Article
Astronomy & Astrophysics
Frederic Galliano, Angelos Nersesian, Simone Bianchi, Ilse De Looze, Sambit Roychowdhury, Maarten Baes, Viviana Casasola, Letizia P. Cassara, Wouter Dobbels, Jacopo Fritz, Maud Galametz, Anthony P. Jones, Suzanne C. Madden, Aleksandr Mosenkov, Emmanuel M. Xilouris, Nathalie Ysard
Summary: This study conducted an empirical statistical analysis on approximately 800 nearby galaxies to quantify the timescales of cosmic dust evolution processes, revealing significant patterns in the evolution of dust properties in galaxies.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Camilla C. Borre, Victor Aguirre Borsen-Koch, Amina Helmi, Helmer H. Koppelman, Martin B. Nielsen, Jakob L. Rorsted, Dennis Stello, Amalie Stokholm, Mark L. Winther, Guy R. Davies, Marc Hon, J. M. Diederik Kruijssen, Chervin F. P. Laporte, Claudia Reyes, Jie Yu
Summary: By studying the ages of remnant stars, we can estimate the merger times of the Milky Way and gain a better understanding of its evolutionary history. Using data from multiple sources, we have successfully determined the ages of 21 red giant stars and classified eight of them as part of one of the largest merger events in the history of our Galaxy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
E. Spitoni, K. Verma, V. Silva Aguirre, F. Vincenzo, F. Matteucci, B. Vaicekauskaite, M. Palla, V. Grisoni, F. Calura
Summary: The analysis of APOGEE DR16 data points towards distinct sequences of disc stars at different Galactocentric distances, with an inside-out formation of the Galaxy disc being suggested. Different chemical evolution models for regions at various distances are examined, with a significant delay time between gas infall events being identified. The best fit model reproduces key observational constraints, indicating how low-alpha stars are distributed in the abundance space at different Galactocentric distances.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
A. C. Krabbe, C. B. Oliveira, I. A. Zinchenko, J. A. Hernandez-Jimenez, O. L. Dors, G. F. Haegele, M. Cardaci, N. R. Telles
Summary: In this study, the oxygen abundance in relation to the hydrogen abundance of the UGC4805 LINER nucleus was investigated using various methods, all of which produced similar O/H values and reliable results, suggesting a stellar origin as the main ionizing source of the UGC4805 nucleus rather than an AGN.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
A. Fraser-McKelvie, L. Cortese, B. Groves, S. Brough, J. Bryant, B. Catinella, S. Croom, F. D'Eugenio, A. R. Lopez-Sanchez, J. van de Sande, S. Sweet, S. Vaughan, J. Bland-Hawthorn, J. Lawrence, N. Lorente, M. Owers
Summary: The combination of gas-phase oxygen abundances and stellar metallicities can provide unique insights into the metal enrichment histories of galaxies. The study shows a strong correlation between stellar and interstellar medium (ISM) metallicities, influenced by the different star formation and metal enrichment histories of the galaxies. Care must be taken when comparing them to constrain models of galaxy formation and evolution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
W. D. Langer, J. L. Pineda, P. F. Goldsmith, E. T. Chambers, D. Riquelme, L. D. Anderson, M. Luisi, M. Justen, C. Buchbender
Summary: The study reveals a widely distributed highly ionized warm interstellar gas with a density intermediate between the warm ionized medium and compact H II regions, indicating a major gap in our understanding of interstellar gas. Dense ionized regions contribute greater than 50% of the observed [C II] intensity, with kinetic temperatures too low to explain the presence of N+ likely ionized by extreme ultraviolet radiation from nearby star-forming regions or as a result of EUV leakage through a clumpy and porous interstellar medium.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
N. Avila-Vergara, L. Carigi, S. L. Hidalgo, A. Arrieta
Summary: The study reveals that the dwarf spheroidal galaxy Tucana behaved like a closed box for majority of its lifespan, with different metallicity models at different stages. Observing the metallicity distribution function and improving observation precision are crucial to differentiate between the models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Benjamin Metha, Michele Trenti, Tingjin Chu, Andrew Battisti
Summary: This study introduces the geostatistical technique of universal kriging to reconstruct the complete 2D metallicity distribution of a galaxy from metallicities measured at H ii regions. High-fidelity metallicity maps of the local spiral galaxy NGC 5236 are constructed and significant correlation in the metallicity of H ii regions is found. The predictions of this method outperform interpolation based on metallicity gradients. The kriging method is also applied to predict metallicities in regions dominated by diffuse ionized gas emission, and comparisons with novel ionization corrections show a systematic offset and scatter.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Alex J. Cameron, Tiantian Yuan, Michele Trenti, David C. Nicholls, Lisa J. Kewley
Summary: Investigated the impact of Hii region temperature structure assumptions on spatially resolved metallicity observations, finding significant differences among direct methods in metallicity gradient studies. Strong-line diagnostics mostly show flat metallicity gradients, with potential contamination from shocked regions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Maria Galloway-Sprietsma, Yancy L. Shirley, James Di Francesco, Jared Keown, Samantha Scibelli, Olli Sipilae, Rachel Smullen
Summary: Understanding the chemical processes during starless core and prestellar core evolution is crucial for comprehending the initial stages of star and disc formation. This study examines deuterated ammonia in the L1251 star-forming region and finds no strong trends in deuterium fraction with any physical or evolutionary variables.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Z. S. Hemler, Paul Torrey, Jia Qi, Lars Hernquist, Mark Vogelsberger, Xiangcheng Ma, Lisa J. Kewley, Dylan Nelson, Annalisa Pillepich, Ruediger Pakmor, Federico Marinacci
Summary: The study presents radial gas-phase, mass-weighted metallicity profiles and gradients of the TNG50 star-forming galaxy population at redshifts z = 0-3, finding predominantly negative gradients with a roughly constant growth rate with redshift. While there is a weak correlation between gradient steepness and galaxy stellar mass, this correlation disappears when normalizing the gradients by a characteristic radius defined by the galactic star formation distribution. The study also compares TNG50 gradients with those observed in high-redshift galaxies and highlights the need for simulation models to incorporate more powerful radial gas mixing mechanisms within the ISM to match potential observations from future telescopes like JWST and ELT.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Jack Fraser, Ralph Schonrich
Summary: This article introduces a high-performance analytical model of Galactic Chemical Evolution, which can search the parameter space associated with the neutron enrichment process and concludes that neutron star mergers are the main contributors to the modern Milky Way neutron abundance.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Alex M. Garcia, Paul Torrey, Z. S. Hemler, Lars Hernquist, Lisa J. Kewley, Erica J. Nelson, Kathryn Grasha, Henry R. M. Zovaro, Qian-Hui Chen
Summary: We present radial gas-phase metallicity profiles, gradients, and break radii in star-forming galaxies at redshift z = 0-3 using the TNG50-1 simulation. The profiles reveal a steep inner gradient and a flat outer gradient, with a break radius marking the transition region. We find that the break radius shows a positive trend with mass that weakens with redshift, and when normalized by stellar half-mass radius, the relation with mass and redshift becomes weaker.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Nimisha Kumari, Roberto Maiolino, James Trussler, Filippo Mannucci, Giovanni Cresci, Mirko Curti, Alessandro Marconi, Francesco Belfiore
Summary: This study extends the Fundamental Metallicity Relation (FMR) to galaxies classified as non-star-forming in the BPT diagrams, finding that galaxies with higher-than-main-sequence SFR are more metal-poor than their counterparts on the main sequence, while low-mass galaxies have higher metallicities than their main sequence counterparts.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
F. Pistis, A. Pollo, M. Scodeggio, M. Figueira, A. Durkalec, K. Malek, A. Iovino, D. Vergani, S. Salim
Summary: This study focuses on comparing galaxy samples with different characteristics and examines the effects of selection biases on the fundamental metallicity relation (FMR). The results show that the median metallicities of samples at z similar to 0 and z similar to 0.7 are consistent, taking into account the biases. The study also reveals the influence of biases on the FMR projections.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
E. Spitoni, K. Verma, V. Silva Aguirre, F. Vincenzo, F. Matteucci, B. Vaicekauskaite, M. Palla, V. Grisoni, F. Calura
Summary: The analysis of APOGEE DR16 data points towards distinct sequences of disc stars at different Galactocentric distances, with an inside-out formation of the Galaxy disc being suggested. Different chemical evolution models for regions at various distances are examined, with a significant delay time between gas infall events being identified. The best fit model reproduces key observational constraints, indicating how low-alpha stars are distributed in the abundance space at different Galactocentric distances.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Adriano Pietrinferni, Sebastian Hidalgo, Santi Cassisi, Maurizio Salaris, Alessandro Savino, Alessio Mucciarelli, Kuldeep Verma, Victor Silva Aguirre, Antonio Aparicio, Jason W. Ferguson
Summary: This paper presents an updated release of the BaSTI stellar model and isochrone library, focusing on alpha-enhanced models and various parameters. The accuracy and reliability of these new calculations have been tested by comparing them with independent calculations and observations. The models and isochrones are publicly available for further research and analysis.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
E. Spitoni, F. Calura, V. Silva Aguirre, R. Gilli
Summary: Analyzing the CMDFs of local star-forming galaxies, we find that galactic winds play a significant role in shaping the function, with low-mass systems showing a greater impact. The CMDFs of low-mass and high-mass galaxies deviate notably from a 'closed-box' model, as the evolution of these systems is influenced by outflows and infall. Additionally, in the context of galactic downsizing, low-mass galaxies are more likely to exhibit downward-concave CMDFs, indicating larger fractions of young systems and substantial deviations from equilibrium.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Kuldeep Verma, Robert J. J. Grand, Victor Silva Aguirre, Amalie Stokholm
Summary: Large-scale stellar surveys combined with magneto-hydrodynamical simulations provide an unprecedented opportunity to study the physical processes driving the evolution of galaxies. By comparing data from over 7000 stars with simulations, researchers found some models capable of reproducing observed abundance patterns and velocity distributions. They also determined upper limits for radial migration in the Milky Way and further constrained migration based on age and metallicity data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. S. Cunha, I. W. Roxburgh, V. Aguirre Borsen-Koch, W. H. Ball, S. Basu, W. J. Chaplin, M-J Goupil, B. Nsamba, J. Ong, D. R. Reese, K. Verma, K. Belkacem, T. Campante, J. Christensen-Dalsgaard, M. T. Clara, S. Deheuvels, M. J. P. F. G. Monteiro, A. Noll, R. M. Ouazzani, J. L. Rorsted, A. Stokholm, M. L. Winther
Summary: Asteroseismology is a powerful tool for inferring fundamental stellar properties, with an experiment revealing the accuracy of inferred values for mass, radius, and age. Different inference procedures, physics assumptions, and weighting of constraints were found to significantly impact the results. Only a few frequencies were needed for accurate mass and radius estimates, while at least one l = 2 mode was crucial for age estimates.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
E. Spitoni, V. Aguirre Borsen-Koch, K. Verma, A. Stokholm
Summary: The analysis of the APOGEE data suggests the presence of two distinct disc star sequences, known as the high- and low-alpha sequences, in the [alpha/Fe] versus [Fe/H] abundance ratio space. This dichotomy is also observed in the vertical distribution of the [alpha/Fe] abundance ratio. The study aims to test if the revised chemical evolution models are capable of predicting the disc bimodality observed in the vertical distribution of [Mg/Fe] in APOGEE DR16 data.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Kuldeep Verma, Jakob L. Rorsted, Aldo M. Serenelli, Victor Aguirre Borsen-Koch, Mark L. Winther, Amalie Stokholm
Summary: Current stellar models differ from observations, but frequency ratios and helium ionization parameters can provide precise constraints on stellar structure and basic properties.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
G. Cescutti, P. Bonifacio, E. Caffau, L. Monaco, M. Franchini, L. Lombardo, A. M. Matas Pinto, F. Lucertini, P. Francois, E. Spitoni, R. Lallement, L. Sbordone, A. Mucciarelli, M. Spite, C. J. Hansen, P. Di Marcantonio, A. Kucinskas, V. Dobrovolskas, A. J. Korn, M. Valentini, L. Magrini, S. Cristallo, F. Matteucci
Summary: Galactic archaeology is a vibrant field of astronomy that focuses on the oldest stars in our Galaxy. However, there has been a bias in the observations, with intermediate metal-poor stars often being overlooked. This study successfully obtained high-quality spectra for a sample of intermediate metallicity stars using multiple telescopes and spectrographs, providing valuable information about their radial velocities and Galactic orbits.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Vasini, F. Matteucci, E. Spitoni
Summary: We present theoretical mass estimates of Al-26 and Fe-60 throughout the Galaxy using a numerical chemical evolution model. We compared different sets of stellar yields and found that massive stars are the dominant source for these isotopes, while low and intermediate mass stars and Type Ia supernovae contribute negligibly. The contribution of nova systems is necessary to reproduce the observations of Al-26. Our best model predicts a mass of 2.12 solar masses for Al-26, in agreement with observations, and a mass estimate of around 1.05 solar masses for Fe-60.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
P. A. Palicio, A. Recio-Blanco, E. Poggio, T. Antoja, P. J. McMillan, E. Spitoni
Summary: This study utilizes the astrometry provided by Gaia EDR3 and the velocities inferred from the RVS spectra of Gaia DR3 to estimate the action variables of a large volume of stars, aiming to locate structures in the Galactic disc. The results reveal arc-like segments in the maps of the percentiles of the radial action J(R), with a high J(R) region centered at R approximately 10.5 kpc. Spiral arms are also identified in the overdensities of the giant population. The dynamics of old stars show consistency with the spatial distribution of spiral arms traced by young populations, with potential contributions from moving groups.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
E. Spitoni, A. Recio-Blanco, P. de Laverny, P. A. Palicio, G. Kordopatis, M. Schultheis, G. Contursi, E. Poggio, D. Romano, F. Matteucci
Summary: This study presents a new chemical evolution model for the Galactic disc components based on the recent Gaia Data Release 3. By comparing the predicted chemical abundances with the Gaia DR3 data, the proposed model successfully reproduces the abundance ratios of different alpha elements for stars in different age bins. It also accurately predicts the young population in Gaia DR3 that has experienced a recent chemical impoverishment.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Eda Gjergo, Aleksei G. G. Sorokin, Anthony Ruth, Emanuele Spitoni, Francesca Matteucci, Xilong Fan, Jinning Liang, Marco Limongi, Yuta Yamazaki, Motohiko Kusakabe, Toshitaka Kajino
Summary: This paper introduces the GalCEM model, a user-friendly, detailed, and modular Galactic Chemical Evolution Model that tracks the mass change of isotopes over time in a given galaxy. The model tracks 86 elements and 451 isotopes, including enrichment from various sources such as stars and supernovae. By utilizing interpolation curves, the model improves the computational efficiency to accurately calculate the convolution integrals.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
Mark Lykke Winther, Victor Aguirre Borsen-Koch, Jakob Lysgaard Rorsted, Amalie Stokholm, Kuldeep Verma
Summary: With the advancement of asteroseismology, it has become possible to study the survival of convective cores within stars during their main-sequence evolution. A recent study on the star Kepler-444 found that the convective core had survived for nearly 8 Gyr, contrary to the predictions of standard stellar evolution theories. This paper aims to investigate the convective core evolution of Kepler-444 and determine its proposed longevity by modifying the input physics of stellar models and fitting the observations to the models using the BASTA pipeline. The analysis reliably constraints the convective core lifetime of Kepler-444 to be short, with a median around 0.6 Gyr and an upper bound around 3.5 Gyr.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)