James Webb Space Telescope Feed Post


Literature
Date: 1/20/2025

Arxiv: JWST Imaging of the Closest Globular Clusters -- V. The White Dwarfs Cooling Sequence of M4 Published: 1/17/2025 11:42:49 AM Updated: 1/17/2025 11:42:49 AM


Paper abstract: We combine infrared (IR) observations collected by the James Webb SpaceTelescope with optical deep images by the Hubble Space Telescope takenapproximately 20 years earlier to compute proper-motion membership for theglobular cluster (GC) M 4 (NGC 6121) along its entire white dwarf (WD) coolingsequence (CS). These new IR observations allow us, for only the second time ina GC, to compare WD models with observations over a wide range of wavelengths,constraining fundamental astrophysical properties of WDs. Furthermore, weinvestigate the presence of WDs with IR excess along the WD CS of M 4, similarto the recent study conducted on the GC NGC 6397. We also determine the agedifference between M 4 and NGC 6397 by comparing the absolute F150W2 magnitudesof the luminosity function peak at the bottom of the observed WD CS, and findthat M 4 is slightly younger, by 0.8+/-0.5 Gyr.