{"id":311,"date":"2025-11-15T11:43:46","date_gmt":"2025-11-15T11:43:46","guid":{"rendered":"https:\/\/astroadnan.com\/?p=311"},"modified":"2025-11-15T12:22:43","modified_gmt":"2025-11-15T12:22:43","slug":"the-birth-and-early-evolution-of-a-low-mass-protostar","status":"publish","type":"post","link":"https:\/\/astroadnan.com\/index.php\/2025\/11\/15\/the-birth-and-early-evolution-of-a-low-mass-protostar\/","title":{"rendered":"The birth and early evolution of a low-mass protostar"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Understanding the collapse of dense molecular cloud cores to stellar densities and the subsequent evolution of the protostar is of importance to model the feedback effects such an object has on its surrounding environment, as well as describing the conditions with which it enters the stellar evolutionary track. This process is fundamentally multi-scale and necessitates the use of robust numerical simulations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We aim to model the birth and early evolution of a low-mass protostar. We also seek to describe the interior structure of the protostar and the radiative behavior of its accretion shock front. We carry out a high resolution numerical simulation of the collapse of a gravitationally unstable 1 <mjx-container class=\"MathJax CtxtMenu_Attached_0\" jax=\"CHTML\" tabindex=\"0\" ctxtmenu_counter=\"0\" style=\"font-size: 113.1%; position: relative;\"><mjx-math class=\"MJX-TEX\" aria-hidden=\"true\"><mjx-texatom texclass=\"ORD\"><mjx-msub><mjx-mi class=\"mjx-n\"><mjx-c class=\"mjx-c4D\"><\/mjx-c><mjx-texatom size=\"s\" texclass=\"ORD\"><mjx-mo class=\"mjx-n\"><mjx-c class=\"mjx-c2299\"><\/mjx-c><\/mjx-mo><\/mjx-texatom><\/mjx-mi><\/mjx-msub><mrow data-mjx-texclass=\"ORD\"><msub><mjx-texatom size=\"s\" texclass=\"ORD\">M<mo>\u2299<\/mo><\/mjx-texatom><\/msub><\/mrow><\/mjx-texatom><\/mjx-math><\/mjx-container> dense molecular cloud core to stellar densities using three-dimensional radiation hydrodynamics under the gray flux-limited diffusion approximation. We follow the initial isothermal phase, the first adiabatic contraction, the second gravitational collapse triggered by the dissociation of <mjx-container class=\"MathJax CtxtMenu_Attached_0\" jax=\"CHTML\" tabindex=\"0\" ctxtmenu_counter=\"1\" style=\"font-size: 113.1%; position: relative;\"><mjx-math class=\"MJX-TEX\" aria-hidden=\"true\"><mjx-msub><mjx-texatom texclass=\"ORD\"><mjx-mi class=\"mjx-n\"><mjx-c class=\"mjx-c48\"><\/mjx-c><mjx-mn class=\"mjx-n\"><mjx-c class=\"mjx-c32\"><\/mjx-c><\/mjx-mn><\/mjx-mi><\/mjx-texatom><\/mjx-msub><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mjx-mi class=\"mjx-n\"><mjx-mn class=\"mjx-n\">H<\/mjx-mn><mn>2<\/mn><\/mjx-mi><\/msub><\/math><\/mjx-math><\/mjx-container> molecules, and <mjx-container class=\"MathJax CtxtMenu_Attached_0\" jax=\"CHTML\" tabindex=\"0\" ctxtmenu_counter=\"2\" style=\"font-size: 113.1%; position: relative;\"><mjx-math class=\"MJX-TEX\" aria-hidden=\"true\"><mjx-mo class=\"mjx-n\"><mjx-c class=\"mjx-c2248\"><\/mjx-c><mo>\u2248<\/mo><\/mjx-mo><\/mjx-math><\/mjx-container> 247 days of the subsequent main accretion phase. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We find that the sub-critical radiative behavior of the protostar\u2019s shock front causes it to swell as it accretes matter. We also find that the protostar is turbulent from the moment of its inception despite its radiative stability. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This turbulence causes significant entropy mixing inside the protostar, which regulates the swelling. Furthermore, we find that the protostar is not fully ionized at birth, but the relative amount of ionized material within it increases as it accretes matter from its surroundings.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Finally, we report in the appendix the results of the first 3D calculations involving a frequency-dependent treatment of radiative transfer, which has not produced any major differences with its gray counterpart.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Recommended citation: Adnan Ali Ahmad, Mathias Gonz\u00e1lez, Patrick Hennebelle, Beno\u00eet Commer\u00e7on, A&amp;A 680, A23 (2023)<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link has-white-color has-text-color has-link-color wp-element-button\" href=\"https:\/\/ui.adsabs.harvard.edu\/abs\/2023A%26A...680A..23A\/abstract\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Download Paper<\/strong><\/a><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Understanding the collapse of dense molecular cloud cores to stellar densities and the subsequent evolution of the protostar is of importance to model the feedback effects such an object has on its surrounding environment, as well as describing the conditions with which it enters the stellar evolutionary track. This process is fundamentally multi-scale and necessitates [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-311","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/posts\/311","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/comments?post=311"}],"version-history":[{"count":3,"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/posts\/311\/revisions"}],"predecessor-version":[{"id":342,"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/posts\/311\/revisions\/342"}],"wp:attachment":[{"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/media?parent=311"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/categories?post=311"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/astroadnan.com\/index.php\/wp-json\/wp\/v2\/tags?post=311"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}