Research on the formation, origin, and evolution of the dichotomy between the thin and thick disk components of the Milky Way has been a major topic of study, as it is key to understanding how our Galaxy formed. However, this is not an easy task, since populations defined by their morphology or kinematics show a mixture of chemically distinct stellar populations. Age therefore becomes a fundamental parameter for understanding the evolution of the Galactic disk. Our goal is to derive the age and metallicity distributions of the thin and thick disks defined kinematically, in order to reveal
In the standard cosmological model (𝜦CDM), galaxies are merely the visible "tips of the icebergs," residing within massive, invisible cocoons of dark matter known as haloes. While these haloes dictate the evolution and motion of galaxies, measuring their true size and mass has long been one of the most challenging tasks in astrophysics. A new study published in Astronomy & Astrophysics by Claudio Dalla Vecchia and Ignacio Trujillo from the Instituto de Astrofísica de Canarias (IAC) proposes a breakthrough: a physically motivated definition of a galaxy’s edge that acts as a precision "ruler"
We present, for the first time, model spectra of single-age, single-metallicity stellar populations computed with the E-MILES evolutionary synthesis code incorporating an environment-dependent, variable galaxy-wide initial mass function (gwIMF). This gwIMF, calculated using the GalIMF code, is rooted in the integrated galactic initial mass function (IGIMF) theory, which predicts IMF variations as a function of the star formation rate and the metallicity. By coupling these two codes, we generated a comprehensive library of single-burst stellar population spectra uniquely sensitive to gwIMF