Article
Astronomy & Astrophysics
Caro Derkenne, Richard M. McDermid, Adriano Poci, J. Trevor Mendel, Francesco D'Eugenio, Seyoung Jeon, Rhea-Silvia Remus, Sabine Bellstedt, Andrew J. Battisti, Joss Bland-Hawthorn, Anna Ferre-Mateu, Caroline Foster, K. E. Harborne, Claudia D. P. Lagos, Yingjie Peng, Piyush Sharda, Gauri Sharma, Sarah Sweet, Kim-Vy H. Tran, Lucas M. Valenzuela, Sam Vaughan, Emily Wisnioski, Sukyoung K. Yi
Summary: We investigate the impact of environment on the internal mass distribution of galaxies using the MAGPI survey. We find that galaxies in high density clusters have less centrally concentrated mass distribution compared to galaxies in low-to-mid density environments. Our results suggest that environment plays a role in the internal mass distribution of galaxies, with no evolution of the slope in the last 3-4 Gyr.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Yuren Zhou, Yanmei Chen, Yong Shi, Dmitry Bizyaev, Hong Guo, Min Bao, Haitong Xu, Xiaoling Yu, Joel R. Brownstein
Summary: In this study, we select 456 gas-star kinematically misaligned galaxies and analyze their properties in detail. We find that misaligned galaxies generally have lower gas detection rates and molecular gas mass fractions, as well as smaller sizes and higher Sersic indices. For misaligned galaxies in star-forming states, they tend to show more asymmetric gas velocity fields. As for misaligned quiescent galaxies, there are possibly three origins.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Haitong Xu, Yanmei Chen, Yong Shi, Yuren Zhou, Dmitry Bizyaev, Min Bao, Minje Beom, Jose G. Fernandez-Trincado, Xiao Cao
Summary: We investigated galaxies with kinematically misaligned gas and stellar components, and classified them into star-forming, green-valley, and quiescent galaxies. Our results show significant differences between misaligned galaxies and control samples in terms of gas and stellar motion ratios, central star formation activity, and gas-phase metallicity. These findings suggest that external gas accretion plays an important role in the evolution of galaxies, affecting both their dynamics and stellar populations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Caro Derkenne, Richard M. McDermid, Adriano Poci, Rhea-Silvia Remus, Inger Jorgensen, Eric Emsellem
Summary: The change in the mass density slope of early-type galaxies over cosmic time can be used to study their evolutionary pathways. Hydrodynamical cosmological simulations suggest that density profiles were steep at high redshifts but became more isothermal as redshift approached zero due to gas-poor mergers. However, gravitational lensing results show a different trend, indicating a potential discrepancy between observations and simulations in understanding the evolutionary mechanisms for early-type galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Jennifer A. Hardwick, Luca Cortese, Danail Obreschkow, Barbara Catinella
Summary: We use a sample of 559 disc galaxies to study the connection between baryonic angular momentum, mass, and atomic gas fraction. We confirm the correlation between specific angular momentum and atomic gas fraction, but find a larger scatter than previously observed. The analytical stability model provides a good approximation but does not fully match our data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
S. M. Croom, D. S. Taranu, J. van de Sande, C. D. P. Lagos, K. E. Harborne, J. Bland-Hawthorn, S. Brough, J. J. Bryant, L. Cortese, C. Foster, M. Goodwin, B. Groves, A. Khalid, J. Lawrence, A. M. Medling, S. N. Richards, M. S. Owers, N. Scott, S. P. Vaughan
Summary: Comparisons between galaxy survey and models are used to study the importance of disc fading in the transition of spirals into lenticular galaxies. The results suggest that while disc fading has a noticeable impact on spin and concentration, it cannot explain all observed differences, indicating that intrinsic dynamical evolution is important. Progenitor bias also plays a role in moving data further from the disc fading model scenario.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Yifan Mai, Sam P. Vaughan, Scott M. Croom, Jesse van de Sande, Stefania Barsanti, Joss Bland-Hawthorn, Sarah Brough, Julia J. Bryant, Matthew Colless, Michael Goodwin, Brent Groves, Iraklis S. Konstantopoulos, Jon S. Lawrence, Nuria P. F. Lorente, Samuel N. Richards
Summary: Using data from the SAMI Galaxy Survey, the study explores the correlation between the rotation of SAMI galaxies and the motion of neighboring galaxies. The results show that there is a significant coherence signal within 1 Mpc, which increases with distance up to 2 Mpc but becomes consistent with zero or negative beyond 3 Mpc. The study suggests that the coherence signals within 2 Mpc might be influenced by the variance of large-scale structure.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jennifer A. Hardwick, Luca Cortese, Danail Obreschkow, Barbara Catinella, Robin H. W. Cook
Summary: We present a detailed study of the stellar mass versus specific angular momentum relation for a sample of 564 nearby galaxies. Our results show that the slope and scatter of the Fall relation vary when considering galaxy type and sample selection. The gas fraction is the most correlated parameter for low stellar masses, while the bulge-to-total ratio becomes more dominant at higher masses. Interestingly, when only the disc components of galaxies are considered, the gas fraction remains the most correlated parameter with the scatter of the relation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Anna de Graaff, Marijn Franx, Eric F. Bell, Rachel Bezanson, Matthieu Schaller, Joop Schaye, Arjen van der Wel
Summary: Using the EAGLE cosmological simulations, we analyze the z=0.1 fundamental plane (FP), which describes the relation between galaxy size, mass, and velocity dispersion. We find that simulated galaxies follow a total mass FP that is close to the virial relation, indicating weak non-homology effects. However, when using stellar mass, there is a strong deviation from the virial plane due to variations in dark matter content. The stellar mass FP can be used as a simple test for cosmological simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jian Wu, Curtis Struck, Bruce G. Elmegreen, Elena D'Onghia
Summary: This study investigates the formation of exponential profiles in galaxy discs through stellar scattering by massive clumps. The authors find that star-clump encounters, particularly those with closest approaches less than 0.5 kpc, can lead to significant changes in the angular momentum of stars. These encounters also increase the random motion of stars, resulting in an increase in the average radial and vertical actions of the stellar population. The direction from which a star approaches a clump influences changes in angular momentum and radial action. Stars initially at higher galactic radii tend to lose angular momentum during encounters, while those at lower radii tend to gain angular momentum. The study also suggests that regardless of the direction of the bias, stellar profile evolution towards an exponential shape seems to occur.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Felipe S. Lohmann, Allan Schnorr-Mueller, Marina Trevisan, T. Ricci, K. Slodkowski Clerici
Summary: We investigate the formation and evolution of massive compact galaxies (MCGs) at z = 0 using the IllustrisTNG cosmological simulation. Our results show that MCGs have similar properties to observed galaxies, including old ages, supersolar metallicities, and alpha-enhanced abundances. We find that MCGs generally assemble their mass early and accrete low angular momentum gas, leading to enhanced supermassive black hole growth and early quenching. Comparisons with non-compact galaxies reveal differences in accretion histories and highlight the role of dry mergers and progenitor bias in shaping the kinematics and stellar populations of these galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jian Wu, Curtis Struck, Bruce G. Elmegreen, Elena D'Onghia
Summary: Previous models have shown that a time-independent surface density distribution that follows an exponential divided by radius can be generated in a two-dimensional galaxy disc through stochastic scattering of stars with a constant inward scattering bias. In this study, we demonstrate that similar profiles can also arise from an outward scattering bias, even though the disc surface density decreases slowly over time due to a net stellar outflow. The trend towards a near-exponential surface profile remains robust, even when the scattering intensity has moderate radial and time dependences, as long as certain limitations on the scattering rates are met.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. A. Sellwood, R. G. Carlberg
Summary: This paper continues to explore different aspects of disc galaxy simulations that support spiral instabilities. The study finds a correlation between the growth rate of the mode and its limiting amplitude, and identifies the role of non-linear orbit deflections and available time in the saturation and decay of the spiral instabilities.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Juan M. Espejo Salcedo, Karl Glazebrook, Deanne B. Fisher, Sarah M. Sweet, Danail Obreschkow, A. M. Swinbank, Steven Gillman, Alfred L. Tiley
Summary: Detailed measurements of stellar specific angular momentum of 10 star-forming galaxies at redshifts around 1.5-2 were conducted using high and low spatial resolution integral field spectroscopic data. The study showed that higher resolution kinematics are required for identifying discs in these galaxies. Systematic errors in measuring j(*) between different analyses were found to be primarily due to the choice of surface mass density model and the measurement of effective radius from photometry.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Catalina Casanueva, Claudia del P. Lagos, Nelson D. Padilla, Thomas A. Davison
Summary: This study investigates the origin of misalignments between the stellar and star-forming gas components in simulated galaxies. The research finds that internal galaxy properties play a crucial role in determining whether the gas aligns with the stellar component, and the environment is also important in setting the conditions for misalignments.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Rajsekhar Mohapatra, Mrinal Jetti, Prateek Sharma, Christoph Federrath
Summary: Turbulence in the intracluster medium plays a key role in gas motion, thermodynamics, and the formation of intermediate temperature gas. Strong turbulence generates larger density fluctuations and faster cooling. Magnetic fields provide pressure support in the cold phase but have minimal effects on gas distribution and perturbations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Chiaki Kobayashi
Summary: Thanks to long-term collaborations between nuclear and astrophysics, we have a good understanding of stellar nucleosynthesis, except for certain elements such as titanium and neutron-capture elements. Comparisons between observations and galactic chemical evolution models suggest the existence of a rapid neutron-capture process associated with core-collapse supernovae, although the explosion mechanism remains unknown. The impact of rotating massive stars on element formation is also discussed. Obtaining UV spectra is crucial for fully understanding the origin of elements in the universe.
EXPERIMENTAL ASTRONOMY
(2023)
Article
Astronomy & Astrophysics
Amit Seta, Christoph Federrath, Jack D. Livingston, N. M. McClure-Griffiths
Summary: Magnetic fields and turbulence are important in the interstellar medium of star-forming galaxies. This study uses numerical simulations to demonstrate how the second-order rotation measure (RM) structure function can probe the properties of small-scale magnetic fields. The results are applied to observations of the Small and Large Magellanic Clouds (SMC and LMC), estimating the correlation length, strength, and slope of the magnetic power spectrum of the small-scale magnetic fields.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Y. T. Yan, C. Henkel, C. Kobayashi, K. M. Menten, Y. Gong, J. S. Zhang, H. Z. Yu, K. Yang, J. J. Xie, Y. X. Wang
Summary: This study used the IRAM 30 meter telescope to observe a large sample of high-mass star-forming regions and measured the abundance ratios of C-12/C-13, S-32/S-34, S-32/S-33, S-32/S-36, S-34/S-33, S-34/S-36, and S-33/S-36 isotopes. The results showed that the C-12/C-13 and S-32/S-34 ratios decrease with increasing galactocentric distance in the Milky Way. Additionally, positive gradients of S-32/S-33, S-34/S-36, S-33/S-36, and S-32/S-36 were observed for the first time in our Galaxy. These findings are important for tracing stellar nucleosynthesis, evaluating stellar ejecta composition, and constraining the chemical evolution of the Milky Way.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Chiaki Kobayashi, Ilya Mandel, Krzysztof Belczynski, Stephane Goriely, Thomas H. Janka, Oliver Just, Ashley J. Ruiter, Dany Vanbeveren, Matthias U. Kruckow, Max M. Briel, Jan J. Eldridge, Elizabeth Stanway
Summary: By comparing galactic chemical evolution models with observed elemental abundances, we find that neutron star mergers can only be a major r-process site if they have short delay times and significant ejecta masses at low metallicities, influenced by the masses of the compact objects. Specifically, black hole-neutron star mergers, depending on black hole spins, can contribute significantly to the early chemical enrichment of the Milky Way. However, none of the binary population synthesis models used in this study can currently reproduce the observed elemental abundance, pointing to potential shortcomings in binary evolution models.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Sajay Sunny Mathew, Christoph Federrath, Amit Seta
Summary: Turbulence is crucial for star formation, but its role in the initial mass function (IMF) is not fully understood. Magnetohydrodynamical simulations reveal that compressive turbulence driving produces a higher fraction of low-mass stars compared to solenoidal driving. The simulations capture the important features of the observed IMF form.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Benjamin Wehmeyer, Andres Yague Lopez, Benoit Cote, Maria Peto, Chiaki Kobayashi, Maria Lugaro
Summary: Modeling the evolution of short-lived radioisotopes provides supplementary timing information on recent nucleosynthesis. Using a three-dimensional galactic chemical evolution model, we investigated the evolution of four short-lived radioisotopes and found that core-collapse supernovae are the dominant propagation mechanism. This explains why live extrasolar Mn-53, Fe-60, and Pu-244 are found within the same or similar layers of deep-sea sediments and predicts that Hf-182 should also be found at similar depths.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Tilman Hartwig, Miho N. Ishigaki, Chiaki Kobayashi, Nozomu Tominaga, Ken'ichi Nomoto
Summary: By analyzing extremely metal-poor stars in the Milky Way, scientists have revealed the nature of the first stars. They classify these stars into mono- or multi-enriched using data-driven methods and find that the majority of extremely metal-poor stars are likely multi-enriched, suggesting that the first stars were born in small clusters.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Rosanne Di Stefano, Matthias U. Kruckow, Yan Gao, Patrick G. Neunteufel, Chiaki Kobayashi
Summary: This article discusses the common envelope (CE) phase in binary evolution, which can lead to mergers or subsequent interactions. Mergers can involve various celestial objects and have different outcomes. The article introduces a new approach using angular momentum to derive the final orbital separation, which is suitable for studying mergers in multiple-star systems.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Aris Tritsis, Shantanu Basu, Christoph Federrath
Summary: In this study, the ion-neutral drift velocity in prestellar cores is studied through simulations and radiative transfer calculations. It is found that temperature significantly affects the amplitude of the drift velocity, and observational challenges and chemical effects can hinder the detection of the ion-neutral drift velocity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Justin Kin Jun Hew, Christoph Federrath
Summary: This study presents novel 3D magnetohydrodynamic simulations of a laser-driven shock propagating into a stratified multiphase medium, investigating the post-shock turbulent magnetic field amplification via the turbulent dynamo mechanism. The results indicate that the growth rate of the magnetic field is consistent with the theoretical predictions for compressive turbulence driving in subsonic, compressible turbulence.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Shyam H. Menon, Christoph Federrath, Mark R. Krumholz
Summary: We use 3D radiation hydrodynamic simulations to study the formation of massive star clusters under the combined effects of direct ultraviolet and dust-reprocessed infrared radiation pressure. We find that star formation can only be regulated by radiation pressure for low mass surface densities, but high-density clouds become super-Eddington and launch gas outflows. These outflows with mass-weighted radial velocities and the importance of UV and IR radiation pressure are quantified.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Boquan Chen, Michael R. Hayden, Sanjib Sharma, Joss Bland-Hawthorn, Chiaki Kobayashi, Amanda Karakas
Summary: We propose a multizone galactic chemical evolution model that considers the most recently updated nucleosynthesis yields. The model incorporates physical processes such as gas feedback, radial flow of gas, infall of fresh gas, and radial migration. We analyze the impact of these processes on the observed properties of the Milky Way. The model successfully reproduces the observed distribution of stars in terms of metallicity and alpha-to-iron ratio.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Chiaki Kobayashi, Souradeep Bhattacharya, Magda Arnaboldi, Ortwin Gerhard
Summary: Using state-of-the-art galactic chemical evolution models, we present evidence of the existence of an alpha/Fe bimodality in the disk structure of the Andromeda galaxy (M31). Our findings indicate the presence of a high-alpha thicker-disk population formed by an intense initial starburst, as well as a young low-alpha thin disk formed by a secondary star formation event. However, the outer disk shows only a slight alpha/Fe offset, suggesting a weaker bimodality. Wide-field multiobject spectroscopy is required for further investigation of the merging history and the overall evolution of M31.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Renier T. Hough, Douglas Rennehan, Chiaki Kobayashi, S. Ilani Loubser, Romeel Dave, Arif Babul, Weiguang Cui
Summary: In this study, a new chemical enrichment and stellar feedback model called SIMBA-C is introduced into GIZMO, based on the SIMBA sub-grid models. SIMBA-C shows significant improvements in key diagnostics such as the knee of the z = 0 galaxy stellar mass function, the faint end of the main sequence, and the ability to track black holes in dwarf galaxies. By not assuming instantaneous recycling, SIMBA-C provides a much better match to galactic abundance ratio measures such as [O/Fe] and [N/O], opening up new avenues to constrain feedback models using detailed chemical abundance measures across cosmic time.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)