Browsing by Author "Cavieres Carrera, Manuel Antonio"

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    An experiment in near field cosmology: A search for the Magellanic Wake
    (2024) Cavieres Carrera, Manuel Antonio; Chanamé, Julio; Pontificia Universidad Católica de Chile. Instituto de Astrofísica
    The infall of the Magellanic Cloud system into the Milky Way halo hasstrong effects on the distribution of the stars and dark matter in the outerhalo of our Galaxy. In particular, N-body simulations predict a large-scaledensity asymmetry that spans the northern Galactic hemisphere (known as thecollective response), along with a localized overdensity (the Wake) that trailsthe LMC’s orbit. In this study, we collected wide-field deep near-infrared andoptical photometry from the VISTA and DECam instruments in four fieldsalong the expected position of the Magellanic Wake, covering most of thedensity range predicted to be found in the outer halo, as predicted by numericalmodels. This data allows us to select a clean sample of halo stars that reachthe oldest main sequence turn-off (MSTO) up to 100 kpc, with ∼ 400 stellarsources further than 60 kpc, on two separate tracers, near main sequence turnoff stars and red giant branch. We found that the Magellanic Wake overdensityis present in our data with a relative overdensity of 3.07 ± 0.7. Comparisonof the radial density profiles of near-MSTO stars with simulations of the MilkyWay/LMC interaction is best fitted by a massive LMC model with a total massof 2.5 × 10^11M⊙. This work provides the first unambiguous detection of thewake with consistent densities between two tracers.