Early onset of the hot circumgalactic medium around Milky Way galaxies

Clicks: 9
ID: 332001
2026
Free PDF
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This article has not been analysed, so there is no overall score — reader engagement is measured and shown alongside.
AI Quality Assessment
Not analyzed
Readership in this journal
Emerging

Ranked #1,269 of 1,339 articles by views in monthly notices of the royal astronomical society

Most read Least read

Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 1,339 in total.

Mint this article as an NFT
Not yet minted

Create a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.

5 SUSD one-off · no wallet required
Sign in to mint
Abstract
Abstract Hot coronae are key regulators in Milky Way (MW)-type galaxy formation and are thought to emerge once a galaxy’s dark matter halo crosses a critical mass threshold, Mvir ~ 1012 M⊙, so that accretion shocks can heat infalling gas to virial temperatures, Tvir. Here we investigate the roles of stellar feedback and accretion shocks in establishing the circumgalactic medium (CGM) around MW-mass galaxies using the VINTERGATAN cosmological simulation suite. We find that stellar feedback drives the early formation of a hot CGM, with TCGM ~ Tvir. By contrast, in feedback-free simulations, accretion shocks alone do not produce a CGM with comparably high average temperatures at early epochs (z > 2), independent of gas metallicity. We show that CGM virialisation (defined when halo-gas cooling time exceeds the free-fall time) begins with the emergence of a hot corona (T > 105 K) that can appear as early as z ≈ 3 at virial radius, Rvir, when feedback is included. This is much earlier than predicted by accretion-shock theory or feedback-free models (z ≲ 1). While accretion shocks alone produce an inside-out virialisation pattern, feedback can alter this behaviour, driving a rapid transition (≲ 0.5 Gyr) that is either outside-in or nearly simultaneous throughout the halo. Finally, these early-forming coronae are largely stable from formation through to the present day, but can appear to evolve simply because the definition of Rvir grows with time. This “CGM pseudo-evolution” is analogous to the pseudo-evolution of dark matter haloes and should be taken into account when interpreting the evolution of hot coronae.
Reference Key
openalex_W7220899642 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors Víctor Rufo-Pastor, Oscar Agertz, S. Roca-Fàbrega, Martin P. Rey, Joss Bland‐Hawthorn, Justin I. Read, Thor Tepper-García, Corentin Cadiou, Anatole Storck
Are you one of these authors? Claim your profile
Journal monthly notices of the royal astronomical society
Year 2026
DOI
10.1093/mnras/stag1931
URL
https://doi.org/10.1093/mnras/stag1931
Keywords Keywords not found

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

Comments

No comments yet. Be the first to comment on this article.