Context. The age, evolution, and chemical properties of the Galactic disk can be effectively ascertained using open clusters. Within the large program Stellar Populations Astrophysics at the Telescopio Nazionale Galileo, we specifically focused on stars in open clusters, to investigate various astrophysical topics, from the chemical content of very young systems to the abundance patterns of lesser studied intermediate-age and old open clusters.

Aims. We investigate the astrophysically interesting element fluorine (F), which has an uncertain and intriguing cosmic origin. We also determine the abundance of cerium (Ce), as F abundance is expected to correlate with the s-process elements. We intend to determine the trend of F abundance across the Galactic disk as a function of metallicity and age. This will offer insights into Galactic chemical evolution models, potentially enhancing our comprehension of this element’s cosmic origin.

Methods. High-resolution near-infrared spectra were obtained using the GIANO-B spectrograph. The Python version of Spectroscopy Made Easy (PySME), was used to derive atmospheric parameters and abundances. The stellar parameters were determined using OH, CN, and CO molecular lines along with Fe I lines. The F and Ce abundances were inferred using two K-band HF lines (λλ 2.28, 2.33 µm) and two atomic H-band lines (λλ 1.66, and 1.71 µm), respectively.

Results. Of all the clusters in our sample, only King 11 had not been previously studied through medium- to high-resolution spectroscopy, and our stellar parameter and metallicity findings align well with those documented in the literature. We have successfully inferred F and Ce abundances in all seven open clusters and probed the radial and age distributions of abundance ratios. This paper presents the first F Galactic radial abundance gradient. Our results are also compared with literature estimates and with Galactic chemical evolution models that have been generated using different F production channels.

Conclusions. Our results indicate a constant, solar pattern in the [F/Fe] ratios across clusters of different ages, supporting the latest findings that fluorine levels do not exhibit any secondary behavior for stars with solar or above-solar metallicity. However, an exception to this trend is seen in NGC 6791, a metal-rich, ancient cluster whose chemical composition is distinct due to its enhanced fluorine abundance. This anomaly strengthens the hypothesis that NGC 6791 originated in the inner regions of the Galaxy before migrating to its present position. By comparing our sample stars with the predictions of Galactic chemical evolution models, we came to the conclusion that both asymptotic giant branch stars and massive stars, including a fraction of fast rotators that increase with decreasing metallicity, are needed to explain the cosmic origin of F.

Context. Open clusters are ideal tools for tracing the abundances of different elements because their stars are expected to have the same age, distance, and metallicity. Therefore, they serve as powerful tracers for investigating the cosmic origins of elements. This paper expands on a recent study by us, in which the element fluorine was studied in seven open clusters; here we add six open clusters and eight field stars.

Aims. The primary objective is to determine the abundance of fluorine (F) to gain insight into its production and evolution. The magnesium (Mg) abundances were derived to categorize the field stars into high and low alpha disk populations. Additionally, cerium (Ce) abundances were determined to better understand the interplay between F and s-process elements. Our goal is to analyze the trend of F abundances across the Galactic disk based on metallicity and age. By comparing observational data with Galactic chemical evolution models, the origin of F can be better understood.

Methods. The spectra were obtained from the high-resolution near-infrared GIANO-B instrument at the Telescopio Nazionale Galileo (TNG). For the derivation of the stellar parameters and abundances, the Python version of Spectroscopy Made Easy (PySME) was used. OH, CN, and CO molecular lines and band heads along with Fe I lines were used to determine the stellar parameters in the H-band region. Two HF lines in the K band (λλ 2.28, and 2.33 μm), three K-band Mg I lines (λλ 2.10, 2.11, and 2.15 μm), and two Ce II lines in the H band (λλ 1.66, and 1.71 μm) were used to derive the abundances of F, Mg, and Ce, respectively.

Results. F, Mg, and Ce abundances were derived for 14 stars from 6 OCs, as well as for 8 field stars. The F and Ce abundances were investigated as a function of metallicity, age, and galactocentric distance. We also compared our findings with different Galactic chemical evolution models.

Conclusions. Our results indicate that asymptotic giant branch stars and massive stars, including a subset of fast rotators (whose rotation speed likely increases as metallicity decreases), are necessary to explain the cosmic origin of F. This finding is consistent with and, with the large sample size, reinforces the conclusion of our previous study.

Context: Open clusters have been extensively used as tracers of Galactic chemical evolution, as their constituent stars possess shared characteristics, including age, Galactocentric radius, metallicity, and chemical composition. By examining the trends of elemental abundances with metallicity, age, and Galactocentric radius, valuable insights can be gained into the distribution and nucleosynthetic origins of chemical elements across the Galactic disk. The infrared domain in particular facilitates the observation of some elemental abundances that can be challenging or impossible to discern in the optical; for example, K and F.

Aims: The objective of this study is to derive the stellar parameters and elemental abundances of up to 23 elements in 114 stars spanning 41 open clusters using high-resolution infrared spectroscopy. In addition, the present study aims to examine the chemical evolution of the Galactic disk. This is achieved by investigating radial abundance gradients, variations in abundance between clusters, and the dependence of chemical abundances on the cluster age.

Methods: The spectra utilized in this study were obtained with the high-resolution near-infrared GIANO-B spectrograph at the Telescopio Nazionale Galileo. The derivation of stellar parameters and chemical abundances was achieved by employing the Python version of Spectroscopy Made Easy. In the H -band region, a combination of atomic and molecular features was utilized to constrain the stellar parameters, including OH, CN, and CO molecular lines, and Mg I, Si I, Ti I, Ti II, C I, and Fe I atomic lines.

Results: Abundances for up to 23 elements, C, N, F, Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Ce, Nd, and Yb, were derived and compared with available literature values where possible. Non-local thermodynamic equilibrium analysis was utilized for the elements C, Na, Mg, Al, Si, S, K, Ca, Ti, Mn, Fe, and Cu. For each element, Galactic trends were examined by analyzing both [X/Fe] and [X/H] as functions of [Fe/H], stellar age, and Galactocentric radius. In particular, the radial abundance gradient of Ytterbium is presented for the first time, thereby extending the observational constraints on heavy neutron-capture elements.

Conclusions: Radial abundance gradients for a wide range of elements in the Galactic disk are found, with [X/Fe] slopes ranging from −0.061 to +0.065 dex/kpc. The observed gradients are consistent with an inside-out formation scenario for the Galactic disk, wherein chemical enrichment proceeds from the inner regions to the outer ones over time. The observed [X/Fe] trends across multiple nucleosynthetic groups, including α elements, odd-Z elements, iron-peak elements, and neutron-capture elements such as Y, Ce, Nd, and Yb, reflect the diverse production sites and timescales associated with each group. In particular, the positive [Zn/H] and [Zn/Fe] gradients suggest a distinctive nucleosynthetic origin for Zn, possibly linked to metallicity-dependent yields. The positive gradient in [Yb/Fe] (0.065 ± 0.031 dex/kpc) provides significant new constraints on neutron-capture enrichment processes and the chemical evolution of the Galactic disk.