IvS Seminar: Tinne Pauwels (06/02/2025)

Tinne Pauwels - "High-contrast imaging of massive stars: characterising companions down to the brown dwarf mass regime" (IvS seminar 06/02/2025)
Abstract: A comprehensive study of the multiplicity properties of massive stars down to very low mass ratios is essential for constraining massive star and binary formation theories. However, past spectroscopic and interferometric multiplicity studies have not reached the contrasts needed to probe the low-mass end of the companion mass function around such massive objects. The Carina High-contrast Imaging Project of massive Stars (CHIPS) recently demonstrated that high-contrast imaging (VLT/SPHERE) enables us to explore the brown dwarf mass regime around massive stars at separations between 0”.15 and 6” (~400-15000 AU). These observations provide key insights into whether low-mass, possibly substellar, companions can form and survive in the harsh UV radiation fields of massive stars. In this seminar, I will present the results of recent high-contrast imaging surveys of massive stars in different environments (Carina region, Sco OB1, M17), including the follow-up of multiple low-mass stellar and substellar companions in Sco OB1 and M17. Finally, I will discuss how bias correction can be applied to determine the intrinsic multiplicity fractions, ultimately providing crucial constraints on massive star and binary formation models.