Stellar streams as gravitational experiments I. The case of Sagittarius

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10371070" target="_blank" >RIV/00216208:11320/17:10371070 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1051/0004-6361/201730531" target="_blank" >http://dx.doi.org/10.1051/0004-6361/201730531</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201730531" target="_blank" >10.1051/0004-6361/201730531</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Stellar streams as gravitational experiments I. The case of Sagittarius

Popis výsledku v původním jazyce

Tidal streams of disrupting dwarf galaxies orbiting around their host galaxy offer a unique way to constrain the shape of galactic gravitational potentials. Such streams can be used as &quot;leaning tower&quot; gravitational experiments on galactic scales. The most well-motivated modification of gravity proposed as an alternative to dark matter on galactic scales is Milgromian dynamics (MOND), and we present here the first ever N-body simulations of the dynamical evolution of the disrupting Sagittarius dwarf galaxy in this framework. Using a realistic baryonic mass model for the Milky Way, we attempt to reproduce the present-day spatial and kinematic structure of the Sagittarius dwarf and its immense tidal stream that wraps around the Milky Way. With very little freedom on the original structure of the progenitor, constrained by the total luminosity of the Sagittarius structure and by the observed stellar mass-size relation for isolated dwarf galaxies, we find reasonable agreement between our simulations and observations of this system. The observed stellar velocities in the leading arm can be reproduced if we include a massive hot gas corona around the Milky Way that is flattened in the direction of the principal plane of its satellites. This is the first time that tidal dissolution in MOND has been tested rigorously at these mass and acceleration scales.

Název v anglickém jazyce

Stellar streams as gravitational experiments I. The case of Sagittarius

Popis výsledku anglicky

Tidal streams of disrupting dwarf galaxies orbiting around their host galaxy offer a unique way to constrain the shape of galactic gravitational potentials. Such streams can be used as &quot;leaning tower&quot; gravitational experiments on galactic scales. The most well-motivated modification of gravity proposed as an alternative to dark matter on galactic scales is Milgromian dynamics (MOND), and we present here the first ever N-body simulations of the dynamical evolution of the disrupting Sagittarius dwarf galaxy in this framework. Using a realistic baryonic mass model for the Milky Way, we attempt to reproduce the present-day spatial and kinematic structure of the Sagittarius dwarf and its immense tidal stream that wraps around the Milky Way. With very little freedom on the original structure of the progenitor, constrained by the total luminosity of the Sagittarius structure and by the observed stellar mass-size relation for isolated dwarf galaxies, we find reasonable agreement between our simulations and observations of this system. The observed stellar velocities in the leading arm can be reproduced if we include a massive hot gas corona around the Milky Way that is flattened in the direction of the principal plane of its satellites. This is the first time that tidal dissolution in MOND has been tested rigorously at these mass and acceleration scales.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

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OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Astronomy &amp; Astrophysics [online]

ISSN

1432-0746

e-ISSN

—

Svazek periodika

603

Číslo periodika v rámci svazku

červenec

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

11

Strana od-do

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Kód UT WoS článku

000406619100107

EID výsledku v databázi Scopus

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