Article
Astronomy & Astrophysics
S. Taibi, G. Battaglia, R. Leaman, A. Brooks, C. Riggs, F. Munshi, Y. Revaz, P. Jablonka
Summary: This study explores the correlations between metallicity gradients in Local Group dwarf galaxies and their stellar mass, star formation history timescales, and environment. The results show that there are no statistical differences in metallicity gradients based on the morphological type of the galaxies or their distance from the Milky Way or M31. Furthermore, there are no correlations found with stellar mass or star formation timescales. The strongest gradients are observed in systems that are likely to have experienced a past merger event.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
C. R. Higgs, A. W. McConnachie, N. Annau, M. Irwin, G. Battaglia, P. Cote, G. F. Lewis, K. Venn
Summary: The study analyzed the 12 closest Solo dwarf galaxies accessible from the Northern hemisphere, including their distances, spatial distributions, morphology, and extended structures. The results show that most of these galaxies can be well described by two-dimensional Sersic functions, but there are also some galaxies that show tentative evidence of two distinct components. Additionally, no prominent extended stellar substructures were identified in the outer regions of any of the systems examined.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
R. K. Alexander, F. Vincenzo, A. P. Ji, H. Richstein, C. J. Jordan, B. K. Gibson
Summary: Ultra-faint dwarf galaxies (UFDs) are metal-poor galaxies without gas, and understanding the chemical abundance dispersion in these extreme environments can provide insights into the first generations of stars. The i-getool model is applied to two UFDs, Carina II and Reticulum II, to study their chemical evolution. The model considers the Monte Carlo sampling of the initial mass function and the chemical enrichment of supernova bubbles in the interstellar medium. The model successfully predicts the abundance patterns of alpha- and odd-Z elements, but underestimates carbon and titanium abundances due to the uncertainty in stellar nucleosynthesis yields. The model also suggests galactic outflows driven by supernova feedback, which quench star formation activity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. Kamann, S. Saracino, N. Bastian, S. Gossage, C. Usher, D. Baade, I Cabrera-Ziri, S. E. de Mink, S. Ekstrom, C. Georgy, M. Hilker, S. S. Larsen, D. Mackey, F. Niederhofer, I Platais, D. Yong
Summary: Young star clusters are important for studying the effects of stellar rotation on stellar evolution. In a study of the star cluster NGC 1850, researchers measured the rotational velocities of stars and found a correlation between rotation and color. The findings impact our understanding of young massive clusters and provide new observational constraints for stellar evolutionary models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Elias K. Oakes, Taylor J. Hoyt, Wendy L. Freedman, Barry F. Madore, Quang H. Tran, William Cerny, Rachael L. Beaton, Mark Seibert
Summary: In this study, the authors determined the distance modulus of the Fornax dwarf spheroidal galaxy using ground-based imaging and proper motion observations. They used multiple methods to calibrate and validate the results, and obtained a distance of 143 +/- 3 kpc for the galaxy.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Santana Mansfield, Pavel Kroupa
Summary: Low-mass M-dwarf models exhibit fluctuation in luminosity and temperature due to the convective kissing instability, leading to a gap in the main sequence that is also observed in the Gaia data. The amplitude and intensity of the instability are found to decrease with increasing convective overshooting but are sustained in the presence of semi-convection. Surface abundances of various elements change over time, albeit with small relative changes. The M-dwarf gap is reproduced in color-magnitude diagrams, showing a large indent into the blueward edge of the main sequence. The width of the main sequence decreases over time, along with changes in the parallel offset and relative angle between the upper and lower parts of the main sequence, and the mass-magnitude relation. Potential age-dating methods for single stars and stellar populations are discussed.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
L. J. A. Scott, R. Hirschi, C. Georgy, W. D. Arnett, C. Meakin, E. A. Kaiser, S. Ekstrom, N. Yusof
Summary: The study on the application of the entrainment law in 1D models reveals that the impact of mass and time on boundary penetrability varies, with the chemical gradient having a greater influence on time.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Viswajith Vanaraj, Florian Niederhofer, Paul Goudfrooij
Summary: Analyzing Large Magellanic Cloud and Galactic globular clusters reveals that the formation of multiple stellar populations might have a minor connection to the galaxy environment.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Sasha R. Brownsberger, Lisa Randall
Summary: This study introduces a method to measure the correspondence between dark matter models and observations of stellar populations in dwarf galaxies without assuming a parametric stellar distribution. Through this method, researchers found the consistency of different shapes and distributions of dark matter models with stellar data, as well as their consistency with stellar positions and velocities. Interestingly, the Fornax dwarf spheroidal galaxy shows no evidence of a disc-like structure and exhibits some features that are inconsistent with predictions from Lambda cold dark matter with baryon simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Nikhil Arora, Andrea Maccio, Stephane Courteau, Tobias Buck, Noam Libeskind, Jenny G. Sorce, Chris B. Brook, Yehuda Hoffman, Gustavo Yepes, Edoardo Carlesi, Connor Stone
Summary: Recent studies of dwarf galaxies in the Local Group have revealed their unique characteristics in star formation history, stellar metallicity, gas content, and kinematics. Simulation results show that Local Group dwarf galaxies have similar total gas mass and stellar properties compared to field galaxies. However, they have more cold gas in their central parts and more metal-rich gas in the halo, likely due to interactions with other dwarfs in the high-density environment of the Local Group. Metal diffusion does not significantly impact the chemical evolution of Local Group dwarf galaxies. These findings highlight the importance of studying the stellar components of Local Group dwarfs for understanding galaxy formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
T. Ruiz-Lara, C. Gallart, M. Monelli, T. K. Fritz, G. Battaglia, S. Cassisi, M. Luis Aznar, A. Russo Cabrera, I Rodriguez-Martin, J. J. Salazar-Gonzalez
Summary: Leo I is considered as one of the youngest dwarf spheroidals in the Local Group, and analysis of its extended star formation history has revealed complexities in its formation process, especially the possible interactions with other systems.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Daniel Lazarz, Renbin Yan, Ronald Wilhelm, Yanping Chen, Lewis Hill, Jon A. Holtzman, Julie Imig, Claudia Maraston, Szabolcs Meszaros, Guy S. Stringfellow, Daniel Thomas, Timothy C. Beers, Dmitry Bizyaev, Niv Drory, Richard R. Lane, Christian Nitschelm
Summary: This study presents a stellar parameter catalog accompanying the MaStar Stellar Library, providing empirical, medium-resolution stellar spectra. By fitting spectra, possible deficiencies in current theoretical model spectra are revealed, highlighting the potential of MaStar spectra to improve models.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
T. Ruiz-Lara, C. Gallart, M. Monelli, T. K. Fritz, G. Battaglia, S. Cassisi, M. Luis Aznar, A. Russo Cabrera, I Rodriguez-Martin, J. J. Salazar-Gonzalez
Summary: Leo I is considered one of the youngest dwarf spheroidals in the Local Group, with a rich star formation history and recent perigalacticon passage that make it one of the most interesting nearby stellar systems. Analysis of deep photometric Hubble data reveals multiple star formation enhancements in Leo I, with the youngest and oldest stars potentially linked to early formation and recent perigalacticon passage. The presence of very metal-poor stars and speculation on a metal-poor population from a merging event suggest complex stellar evolution in Leo I.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Valeriya Korol, Vasily Belokurov, Silvia Toonen
Summary: The study detects unresolved binary stars by measuring the wobble of their orbits and finds a deep gap around 1 astronomical unit. Models suggest a significant change in the distribution of double white dwarfs in this gap.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Sergey Khoperskov, Ivan Minchev, Noam Libeskind, Misha Haywood, Paola Di Matteo, Vasily Belokurov, Matthias Steinmetz, Facundo A. Gomez, Robert J. J. Grand, Yehuda Hoffman, Alexander Knebe, Jenny G. Sorce, Martin Spaare, Elmo Tempel, Mark Vogelsberger
Summary: This study explores the phase-space structure of merged stars by analyzing six analogues of M31/MW, finding significant overlaps between merger remnants and in situ stars in different coordinate systems. Moreover, the positions of merger debris frequently change with time. An age gradient is observed in the L-z-E coordinate system, allowing for the use of stellar ages to determine the date of merger events. Accreted stars can be identified using root J(r) values, and different merger debris can be better distinguished from each other and in situ stars using the (J(z)/J(r)-orbital eccentricity) kinematic space.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
W. V. Jacobson-Galan, L. Dessart, D. O. Jones, R. Margutti, D. L. Coppejans, G. Dimitriadis, R. J. Foley, C. D. Kilpatrick, D. J. Matthews, S. Rest, G. Terreran, P. D. Aleo, K. Auchettl, P. K. Blanchard, D. A. Coulter, K. W. Davis, T. J. L. de Boer, L. DeMarchi, M. R. Drout, N. Earl, A. Gagliano, C. Gall, J. Hjorth, M. E. Huber, A. L. Ibik, D. Milisavljevic, Y. -C. Pan, A. Rest, R. Ridden-Harper, C. Rojas-Bravo, M. R. Siebert, K. W. Smith, K. Taggart, S. Tinyanont, Q. Wang, Y. Zenati
Summary: We present panchromatic observations and modeling of supernova (SN) 2020tlf, the first normal Type II-P/L SN with confirmed precursor emission. The pre-SN emission and associated mass loss occurred in a red supergiant (RSG) progenitor with dense circumstellar material (CSM). The modeling suggests a mass-loss rate and limited CSM density.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Federica B. Bianco, Zeljko Ivezic, R. Lynne Jones, Melissa L. Graham, Phil Marshall, Abhijit Saha, Michael A. Strauss, Peter Yoachim, Tiago Ribeiro, Timo Anguita, A. E. Bauer, Franz E. Bauer, Eric C. Bellm, Robert D. Blum, William N. Brandt, Sarah Brough, Marcio Catelan, William Clarkson, Andrew J. Connolly, Eric Gawiser, John E. Gizis, Renee Hlozek, Sugata Kaviraj, Charles T. Liu, Michelle Lochner, Ashish A. Mahabal, Rachel Mandelbaum, Peregrine McGehee, Eric H. Jr Jr Neilsen, Knut A. G. Olsen, Hiranya Peiris, Jason Rhodes, Gordon T. Richards, Stephen Ridgway, Megan E. Schwamb, Dan Scolnic, Ohad Shemmer, Colin T. Slater, Anze Slosar, Stephen J. Smartt, Jay Strader, Rachel Street, David E. Trilling, Aprajita Verma, A. K. Vivas, Risa H. Wechsler, Beth Willman
Summary: The Vera C. Rubin Observatory is a ground-based astronomical facility designed to conduct a 10-year optical survey of the Southern Hemisphere sky. It aims to probe dark energy and dark matter, catalog the solar system, explore the transient optical sky, and map the Milky Way. The massive data throughput of the survey will have transformative effects on other areas of astrophysics.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
Shubham Srivastav, S. J. Smartt, M. E. Huber, K. C. Chambers, C. R. Angus, T-W Chen, F. P. Callan, J. H. Gillanders, O. R. McBrien, S. A. Sim, M. Fulton, J. Hjorth, K. W. Smith, D. R. Young, K. Auchettl, J. P. Anderson, G. Pignata, T. J. L. de Boer, C-C Lin, E. A. Magnier
Summary: The study presents multiwavelength follow-up observations of the faint Iax supernova SN 2020kyg, revealing key data such as the bolometric light curve, ejected mass, and kinetic energy. A homogeneous volume-limited sample of 902 transients observed by ATLAS within 100 Mpc is constructed, showing the relative rates of faint Iax events compared to SN Ia events and the dominance of low-luminosity events in the overall Iax rate.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
T. J. L. de Boer, M. E. Huber, E. A. Magnier, P. M. Onaka, K. C. Chambers, C-C Lin, H. Gao, J. Fairlamb, R. J. Wainscoat
Summary: Using data from a year-long dedicated observation of bright stars, this study analyzes crosstalk channels in the GPC1 camera and constructs a dataset to check for potential crosstalk occurrences. The research reveals a dependence of attenuation factors on crosstalk movement and a correlation with cell column offsets.
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
(2022)
Article
Astronomy & Astrophysics
Yumi Choi, Knut A. G. Olsen, Gurtina Besla, Roeland P. van der Marel, Paul Zivick, Nitya Kallivayalil, David L. Nidever
Summary: In this study, the PM field of red clump stars in the LMC disk is analyzed using the Gaia Early Data Release 3 catalog. By comparing with numerical simulations, it is found that the present-day LMC is not in dynamical equilibrium and constraints on the LMC-SMC interaction history are proposed. Additionally, consistent radial trends in the disk inclination and line-of-node position angles are discovered.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Xinlun Cheng, Yumi Choi, Knut Olsen, David L. Nidever, Steven R. Majewski, Antonela Monachesi, Gurtina Besla, Cesar Munoz Gonzalez, Borja Anguiano, Andres Almeida, Ricardo R. Munoz, Richard R. Lane, Christian Nitschelm
Summary: This study presents the first 3D kinematic measurements of 88 stars in the southern periphery of the Large Magellanic Cloud (LMC) using Gaia proper motions and APOGEE-2 survey radial velocities. The results show that a significant portion of these stars have extreme space velocities that are distinct from the LMC disk, and they may be tidal debris created during the interaction between LMC and Small Magellanic Cloud (SMC). Additionally, many stars in the southern periphery of LMC are located outside of its plane by several kiloparsecs, suggesting a need for a wider exploration of the interaction history of the Magellanic Clouds.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
P. Massana, T. Ruiz-Lara, N. E. D. Noel, C. Gallart, D. L. Nidever, Y. Choi, J. D. Sakowska, G. Besla, K. A. G. Olsen, M. Monelli, A. Dorta, G. S. Stringfellow, S. Cassisi, E. J. Bernard, D. Zaritsky, M. -R. L. Cioni, A. Monachesi, R. P. Van der Marel, T. J. L. De Boer, A. R. Walker
Summary: We used the SMASH survey to quantitatively derive the star formation history of the Small Magellanic Cloud (SMC) and found five distinctive peaks of star formation in the last 3.5 billion years. We compared the star formation history of the SMC with that of the Large Magellanic Cloud (LMC) and found clear synchronicity. Tidal interactions between the two galaxies have played an important role in their evolution for the past 3.5 billion years.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Maria Tantalo, Massimo Dall'Ora, Giuseppe Bono, Peter B. Stetson, Michele Fabrizio, Ivan Ferraro, Mario Nonino, Vittorio F. Braga, Ronaldo da Silva, Giuliana Fiorentino, Giacinto Iannicola, Massimo Marengo, Matteo Monelli, Joseph P. Mullen, Adriano Pietrinferni, Maurizio Salaris
Summary: This study presents accurate photometry measurements of the Local Group dwarf irregular galaxy NGC 6822. It reveals the different radial distributions of stars of different ages and estimates the iron abundance based on observed carbon-to-M-type star ratio.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
David H. Weinberg, Jon A. Holtzman, Jennifer A. Johnson, Christian Hayes, Sten Hasselquist, Matthew Shetrone, Yuan-Sen Ting, Rachael L. Beaton, Timothy C. Beers, Jonathan C. Bird, Dmitry Bizyaev, Michael R. Blanton, Katia Cunha, Jose G. Fernandez-Trincado, Peter M. Frinchaboy, D. A. Garcia-Hernandez, Emily Griffith, James W. Johnson, Henrik Jonsson, Richard R. Lane, Henry W. Leung, J. Ted Mackereth, Steven R. Majewski, Szabolcs Meszaros, Christian Nitschelm, Kaike Pan, Ricardo P. Schiavon, Donald P. Schneider, Mathias Schultheis, Verne Smith, Jennifer S. Sobeck, Keivan G. Stassun, Guy S. Stringfellow, Fiorenzo Vincenzo, John C. Wilson, Gail Zasowski
Summary: We applied a statistical analysis to measurements of elemental abundances in Milky Way disk stars and found complex structures and correlations in the abundance patterns. Using residual abundance analysis, we discovered differences in abundance patterns among different regions and populations, and confirmed the stochasticity in the production and redistribution of elements in chemical evolution models.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
Christian R. Hayes, Thomas Masseron, Jennifer Sobeck, D. A. Garcia-Hernandez, Carlos Allende Prieto, Rachael L. Beaton, Katia Cunha, Sten Hasselquist, Jon A. Holtzman, Henrik Jonsson, Steven R. Majewski, Matthew Shetrone, Verne V. Smith, Andres Almeida
Summary: In this study, we utilized high signal-to-noise spectra data of approximately 120,000 giants to measure the chemical abundances of weak and blended species. By employing an updated version of the BACCHUS code and stellar parameters measured by APOGEE, we obtained precise measurements for Na, P, S, V, Cu, Ce, Nd abundances as well as C-12/C-13 isotopic ratios. The new catalog of chemical abundances provides significant improvements over previous methods and can be applied to a wide range of scientific applications.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
V. F. Braga, G. Fiorentino, G. Bono, P. B. Stetson, C. E. Martinez-Vazquez, S. Kwak, M. Tantalo, M. Dall'Ora, M. Di Criscienzo, M. Fabrizio, M. Marengo, S. Marinoni, P. M. Marrese, M. Monelli
Summary: We investigated the properties of mixed-mode RR Lyrae variables in the Fornax dwarf spheroidal galaxy and compared them with variables in the Magellanic Clouds and nearby dwarf spheroidals. We found that the ratio of mixed-mode RR Lyrae decreases with metallicity, and Fornax fills a period gap in the Petersen diagram similarly to Small Magellanic Cloud variables. Additionally, a new pulsation diagnostics method reveals that Large Magellanic Cloud variables can be separated into two groups with different evolutionary properties. Our findings suggest that Fornax and Sculptor dwarf spheroidals have undergone different chemical enrichment histories.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Eric L. Sandquist, Andrew J. Buckner, Matthew D. Shetrone, Samuel C. Barden, Catherine A. Pilachowski, Constantine P. Deliyannis, Dianne Harmer, Robert Mathieu, Soren Meibom, Soren Frandsen, Jerome A. Orosz
Summary: We present analyses of improved photometric and spectroscopic observations for two detached eclipsing binaries at the turnoff of the open cluster NGC 752. The results reveal unusual characteristics of the stars in these binaries, suggesting nonstandard evolution. This research is important for understanding cluster and stellar evolution.
ASTRONOMICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
M. Di Criscienzo, S. Leccia, V. Braga, I. Musella, G. Bono, M. Dall'Ora, G. Fiorentino, M. Marconi, R. Molinaro, V. Ripepi, K. Carrell, Y. Choi, S. Savarese, L. Schreiber
Summary: This investigation focuses on the LSST Survey Strategy Optimization process and the development of a new tool called PulsationStarRecovery. It demonstrates the importance of excellent recovery in understanding the potential of LSST in using pulsating stars as stellar tracers and distance indicators. The study also shows the difference in recovery based on distance and variable-star type.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
Sam M. Ward, Stephen Thorp, Kaisey S. Mandel, Suhail Dhawan, David O. Jones, Kirsty Taggart, Ryan J. Foley, Gautham Narayan, Kenneth C. Chambers, David A. Coulter, Kyle W. Davis, Thomas de Boer, Kaylee de Soto, Nicholas Earl, Alex Gagliano, Hua Gao, Jens Hjorth, Mark E. Huber, Luca Izzo, Danial Langeroodi, Eugene A. Magnier, Peter McGill, Armin Rest, Cesar Rojas-Bravo, Radoslaw Wojtak, Young Supernova Experiment
Summary: This paper analyzes the Young Supernova Experiment data on the Ia-type supernova siblings of SN 2021hpr in NGC 3147, proposing a Bayesian framework for analyzing supernova siblings and obtaining robust estimates by marginalizing intrinsic scatter parameters. The study also explores the impact of siblings on dust parameters.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
W. Cerny, A. Drlica-Wagner, T. S. Li, A. B. Pace, K. A. G. Olsen, N. E. D. Noel, R. P. van der Marel, J. L. Carlin, Y. Choi, D. Erkal, M. Geha, D. J. James, C. E. Martinez-Vazquez, P. Massana, G. E. Medina, A. E. Miller, B. Mutlu-Pakdil, D. L. Nidever, J. D. Sakowska, G. S. Stringfellow, J. A. Carballo-Bello, P. S. Ferguson, N. Kuropatkin, S. Mau, E. J. Tollerud, A. K. Vivas, DELVE Collaboration
Summary: We discovered DELVE 6, an ultra-faint stellar system in the second data release of the DECam Local Volume Exploration (DELVE) survey. DELVE 6 is an old and metal-poor stellar system with certain physical properties consistent with other ultra-faint star clusters. It is located near the Small Magellanic Cloud (SMC) and potentially associated with the SMC/LMC.
ASTROPHYSICAL JOURNAL LETTERS
(2023)