English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Local Group Analogs (LGA) are galaxy associations dominated by few brightSpirals, reminiscent of the LG. The NGC3447/NGC3447A system, member of the LGG225 group, a nearby LGA, is considered a physical pair: an intermediateluminosity late type spiral, NGC3447, and an irregular companion, NGC3447A,linked by a faint filament of matter. A ring-like structure in the NGC3447outskirts is emphasised by UV observations. This work aims to contribute to theunderstanding of galaxy evolution in low density environments, favourablehabitat to highly effective encounters. We performed a multi-wavelengthanalysis of the surface photometry of this system to derive spectral energydistribution and structural properties using UV and optical images. We alsocharacterised the velocity field of the pair using new kinematic observations.All these data are used to constrain smooth particle hydrodynamic simulationswith chemo-photometric implementation to shed light on the evolution of thissystem. Luminosity profiles are all consistent with the presence of a discextending and including NGC3447A. The overall velocity field does not emphasiseany significant rotation pattern, rather a small velocity gradient betweenNGC3447 and NGC3447A. Our simulation, detached from a large grid explored tobest-fit the global properties of the system, suggests that this arises from anencounter between two halos of equal mass. NGC3447 and NGC3447A belong to thesame halo, NGC3447A being a substructure of the same disk as NGC3447. The halogravitational instability, enhanced by the encounter, fuels a long livedinstability in this dark matter dominated disk, driving its morphology. Thissystem may warn about a new class of "false pairs" and the potential danger ofa misunderstanding of such objects in pair surveys that could produce a severeunderestimate of the total mass of the system. (abridged)

Galaxy evolution in groups. NGC 3447/NGC 3447A: the odd couple in LGG 225