-main-sequence Population in the Low-metallicity Star-forming Region Dolidze 25 Using VLT-MUSE
Abstract 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 ⊙ ) in the exceptionally metal-poor cluster Dolidze 25 ( Z ≈ 0.2 Z ⊙ ), using Very Large Telescope/MUSE observations to probe accretion processes and disk evolution in a subsolar environment. We identify 132 cluster members using a combination of Gaia 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, and luminosities enabling robust estimates of stellar masses and ages. Mass accretion rates ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>̇</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">acc</mml:mi> </mml:mrow> </mml:msub> </mml:math> ) derived from H α emission span 10 −10 –10 −8 M ⊙ yr −1 with a median value of 8 × 10 −10 M ⊙ yr −1 . These rates are comparable to those in solar-metallicity regions of a 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 eff (by approximately 300 K) and A V (by around 0.5 mag), 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.
Authors
- Kiran Kumar Sunil
- Mizna Ashraf
- Megan Reiter
- Min Fang
- Varsha Ramachandran
- Jessy Jose
- Gregory J. Herczeg
- Carlo F. Manara
- Christian Schneider
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2026-02-05
- DOI
- https://doi.org/10.3847/1538-4357/ae28cf
- Primary Topic
- Astrophysics and Star Formation Studies
- Type
- article
- Field-Weighted Citation Impact
- 0.00