The distribution and morphologies of Fornax Cluster dwarf galaxies suggest they lack dark matter

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10456056" target="_blank" >RIV/00216208:11320/22:10456056 - isvavai.cz</a>

Result on the web

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

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stac1765" target="_blank" >10.1093/mnras/stac1765</a>

Result language

angličtina

Original language name

The distribution and morphologies of Fornax Cluster dwarf galaxies suggest they lack dark matter

Original language description

Due to their low surface brightness, dwarf galaxies are particularly susceptible to tidal forces. The expected degree of disturbance depends on the assumed gravity law and whether they have a dominant dark halo. This makes dwarf galaxies useful for testing different gravity models. In this project, we use the Fornax Deep Survey (FDS) dwarf galaxy catalogue to compare the properties of dwarf galaxies in the Fornax Cluster with those predicted by the Lambda cold dark matter (Lambda CDM) standard model of cosmology and Milgromian dynamics (MOND). We construct a test particle simulation of the Fornax system. We then use the Markov Chain Monte Carlo (MCMC) method to fit this to the FDS distribution of tidal susceptibility eta (half-mass radius divided by theoretical tidal radius), the fraction of dwarfs that visually appear disturbed as a function of eta, and the distribution of projected separation from the cluster centre. This allows us to constrain the eta value at which dwarfs should get destroyed by tides. Accounting for an r&apos;-band surface brightness limit of 27.8 magnitudes per square arcsec, the required stability threshold is eta(dest) = 0.25(-0.03)(+0.07) in Lambda CDM and 1.88(-0.53)(+0.85) in MOND. The Lambda CDM value is in tension with previous N-body dwarf galaxy simulations, which indicate that eta(destr) approximate to 1. Our MOND N-body simulations indicate that eta(destr) = 1.70 +/- 0.30, which agrees well with our MCMC analysis of the FDS. We therefore conclude that the observed deformations of dwarf galaxies in the Fornax Cluster and the lack of low surface brightness dwarfs towards its centre are incompatible with Lambda CDM expectations but well consistent with MOND.

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

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

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

515

Issue of the periodical within the volume

2

Country of publishing house

GB - UNITED KINGDOM

Number of pages

33

Pages from-to

2981-3013

UT code for WoS article

000836408700001

EID of the result in the Scopus database

2-s2.0-85136223157