Speaker: Kseniia Sysoliatina (AIP)

Title: White Dwarfs as Probes of the Milky Way’s Star Formation History

Abstract: Over the last decade, the rapidly growing volume of data for faint Milky Way (MW) stars has led to an increasing interest in white dwarf (WD) population. The Gaia mission has provided an unprecedented view of the WD sequence in the color–magnitude diagram and, for the first time, enabled the construction of a complete local WD sample. Because the WD population retains a record of the Galactic star formation history (SFH), it has begun to be increasingly used as a tracer for SFH reconstruction. However, results obtained from WDs are often contradictory and show tension with the MW SFHs derived from other
stellar populations.
In this study, I work within a framework of the semi-analytic Just–Jahreiß model of the Solar neighborhood. Using Gaia DR3 data and accounting for completeness limits, I model all stellar populations, including WDs, within 1 kpc from the Sun. The model is optimized using MCMC, simultaneously constraining the SFH and IMF parameters as well as key WD-model parameters, such as the slopes of the initial–final mass relation (IFMR) and a fraction of DA WDs. This allows to quantify the impact of the WD model on the predicted WD star counts and SFH parameters. I find that uncertainties in the WD modeling contribute strongly to the total uncertainty in the predicted WD population. This shows that our current uncertainty in WD physics and evolution may propagate into the SFH uncertainty and bias the SFH when it is derived from WDs alone; however, WD populations can nevertheless provide an additional constraint on the SFH when used in combination with other stellar populations.

• Date:
  Feb. 17, 2026, 2:30 p.m. – 3:30 p.m.
  
  
• Location:

  AIP; Kirch building, Conference room

  
  
• Contact:
  Rainer Arlt
  rarlt@aip.de