Breaks in radial metallicity gradients of spiral galaxies

Radial abundance gradients in spiral galaxy disks provide key constraints on chemical evolution and galaxy formation. While inside-out growth predicts negative gradients, observations often reveal deviations such as inner drops or outer flattenings.

I will present recent results from our group on O/H gradients in spiral galaxies using H II region data from the CALIFA survey. We apply an automated fitting procedure to explore correlations between the physical properties of galaxies and bulges and the presence of these inner drops, seeking possible explanations for the observed variations. We also examine how ionization source classification and diffuse ionized gas (DIG) contamination influence the inner gradient.

Finally, I will present new results for the Milky Way based on planetary nebulae with improved distances from a recalibrated Hα surface brightness–radiusrelation and Gaia DR3 parallaxes. These indicate a flatter O/H gradient than previously reported, with a slope change near 8 kpc, coinciding with the corotation radius.

Fecha y lugar: 21/10/2025 – 12:30 | Salón de Actos
Prof. Oscar Cavichia
Instituto de Fisíca e Química, Universidade Federal de Itajubá, Brasil