{"title":"Dark matter mass loss in galaxy flybys: dependence on impact parameter","authors":"A. Mitravsinovi'c","doi":"10.2298/SAJ210915001M","DOIUrl":null,"url":null,"abstract":"Galaxy flybys, interactions where two independent halos inter-penetrate but detach at a later time and do not merge, occur frequently at lower redshifts. These interactions can significantly impact the evolution of individual galaxies from mass loss and shape transformation to the emergence of tidal features and the formation of morphological disc structures. The main focus of this paper is on the dark matter mass loss of the secondary, intruder galaxy, with the goal of determining a functional relationship between impact parameter and dark matter mass loss. Series of N-body simulations of typical galaxy flybys (10:1 mass ratio) with differing impact parameters show that dark matter halo leftover mass of intruder galaxy follows logarithmic growth law with impact parameter, regardless of the way total halo mass is estimated. Lost mass then, clearly, follows exponential decay law. Stellar component stretches faster as impact parameter decreases, following exponential decay law with impact parameter. Functional dependence on impact parameter in all cases seems universal, but fitting parameters are likely sensitive to interaction parameters and initial conditions (e.g. mass ratio of interacting galaxies, the initial relative velocity of intruder galaxy, interaction duration). While typical flybys, investigated here, could not be the sole culprit behind the formation of ultra-diffuse or dark matter deficient galaxies, their effects should not be disregarded as they can at least contribute substantially. Rare, atypical and stronger flybys are worth exploring further.","PeriodicalId":48878,"journal":{"name":"Serbian Astronomical Journal","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Serbian Astronomical Journal","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.2298/SAJ210915001M","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Galaxy flybys, interactions where two independent halos inter-penetrate but detach at a later time and do not merge, occur frequently at lower redshifts. These interactions can significantly impact the evolution of individual galaxies from mass loss and shape transformation to the emergence of tidal features and the formation of morphological disc structures. The main focus of this paper is on the dark matter mass loss of the secondary, intruder galaxy, with the goal of determining a functional relationship between impact parameter and dark matter mass loss. Series of N-body simulations of typical galaxy flybys (10:1 mass ratio) with differing impact parameters show that dark matter halo leftover mass of intruder galaxy follows logarithmic growth law with impact parameter, regardless of the way total halo mass is estimated. Lost mass then, clearly, follows exponential decay law. Stellar component stretches faster as impact parameter decreases, following exponential decay law with impact parameter. Functional dependence on impact parameter in all cases seems universal, but fitting parameters are likely sensitive to interaction parameters and initial conditions (e.g. mass ratio of interacting galaxies, the initial relative velocity of intruder galaxy, interaction duration). While typical flybys, investigated here, could not be the sole culprit behind the formation of ultra-diffuse or dark matter deficient galaxies, their effects should not be disregarded as they can at least contribute substantially. Rare, atypical and stronger flybys are worth exploring further.
期刊介绍:
Serbian Astronomical Journal publishes original observations and researches in all branches of astronomy. The journal publishes:
Invited Reviews - review article on some up-to-date topic in astronomy, astrophysics and related fields (written upon invitation only),
Original Scientific Papers - article in which are presented previously unpublished author''s own scientific results,
Preliminary Reports - original scientific paper, but shorter in length and of preliminary nature,
Professional Papers - articles offering experience useful for the improvement of professional practice i.e. article describing methods and techniques, software, presenting observational data, etc.
In some cases the journal may publish other contributions, such as In Memoriam notes, Obituaries, Book Reviews, as well as Editorials, Addenda, Errata, Corrigenda, Retraction notes, etc.