Origin of the spectacular tidal shells of galaxy NGC 474 & x22c6;

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10456049" target="_blank" >RIV/00216208:11320/22:10456049 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=ukVat0.SaZ" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=ukVat0.SaZ</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202141709" target="_blank" >10.1051/0004-6361/202141709</a>

Result language

angličtina

Original language name

Origin of the spectacular tidal shells of galaxy NGC 474 & x22c6;

Original language description

Context. The lenticular galaxy NGC 474 hosts a rich system of tidal shells and streams, some of which are exceptionally bright. Two teams recently presented spectroscopic observations of the brightest shells. These were the first shell spectra ever observed in integrated starlight. The authors studied the stellar populations of the shell, of the center of the galaxy, and of its globular clusters. The precise formation scenario for the tidal features of this prominent galaxy still remained unclear, however. Aims. Here, we add further clues on their formation from the radii of the shells, and we present a scenario for the formation of the tidal features that seems to be unique and can explain all available data. Methods. Shell radii were analyzed with the shell identification method, and we ran self-consistent simulations of the formation of the tidal features. We considered Newtonian as well as MOND gravity. Results. Observations suggest that the tidal features originate from the accretion of a spiral galaxy. According to the shell identification method, the merging galaxies first collided 1.3 Gyr ago and then again 0.9 Gyr ago, thereby forming the shells in two generations. This would also explain the young ages of stellar populations in the center of the galaxy and the young age of the globular clusters. The analytic models of shell propagation that underlie the shell identification method are verified by a simulation. The simulations reproduce the observed morphology of the tidal features well. The accreted spiral likely reached NGC 474 on the plane of the sky nearly radially from the south, its rotation axis pointing toward us. It probably had a stellar mass of about one-sixth of NGC 474, that is, 10(9.8)&amp; x2006;M-circle dot. Apparently, all tidal features in the galaxy originate from one merger.

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

Astronomy &amp; Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

660

Issue of the periodical within the volume

duben

Country of publishing house

FR - FRANCE

Number of pages

20

Pages from-to

A28

UT code for WoS article

000778326600001

EID of the result in the Scopus database

2-s2.0-85128329486