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Linking the brightest stellar streams with the accretion history of Milky Way like galaxies

Vera-Casanova, Alex; Gómez, Facundo A; Monachesi, Antonela; Gargiulo, Ignacio; Pallero, Diego; Grand, Robert JJ; Marinacci, Federico; Pakmor, Rüdiger; Simpson, Christine M; Frenk, Carlos S; Morales, Gustavo

Linking the brightest stellar streams with the accretion history of Milky Way like galaxies Thumbnail


Alex Vera-Casanova

Facundo A Gómez

Antonela Monachesi

Ignacio Gargiulo

Diego Pallero

Robert JJ Grand

Federico Marinacci

Rüdiger Pakmor

Christine M Simpson

Gustavo Morales


According to the current galaxy-formation paradigm, mergers and interactions play an important role in shaping present-day galaxies. The remnants of this merger activity can be used to constrain galaxy-formation models. In this work, we use a sample of 30 hydrodynamical simulations of Milky Way mass haloes, from the AURIGA project, to generate surface brightness maps and search for the brightest stream in each halo as a function of varying limiting magnitude. We find that none of the models shows signatures of stellar streams at μlimr≤25 mag arcsec−2. The stream detection increases significantly between 28 and 29 mag arcsec−2. Nevertheless, even at 31 mag arcsec−2, 13 per cent of our models show no detectable streams. We study the properties of the brightest streams progenitors (BSPs). We find that BSPs are accreted within a broad range of infall times, from 1.6 to 10 Gyr ago, with only 25 per cent accreted within the last 5 Gyrs; thus, most BSPs correspond to relatively early accretion events. We also find that 37 per cent of the BSPs survive to the present day. The median infall times for surviving and disrupted BSPs are 5.6 and 6.7 Gyr, respectively. We find a clear relation between infall time and infall mass of the BSPs, such that more massive progenitors tend to be accreted at later times. However, we find that the BSPs are not, in most cases, the dominant contributor to the accreted stellar halo of each galaxy.


Vera-Casanova, A., Gómez, F. A., Monachesi, A., Gargiulo, I., Pallero, D., Grand, R. J., …Morales, G. (2022). Linking the brightest stellar streams with the accretion history of Milky Way like galaxies. Monthly Notices of the Royal Astronomical Society, 514(4), 4898-4911.

Journal Article Type Article
Acceptance Date Jun 8, 2022
Online Publication Date Jun 15, 2022
Publication Date 2022-08
Deposit Date Jul 27, 2022
Publicly Available Date Jul 27, 2022
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 514
Issue 4
Pages 4898-4911


Published Journal Article (2.6 Mb)

Copyright Statement
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society. ©: 2022 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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