Browsing by Author "Garcia Lambas, D."

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    Following the crumbs: statistical effects of ram pressure in galaxies
    (OUP, 2019) Rodríguez, S.; Garcia Lambas, D.; Padilla, Nelson; Troncoso-Iribarre, P.
    We analyse the presence of dust around galaxy group members through the reddening of background quasars. By taking into account quasar colour and their dependence on redshift and angular position, we derive mean quasar colours excess in projected regions around member galaxies and infer the associated dust mass. For disc-like galaxies perpendicular to the plane of the sky, and at groupcentric distances of the order of the virial radius, thus likely to reside in the infall regions of groups, we find systematic colour excess values e ∼ 0.009 ± 0.004 for g − r colour. Under the hypothesis of Milky Way dust properties, we derive dust masses of 5.8±2.5×108M⊙h−1 , implying that a large fraction of dust is being stripped from galaxies in their path to groups. We also studied the photometry of member galaxies to derive a colour asymmetry relative to the group centre direction from a given galaxy. We conclude that the regions of galaxies facing the centre are bluer, consistent with the effects of gas compression and star formation. We also combine these two procedures finding that galaxies with a small colour asymmetry show the largest amounts of dust towards the external regions compared to a control sample. We conclude that dust removal is very efficient in galaxies on infall. The fact that galaxies redder towards groups centres are associated with the strongest reddening of background quasars suggest that gas removal induced by ram pressure stripping plays a key role in galaxy evolution and dust content.
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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.