https://samecutler.github.io/tag/globular-clusters/Globular ClustersWowchemy (https://wowchemy.com)en-us© 2026 Sam CutlerThu, 08 Oct 2026 00:51:36 +0000https://samecutler.github.io/media/icon_hue11b335ae175fd4abb2262113e3113ef_438264_512x512_fill_lanczos_center_3.pnghttps://samecutler.github.io/tag/globular-clusters/https://samecutler.github.io/project/the-relic/Thu, 08 Oct 2026 00:51:36 +0000https://samecutler.github.io/project/the-relic/<p>Enhanced sensitivity and spatial resolution from JWST+gravitational lensing allow us to detect and resolve candidate globular clusters (GCs) in a massive, z&gt;2.5 quiescent galaxy: <em>The Relic</em></p> <h2 id="the-relic-i-photometric-analysis---whitaker-et-al-2026">The Relic I: Photometric Analysis - Whitaker et al. 2026</h2> <p><a href="https://ui.adsabs.harvard.edu/abs/2026ApJ..1001..107W/abstract" target="_blank" rel="noopener"><em>The Astrophysical Journal</em>, doi:10.3847/1538-4357/ae5177</a> | <a href="https://arxiv.org/abs/2501.07627" target="_blank" rel="noopener">arXiv:2501.07627</a></p> <p>Using deep JWST imaging from UNCOVER and MegaScience, we discover 36 candidate GCs within the Relic, a massive quiescent galaxy at z=2.5 in the Abell 2744 lensing field. The clusters span formation ages from 8 Myr to ~2 Gyr, tracing a rich assembly history back to z~10, with masses of ~10⁶–10⁷ M☉ consistent with precursors to the most-massive present-day GCs. Their spatial distribution and low metallicities point to a combination of early <em>in situ</em> formation and later cluster accretion, providing the first direct link between high-redshift star cluster populations and local GCs.</p> <p> <figure > <div class="d-flex justify-content-center"> <div class="w-100" ><img alt="The ages and stellar masses of candidate globular clusters in the Relic." srcset=" /project/the-relic/ages_hu7ceefc86952febeeedccc22d7437f100_136173_1096c421516f862792134988dbef08e3.jpg 400w, /project/the-relic/ages_hu7ceefc86952febeeedccc22d7437f100_136173_43923a0156d7ccff90a7e28acc090d23.jpg 760w, /project/the-relic/ages_hu7ceefc86952febeeedccc22d7437f100_136173_1200x1200_fit_q75_lanczos.jpg 1200w" src="https://samecutler.github.io/project/the-relic/ages_hu7ceefc86952febeeedccc22d7437f100_136173_1096c421516f862792134988dbef08e3.jpg" width="595" height="542" loading="lazy" data-zoomable /></div> </div></figure> </p> <h2 id="the-relic-ii-ifu-prism-spectroscopy---cutler-et-al-in-prep">The Relic II: IFU PRISM Spectroscopy - Cutler et al. in prep.</h2> <p>We obtained deep (14.5 hr) NIRSpec/IFU PRISM spectroscopy for the Relic in Cycle 3 (JWST-GO-6405, PIs: Cutler/Whitaker). Following initial data reduction, we found distinct emission lines (e.g., Hα+[NII], [OIII]+Hβ) in two young, blue GCs. Using spectrophotometric modeling, we confirmed the redshift of these GCs to be consistent with the cluster and found ages as young as 6 Myr. Notably, <strong>these young GCs show significant HeI 10830 emission</strong>, suggesting self-enrichment from:</p> <ol> <li>Active enrichment from very massive star or Wolf-Rayet stellar winds</li> <li>Enrichment of birth gas prior to star formation</li> <li>Delayed enrichment after the first ~2 Myr</li> </ol> <p> <figure > <div class="d-flex justify-content-center"> <div class="w-100" ><img src="output.png" alt="PRISM spectra of the two young GCs in the Relic" loading="lazy" data-zoomable /></div> </div></figure> </p>