Properties of intermediate- to high-mass stars in the young cluster M17 -- Characterizing the (pre-)zero-age main sequence

• DOI: 10.48550/arxiv.2408.11713
• Publication Date: 2024-08-21
• Authors: F. Backs; S. A. Brands; M. C. Ramírez-Tannus; Annelotte Derkink; A. de Koter; J. Poorta; J. Puls; Lex Kaper
• Keywords: Zero (linguistics); Sequence (biology)

The outcome of the formation massive stars is an important anchor point in their evolution. It provides insight into physics assembly process, and sets conditions for stellar We characterize a population 18 highly reddened O4.5 to B9 very young star-forming region M17. Their properties allow us identify empirical location ZAMS, rotation mass-loss rate there. performed quantitative spectroscopic modeling VLT/X-shooter spectra using NLTE atmosphere code Fastwind fitting approach Kiwi-GA. observed SEDs were used determine line-of-sight extinction. From comparison positions HRD with MIST evolutionary tracks, we inferred masses ages. find age $0.4_{-0.2}^{+0.6}$ Myr our sample, however also strong relation between mass stars. extinction towards sources ranges from $A_V = 3.6$ 10.6. Stars more than 10 M$_{\odot}$ have reached ZAMS. projected ZAMS spin distribution extends 0.3 critical velocity; rates agree those other main-sequence OB range $3 < M/$M$_{\odot} 7$ are still on pre-main sequence (PMS). Evolving $v \sin i$ yields values up $\sim 0.6 v_{\rm crit}$. For PMS without disks, tentative $10^{-8.5}\,$M$_{\odot}$\,yr$^{-1}$. constrain ($10 50$) intermediate-mass twice as high stars, suggesting that angular momentum gain processes differ two groups. suggests lag relative lower