[et_pb_section fb_built=”1″ admin_label=”Section” _builder_version=”4.16″ _module_preset=”default” background_image=”https:\/\/www.ieec.cat\/wp-content\/uploads\/2022\/02\/slider-comunicacio.jpg” max_height=”130px” custom_padding=”0px||0px||false|false” da_disable_devices=”off|off|off” global_colors_info=”{}” da_is_popup=”off” da_exit_intent=”off” da_has_close=”on” da_alt_close=”off” da_dark_close=”off” da_not_modal=”on” da_is_singular=”off” da_with_loader=”off” da_has_shadow=”on”][\/et_pb_section][et_pb_section fb_built=”1″ admin_label=”Section” _builder_version=”4.16″ _module_preset=”default” custom_padding=”24px||11px|||” da_disable_devices=”off|off|off” global_colors_info=”{}” da_is_popup=”off” da_exit_intent=”off” da_has_close=”on” da_alt_close=”off” da_dark_close=”off” da_not_modal=”on” da_is_singular=”off” da_with_loader=”off” da_has_shadow=”on”][et_pb_row _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text admin_label=”Unitats de recerca” module_class=”ieec-orgs” _builder_version=”4.27.4″ _dynamic_attributes=”content” _module_preset=”default” text_font=”|700||on|||||” text_font_size=”16px” header_font=”|700|||||||” custom_margin=”||10px||false|false” header_font_size_tablet=”28px” header_font_size_phone=”26px” header_font_size_last_edited=”on|phone” global_colors_info=”{}”]@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoiY3VzdG9tX21ldGFfb3JnYW5pemFjaW9uZXMiLCJzZXR0aW5ncyI6eyJiZWZvcmUiOiIiLCJhZnRlciI6IiIsImVuYWJsZV9odG1sIjoib2ZmIn19@[\/et_pb_text][et_pb_post_title author=”off” categories=”off” comments=”off” featured_image=”off” admin_label=”T\u00edtol i data” module_class=”ieec-title” _builder_version=”4.27.4″ _module_preset=”default” title_font=”Cairo|300|||||||” title_font_size=”40px” meta_font=”||on||||||” meta_font_size=”16px” title_font_size_tablet=”35px” title_font_size_phone=”30px” title_font_size_last_edited=”on|desktop” global_colors_info=”{}”][\/et_pb_post_title][et_pb_text admin_label=”Subt\u00edtols” module_class=”ieec-summary” _builder_version=”4.27.4″ _module_preset=”default” text_font=”Source Sans Pro||on||||||” text_font_size=”24px” text_line_height=”1.1em” text_font_size_tablet=”22px” text_font_size_phone=”20px” text_font_size_last_edited=”on|phone” global_colors_info=”{}”]<\/p>\n
[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_2,1_2″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”1_2″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_post_title title=”off” meta=”off” module_class=”ieec-img-container” _builder_version=”4.27.2″ _module_preset=”default” custom_margin=”||0px||false|false” border_width_top=”10px” border_color_top=”#406fda” global_colors_info=”{}”][\/et_pb_post_title][et_pb_text module_class=”ieec-img-footer” _builder_version=”4.27.4″ _module_preset=”default” text_font=”||||||||” text_font_size=”15px” text_line_height=”1.1em” background_color=”rgba(64,111,218,0.15)” custom_margin=”0px||||false|false” custom_padding=”30px|20px|30px|20px|true|true” global_colors_info=”{}”]<\/p>\n
This image shows the gas disc in a computer simulation of a Milky Way-like galaxy from the Auriga suite. Colours represent the ratio of magnesium to iron, revealing that the galactic centre (pink) is poor in magnesium, while the outskirts (green) are rich in this material. These chemical patterns provide important clues about how the galaxy formed. Matthew D. A. Orkney (ICCUB-IEEC)\/Auriga project<\/strong><\/p>\n [\/et_pb_text][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” link_font=”|700|||on||||” global_colors_info=”{}”]<\/p>\n A research team led by experts from the <\/span>Insitute of Space Studies of Catalonia<\/span><\/a> (IEEC \u2014 Institut d\u2019Estudis Espacials de Catalunya) at the <\/span>Institute of Cosmos Sciences of the University of Barcelona<\/span><\/a> (ICCUB) and the <\/span>Centre national de la recherche scientifique<\/span><\/a> (CNRS) has published a study that offers fresh insights into how galaxies like our Milky Way form and evolve and why their stars show surprising chemical patterns.<\/span><\/p>\n The work, which has the collaboration of scientists from Liverpool John Moores University and the Max-Planck-Institut f\u00fcr Astrophysik, is published in the journal <\/span>Monthly Notices of the Royal Astronomical Society<\/span><\/i>. The research explores the origins of a puzzling feature in the Milky Way: the presence of <\/span>two distinct groups of stars with different chemical compositions<\/b>, known as the \u201cchemical bimodality.\u201d<\/span><\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text module_class=”section-title” _builder_version=”4.27.4″ _module_preset=”default” header_2_font=”|700|||||||” header_2_font_size=”25px” header_2_font_size_tablet=”23px” header_2_font_size_phone=”23px” header_2_font_size_last_edited=”on|phone” global_colors_info=”{}”]<\/p>\n [\/et_pb_text][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” link_font=”|700|||on||||” locked=”off” global_colors_info=”{}”]<\/p>\n When scientists study stars near the Sun, they find <\/span>two main types based on their chemical makeup, specifically, the amounts of iron and magnesium\u00a0 they contain<\/b>. These two groups form separate \u201csequences\u201d in a chemical diagram, even though they overlap in metallicity (how rich they are in heavy elements like iron). This has long puzzled astronomers.<\/span><\/p>\n The study uses advanced computer simulations (called the <\/span>Auriga<\/span><\/a> simulations) to recreate the formation of galaxies like the Milky Way in a virtual universe. By analyzing 30 simulated galaxies, the team looked for clues about how these chemical sequences form.<\/span><\/p>\n Understanding the chemical history of the Milky Way helps scientists piece together <\/span>how our Galaxy, and others like it, came to be<\/b>. This includes our sister galaxy, Andromeda, in which no bimodality has yet been detected. It also provides clues about the conditions in the early universe and the role of cosmic gas flows and galaxy mergers.<\/span><\/p>\n \u201cThis study shows that the Milky Way\u2019s chemical structure is not a universal blueprint,\u201d says lead author Matthew D. A. Orkney, IEEC researcher at ICCUB. \u201cGalaxies can follow different paths to reach similar outcomes, and that diversity is key to understanding galaxy evolution,\u201d he adds.<\/span><\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text module_class=”section-title” _builder_version=”4.27.4″ _module_preset=”default” header_2_font=”|700|||||||” header_2_font_size=”25px” header_2_font_size_tablet=”23px” header_2_font_size_phone=”23px” header_2_font_size_last_edited=”on|phone” global_colors_info=”{}”]<\/p>\n [\/et_pb_text][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” link_font=”|700|||on||||” hover_enabled=”0″ locked=”off” global_colors_info=”{}” sticky_enabled=”0″]<\/p>\n The study reveals that galaxies like the Milky Way <\/span>can develop two distinct chemical sequences through various mechanisms.<\/b> In some cases, this bimodality arises from bursts of star formation followed by periods of little activity, while in others it results from changes in the inflow of gas from the galaxy\u2019s surroundings.\u00a0<\/span><\/p>\n Contrary to previous assumptions,<\/span> the collision with a smaller galaxy<\/b> known as Gaia-Sausage-Enceladus (GSE) <\/span>is not a necessary condition for this chemical pattern to emerge<\/b>. Instead, the simulations show that metal-poor gas from the circumgalactic medium (CGM) plays a crucial role in forming the second sequence of stars. Moreover, the shape of these chemical sequences is closely linked to the galaxy\u2019s star formation history.<\/span><\/p>\n As new telescopes like the James Webb Space Telescope (JWST) and upcoming missions such as <\/span>Plato<\/span><\/a> and Chronos provide more detailed data on stars and galaxies, researchers will be able to test these findings and refine our picture of the cosmos.<\/span><\/p>\n \u201cThis study predicts that other galaxies should exhibit a diversity of chemical sequences. This will soon be probed in the era of 30m telescopes where such studies in external galaxies will become routine,\u201d says Chervin Laporte, IEEC researcher at ICCUB and also member of CNRS-Observatoire de Paris and Kavli IPMU \u201cUltimately, these will also help us further refine the physical evolutionary path of our own Milky Way,\u201d he concludes.<\/span><\/p>\n Press release prepared in collaboration with the Institute of Cosmos Sciences (ICCUB).<\/span><\/em><\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.16″ _module_preset=”default” custom_margin=”30px||||false|false” locked=”off” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider color=”#406fda” _builder_version=”4.16″ _module_preset=”default” custom_margin=”||10px||false|false” global_colors_info=”{}”][\/et_pb_divider][et_pb_text admin_label=”M\u00e9s informaci\u00f3” module_class=”ieec-sub-title” _builder_version=”4.27.4″ _module_preset=”default” text_font=”Cairo|700|||||||” text_text_color=”#406fda” text_font_size=”20px” custom_margin=”||10px||false|false” global_colors_info=”{}”]<\/p>\n More information<\/p>\n [\/et_pb_text][et_pb_text module_class=”ieec-sub-text” _builder_version=”4.27.4″ _module_preset=”default” text_font_size=”16px” text_line_height=”1.1em” link_font=”|700|||on||||” custom_margin=”20px||||false|false” global_colors_info=”{}”]<\/p>\n This research is presented in a paper entitled \u201c<\/span>The Milky Way in context: The formation of galactic discs and chemical sequences from a cosmological perspective<\/span><\/a>\u201d, by <\/span>Orkney, M. D. A.<\/span> et al.<\/span><\/i>, to appear in the journal Monthly Notices of the Royal Astronomical Society on 8 December 2025.<\/span><\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.16″ _module_preset=”default” custom_margin=”||||false|false” locked=”off” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider color=”#406fda” _builder_version=”4.16″ _module_preset=”default” custom_margin=”||10px||false|false” global_colors_info=”{}”][\/et_pb_divider][et_pb_text admin_label=”Enlla\u00e7os” module_class=”ieec-sub-title” _builder_version=”4.27.4″ _module_preset=”default” text_font=”Cairo|700|||||||” text_text_color=”#406fda” text_font_size=”20px” custom_margin=”||10px||false|false” global_colors_info=”{}”]<\/p>\n Links<\/p>\n [\/et_pb_text][et_pb_text module_class=”ieec-sub-text” _builder_version=”4.27.4″ _module_preset=”default” text_font_size=”16px” text_line_height=”1.1em” link_font=”|700|||on|||#1a1140|” link_text_color=”#1a1140″ link_line_height=”1.4em” custom_margin=”20px||||false|false” global_colors_info=”{}”]<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.16″ _module_preset=”default” custom_margin=”||||false|false” locked=”off” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider color=”#406fda” _builder_version=”4.16″ _module_preset=”default” custom_margin=”||10px||false|false” global_colors_info=”{}”][\/et_pb_divider][et_pb_text admin_label=”Contactes” module_class=”ieec-sub-title” _builder_version=”4.27.4″ _module_preset=”default” text_font=”Cairo|700|||||||” text_text_color=”#406fda” text_font_size=”20px” custom_margin=”||10px||false|false” global_colors_info=”{}”]<\/p>\n Contacts<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”2_5,3_5″ admin_label=”Row” _builder_version=”4.16″ _module_preset=”default” custom_margin=”0px||||false|false” custom_padding=”0px||||false|false” global_colors_info=”{}”][et_pb_column type=”2_5″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”|||20px|false|false” border_width_left=”1px” border_color_left=”#406fda” global_colors_info=”{}”][et_pb_text _builder_version=”4.16″ _module_preset=”default” text_font_size=”16px” text_line_height=”1.1em” link_font=”|700|||on|||#1a1140|” link_text_color=”#1a1140″ link_line_height=”1.4em” header_4_font=”|700|||||||” header_4_text_color=”#1a1140″ custom_margin=”||||false|false” locked=”off” global_colors_info=”{}”]<\/p>\n Castelldefels, Barcelona [\/et_pb_text][\/et_pb_column][et_pb_column type=”3_5″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”|||20px|false|false” border_width_left=”1px” border_color_left=”#406fda” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” text_font_size=”16px” text_line_height=”1em” link_font=”|700|||on||||” link_text_color=”#1a1140″ header_4_font=”|700|||||||” header_4_text_color=”#1a1140″ global_colors_info=”{}”]<\/p>\n Institute of Space Studies of Catalonia (IEEC) [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row module_id=”ieec-about” module_class=”about-ieec” _builder_version=”4.27.4″ _module_preset=”default” background_color=”rgba(64,111,218,0.15)” global_module=”17324″ global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”20px|50px|20px|50px|true|true” global_colors_info=”{}”][et_pb_text admin_label=”Sobre l’IEEC” _builder_version=”4.16″ _module_preset=”default” header_2_font=”|700|||||||” header_2_font_size=”25px” custom_margin=”||10px||false|false” header_2_font_size_tablet=”23px” header_2_font_size_phone=”23px” header_2_font_size_last_edited=”on|phone” locked=”off” global_colors_info=”{}”]<\/p>\n [\/et_pb_text][et_pb_text admin_label=”Text” _builder_version=”4.16″ _module_preset=”default” text_font=”||on||||||” link_font=”|700|||on||||” locked=”off” global_colors_info=”{}”]<\/p>\n The Institute of Space Studies of Catalonia (IEEC \u2014 Institut d\u2019Estudis Espacials de Catalunya) promotes and coordinates space research and technology development in Catalonia for the benefit of society. IEEC fosters collaborations both locally and worldwide and is an efficient agent of knowledge, innovation and technology transfer. As a result of more than 25 years of high-quality research, done in collaboration with major international organisations, IEEC ranks among the best international research centres, focusing on areas such as: astrophysics, cosmology, planetary science, and Earth Observation. IEEC\u2019s engineering division develops instrumentation for ground- and space-based projects, and has extensive experience in working with private or public organisations from the aerospace and other innovation sectors.<\/p>\n The IEEC is a non-profit public sector foundation that was established in February 1996. It has a Board of Trustees composed of the Generalitat de Catalunya, Universitat de Barcelona (UB), Universitat Aut\u00f2noma de Barcelona (UAB), Universitat Polit\u00e8cnica de Catalunya \u00b7 BarcelonaTech (UPC), and the Spanish Research Council (CSIC). The IEEC is also a CERCA centre.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":" Galaxies like our own can develop two populations of stars with different chemical compositions through various processes.<\/p>\n","protected":false},"author":5,"featured_media":41848,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"2880","footnotes":""},"categories":[111,74,98],"tags":[],"class_list":["post-41857","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-highlighted-news-small","category-news","category-science"],"yoast_head":"\nWhat is chemical bimodality?<\/h2>\n
Various mechanisms for the same results<\/h2>\n
\n
IEEC Communication Office<\/h4>\n
E-mail: comunicacio@ieec.cat<\/a><\/p>\nLead Researcher at the IEEC<\/h4>\n
Matthew D. A. Orkney<\/h4>\n
Institute of Cosmos Sciences (ICCUB)
E-mail: morkney@ieec.cat,<\/a> morkney@icc.ub.edu<\/a><\/p>\nAbout the IEEC<\/h2>\n