{"id":22,"date":"2025-12-13T14:21:40","date_gmt":"2025-12-13T13:21:40","guid":{"rendered":"https:\/\/www.harmoni-elt.eu\/?page_id=22"},"modified":"2025-12-13T14:39:09","modified_gmt":"2025-12-13T13:39:09","slug":"22-2","status":"publish","type":"page","link":"https:\/\/www.harmoni-elt.eu\/harmoni\/harmoni\/17-2\/22-2\/","title":{"rendered":"StellarPopWithHARMONI"},"content":{"rendered":"\n
\n
\n

Understanding how galaxies form and evolve:<\/strong> Stellar Populations with HARMONI<\/strong><\/h2>\n\n\n\n

Stellar populations preserve the fossil record of galaxy formation. The ages, chemical compositions, and motions of individual stars encode when and how galaxies assembled their mass, formed stars, and enriched their interstellar medium. Accessing this information requires resolved spectroscopy of individual stars<\/strong>, particularly in crowded environments such as galaxy centres, dense clusters, and nearby galaxies beyond the Milky Way.<\/p>\n<\/div>\n\n\n\n

With its combination of extreme angular resolution<\/strong>, integral-field spectroscopy<\/strong>, and near-infrared wavelength coverage<\/strong>, HARMONI on the ELT will revolutionise the study of resolved stellar populations<\/strong> well beyond the Local Group.<\/p>\n<\/div>\n\n\n\n

\n\n\n\n
\n

From the Milky Way to the Local Volume<\/strong><\/h2>\n\n\n\n

HARMONI will enable spectroscopic studies of individual stars across a wide range of environments and distances, including:<\/p>\n\n\n\n

    \n
  • The Galactic Centre<\/strong>, probing stellar populations down to the main-sequence turn-off in extremely crowded fields<\/li>\n\n\n\n
  • Massive star clusters<\/strong>, such as R136 in the Large Magellanic Cloud, resolving their dense cores<\/li>\n\n\n\n
  • Nearby galaxies in the Local Volume<\/strong>, including systems like Centaurus A, where individual stars can be studied out to significant fractions of the effective radius<\/li>\n\n\n\n
  • Low surface brightness regions<\/strong> of galaxies, such as outskirts and dwarf galaxies, potentially out to the distance of the Virgo and Fornax clusters<\/li>\n<\/ul>\n<\/div>\n\n\n\n
    \n\n\n\n
    \n

    Resolved spectroscopy with HARMONI will allow detailed measurements of stellar properties, including:<\/p>\n\n\n\n

      \n
    • Radial velocities<\/strong>, tracing galaxy dynamics and substructure<\/li>\n\n\n\n
    • Chemical abundances<\/strong> (e.g. iron, \u03b1-elements, CNO), which record the timescales and mechanisms of chemical enrichment<\/li>\n\n\n\n
    • Age and population diagnostics<\/strong>, linking stellar populations to past star formation episodes<\/li>\n<\/ul>\n\n\n\n

      Medium spectral resolution in the near-infrared provides an optimal balance between sensitivity and diagnostic power, enabling robust abundance measurements for a wide range of stellar types. This capability is essential to extract clean spectra of individual stars and avoid contamination from neighbours.<\/p>\n<\/div>\n\n\n\n

      \n\n\n\n
      \n

      A cornerstone science case for HARMONI<\/strong><\/h2>\n\n\n\n

      Resolved stellar populations represent one of the core, transformative science drivers<\/strong> for HARMONI. By extending detailed stellar spectroscopy far beyond the Milky Way, HARMONI will:<\/p>\n\n\n\n

        \n
      • Bridge the gap between nearby resolved galaxies and distant unresolved systems<\/li>\n\n\n\n
      • Provide essential calibration for galaxy evolution studies across cosmic time<\/li>\n\n\n\n
      • Deliver unique datasets that cannot be obtained with any existing or planned facility<\/li>\n<\/ul>\n<\/div>\n\n\n\n
        \n

        <\/p>\n<\/div>\n\n\n\n

        <\/p>\n\n\n\n

        <\/p>\n","protected":false},"excerpt":{"rendered":"

        Understanding how galaxies form and evolve: Stellar Populations with HARMONI Stellar populations preserve the fossil record of galaxy formation. The ages, chemical compositions, and motions of individual stars encode when and how galaxies assembled their mass, formed stars, and enriched their interstellar medium. Accessing this information requires resolved spectroscopy of individual stars, particularly in crowded […]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":17,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-no-title","meta":{"footnotes":""},"class_list":["post-22","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/pages\/22","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/comments?post=22"}],"version-history":[{"count":9,"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/pages\/22\/revisions"}],"predecessor-version":[{"id":87,"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/pages\/22\/revisions\/87"}],"up":[{"embeddable":true,"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/pages\/17"}],"wp:attachment":[{"href":"https:\/\/www.harmoni-elt.eu\/harmoni\/wp-json\/wp\/v2\/media?parent=22"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}