A new formulation of the external field effect in MOND and numerical simulations of ultra-diffuse dwarf galaxies - application to NGC 1052-DF2 and NGC 1052-DF4

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10406390" target="_blank" >RIV/00216208:11320/19:10406390 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=O_mv_hQk_0" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=O_mv_hQk_0</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stz1465" target="_blank" >10.1093/mnras/stz1465</a>

Jazyk výsledku

angličtina

Název v původním jazyce

A new formulation of the external field effect in MOND and numerical simulations of ultra-diffuse dwarf galaxies - application to NGC 1052-DF2 and NGC 1052-DF4

Popis výsledku v původním jazyce

The ultra-diffuse dwarf galaxy NGC 1052-DF2 (DF2) has 10 (11) measured globular clusters (GCs) with a line-of-sight velocity dispersion of sigma = 7.8(-2.2)(+5.2) km s(-1) (sigma = 10.6(-2.3)(+3.9) km s(-1)). Our conventional statistical analysis of the original 10 GCs gives sigma = 8.0(-3.0)(+4.3) km s(-1). The overall distribution of velocities agrees well with a Gaussian of this width. Due to the non-linear Poisson equation in MOND, a dwarf galaxy has weaker self-gravity when in close proximity to a massive host. This external field effect is investigated using a new analytic formulation and fully self-consistent live N-body models in MOND. Our formulation agrees well with that of Famaey and McGaugh. These new simulations confirm our analytic results and suggest that DF2 may be in a deep-freeze state unique to MOND. The correctly calculated MOND velocity dispersion agrees with our inferred dispersion and that of van Dokkum et al. if DF2 is within 150 kpc of NGC 1052 and both are 20 Mpc away. The GCs of DF2 are however significantly brighter and larger than normal GCs, a problem which disappears if DF2 is significantly closer to us. A distance of 10-13 Mpc makes DF2 a normal dwarf galaxy even more consistent with MOND and the 13 Mpc distance reported by Trujillo et al.. We discuss the similar dwarf DF4, finding good agreement with MOND. We also discuss possible massive galaxies near DF2 and DF4 along with their distances and peculiar velocities, noting that NGC 1052 may lie at a distance near 10 Mpc.

Název v anglickém jazyce

A new formulation of the external field effect in MOND and numerical simulations of ultra-diffuse dwarf galaxies - application to NGC 1052-DF2 and NGC 1052-DF4

Popis výsledku anglicky

The ultra-diffuse dwarf galaxy NGC 1052-DF2 (DF2) has 10 (11) measured globular clusters (GCs) with a line-of-sight velocity dispersion of sigma = 7.8(-2.2)(+5.2) km s(-1) (sigma = 10.6(-2.3)(+3.9) km s(-1)). Our conventional statistical analysis of the original 10 GCs gives sigma = 8.0(-3.0)(+4.3) km s(-1). The overall distribution of velocities agrees well with a Gaussian of this width. Due to the non-linear Poisson equation in MOND, a dwarf galaxy has weaker self-gravity when in close proximity to a massive host. This external field effect is investigated using a new analytic formulation and fully self-consistent live N-body models in MOND. Our formulation agrees well with that of Famaey and McGaugh. These new simulations confirm our analytic results and suggest that DF2 may be in a deep-freeze state unique to MOND. The correctly calculated MOND velocity dispersion agrees with our inferred dispersion and that of van Dokkum et al. if DF2 is within 150 kpc of NGC 1052 and both are 20 Mpc away. The GCs of DF2 are however significantly brighter and larger than normal GCs, a problem which disappears if DF2 is significantly closer to us. A distance of 10-13 Mpc makes DF2 a normal dwarf galaxy even more consistent with MOND and the 13 Mpc distance reported by Trujillo et al.. We discuss the similar dwarf DF4, finding good agreement with MOND. We also discuss possible massive galaxies near DF2 and DF4 along with their distances and peculiar velocities, noting that NGC 1052 may lie at a distance near 10 Mpc.

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

2019

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

487

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

14

Strana od-do

2441-2454

Kód UT WoS článku

000474919700068

EID výsledku v databázi Scopus

2-s2.0-85071133469