FLASH Talks: Ryan Lau (NOIRLab) & Rafael Bertolotto (University of Arizona)


Friday, 06 September 2024 noon — 1 p.m. MST

NOIRLab Headquarters | 950 North Cherry Ave., Tucson, AZ 85719

FLASH Talks
Ryan Lau (NOIRLab) & Rafael Bertolotto (University of Arizona)

Ryan Lau (NOIRLab)
Unraveling Dust Production from Wolf-Rayet Binaries with JWST

Dust is a key ingredient in the formation of stars and planets. However, the dominant channels of dust production throughout cosmic time are still unclear. With its unprecedented sensitivity and spatial resolution in the mid-IR, the James Webb Space Telescope (JWST) is the ideal platform to address this issue by investigating the dust abundance, composition, and production rates of various dusty sources. In particular, colliding-wind Wolf-Rayet (WR) binaries are efficient dust producers in the local Universe, and likely existed in the earliest galaxies. In this talk, I will discuss the results and on-going work initiated by our WR DustERS Team from Cycle 1 Early Release Science with JWST using the Mid-Infrared Instrument (MIRI) and the Aperture Masking Interferometry mode in the Near Infrared Imager and Slitless Spectrograph (NIRISS).

Rafael Bertolotto (University of Arizona)
Inferring the initial mass function of young stellar co-moving groups in the solar neighborhood

The solar neighborhood is populated by groups of young, co-moving stars. Their youth suggests that they are remnants of stellar groups dispersing in the galactic disk, which combined with their proximity makes them ideal candidates for the study of the Initial Mass Function (IMF). In this work, we develop and implement a method to detect members of these groups based on their distribution in a five-dimensional kinematic space constructed from Gaia DR3 survey data, and to infer their IMF in the mass range 0.01 < m/M⊙ < 5. We apply the method to ten known groups, detecting a total of 1229 kinematic and photometric candidate members, recovering 66 % of the known members and detecting 604 new candidates from which we estimate that between 105 and 287 are contaminants. Finally, we obtained the IMF for the ten groups, nine of which are new, and calculated the average normalized IMF of the ten groups. We found that IMF parameterizations as log-normal functions for masses m/M⊙ < 1 are consistent with those estimated by Chabrier (2003) and Sua ́rez et al. (2019) from both literature members and our detections, and that our results show better agreement with the IMF of Salpeter (1955) in the mass range m/M⊙ > 1 than the mass functions obtained from literature members. Finally, we found evidence of contamination on average around 1 M⊙ and incompleteness for objects with masses m/M⊙ < 0,02 that will be studied in future work. The observed incompleteness could be the result of a kinematic dispersion process that needs further studies. This work represents a significant advance in the study of young groups in the solar neighborhood, both as the first to report the mass functions of nine of these groups and by providing information on their possible origin.