Dynamics of baryon ejection in magnetar giant flares: implications for radio afterglows, r-process nucleosynthesis, and fast radio bursts

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10491427" target="_blank" >RIV/00216208:11320/24:10491427 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=akw6-Jk_eZ" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=akw6-Jk_eZ</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stae358" target="_blank" >10.1093/mnras/stae358</a>

Result language

angličtina

Original language name

Dynamics of baryon ejection in magnetar giant flares: implications for radio afterglows, r-process nucleosynthesis, and fast radio bursts

Original language description

We explore the impact of a magnetar giant flare (GF) on the neutron star (NS) crust, and the associated baryon mass ejection. We consider that sudden magnetic energy dissipation creates a thin high-pressure shell above a portion of the NS surface, which drives a relativistic shockwave into the crust, heating a fraction of these layers sufficiently to become unbound along directions unconfined by the magnetic field. We explore this process using spherically-symmetric relativistic hydrodynamical simulations. For an initial shell pressure PGF we find the total unbound ejecta mass roughly obeys the relation Mej similar to 4-9x10(24)g(PGF/10(30)ergscm(-3))(1.43). For PGF similar to 10(30)-10(31)ergscm(-3) corresponding to the dissipation of a magnetic field of strength similar to 10(15.5)-10(16)G, we find Mej similar to 10(25)-1026g with asymptotic velocities vej/c similar to 0.3-0.6 compatible with the ejecta properties inferred from the afterglow of the December 2004 GF from SGR 1806-20. Because the flare excavates crustal material to a depth characterized by an electron fraction Ye approximate to 0.40-0.46, and is ejected with high entropy and rapid expansion timescale, the conditions are met for heavy element r-process nucleosynthesis via the alpha-rich freeze-out mechanism. Given an energetic GF rate of roughly once per century in the Milky Way, we find that magnetar GFs could be an appreciable heavy r-process source that tracks star formation. We predict that GFs are accompanied by short similar to minutes long, luminous similar to 10(39)ergss(-1) optical transients powered by r-process decay (&quot;nova brevis&quot;), akin to scaled-down kilonovae. Our findings also have implications for the synchrotron nebulae surrounding some repeating fast radio burst sources.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

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Continuities

R - Projekt Ramcoveho programu EK

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

1365-2966

Volume of the periodical

528

Issue of the periodical within the volume

3

Country of publishing house

GB - UNITED KINGDOM

Number of pages

23

Pages from-to

5323-5345

UT code for WoS article

001177394000013

EID of the result in the Scopus database

2-s2.0-85185405290