Browsing by Author "Valenti, Elena"

Now showing 1 - 8 of 8
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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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    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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    The 3D Structure of the Galactic Bulge
    (2016) Zoccali, Manuela; Valenti, Elena
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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 Milky Way bulge
    (2025) Zoccali, Manuela; Valenti, Elena
    This chapter reviews the three-dimensional structure, age, kinematics, and chemistry of the Milky Way (MW) region within ~2 kpc from its center (hereafter referred to as the 'bulge') from an observational perspective. While not exhaustive in citations, this review provides historical context and discusses the main controversies and limitations in the current consensus. The nuclear bulge region, within ∼200 pc from the Galactic center, has been excluded from this review. This very complex region, hosting dense molecular clouds and active star formation, would deserve a dedicated paper.
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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
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    The VVV Survey RR Lyrae Population in the Galactic Center Region
    (2018) Contreras Ramos, Rodrigo Andrés; Minniti, D.; Gran, Felipe; Zoccali, Manuela; Alonso-Garcia, Javier; Huijse, Pablo; Gabriela Navarro, Maria; Rojas-Arriagada, Alvaro; Valenti, Elena
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    The WFC3 Galactic Bulge Treasury Program: Relative Ages of Bulge Stars of High and Low Metallicity
    (2018) Renzini, Alvio; Gennaro, Mario; Zoccali, Manuela; Brown, Thomas M.; Anderson, Jay; Minniti, D.; Sahu, Kailash C.; Valenti, Elena; VandenBerg, Don A.