Browsing by Author "Santos-Santos, Isabel"

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    Planes of Satellites around Simulated Disk Galaxies. II. Time-persistent Planes of Kinematically Coherent Satellites in ?CDM
    (2023) Santos-Santos, Isabel; Gamez-Marin, Matias; Dominguez-Tenreiro, Rosa; Tissera, Patricia B.; Bignone, Lucas; Pedrosa, Susana E.; Artal, Hector; Gomez-Flechoso, M. Angeles; Rufo-Pastor, Victor; Martinez-Serrano, Francisco; Serna, Arturo
    We use two zoom-in ?CDM hydrodynamical simulations of massive disk galaxies to study the possible existence of fixed satellite groups showing a kinematically coherent behavior across evolution (angular momentum conservation and clustering). We identify three such groups in the two simulations, defining kinematically coherent persistent planes (KPPs) that last at least from virialization to z = 0 (more than 7 Gyr). This proves that orbital pole clustering is not necessarily set in at low redshift, representing a long-lived property of galaxy systems. KPPs are thin and oblate, represent similar to 25%-40% of the total number of satellites in the system, and are roughly perpendicular to their corresponding central disk galaxies during certain periods, consistently with Milky Way z = 0 data. KPP satellite members are statistically distinguishable from satellites outside KPPs: they show higher specific orbital angular momenta, orbit more perpendicularly to the central disk galaxy, and have larger pericentric distances than the latter. We numerically prove, for the first time, that KPPs and the best-quality positional planes share the same space configuration across time, such that KPPs act as "skeletons" preventing the latter from being washed out in short timescales. In one of the satellite-host systems, we witness the late capture of a massive dwarf galaxy endowed with its own satellite system, also organized into a KPP configuration prior to its capture. We briefly explore the consequences this event has on the host's KPP and on the possible enhancement of the asymmetry in the number of satellites rotating in one sense or the opposite within the KPP.
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    The Origin of Kinematically Persistent Planes of Satellites as Driven by the Early Evolution of the Cosmic Web in ΛCDM
    (2024) Gamez-Marin, Matias; Santos-Santos, Isabel; Dominguez-Tenreiro, Rosa; Pedrosa, Susana E.; Tissera, Patricia B.; Gomez-Flechoso, M. Angeles; Artal, Hector
    Kinematically persistent planes (KPPs) of satellites are fixed sets of satellites co-orbiting around their host galaxy, whose orbital poles are conserved and clustered across long cosmic time intervals. They play the role of "skeletons," ensuring the long-term durability of positional planes. We explore the physical processes behind their formation in terms of the dynamics of the local cosmic web (CW), characterized via the so-called Lagrangian volumes (LVs) built up around two zoom-in, cosmological hydro-simulations of Milky Way-mass disk galaxy + satellites systems, where three KPPs have been identified. By analyzing the LV deformations in terms of the reduced tensor of inertia (TOI), we find an outstanding alignment between the LV principal directions and the KPP satellites' orbital poles. The most compressive local mass flows (along the e 3 eigenvector) are strong at early times, feeding the so-called e 3 -structure, while the smallest TOI axis rapidly decreases. The e 3 -structure collapse marks the end of this regime and is the timescale for the establishment of satellite orbital pole clustering when the Universe is less than or similar to 4 Gyr old. KPP protosatellites aligned with e 3 are those whose orbital poles are either aligned from early times or have been successfully bent at e 3 -structure collapse. KPP satellites associated with e 1 tend to have early trajectories already parallel to e 3 . We show that KPPs can arise as a result of the Lambda CDM-predicted large-scale dynamics acting on particular sets of protosatellites, the same dynamics that shape the local CW environment.