{"id":22,"date":"2026-11-11T17:06:16","date_gmt":"2026-11-11T16:06:16","guid":{"rendered":"https:\/\/www.oa-roma.inaf.it\/limongi\/?page_id=22"},"modified":"2026-11-11T17:20:20","modified_gmt":"2026-11-11T16:20:20","slug":"massive-stars-as-cosmic-clocks","status":"publish","type":"page","link":"https:\/\/www.oa-roma.inaf.it\/limongi\/massive-stars-as-cosmic-clocks\/","title":{"rendered":"Massive Stars As Cosmic Clocks"},"content":{"rendered":"\n<div style=\"max-width: 900px;margin: 0 auto;padding: 20px 30px\">\n\n\n  \n  \n  \n  \n  <title>Massive Stars as Cosmic Clocks \u2014 O.R.F.E.O.<\/title>\n\n\n  <main class=\"wrap\">\n    <section class=\"hero\" aria-labelledby=\"project-title\">\n      <div>\n        <div class=\"eyebrow\">INAF Theory Grant \u00b7 Principal Investigator: Marco Limongi<\/div>\n        <h1 id=\"project-title\">Massive Stars as Cosmic Clocks<\/h1>\n        <p class=\"subtitle\">Shaping the evolution of infant galaxies<\/p>\n        <div class=\"actions\">\n<a class=\"button\" href=\"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-content\/uploads\/sites\/24\/2026\/11\/Cosmic-Clocks.pdf\" target=\"_blank\">View project proposal (PDF)<\/a>\n\n<br><br>\n          \n        <\/div>\n      <\/div>\n      \n    <\/section>\n\n    <div class=\"facts\" aria-label=\"Project details\">\n      <div class=\"fact\"><strong>INAF<\/strong> <span>Fundamental Astrophysics Theory Grant<\/span><\/div>\n      <div class=\"fact\"><strong>\u20ac50,000<\/strong> <span>Grant amount<\/span><\/div>\n      \n    <\/div>\n\n<br>\n\n    <section class=\"section\" aria-labelledby=\"overview-title\">\n      <div class=\"section-heading\">\n        <div class=\"eyebrow\">Project overview<\/div>\n        <h2 id=\"overview-title\">How massive stars shape the first galaxies<\/h2>\n      <\/div>\n      <div class=\"panel\">\n        <p>The earliest galaxies are dominated by young stellar populations, and massive stars act as their \u201ccosmic clocks\u201d during the first tens of millions of years of star formation. Their radiation shapes what we observe; stellar winds and supernovae inject energy into the interstellar medium; and the elements and dust they produce drive chemical enrichment. Their remnants may also form black-hole seeds. This project combines state-of-the-art stellar models, galaxy-evolution tools and cosmological simulations to investigate how the mass, metallicity and rotation of massive stars influence the assembly and observable properties of infant galaxies.<\/p>\n      <\/div>\n    <\/section>\n\n    <section class=\"section\" aria-labelledby=\"objectives-title\">\n      <div class=\"section-heading\">\n        <div class=\"eyebrow\">Research goals<\/div>\n        <h2 id=\"objectives-title\">Four connected objectives<\/h2>\n      <\/div>\n      <div class=\"objectives\">\n        <article class=\"panel objective\"><span class=\"objective-number\">01<\/span><p>Determine which massive stars explode and enrich the interstellar medium, what elemental abundances they produce, and how initial stellar mass relates to final black-hole mass.<\/p><\/article>\n        <article class=\"panel objective\"><span class=\"objective-number\">02<\/span><p>Understand the timescales of mechanical and chemical feedback in the first galaxies.<\/p><\/article>\n        <article class=\"panel objective\"><span class=\"objective-number\">03<\/span><p>Explore the statistical properties of the first galaxies and active galactic nuclei (AGNs).<\/p><\/article>\n        <article class=\"panel objective\"><span class=\"objective-number\">04<\/span><p>Investigate how dust is produced and enriches the first galaxies.<\/p><\/article>\n      <\/div>\n    <\/section>\n\n    <section class=\"section\" aria-labelledby=\"work-packages-title\">\n      <div class=\"section-heading\">\n        <div class=\"eyebrow\">Approach<\/div>\n        <h2 id=\"work-packages-title\">Four work packages<\/h2>\n      <\/div>\n      <div class=\"work-packages\">\n        <article class=\"panel work-package\">\n          <div class=\"wp-label\">WP1 \u00b7 Massive stellar models<\/div>\n          <h3>From stellar birth to remnant<\/h3>\n          <p>Extend presupernova model grids across initial masses of 13\u2013120 M\u2609, metallicities from zero to 2 Z\u2609, and rotation velocities of 0, 150 and 300 km\/s. Calculate explosions, nucleosynthetic yields and final neutron-star or black-hole masses.<\/p>\n          <div class=\"tools\">FRANEC \u00b7 HYPERION<\/div>\n        <\/article>\n        <article class=\"panel work-package\">\n          <div class=\"wp-label\">WP2 \u00b7 Infant-galaxy models<\/div>\n          <h3>Track feedback and observables<\/h3>\n          <p>Use simplified galaxy-evolution models and a redshift- and metallicity-dependent stellar initial mass function to explore star-formation histories, ultraviolet luminosities, chemical abundances and black-hole populations. Predict spectra for comparison with JWST observations.<\/p>\n          <div class=\"tools\">Toy models \u00b7 CLOUDY<\/div>\n        <\/article>\n        <article class=\"panel work-package\">\n          <div class=\"wp-label\">WP3 \u00b7 First galaxies and AGNs<\/div>\n          <h3>Explore the high-redshift population<\/h3>\n          <p>Use the CAT semi-analytical model with the new stellar grids and feedback prescriptions to study the statistical properties of galaxies and AGNs, their star-formation history and black-hole seed populations at high redshift.<\/p>\n          <div class=\"tools\">CAT \u00b7 Semi-analytical modelling<\/div>\n        <\/article>\n        <article class=\"panel work-package\">\n          <div class=\"wp-label\">WP4 \u00b7 Zoom-in simulations<\/div>\n          <h3>Follow dust and metals in detail<\/h3>\n          <p>Update cosmological hydrodynamical zoom-in simulations with new stellar yields, supernova dust production and feedback to investigate the enrichment histories of the first star-forming galaxies.<\/p>\n          <div class=\"tools\">dustyGadget \u00b7 Cosmological simulations<\/div>\n        <\/article>\n      <\/div>\n    <\/section>\n\n    <section class=\"section\" aria-labelledby=\"team-title\">\n      <div class=\"section-heading\">\n        <div class=\"eyebrow\">Collaboration<\/div>\n        <h2 id=\"team-title\">Project team<\/h2>\n      <\/div>\n      <div class=\"team\">\n        <article class=\"team-member\"><h3><a href=\"mailto:marco.limongi@inaf.it\">Marco Limongi<\/a><\/h3><p>Principal Investigator; FRANEC stellar models and HYPERION explosions, nucleosynthesis and remnants.<\/p><\/article>\n        <article class=\"team-member\"><h3>Alessandro Chieffi<\/h3><p>FRANEC presupernova models and nucleosynthesis; HYPERION explosions and yields.<\/p><\/article>\n        <article class=\"team-member\"><h3>Lorenzo Roberti<\/h3><p>Massive-star models, nucleosynthesis and explosion calculations.<\/p><\/article>\n        <article class=\"team-member\"><h3>Cristiano Ugolini<\/h3><p>HYPERION explosion calculations, yields and remnant masses.<\/p><\/article>\n        <article class=\"team-member\"><h3>Raffaella Schneider<\/h3><p>Galaxy toy models and implications for high-redshift galaxy evolution.<\/p><\/article>\n        <article class=\"team-member\"><h3>Rosa Valiante<\/h3><p>CAT semi-analytical modelling and galaxy and AGN predictions.<\/p><\/article>\n        <article class=\"team-member\"><h3>Alessandro Trinca<\/h3><p>CAT implementation and statistical properties of galaxies and AGNs.<\/p><\/article>\n        <article class=\"team-member\"><h3>Luca Graziani<\/h3><p>Hydrodynamical models, cosmic enrichment and dust yields.<\/p><\/article>\n        <article class=\"team-member\"><h3>Federico Angeloni<\/h3><p>Dusty-galaxy simulations and chemical evolution.<\/p><\/article>\n        <article class=\"team-member\"><h3>Alessandra Venditti<\/h3><p>Cosmological simulations and chemical evolution of dust.<\/p><\/article>\n      <\/div>\n      <p class=\"team-note\">Roles are summarized from the project proposal; participants and work-package assignments are those listed in the attached document.<\/p>\n    <\/section>\n\n    <p class=\"source-note\">Project details are summarized from the <a href=\".\/Cosmic%20Clocks.pdf\">INAF project proposal (PDF)<\/a> and the CV. The proposal describes planned research and deliverables.<\/p>\n  <\/main>\n\n  <footer>\n    <div class=\"wrap footer-inner\">\n      <span><strong>Massive Stars as Cosmic Clocks<\/strong> \u00b7 INAF Theory Grant<\/span>\n      <a href=\".\/marco-limongi.html\">Marco Limongi<\/a>\n    <\/div>\n  <\/footer>\n\n\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Massive Stars as Cosmic Clocks \u2014 O.R.F.E.O. INAF Theory Grant \u00b7 Principal Investigator: Marco Limongi Massive Stars as Cosmic Clocks Shaping the evolution of infant galaxies View project proposal (PDF) INAF Fundamental Astrophysics Theory Grant \u20ac50,000 Grant amount Project overview How massive stars shape the first galaxies The earliest galaxies are dominated by young stellar [&hellip;]<\/p>\n","protected":false},"author":1470,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-22","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-json\/wp\/v2\/pages\/22","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-json\/wp\/v2\/users\/1470"}],"replies":[{"embeddable":true,"href":"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-json\/wp\/v2\/comments?post=22"}],"version-history":[{"count":3,"href":"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-json\/wp\/v2\/pages\/22\/revisions"}],"predecessor-version":[{"id":28,"href":"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-json\/wp\/v2\/pages\/22\/revisions\/28"}],"wp:attachment":[{"href":"https:\/\/www.oa-roma.inaf.it\/limongi\/wp-json\/wp\/v2\/media?parent=22"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}