Browsing by Author "Gonzalez, Oscar A."

Now showing 1 - 6 of 6
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    Characterization of the VVV Survey RR Lyrae Population across the Southern Galactic Plane
    (2017) Minniti, D.; Dekany, Istvan; Majaess, Daniel; Palma, Tali; Pullen, Joyce; Rejkuba, Marina; Alonso-García, Javier; Catelan, Márcio; Hempel, Maren; Zoccali, Manuela; Contreras Ramos, Rodrigo Andrés; Gonzalez, Oscar A.; Irwin, Mike; Lucas, Philip W.; Saito, Roberto K.; Tissera, Patricia; Valenti, Elena
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    Extinction Ratios in the Inner Galaxy as Revealed by the VVV Survey
    (2017) Alonso-García Javier; Minniti, D.; Catelan, Márcio; Contreras Ramos, Rodrigo Andrés; Gonzalez, Oscar A.; Hempel, Maren; Lucas Philip W.; Saito Roberto K.; Valenti Elena; Zoccali, Manuela
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    Milky Way demographics with the VVV survey IV. PSF photometry from almost one billion stars in the Galactic bulge and adjacent southern disk
    (2018) Alonso-Garcia, Javier; Saito, Roberto K.; Hempel, Maren; Minniti, D.; Pullen, Joyce; Catelan, Márcio; Contreras Ramos, Rodrigo Andrés; Cross, Nicholas J.G.; Gonzalez, Oscar A.; Zoccali, Manuela; Lucas, Philip W.; Palma, Tali; Valenti, Elena
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    Separation of stellar populations by an evolving bar: implications for the bulge of the Milky Way
    (2017) Debattista, Victor P.; Ness, Melissa; Gonzalez, Oscar A.; Freeman, K.; Zoccali, Manuela; Minniti, D.
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    The Imprint of Clump Formation at High Redshift. II. The Chemistry of the Bulge
    (2023) Debattista, Victor P.; Liddicott, David J.; Gonzalez, Oscar A.; Beraldo e Silva, Leandro; Amarante, Joao A. S.; Lazar, Ilin; Zoccali, Manuela; Valenti, Elena; Fisher, Deanne B.; Khachaturyants, Tigran; Nidever, David L.; Quinn, Thomas R.; Du, Min; Kassin, Susan
    In Paper I, we showed that clumps in high-redshift galaxies, having a high star formation rate density (sigma(SFR)), produce disks with two tracks in the [Fe/H]-[alpha/Fe] chemical space, similar to that of the Milky Way's (MW's) thin+thick disks. Here we investigate the effect of clumps on the bulge's chemistry. The chemistry of the MW's bulge is comprised of a single track with two density peaks separated by a trough. We show that the bulge chemistry of an N-body + smoothed particle hydrodynamics clumpy simulation also has a single track. Star formation within the bulge is itself in the high-sigma(SFR) clumpy mode, which ensures that the bulge's chemical track follows that of the thick disk at low [Fe/H] and then extends to high [Fe/H], where it peaks. The peak at low metallicity instead is comprised of a mixture of in situ stars and stars accreted via clumps. As a result, the trough between the peaks occurs at the end of the thick disk track. We find that the high-metallicity peak dominates near the mid-plane and declines in relative importance with height, as in the MW. The bulge is already rapidly rotating by the end of the clump epoch, with higher rotation at low [alpha/Fe]. Thus clumpy star formation is able to simultaneously explain the chemodynamic trends of the MW's bulge, thin+thick disks, and the splash.
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    The structure behind the galactic bar traced by red clump stars in the VVV survey
    (2018) Gonzalez, Oscar A.; Minniti, D.; Valenti, Elena; Alonso-Garcia, Javier; Debattista, Victor P.; Zoccali, Manuela; Rejkuba, Marina; Dias, Bruno; Surot, Bruno; Hempel, Maren