Browsing by Author "Pedrosa, S."

Now showing 1 - 3 of 3
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    Impact of primordial black hole dark matter on gas properties at very high redshift: Semianalytical model
    (2024) Casanueva-Villarreal, C.; Tissera, P. B.; Padilla, N.; Liu, B.; Bromm, V.; Pedrosa, S.; Bignone, L.; Dominguez-Tenreiro, R.
    Context. Primordial black holes (PBHs) have been proposed as potential candidates for dark matter (DM) and have garnered significant attention in recent years. Aims. Our objective is to delve into the distinct impact of PBHs on the gas properties and their potential role in shaping the cosmic structure. Specifically, we aim to analyze the evolving gas properties while considering the presence of accreting PBHs with varying monochromatic masses and in different quantities. By studying the feedback effects produced by this accretion, our final goal is to assess the plausibility of PBHs as candidates for DM. Methods. We developed a semianalytical model that works on top of the CIELO hydrodynamical simulation around z similar to 23. This model enables a comprehensive analysis of the evolution of gas properties affected by PBHs. Our focus lies on the temperature and hydrogen abundances, with specific emphasis on the region closest to the halo center. We explore PBH masses of 1, 33, and 100 M-circle dot, located within mass windows in which a substantial fraction of DM could exist in the form of PBHs. We investigated various DM fractions composed of these PBHs (f(PBH )> 10(-4)). Results. Our findings suggest that PBHs with masses of 1 M-circle dot and fractions greater than or equal to approximately 10(-2) would be ruled out due to the significant changes induced in the gas properties. The same applies to PBHs with a mass of 33 M-circle dot and 100 M-circle dot and fractions greater than approximately 10(-3). These effects are particularly pronounced in the region nearest to the halo center, potentially leading to delayed galaxy formation within halos.
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    Mild evolution of the stellar metallicity gradients of disc galaxies
    (2017) Tissera, P.; Machado, R.; Vilchez, J.; Pedrosa, S.; Sánchez Blazquez, Patricia; Varela, S.
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    Satellite galaxies in groups in the CIELO Project I. Gas removal from galaxies and its re-distribution in the intragroup medium
    (2022) Rodriguez, S.; Garcia Lambas, D.; Padilla, N. D.; Tissera, P.; Bignone, L.; Dominguez-Tenreiro, R.; Gonzalez, R.; Pedrosa, S.
    We study the impact of the environment on galaxies as they fall in and orbit in the potential well of a Local Group (LG) analogue, following them with high cadence. The analysis is performed on eight disc satellite galaxies from the CIELO suite of hydrodynamical simulations. All galaxies have stellar masses within the range [10(8.1)-10(9.56)] M(circle dot)h(-1). We measure tidal torques, ram pressure, and specific star formation rates (sSFRs) as a function of time, and correlate them with the amount of gas lost by satellites along their orbits. Stronger removal episodes occur when the disc plane is oriented perpendicular to the direction of motion. More than one peripassage is required to significantly modify the orientations of the discs with respect to the orbital plane. The gas removed during the interaction with the central galaxies may also be found opposite to the direction of motion, depending on the orbital configuration. Satellites are not totally quenched when the galaxies reach their first peripassage and continue forming about 10 per cent of the final stellar mass after this event. The fraction of removed gas is found to be the product of the joint action of tidal torque and ram pressure, which can also trigger new star formation activity and subsequent supernova feedback.