Revisiting the globular clusters of NGC 1052-DF2

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F25%3A00141867" target="_blank" >RIV/00216224:14310/25:00141867 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1051/0004-6361/202452454" target="_blank" >https://doi.org/10.1051/0004-6361/202452454</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202452454" target="_blank" >10.1051/0004-6361/202452454</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Revisiting the globular clusters of NGC 1052-DF2

Popis výsledku v původním jazyce

The ultra-diffuse galaxy (UDG) NGC 1052-DF2 has captured the interest of astronomers ever since the low velocity dispersion measured from ten globular clusters (GCs) suggested a low dark matter fraction. Also, its GC system was found to be unusually bright, with a GC luminosity function peak at least one magnitude brighter than expected for a galaxy at a distance of 20 Mpc. In this work we present an updated view of the GC system of NGC 1052-DF2. We analysed archival MUSE data of NGC 1052-DF2 to confirm the membership of four additional GCs based on their radial velocities, thereby raising the number of spectroscopically confirmed GCs to 16. We measured the ages and metallicities of 11 individual GCs, finding them to be old (&gt; 9 Gyr) and with a range of metallicities from [M/H] = −0.7 to −1.8 dex. The majority of GCs are found to be more metal-poor than the host galaxy, with some metal-rich GCs sharing the metallicity of the host ([M/H] = −1.09−0.07+0.09 dex). The host galaxy shows a flat age and metallicity gradient out to 1 Re. Using a distance measurement based on the internal GC velocity dispersions (D = 16.2 Mpc), we derived photometric GC masses and find that the peak of the GC mass function compares well with that of the Milky Way. From updated GC velocities, we estimated the GC system velocity dispersion of NGC 1052-DF2 with a simple kinematic model and find σGCS = 14.86−2.83+3.89 km s−1. However, this value is reduced to σGCS = 8.63−2.14+2.88 km s−1 when the GC that has the highest relative velocity based on a low S/N spectrum is considered an interloper. We discuss the possible origin of NGC 1502-DF2, taking the lower distance, spread in GC metallicities, flat stellar population profiles, and dynamical mass estimate into consideration.

Název v anglickém jazyce

Revisiting the globular clusters of NGC 1052-DF2

Popis výsledku anglicky

The ultra-diffuse galaxy (UDG) NGC 1052-DF2 has captured the interest of astronomers ever since the low velocity dispersion measured from ten globular clusters (GCs) suggested a low dark matter fraction. Also, its GC system was found to be unusually bright, with a GC luminosity function peak at least one magnitude brighter than expected for a galaxy at a distance of 20 Mpc. In this work we present an updated view of the GC system of NGC 1052-DF2. We analysed archival MUSE data of NGC 1052-DF2 to confirm the membership of four additional GCs based on their radial velocities, thereby raising the number of spectroscopically confirmed GCs to 16. We measured the ages and metallicities of 11 individual GCs, finding them to be old (&gt; 9 Gyr) and with a range of metallicities from [M/H] = −0.7 to −1.8 dex. The majority of GCs are found to be more metal-poor than the host galaxy, with some metal-rich GCs sharing the metallicity of the host ([M/H] = −1.09−0.07+0.09 dex). The host galaxy shows a flat age and metallicity gradient out to 1 Re. Using a distance measurement based on the internal GC velocity dispersions (D = 16.2 Mpc), we derived photometric GC masses and find that the peak of the GC mass function compares well with that of the Milky Way. From updated GC velocities, we estimated the GC system velocity dispersion of NGC 1052-DF2 with a simple kinematic model and find σGCS = 14.86−2.83+3.89 km s−1. However, this value is reduced to σGCS = 8.63−2.14+2.88 km s−1 when the GC that has the highest relative velocity based on a low S/N spectrum is considered an interloper. We discuss the possible origin of NGC 1502-DF2, taking the lower distance, spread in GC metallicities, flat stellar population profiles, and dynamical mass estimate into consideration.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Astronomy and Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Svazek periodika

697

Číslo periodika v rámci svazku

May

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

13

Strana od-do

1-13

Kód UT WoS článku

001488693800005

EID výsledku v databázi Scopus

2-s2.0-105005512497