The Milky Way's disc of classical satellite galaxies in light of Gaia DR2

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10423388" target="_blank" >RIV/00216208:11320/20:10423388 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=02-dcMLzQL" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=02-dcMLzQL</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stz3163" target="_blank" >10.1093/mnras/stz3163</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The Milky Way's disc of classical satellite galaxies in light of Gaia DR2

Popis výsledku v původním jazyce

We study the correlation of orbital poles of the 11 classical satellite galaxies of theMilkyWay, comparing results from previous proper motions with the independent data by Gaia DR2. Previous results on the degree of correlation and its significance are confirmed by the new data. Amajority of the satellites co-orbit along theVast Polar Structure, the plane (or disc) of satellite galaxies defined by their positions. The orbital planes of eight satellites align to &lt;20. with a common direction, seven even orbit in the same sense. Most also share similar specific angular momenta, though their wide distribution on the sky does not support a recent group infall or satellites-of-satellites origin. The orbital pole concentration has continuously increased as more precise proper motions were measured, as expected if the underlying distribution shows true correlation that is washed out by observational uncertainties. The orbital poles of the up to seven most correlated satellites are in fact almost as concentrated as expected for the best-possible orbital alignment achievable given the satellite positions. Combining the best-available proper motions substantially increases the tension with CDM cosmological expectations: &lt;0.1 per cent of simulated satellite systems in IllustrisTNG contain seven orbital poles as closely aligned as observed. Simulated systems that simultaneously reproduce the concentration of orbital poles and the flattening of the satellite distribution have a frequency of &lt;0.1 per cent for any number of k &gt; 3 combined orbital poles, indicating that these results are not affected by a look-elsewhere effect. This compounds the Planes of Satellite Galaxies Problem.

Název v anglickém jazyce

The Milky Way's disc of classical satellite galaxies in light of Gaia DR2

Popis výsledku anglicky

We study the correlation of orbital poles of the 11 classical satellite galaxies of theMilkyWay, comparing results from previous proper motions with the independent data by Gaia DR2. Previous results on the degree of correlation and its significance are confirmed by the new data. Amajority of the satellites co-orbit along theVast Polar Structure, the plane (or disc) of satellite galaxies defined by their positions. The orbital planes of eight satellites align to &lt;20. with a common direction, seven even orbit in the same sense. Most also share similar specific angular momenta, though their wide distribution on the sky does not support a recent group infall or satellites-of-satellites origin. The orbital pole concentration has continuously increased as more precise proper motions were measured, as expected if the underlying distribution shows true correlation that is washed out by observational uncertainties. The orbital poles of the up to seven most correlated satellites are in fact almost as concentrated as expected for the best-possible orbital alignment achievable given the satellite positions. Combining the best-available proper motions substantially increases the tension with CDM cosmological expectations: &lt;0.1 per cent of simulated satellite systems in IllustrisTNG contain seven orbital poles as closely aligned as observed. Simulated systems that simultaneously reproduce the concentration of orbital poles and the flattening of the satellite distribution have a frequency of &lt;0.1 per cent for any number of k &gt; 3 combined orbital poles, indicating that these results are not affected by a look-elsewhere effect. This compounds the Planes of Satellite Galaxies Problem.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

—

Svazek periodika

491

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

18

Strana od-do

3042-3059

Kód UT WoS článku

000512302100109

EID výsledku v databázi Scopus

2-s2.0-85079627331