Browsing by Author "Villanueva, Vicente"

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    The ALMA-CRISTAL Survey: Spatially Resolved Star Formation Activity and Dust Content in 4 < z < 6 Star-forming Galaxies
    (2024) Li, Juno; Da Cunha, Elisabete; Gonzalez-Lopez, Jorge; Aravena, Manuel; De Looze, Ilse; Schreiber, N. M. Foerster; Herrera-Camus, Rodrigo; Spilker, Justin; Tadaki, Ken-ichi; Barcos-Munoz, Loreto; Battisti, Andrew J.; Birkin, Jack E.; Bowler, Rebecca A. A.; Davies, Rebecca; Diaz-Santos, Tanio; Ferrara, Andrea; Fisher, Deanne B.; Hodge, Jacqueline; Ikeda, Ryota; Killi, Meghana; Lee, Lilian; Liu, Daizhong; Lutz, Dieter; Mitsuhashi, Ikki; Naab, Thorsten; Posses, Ana; Relano, Monica; Solimano, Manuel; Uebler, Hannah; van der Giessen, Stefan Anthony; Villanueva, Vicente
    Using a combination of Hubble Space Telescope (HST), JWST, and Atacama Large Millimeter/submillimeter Array (ALMA) data, we perform spatially resolved spectral energy distributions (SED) fitting of fourteen 4 < z < 6 ultraviolet (UV)-selected main-sequence galaxies targeted by the ALMA Large Program [C ii] Resolved ISM in Star-forming Galaxies. We consistently model the emission from stars and dust in similar to 0.5-1 kpc spatial bins to obtain maps of their physical properties. We find no offsets between the stellar masses (M-*) and star formation rates (SFRs) derived from their global emission and those from adding up the values in our spatial bins, suggesting there is no bias of outshining by young stars on the derived global properties. We show that ALMA observations are important to derive robust parameter maps because they reduce the uncertainties in L-dust (hence, A(V) and SFR). Using these maps, we explore the resolved star-forming main sequence for z similar to 5 galaxies, finding that this relation persists in typical star-forming galaxies in the early Universe. We find less obscured star formation where the M-* (and SFR) surface densities are highest, typically in the central regions, contrary to the global relation between these parameters. We speculate this could be caused by feedback driving gas and dust out of these regions. However, more observations of IR luminosities with ALMA are needed to verify this. Finally, we test empirical SFR prescriptions based on the UV+IR and [C ii] line luminosity, finding they work well at the scales probed (approximately kiloparsec). Our work demonstrates the usefulness of joint HST-, JWST-, and ALMA-resolved SED modeling analyses at high redshift.
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    The CHIMERA Survey: The first CO detection in Leo T, the lowest mass known galaxy still hosting cold molecular gas
    (2025) Villanueva, Vicente; Blaña Díaz, Matías; Bolatto, Alberto D.; Rubio, Mónica; Tarantino, Elizabeth; Herrera Camus, Rodrigo Ignacio; Burkert, Andreas; Vaz, Daniel; Read, Justin I.; Galaz Lladser, Gaspar; Muñoz, César; Calderón Espinoza, Diego Nicolas; Behrendt, Manuel; Carballo Bello, Julio A.; Gray, Emily; Fellhauer, Michael
    We report the first CO detection in Leo T, representing the most extreme observation of carbon monoxide molecules in the lowest stellar mass gas-rich dwarf galaxy (M⋆ ∼ 105 M⊙) known to date. We acquired and present new Atacama Compact Array (ACA) 12CO(J = 1–0) data within our CHIMERA Survey project for the central region of Leo T, a metal-poor ([M/H] ∼ ‑1.7) dwarf in the Milky Way (MW) outskirts. We identified three compact molecular clouds (< 13 pc) with estimated upper limit virial masses of Mmol ∼ 5 × 103 M⊙ each and a total of 1.4 ± 0.4 × 104 M⊙, corresponding to ∼3% of the total gas mass. We obtained CO-to-H2 conversion factors (αCO) as high as ∼ 155 M⊙(K km s‑1 pc2)‑1 and mean molecular gas surface densities of Σmol ∼ 9 M⊙ pc‑2 that are consistent with values found in dwarf galaxies with extremely low metal content. All CO clouds are shifted (∼60 pc) from the stellar population centers, and only one cloud appears within the densest HI region. Two clouds have velocity offsets with the HI of Δvlos ∼ + 13 km s‑1 being within twice the velocity dispersion (Δvlos/σHI, los ∼ 2) and probably bound. However, the northern cloud is faster (Δvlos ∼ + 57 km s‑1); our models with low halo masses (Mh ≲ 109 M⊙) result in unbound orbits, suggesting that this material is likely being expelled from the dwarf, providing evidence for molecular gas depletion. These properties reveal a perturbed dynamics intertwined with star formation processes in low-mass dwarf galaxies, supporting a scenario of episodic bursts until they are fully quenched by the MW environment....