Article
Astronomy & Astrophysics
L. Mashonkina, A. Arentsen, D. S. Aguado, A. Smogorzhevskii, M. Hampel, A. Karakas, F. Sestito, N. F. Martin, K. A. Venn, J. I. Gonzalez Hernandez
Summary: This study presents high-resolution spectroscopic follow-up of the carbon-enhanced metal-poor star Pristine 184237. The atmospheric parameters and abundances for 32 elements were determined, revealing unique element abundance patterns. It is the first star of the CEMP-r/s subclass identified in the inner Galaxy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jinning Liang, Eda Gjergo, XiLong Fan
Summary: This paper investigates the consistency between Galactic chemical evolution models and observed abundance patterns. Different yield models are tested and found to produce different results, and the scatter of observed abundances cannot be explained by simple averaging of results.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
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
Meenakshi Purandardas, Aruna Goswami, J. Shejeelammal, Mayani Sonamben, Ganesh Pawar, David Mkrtichian, Vijayakumar H. Doddamani, Santosh Joshi
Summary: This article presents the results of a high-resolution spectroscopic analysis of a star from the list of carbon stars of LAMOST DR2. The star, named J045, does not exhibit the spectral characteristics of carbon stars and has elemental abundances that closely resemble those found in stars from the Sculptor Dwarf galaxy. Based on these findings, it is suggested that J045 may be an escapee from the Sculptor Dwarf Galaxy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Baitian Tang, Jiajun Zhang, Zhiqiang Yan, Zhiyu Zhang, Leticia Carigi, Jose G. Fernandez-Trincado
Summary: By studying the high-resolution O, Si, and Al abundances in 43 giant stars of the Sculptor dwarf galaxy using near-infrared APOGEE spectra, we confirm the trend of lower [alpha/Fe] in less massive galaxies. The low [Al/Fe] in Sculptor demonstrates its value in identifying stars born in dwarf galaxies rather than the Milky Way field stars.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Anastasiya D. Yarovova, Oleg Egorov, Alexei Moiseev, Olga Maryeva
Summary: We discovered an unusual emission-line stellar-like object in the low-metallicity dwarf galaxy NGC 4068, characterized by high velocity dispersion, the presence of He II lambda 4686 angstrom line, and peculiarly low [S II]/[N II] fluxes ratio. Our observations suggest that this object is a single star with high bolometric luminosity surrounded by an expanding nebula. The peculiar nitrogen overabundance in the nebula indicates interaction between the star's ejecta and the interstellar medium, possibly a massive blue supergiant or Wolf-Rayet star.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
T. T. Hansen, J. D. Simon, T. S. Li, A. Frebel, I. Thompson, S. Shectman
Summary: Carbon-enhanced metal-poor (CEMP) stars are important tracers of early Galactic chemical evolution. This study focuses on six CEMP stars in the Carina dSph and compares their abundances to CEMP stars in other dSph galaxies and the Milky Way halo. Detailed elemental abundances were derived through spectroscopic analysis.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Wan-Qiang Han, Guo-Chao Yang, Lu Zhang, Wen-Yuan Cui, Ping Niu, Fang Wen, Bo Zhang
Summary: This study investigates the abundance characteristics of EMP stars in different abundance spaces to uncover the chemical evolution history in the early universe. It identifies three boundaries for the distribution region of EMP stars, including an Fe-normal belt and different sources of iron elements.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. L. L. Dantas, R. Smiljanic, R. Boesso, H. J. Rocha-Pinto, L. Magrini, G. Guiglion, G. Tautvaisiene, G. Gilmore, S. Randich, T. Bensby, A. Bragaglia, M. Bergemann, G. Carraro, P. Jofre, S. Zaggia
Summary: This study reports the discovery of a group of old dwarf stars with high metallicity in the solar vicinity, suggesting they may have originated from the inner regions of the Milky Way before migrating to the solar neighborhood. These stars have low eccentricity orbits and reach a maximum height from the Galactic plane. The findings provide insights into the origin and evolution of stars near the Sun.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
L. Mashonkina, Yu Pakhomov, T. Sitnova, P. Jablonka, S. A. Yakovleva, A. K. Belyaev
Summary: This study presents accurate atmospheric parameters and NLTE abundances for very metal-poor stars in the Sextans dwarf spheroidal galaxy. The stars exhibit alpha-enhancements and a tight relationship between Ba and Mg, suggesting a common origin in massive stars. Additionally, the study reveals a decline in alpha/Fe for stars with higher [Fe/H] values and a distinctive Ba enrichment pattern in one C-enhanced star.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Federico Sestito, Daria Zaremba, Kim A. Venn, Lina D'Aoust, Christian Hayes, Jaclyn Jensen, Julio F. Navarro, Pascale Jablonka, Emma Fernandez-Alvar, Jennifer Glover, Alan W. Mcconnachie, Andre-Nicolas Chene
Summary: Stellar candidates in the extreme outskirts of the Ursa Minor dwarf galaxy have been discovered and confirmed to be part of the galaxy through observations and chemical analysis. The chemical patterns in UMi suggest an outside-in star-formation history and a low star-formation efficiency. Additionally, the analysis of the surface number density profile indicates that UMi's outskirts have been influenced by tidal effects.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Junichi Baba, Takayuki R. Saitoh, Takuji Tsujimoto
Summary: This study explores the influence of the Milky Way galaxy's chemical evolution on the formation, structure, and habitability of the Solar system. By using a multizone Galactic chemical evolution (GCE) model, key observational constraints and trends are successfully reproduced, and the potential impact of the Sun's birth location on the overall structure and habitability of the Solar system is discussed.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Fiorenzo Vincenzo, Todd A. Thompson, David H. Weinberg, Emily J. Griffith, James W. Johnson, Jennifer A. Johnson
Summary: The observed elemental abundances in low-metallicity Milky Way stars can be explained by a contribution from neutrino-driven winds originating in highly magnetic and rapidly rotating proto-neutron stars. Models incorporating these winds fit well with the observed trends for certain elements, while models without this contribution severely underpredict the abundances at low metallicity. Alternatively, models using yields from rapidly rotating massive stars may also explain the observed abundance levels at low metallicity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Pratik J. Gandhi, Andrew Wetzel, Philip F. Hopkins, Benjamin J. Shappee, Coral Wheeler, Claude-Andre Faucher-Giguere
Summary: Type la supernovae play a crucial role in feedback and elemental enrichment in galaxies. Recent surveys have found that the rate of supernova la in lower mass galaxies may be higher than in the Milky Way. The study suggests that models in which the supernova la rate increases with decreasing metallicity provide better agreement with observations. These findings are important for understanding galaxy formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Yutaka Hirai, Timothy C. Beers, Masashi Chiba, Wako Aoki, Derek Shank, Takayuki R. Saitoh, Takashi Okamoto, Junichiro Makino
Summary: Research suggests that most highly r-process-enhanced (RPE) stars are formed in low-mass dwarf galaxies, while stars with higher metallicity may be formed in situ. These findings contribute to our understanding of the assembly history of the Milky Way and the nucleosynthesis of heavy elements.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Aroa del Mar Matas Pinto, Elisabetta Caffau, Patrick Francois, Monique Spite, Piercarlo Bonifacio, Shinya Wanajo, Wako Aoki, Lorenzo Monaco, Takuma Suda, Francois Spite, Luca Sbordone, Linda Lombardo, Alessio Mucciarelli
Summary: Studying metal poor stars sheds light on the early Universe. The analysis of two high-speed stars provides insights into the nature of first-generation stars and nucleosynthesis in metal-poor environments. These stars have unique chemical compositions and kinematic properties, similar to other Galactic halo stars.
ASTRONOMISCHE NACHRICHTEN
(2022)
Article
Astronomy & Astrophysics
Carlos Viscasillas Vazquez, L. Magrini, G. Casali, G. Tautvaisiene, L. Spina, M. van der Swaelmen, S. Randich, T. Bensby, A. Bragaglia, E. Friel, S. Feltzing, G. G. Sacco, A. Turchi, F. Jimenez-Esteban, V. D'Orazi, E. Delgado-Mena, S. Mikolaitis, A. Drazdauskas, R. Minkeviciute, E. Stonkute, V. Bagdonas, D. Montes, G. Guiglion, M. Baratella, H. M. Tabernero, G. Gilmore, E. Alfaro, P. Francois, A. Korn, R. Smiljanic, M. Bergemann, E. Franciosini, A. Gonneau, A. Hourihane, C. C. Worley, S. Zaggia
Summary: The past decade has seen significant advancements in understanding the Galaxy, with the help of space missions and spectroscopic surveys. Mapping the ages of stellar populations is crucial to completing our picture of the Galaxy. This study aims to analyze the relation between stellar ages and abundance ratios in different regions of the Galactic disc, using data from the Gaia-ESO survey and open clusters. The results show that there is no universal age-chemical clock relationship in the disc, indicating a dependence on galactocentric position and metallicity.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
E. Franciosini, E. Tognelli, S. Degl'Innocenti, P. G. Prada Moroni, S. Randich, G. G. Sacco, L. Magrini, E. Pancino, A. C. Lanzafame, R. Smiljanic, L. Prisinzano, N. Sanna, V Roccatagliata, R. Bonito, P. de Laverny, M. L. Gutierrez Albarran, D. Montes, F. Jimenez-Esteban, G. Gilmore, M. Bergemann, G. Carraro, F. Damiani, A. Gonneau, A. Hourihane, L. Morbidelli, C. C. Worley, S. Zaggia
Summary: This study tested a new set of pre-main-sequence models that include radius inflation due to the presence of starspots or to magnetic inhibition of convection. The results indicate that a reduced convection efficiency and effective surface spot coverage are required to reproduce the observed color-magnitude diagram and lithium depletion pattern in young star clusters. Older clusters are consistent with standard models, but increasing spot coverage appears to improve the sequence of M-type stars and explain the observed spread in lithium abundances. The quality of Gaia-ESO data combined with Gaia allows for important insights into pre-main-sequence evolution.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
F. Lucertini, L. Monaco, E. Caffau, P. Bonifacio, A. Mucciarelli
Summary: This study aims to improve our understanding of the behavior of sulfur in the Galactic bulge by analyzing the abundances of sulfur in multiple stars. The results confirm that sulfur behaves like an alpha-element in the Galactic bulge and suggest that the Galactic bulge is sulfur-rich compared to the disk.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Bragaglia, E. J. Alfaro, E. Flaccomio, R. Blomme, P. Donati, M. Costado, F. Damiani, E. Franciosini, L. Prisinzano, S. Randich, E. D. Friel, D. Hatztidimitriou, A. Vallenari, A. Spagna, L. Balaguer-Nunez, R. Bonito, T. Cantat Gaudin, L. Casamiquela, R. D. Jeffries, C. Jordi, L. Magrini, J. E. Drew, R. J. Jackson, U. Abbas, M. Caramazza, C. Hayes, F. M. Jimenez-Esteban, P. Re Fiorentin, N. Wright, A. Bayo, T. Bensb, M. Bergemann, G. Gilmore, A. Gonneau, U. Heiter, A. Hourihane, E. Pancino, G. Sacco, R. Smiljanic, S. Zaggia, J. S. Vink
Summary: This article introduces the background and objectives of the Gaia-ESO Survey, as well as the work of three working groups involved in the survey. By selecting observation targets based on public and private photometry and using ground-based kinematic and astronomical data to define the positions of stellar evolution, the survey team has successfully collected the largest, most accurate, and most homogeneous spectroscopic dataset on open star clusters ever achieved.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
G. Tautvaisiene, A. Drazdauskas, A. Bragaglia, S. L. Martell, E. Pancino, C. Lardo, S. Mikolaitis, R. Minkeviciute, E. Stonkute, M. Ambrosch, V. Bagdonas, Y. Chorniy, N. Sanna, E. Franciosini, R. Smiljanic, S. Randich, G. Gilmore, T. Bensby, M. Bergemann, A. Gonneau, G. Guiglion, G. Carraro, U. Heiter, A. Korn, L. Magrini, L. Morbidelli, S. Zaggia
Summary: The study aimed to determine carbon, nitrogen, and oxygen abundances for evolved giants in the globular cluster NGC 1851 to investigate the coeval nature of the double populations of stars. The results showed differences in mean metallicity, C/N ratio, and s-process dominated element-to-iron abundance ratios between the two populations, suggesting that NGC 1851 is composed of two clusters with different ages.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
R. J. Jackson, R. D. Jeffries, N. J. Wright, S. Randich, G. Sacco, A. Bragaglia, A. Hourihane, E. Tognelli, S. Degl'Innocenti, P. G. Prada Moroni, G. Gilmore, T. Bensby, E. Pancino, R. Smiljanic, M. Bergemann, G. Carraro, E. Franciosini, A. Gonneau, P. Jofre, J. Lewis, L. Magrini, L. Morbidelli, L. Prisinzano, C. Worley, S. Zaggia, G. Tautvaisiene, M. L. Gutierrez Albarran, D. Montes, F. Jimenez-Esteban
Summary: Spectroscopy from the Gaia-ESO Survey has been combined with Gaia data to assign membership probabilities to targets towards 63 Galactic open clusters and 7 globular clusters. Most targets are identified as highly probable cluster members, and the inclusion of GES radial velocities helps reduce false positives. This study provides an ideal dataset for investigating the photometric and chemical properties of clusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Chris Evans, Stefano Cristiani, Cyrielle Opitom, Gabriele Cescutti, Valentina D'Odorico, Juan Manuel Alcala, Silvia H. P. Alencar, Sergei Balashev, Beatriz Barbuy, Nate Bastian, Umberto Battino, Pamela Cambianica, Roberta Carini, Brad Carter, Santi Cassisi, Bruno Vaz Castilho, Norbert Christlieb, Ryan Cooke, Stefano Covino, Gabriele Cremonese, Katia Cunha, Andre R. da Silva, Valerio D'Elia, Annalisa De Cia, Gayandhi De Silva, Marcos Diaz, Paolo Di Marcantonio, Heitor Ernandes, Alan Fitzsimmons, Mariagrazia Franchini, Boris T. Gansicke, Matteo Genoni, Riano E. Giribaldi, Andrea Grazian, Camilla Juul Hansen, Fiorangela La Forgia, Monica Lazzarin, Wagner Marcolino, Marcella Marconi, Alessandra Migliorini, Pasquier Noterdaeme, Claudio Pereira, Bogumil Pilecki, Andreas Quirrenbach, Sofia Randich, Silvia Rossi, Rodolfo Smiljanic, Colin Snodgrass, Julian Stuermer, Andrea Trost, Eros Vanzella, Paolo Ventura, Duncan Wright, Tayyaba Zafar
Summary: This paper introduces the scientific motivations for the development of the Cassegrain U-Band Efficient Spectrograph (CUBES) for the Very Large Telescope. It covers a wide range of astronomical topics where current ground-based spectrographs are limited. Each topic's background is presented, and specific technical requirements for the instrument design are identified. The CUBES design aims to greatly improve the efficiency of astronomical spectroscopy over a specific wavelength range, and its predicted performance is compared to existing facilities.
EXPERIMENTAL ASTRONOMY
(2023)
Article
Astronomy & Astrophysics
Ben Davies, Bertrand Plez, Mike Petrault
Summary: From the early radiation of type II-P supernovae (SNe), it has been claimed that the majority of their red supergiant (RSG) progenitors are enshrouded by large amounts of circumstellar material (CSM) at the point of explosion. In this paper, simulations show that the CSM suppresses the optical and near-IR flux by a factor of over 100 and 10, respectively. The "superwind" model is excluded as it contradicts observations of II-P progenitors taken within 10 years of core-collapse, and abrupt outbursts less than a year before explosion are favored as the explanation for the early optical radiation of II-P SNe.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Rafael Guerco, Verne V. Smith, Katia Cunha, Sylvia Ekstrom, Carlos Abia, Bertrand Plez, Georges Meynet, Solange Ramirez, Nikos Prantzos, Kris Sellgren, Cristian R. Hayes, Steven R. Majewski
Summary: The chemical abundance analysis of IRS 7 in the nuclear star cluster at the centre of the Milky Way reveals carbon and oxygen depletion, enhanced nitrogen abundance, and derived abundances of other isotopes. This finding provides important clues for studying the process of stellar mixing and confirms the predictions of stellar models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
F. Lucertini, L. Monaco, E. Caffau, A. Mucciarelli, S. Villanova, P. Bonifacio, L. Sbordone
Summary: This study investigates the sulfur content of Ruprecht 106 globular cluster and Trumpler 5 open cluster. The results show that Ruprecht 106 has lower sulfur content and supports its extra-galactic origin, while Trumpler 5 follows the trend of the Galactic disk in terms of sulfur abundance.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Alice Minelli, Michele Bellazzini, Alessio Mucciarelli, Piercarlo Bonifacio, Rodrigo Ibata, Donatella Romano, Lorenzo Monaco, Elisabetta Caffau, Emanuele Dalessandro, Raffaele Pascale
Summary: We present the metallicity and radial velocity of 450 bona fide members of the Sagittarius dwarf spheroidal (Sgr dSph) galaxy, measured from high-resolution spectra obtained at the VLT. The metallicity distribution of the core of Sgr dSph ranges from [Fe/H] similar or equal to -2.3 to [Fe/H] similar or equal to 0.0, with a strong peak at [Fe/H] similar or equal to -0.5 and a metal-poor tail. We confirm previous evidence of correlations between chemical and kinematical properties of stars in the core of Sgr.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Daniela Carollo, Norbert Christlieb, Patricia B. Tissera, Emanuel Sillero
Summary: We studied the chemodynamical properties of very metal-poor (VMP) stars from the Hamburg/ESO survey matched with Gaia EDR3. By analyzing the phase space using the three integrals of motion, we found VMP stars with disk kinematics and extremely metal-poor stars. We also identified halo stars bound to the gravitational potential of the progenitor halo. Comparison with simulated galaxies suggests that VMP stars with disk kinematics can form through accretion from early satellites and in situ formation.
ASTROPHYSICAL JOURNAL
(2023)
Article
Multidisciplinary Sciences
Francesco. R. R. Ferraro, Alessio Mucciarelli, Barbara Lanzoni, Cristina Pallanca, Mario Cadelano, Alex Billi, Alison Sills, Enrico Vesperini, Emanuele Dalessandro, Giacomo Beccari, Lorenzo Monaco, Mario Mateo
Summary: Blue stragglers are anomalously luminous stars formed through mass transfer and collisions, and their properties are largely unknown. By analyzing high-resolution spectra of blue stragglers in galactic globular clusters, the authors find that the fraction of fast rotating blue stragglers increases in low-density environments. This suggests a correlation between fast spinning blue stragglers and host system central density, providing new insights into their evolutionary processes.
NATURE COMMUNICATIONS
(2023)
Proceedings Paper
Astronomy & Astrophysics
S. Di Rosa, R. Ragazzoni, D. Magrin, C. Arcidiacono, M. Dima, J. Farinato, S. Zaggia, S. Debei
Summary: Mezzocielo is an innovative type of telescope designed for simultaneous observations of the available sky. Its main purpose is to detect and observe space debris. This study aims to demonstrate the feasibility of the instrument and verify the reliability of the analytical procedure through finite element analysis.
GROUND-BASED AND AIRBORNE TELESCOPES IX
(2022)
