Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202449255
Sara Rezaei Kh., Henrik Beuther, Robert A. Benjamin, Anna-Christina Eilers, Thomas Henning, Maria J. Jiménez-Donaire, Marc-Antoine Miville-Deschênes
Understanding the 3D structure of the Milky Way is a crucial step in deriving properties of the star-forming regions, as well as the Galaxy as a whole. We present a novel 3D map of the Milky Way plane that extends to 10 kpc distance from the Sun. We leverage the wealth of information in the near-infrared dataset of the Sloan Digital Sky Survey’s Apache Point Observatory Galactic Evolution Experiment (APOGEE) and combine that with our state-of-the-art 3D mapping technique using Bayesian statistics and the Gaussian process to provide a large-scale 3D map of the dust in the Milky Way. Our map stretches across 10 kpc along both the X and Y axes, and 750 pc in the Z direction, perpendicular to the Galactic plane. Our results reveal multi-scale over-densities as well as large cavities in the Galactic plane and shed new light on the Galactic structure and spiral arms. We also provide a catalogue of large molecular clouds identified by our map with accurate distance and volume density estimates. Utilising volume densities derived from this map, we explore mass distribution across various galactocentric radii. A general decline towards the outer Galaxy is observed, followed by local peaks, some aligning with established features such as the molecular ring and segments of the spiral arms. Moreover, this work explores extragalactic observational effects on derived properties of molecular clouds by demonstrating the potential biases arising from column density measurements in inferring properties of these regions, and opens exciting avenues for further exploration and analysis, offering a deeper perspective on the complex processes that shape our galaxy and beyond.
{"title":"3D structure of the Milky Way out to 10 kpc from the Sun","authors":"Sara Rezaei Kh., Henrik Beuther, Robert A. Benjamin, Anna-Christina Eilers, Thomas Henning, Maria J. Jiménez-Donaire, Marc-Antoine Miville-Deschênes","doi":"10.1051/0004-6361/202449255","DOIUrl":"https://doi.org/10.1051/0004-6361/202449255","url":null,"abstract":"Understanding the 3D structure of the Milky Way is a crucial step in deriving properties of the star-forming regions, as well as the Galaxy as a whole. We present a novel 3D map of the Milky Way plane that extends to 10 kpc distance from the Sun. We leverage the wealth of information in the near-infrared dataset of the Sloan Digital Sky Survey’s Apache Point Observatory Galactic Evolution Experiment (APOGEE) and combine that with our state-of-the-art 3D mapping technique using Bayesian statistics and the Gaussian process to provide a large-scale 3D map of the dust in the Milky Way. Our map stretches across 10 kpc along both the <i>X<i/> and <i>Y<i/> axes, and 750 pc in the <i>Z<i/> direction, perpendicular to the Galactic plane. Our results reveal multi-scale over-densities as well as large cavities in the Galactic plane and shed new light on the Galactic structure and spiral arms. We also provide a catalogue of large molecular clouds identified by our map with accurate distance and volume density estimates. Utilising volume densities derived from this map, we explore mass distribution across various galactocentric radii. A general decline towards the outer Galaxy is observed, followed by local peaks, some aligning with established features such as the molecular ring and segments of the spiral arms. Moreover, this work explores extragalactic observational effects on derived properties of molecular clouds by demonstrating the potential biases arising from column density measurements in inferring properties of these regions, and opens exciting avenues for further exploration and analysis, offering a deeper perspective on the complex processes that shape our galaxy and beyond.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"103 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202452595
Iris Breda, Glenn van de Ven, Sabine Thater, Jesus Falcón-Barroso, Prashin Jethwa, Dimitri A. Gadotti, Masato Onodera, Ismael Pessa, Joop Schaye, Gerhard Hensler, Jarle Brinchmann, Anja Feldmeier-Krause, Davor Krajnović, Bodo Ziegler
The processes driving the formation and evolution of late-type galaxies continue to be a debated subject in extragalactic astronomy. Investigating stellar kinematics, especially when combined with age estimates, provides crucial insights into the formation and subsequent development of galactic discs. Post-processing of exceptionally high-quality integral field spectroscopy data of NGC 4030 acquired with the Multi Unit Spectroscopic Explorer (MUSE) has revealed a striking grand design spiral pattern in the velocity dispersion map, that has not been detected in other galaxies. This pattern spatially correlates with HII regions, suggesting that stars currently being born exhibit lower velocity dispersion as compared to surrounding areas where star-formation is less active. We examined the age-velocity relation (AVR) and propose that its configuration might be shaped by a combination of heating mechanisms, seemingly consistent with findings from recent high-resolution cosmological zoom-in simulations. The complex structure of the uncovered AVR of NGC 4030 supports the hypothesis that stellar populations initially inherit the velocity dispersion σ of the progenitor cold molecular gas, which depends on formation time and galactocentric distance, subsequently experiencing kinematic heating due to cumulative gravitational interactions during their lifetime. While advancing our understanding of the AVR, these findings also offer a new framework for investigating disc heating mechanisms and their role in the evolution of galactic discs.
{"title":"Large-scale stellar age-velocity spiral pattern in NGC 4030","authors":"Iris Breda, Glenn van de Ven, Sabine Thater, Jesus Falcón-Barroso, Prashin Jethwa, Dimitri A. Gadotti, Masato Onodera, Ismael Pessa, Joop Schaye, Gerhard Hensler, Jarle Brinchmann, Anja Feldmeier-Krause, Davor Krajnović, Bodo Ziegler","doi":"10.1051/0004-6361/202452595","DOIUrl":"https://doi.org/10.1051/0004-6361/202452595","url":null,"abstract":"The processes driving the formation and evolution of late-type galaxies continue to be a debated subject in extragalactic astronomy. Investigating stellar kinematics, especially when combined with age estimates, provides crucial insights into the formation and subsequent development of galactic discs. Post-processing of exceptionally high-quality integral field spectroscopy data of NGC 4030 acquired with the Multi Unit Spectroscopic Explorer (MUSE) has revealed a striking grand design spiral pattern in the velocity dispersion map, that has not been detected in other galaxies. This pattern spatially correlates with HII regions, suggesting that stars currently being born exhibit lower velocity dispersion as compared to surrounding areas where star-formation is less active. We examined the age-velocity relation (AVR) and propose that its configuration might be shaped by a combination of heating mechanisms, seemingly consistent with findings from recent high-resolution cosmological zoom-in simulations. The complex structure of the uncovered AVR of NGC 4030 supports the hypothesis that stellar populations initially inherit the velocity dispersion <i>σ<i/> of the progenitor cold molecular gas, which depends on formation time and galactocentric distance, subsequently experiencing kinematic heating due to cumulative gravitational interactions during their lifetime. While advancing our understanding of the AVR, these findings also offer a new framework for investigating disc heating mechanisms and their role in the evolution of galactic discs.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"4 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142840858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202451435
Jonathan A. Jäger, Stefan Reissl, Ralf S. Klessen
Aims. It is quintessential for the analysis of the observed dust polarization signal to understand the rotational dynamics of interstellar dust grains. Additionally, high rotation velocities may rotationally disrupt the grains, which impacts the grain-size distribution. We aim to constrain the set of parameters for an accurate description of the rotational spin-up process of ballistic dust grain aggregates driven by radiative torques (RATs).Methods. We modeled the dust grains as complex fractal aggregates grown by the ballistic aggregation of uniform spherical particles (monomers) of different sizes. A broad variation of dust materials, shapes, and sizes were studied in the presence of different radiation sources.Results. We find that the canonical parameterization for the torque efficiency overestimates the maximum angular velocity ωRAT caused by RATs acting on ballistic grain aggregates. To resolve this problem, we propose a new parameterization that predicts ωRAT more accurately. We find that RATs are most efficient for larger grains with a lower monomer density. This manifests itself as a size- and monomer-density dependence in the constant part of the parameterization. Following the constant part, the parameterization has two power laws with different slopes that retain universality for all grain sizes. The maximum grain rotation does not scale linearly with radiation strength because different drag mechanisms dominate, depending on the grain material and environment. The angular velocity ωRAT of individual single dust grains has a wide distribution and may even differ from the mean by up to two orders of magnitude. Even though ballistic aggregates have a lower RAT efficiency, strong sources of radiation (stronger than ≈100 times the typical interstellar radiation field) may still produce rotation velocities high enough to cause the rotational disruption of dust grains.
{"title":"The radiative torque spin-up efficiency of ballistic dust-grain aggregates","authors":"Jonathan A. Jäger, Stefan Reissl, Ralf S. Klessen","doi":"10.1051/0004-6361/202451435","DOIUrl":"https://doi.org/10.1051/0004-6361/202451435","url":null,"abstract":"<i>Aims.<i/> It is quintessential for the analysis of the observed dust polarization signal to understand the rotational dynamics of interstellar dust grains. Additionally, high rotation velocities may rotationally disrupt the grains, which impacts the grain-size distribution. We aim to constrain the set of parameters for an accurate description of the rotational spin-up process of ballistic dust grain aggregates driven by radiative torques (RATs).<i>Methods.<i/> We modeled the dust grains as complex fractal aggregates grown by the ballistic aggregation of uniform spherical particles (monomers) of different sizes. A broad variation of dust materials, shapes, and sizes were studied in the presence of different radiation sources.<i>Results.<i/> We find that the canonical parameterization for the torque efficiency overestimates the maximum angular velocity <i>ω<i/><sub>RAT<sub/> caused by RATs acting on ballistic grain aggregates. To resolve this problem, we propose a new parameterization that predicts <i>ω<i/><sub>RAT<sub/> more accurately. We find that RATs are most efficient for larger grains with a lower monomer density. This manifests itself as a size- and monomer-density dependence in the constant part of the parameterization. Following the constant part, the parameterization has two power laws with different slopes that retain universality for all grain sizes. The maximum grain rotation does not scale linearly with radiation strength because different drag mechanisms dominate, depending on the grain material and environment. The angular velocity <i>ω<i/><sub>RAT<sub/> of individual single dust grains has a wide distribution and may even differ from the mean by up to two orders of magnitude. Even though ballistic aggregates have a lower RAT efficiency, strong sources of radiation (stronger than ≈100 times the typical interstellar radiation field) may still produce rotation velocities high enough to cause the rotational disruption of dust grains.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"27 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142848994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202451758
Vardan G. Elbakyan, Sergei Nayakshin, Alessio Caratti o Garatti, Rolf Kuiper, Zhen Guo
Context. High-mass young stellar objects (HMYSOs) can exhibit episodic bursts of accretion, accompanied by intense outflows and luminosity variations. Understanding the underlying mechanisms driving these phenomena is crucial for elucidating the early evolution of massive stars and their feedback on star formation processes.Aims. Thermal instability (TI) due to hydrogen ionisation is among the most promising mechanisms of episodic accretion in low-mass (M* ≲ 1 M⊙) protostars. Its role in HMYSOs has not yet been determined. Here we investigate the properties of TI outbursts in young massive (M* ≳ 5 M⊙) stars, and compare them to those that have been observed to date.Methods. We employed a 1D numerical model to simulate TI outbursts in HMYSO accretion discs. We varied the key model parameters, such as stellar mass, mass accretion rate onto the disc, and disc viscosity, to assess the TI outburst properties.Results. Our simulations show that modelled TI bursts can replicate the durations and peak accretion rates of long outbursts (a few years to decades) observed in HMYSOs with similar mass characteristics. However, they struggle with short-duration bursts (less than a year) with short rise times (a few weeks or months), suggesting the need for alternative mechanisms. Moreover, while our models match the durations of longer bursts, they fail to reproduce the multiple outbursts seen in some HMYSOs, regardless of model parameters. We also emphasise the significance of not just evaluating model accretion rates and durations, but also performing photometric analysis to thoroughly evaluate the consistency between model predictions and observational data.Conclusions. Our findings suggest that some other plausible mechanisms, such as gravitational instabilities and disc fragmentation, can be responsible for generating the observed outburst phenomena in HMYSOs, and we underscore the need for further investigation into alternative mechanisms driving short outbursts. However, the physics of TI is crucial in sculpting the inner disc physics in the early bright epoch of massive star formation, and comprehensive parameter space exploration; the use of 2D modelling is essential to obtaining a more detailed understanding of the underlying physical processes. By bridging theoretical predictions with observational constraints, this study contributes to advancing our knowledge of HMYSO accretion physics and the early evolution of massive stars.
{"title":"The role of thermal instability in accretion outbursts in high-mass stars","authors":"Vardan G. Elbakyan, Sergei Nayakshin, Alessio Caratti o Garatti, Rolf Kuiper, Zhen Guo","doi":"10.1051/0004-6361/202451758","DOIUrl":"https://doi.org/10.1051/0004-6361/202451758","url":null,"abstract":"<i>Context.<i/> High-mass young stellar objects (HMYSOs) can exhibit episodic bursts of accretion, accompanied by intense outflows and luminosity variations. Understanding the underlying mechanisms driving these phenomena is crucial for elucidating the early evolution of massive stars and their feedback on star formation processes.<i>Aims.<i/> Thermal instability (TI) due to hydrogen ionisation is among the most promising mechanisms of episodic accretion in low-mass (<i>M<i/><sub>*<sub/> ≲ 1 M<sub>⊙<sub/>) protostars. Its role in HMYSOs has not yet been determined. Here we investigate the properties of TI outbursts in young massive (<i>M<i/><sub>*<sub/> ≳ 5 M<sub>⊙<sub/>) stars, and compare them to those that have been observed to date.<i>Methods.<i/> We employed a 1D numerical model to simulate TI outbursts in HMYSO accretion discs. We varied the key model parameters, such as stellar mass, mass accretion rate onto the disc, and disc viscosity, to assess the TI outburst properties.<i>Results.<i/> Our simulations show that modelled TI bursts can replicate the durations and peak accretion rates of long outbursts (a few years to decades) observed in HMYSOs with similar mass characteristics. However, they struggle with short-duration bursts (less than a year) with short rise times (a few weeks or months), suggesting the need for alternative mechanisms. Moreover, while our models match the durations of longer bursts, they fail to reproduce the multiple outbursts seen in some HMYSOs, regardless of model parameters. We also emphasise the significance of not just evaluating model accretion rates and durations, but also performing photometric analysis to thoroughly evaluate the consistency between model predictions and observational data.<i>Conclusions.<i/> Our findings suggest that some other plausible mechanisms, such as gravitational instabilities and disc fragmentation, can be responsible for generating the observed outburst phenomena in HMYSOs, and we underscore the need for further investigation into alternative mechanisms driving short outbursts. However, the physics of TI is crucial in sculpting the inner disc physics in the early bright epoch of massive star formation, and comprehensive parameter space exploration; the use of 2D modelling is essential to obtaining a more detailed understanding of the underlying physical processes. By bridging theoretical predictions with observational constraints, this study contributes to advancing our knowledge of HMYSO accretion physics and the early evolution of massive stars.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"90 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202450112
Massimo Dotti, Riccardo Buscicchio, Francesco Bollati, Roberto Decarli, Walter Del Pozzo, Alessia Franchini
Spins play a crucial role in the appearance, evolution, and occupation fraction of massive black holes (MBHs). To date, observational estimates of MBH spins are scarce, and the assumptions commonly made in such estimates have recently been questioned. Similarly, theoretical models for MBH spin evolution, while reproducing the few observational constraints, are based on possibly oversimplified assumptions. New independent constraints on MBH spins are therefore of primary importance. We present a rigorous statistical analysis of the relative orientation of radio jets and megamaser disks in ten low-redshift galaxies. We find a strong preference for (partial) alignment between jets and megamaser that can be attributed to two different causes: coherent accretion and selective accretion. In the first case the partial alignment is due to an anisotropy in the gas reservoir fueling the growth of MBHs. In the second case the spin-dependent anisotropic feedback allows long-lived accretion only if the orbits of the gas inflows are almost aligned to the MBH equatorial plane. A discussion of the implications of the two accretion scenarios regarding the evolution of MBHs is presented, together with an outlook on future observational tests aiming at discriminating between the two scenarios and checking whether either applies to different redshifts and black hole mass regimes.
{"title":"Partial alignment between jets and megamasers: Coherent versus selective accretion","authors":"Massimo Dotti, Riccardo Buscicchio, Francesco Bollati, Roberto Decarli, Walter Del Pozzo, Alessia Franchini","doi":"10.1051/0004-6361/202450112","DOIUrl":"https://doi.org/10.1051/0004-6361/202450112","url":null,"abstract":"Spins play a crucial role in the appearance, evolution, and occupation fraction of massive black holes (MBHs). To date, observational estimates of MBH spins are scarce, and the assumptions commonly made in such estimates have recently been questioned. Similarly, theoretical models for MBH spin evolution, while reproducing the few observational constraints, are based on possibly oversimplified assumptions. New independent constraints on MBH spins are therefore of primary importance. We present a rigorous statistical analysis of the relative orientation of radio jets and megamaser disks in ten low-redshift galaxies. We find a strong preference for (partial) alignment between jets and megamaser that can be attributed to two different causes: coherent accretion and selective accretion. In the first case the partial alignment is due to an anisotropy in the gas reservoir fueling the growth of MBHs. In the second case the spin-dependent anisotropic feedback allows long-lived accretion only if the orbits of the gas inflows are almost aligned to the MBH equatorial plane. A discussion of the implications of the two accretion scenarios regarding the evolution of MBHs is presented, together with an outlook on future observational tests aiming at discriminating between the two scenarios and checking whether either applies to different redshifts and black hole mass regimes.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202451266
Pengfei Li, Ang Liu, Matthias Kluge, Johan Comparat, Yong Tian, Mariana P. Júlio, Marcel S. Pawlowski, Jeremy Sanders, Esra Bulbul, Axel Schwope, Vittorio Ghirardini, Xiaoyuan Zhang, Yunus Emre Bahar, Miriam E. Ramos-Ceja, Fabian Balzer, Christian Garrel
The mass of galaxy clusters is a critical quantity for probing cluster cosmology and testing theories of gravity, but its measurement could be biased, given that assumptions are inevitable in order to make use of any approach. In this paper, we employ and compare two mass proxies for galaxy clusters: thermodynamics of the intracluster medium and kinematics of member galaxies. We selected 22 galaxy clusters from the cluster catalog in the first SRG/eROSITA All-Sky Survey (eRASS1) that have sufficient optical and near-infrared observations. We generated multiband images in the energy range of (0.3, 7) keV for each cluster, and derived their temperature profiles, gas mass profiles, and hydrostatic mass profiles using a parametric approach that does not assume dark matter halo models. With spectroscopically confirmed member galaxies collected from multiple surveys, we numerically solved the spherical Jeans equation for their dynamical mass profiles. Our results quantify the correlation between dynamical mass and the line-of-sight velocity dispersion, log Mdyn = (1.296 ± 0.001)log(σlos2rproj/G)−(3.87 ± 0.23), with a root mean square (rms) scatter of 0.14 dex. We find that the two mass proxies lead to roughly the same total mass, with no observed systematic bias. As such, the σ8 tension is not specific to hydrostatic mass or weak lensing shears, but also appears with galaxy kinematics. Interestingly, the hydrostatic-to-dynamical mass ratios decrease slightly toward large radii, which could possibly be evidence for accreting galaxies in the outskirts. We also compared our hydrostatic masses with the latest weak lensing masses inferred with scaling relations. The comparison shows that the weak lensing mass is significantly higher than our hydrostatic mass by ∼110%. This might explain the significantly larger value of σ8 from the latest measurement using eRASS1 clusters than almost all previous estimates in the literature. Finally, we tested the radial acceleration relation established in disk galaxies. We confirm the missing baryon problem in the inner region of galaxy clusters using three independent mass proxies for the first time. As ongoing and planned surveys are providing deeper X-ray observations and more galaxy spectra for cluster members, we expect to extend the study to cluster outskirts in the near future.
{"title":"Gas thermodynamics meets galaxy kinematics: Joint mass measurements for eROSITA galaxy clusters","authors":"Pengfei Li, Ang Liu, Matthias Kluge, Johan Comparat, Yong Tian, Mariana P. Júlio, Marcel S. Pawlowski, Jeremy Sanders, Esra Bulbul, Axel Schwope, Vittorio Ghirardini, Xiaoyuan Zhang, Yunus Emre Bahar, Miriam E. Ramos-Ceja, Fabian Balzer, Christian Garrel","doi":"10.1051/0004-6361/202451266","DOIUrl":"https://doi.org/10.1051/0004-6361/202451266","url":null,"abstract":"The mass of galaxy clusters is a critical quantity for probing cluster cosmology and testing theories of gravity, but its measurement could be biased, given that assumptions are inevitable in order to make use of any approach. In this paper, we employ and compare two mass proxies for galaxy clusters: thermodynamics of the intracluster medium and kinematics of member galaxies. We selected 22 galaxy clusters from the cluster catalog in the first SRG/eROSITA All-Sky Survey (eRASS1) that have sufficient optical and near-infrared observations. We generated multiband images in the energy range of (0.3, 7) keV for each cluster, and derived their temperature profiles, gas mass profiles, and hydrostatic mass profiles using a parametric approach that does not assume dark matter halo models. With spectroscopically confirmed member galaxies collected from multiple surveys, we numerically solved the spherical Jeans equation for their dynamical mass profiles. Our results quantify the correlation between dynamical mass and the line-of-sight velocity dispersion, log <i>M<i/><sub>dyn<sub/> = (1.296 ± 0.001)log(<i>σ<i/><sub>los<sub/><sup>2<sup/><i>r<i/><sub>proj<sub/>/<i>G<i/>)−(3.87 ± 0.23), with a root mean square (rms) scatter of 0.14 dex. We find that the two mass proxies lead to roughly the same total mass, with no observed systematic bias. As such, the <i>σ<i/><sub>8<sub/> tension is not specific to hydrostatic mass or weak lensing shears, but also appears with galaxy kinematics. Interestingly, the hydrostatic-to-dynamical mass ratios decrease slightly toward large radii, which could possibly be evidence for accreting galaxies in the outskirts. We also compared our hydrostatic masses with the latest weak lensing masses inferred with scaling relations. The comparison shows that the weak lensing mass is significantly higher than our hydrostatic mass by ∼110%. This might explain the significantly larger value of <i>σ<i/><sub>8<sub/> from the latest measurement using eRASS1 clusters than almost all previous estimates in the literature. Finally, we tested the radial acceleration relation established in disk galaxies. We confirm the missing baryon problem in the inner region of galaxy clusters using three independent mass proxies for the first time. As ongoing and planned surveys are providing deeper X-ray observations and more galaxy spectra for cluster members, we expect to extend the study to cluster outskirts in the near future.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"21 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202348274
Eduárd Illés, Dániel Jánosi, Tamás Kovács
Context. Time-dependent potentials are common in galactic systems that undergo significant evolution, interactions, or encounters with other galaxies, or when there are dynamic processes such as star formation and merging events. Recent studies show that an ensemble approach along with the so-called snapshot framework in the theory of dynamical systems provide a powerful tool to analyze the time-dependent dynamics.Aims. In this work, we aim to explore and quantify the phase space structure and dynamical complexity in time-dependent galactic potentials consisting of multiple components.Methods. We applied the classical method of Poincaré surface of sections to analyze the phase space structure in a chaotic Hamiltonian system subjected to parameter drift. This, however, makes sense only when the evolution of a large ensemble of initial conditions is followed. Numerical simulations explore the phase space structure of such ensembles while the system undergoes a continuous parameter change. The pair-wise average distance of ensemble members allowed us to define a generalized Lyapunov exponent, which might also be time-dependent, to describe the system stability.Results. We provide a comprehensive dynamical analysis of the system under circumstances where linear mass transfer occurs between the disk and bulge components of the model.
{"title":"Orbital dynamics in galactic potentials under mass transfer","authors":"Eduárd Illés, Dániel Jánosi, Tamás Kovács","doi":"10.1051/0004-6361/202348274","DOIUrl":"https://doi.org/10.1051/0004-6361/202348274","url":null,"abstract":"<i>Context.<i/> Time-dependent potentials are common in galactic systems that undergo significant evolution, interactions, or encounters with other galaxies, or when there are dynamic processes such as star formation and merging events. Recent studies show that an ensemble approach along with the so-called snapshot framework in the theory of dynamical systems provide a powerful tool to analyze the time-dependent dynamics.<i>Aims.<i/> In this work, we aim to explore and quantify the phase space structure and dynamical complexity in time-dependent galactic potentials consisting of multiple components.<i>Methods.<i/> We applied the classical method of Poincaré surface of sections to analyze the phase space structure in a chaotic Hamiltonian system subjected to parameter drift. This, however, makes sense only when the evolution of a large ensemble of initial conditions is followed. Numerical simulations explore the phase space structure of such ensembles while the system undergoes a continuous parameter change. The pair-wise average distance of ensemble members allowed us to define a generalized Lyapunov exponent, which might also be time-dependent, to describe the system stability.<i>Results.<i/> We provide a comprehensive dynamical analysis of the system under circumstances where linear mass transfer occurs between the disk and bulge components of the model.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"30 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142840857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202450809
M. Argudo-Fernández, C. Gómez Hernández, S. Verley, A. Zurita, S. Duarte Puertas, G. Blázquez Calero, J. Domínguez-Gómez, D. Espada, E. Florido, I. Pérez, L. Sánchez-Menguiano
Context. Among the largest structures in which matter is distributed in the Universe, we find cosmic voids, which are large, under-dense regions almost devoid of galaxies. The study of these structures and the galaxies that inhabit them, the void galaxies, provides key information for understanding galaxy evolution.Aims. In this work we investigate the effects of the environment on the evolution of void galaxies. In particular, we study their morphology and explore its dependence on the location within the void where the galaxies reside, as well as on the properties of the void, such as its size and the galaxy number density.Methods. The sample of void galaxies that we use in this study is based on the catalogue of cosmic voids and void galaxies in the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). As we are interested in studying the morphology of void galaxies, we select galaxies in the redshift range of 0.005 ≤ z ≤ 0.080, and use the public galaxy morphologies of the SDSS sample together with deep learning algorithms to divide the sample into early- and late-type void galaxies. We analyse the fractions of galaxies of each morphological type as a function of the void-centric distance, the size of the voids, and the density of galaxies in each void.Results. There is a higher abundance of late-type galaxies with respect to early-type galaxies within voids, which remains nearly constant from the inner to the outer part of the voids. We do not find any dependence of the fraction of early- and late-type galaxies on void size or on the number-density of galaxies in the voids.Conclusions. Galaxies in voids follow the morphology–density relation, in the sense that the majority of the galaxies in voids (the most under-dense large-scale environments) are late-type galaxies. However, we find no difference between voids with lower or higher volume number-density of galaxies: the fractions of early- and late-type galaxies do not depend on the density of the voids. The physical processes responsible for the evolution from late towards earlier types (such as external environmental quenching) are not sufficiently effective in voids or are so slow (internal secular quenching) that their contributions do not appear in the morphology–density relation.
{"title":"Morphologies of galaxies within voids","authors":"M. Argudo-Fernández, C. Gómez Hernández, S. Verley, A. Zurita, S. Duarte Puertas, G. Blázquez Calero, J. Domínguez-Gómez, D. Espada, E. Florido, I. Pérez, L. Sánchez-Menguiano","doi":"10.1051/0004-6361/202450809","DOIUrl":"https://doi.org/10.1051/0004-6361/202450809","url":null,"abstract":"<i>Context.<i/> Among the largest structures in which matter is distributed in the Universe, we find cosmic voids, which are large, under-dense regions almost devoid of galaxies. The study of these structures and the galaxies that inhabit them, the void galaxies, provides key information for understanding galaxy evolution.<i>Aims.<i/> In this work we investigate the effects of the environment on the evolution of void galaxies. In particular, we study their morphology and explore its dependence on the location within the void where the galaxies reside, as well as on the properties of the void, such as its size and the galaxy number density.<i>Methods.<i/> The sample of void galaxies that we use in this study is based on the catalogue of cosmic voids and void galaxies in the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). As we are interested in studying the morphology of void galaxies, we select galaxies in the redshift range of 0.005 ≤ <i>z<i/> ≤ 0.080, and use the public galaxy morphologies of the SDSS sample together with deep learning algorithms to divide the sample into early- and late-type void galaxies. We analyse the fractions of galaxies of each morphological type as a function of the void-centric distance, the size of the voids, and the density of galaxies in each void.<i>Results.<i/> There is a higher abundance of late-type galaxies with respect to early-type galaxies within voids, which remains nearly constant from the inner to the outer part of the voids. We do not find any dependence of the fraction of early- and late-type galaxies on void size or on the number-density of galaxies in the voids.<i>Conclusions.<i/> Galaxies in voids follow the morphology–density relation, in the sense that the majority of the galaxies in voids (the most under-dense large-scale environments) are late-type galaxies. However, we find no difference between voids with lower or higher volume number-density of galaxies: the fractions of early- and late-type galaxies do not depend on the density of the voids. The physical processes responsible for the evolution from late towards earlier types (such as external environmental quenching) are not sufficiently effective in voids or are so slow (internal secular quenching) that their contributions do not appear in the morphology–density relation.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"49 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142840859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202452075
S. Hümmerich, K. Bernhard, E. Paunzen
Context. The magnetic chemically peculiar Ap stars exhibit an extreme spread of rotational velocities, the cause of which is not clearly understood. Ap stars with rotation periods of 50 days or longer are know as super-slowly rotating Ap (ssrAp) stars. Photometrically variable Ap stars are commonly termed α2 Canum Venaticorum (ACV) variables.Aims. Our study aims to enlarge the sample of known ssrAp stars using data from the Zwicky Transient Facility (ZTF) survey to enable more robust and significant statistical studies of these objects.Methods. Using selection criteria based on the known characteristics of ACV variables, candidate stars were gleaned from the ZTF catalogues of periodic and suspected variable stars and from ZTF raw data. ssrAp stars were identified from this list via their characteristic photometric properties, Δa photometry, and spectral classification.Results. The final sample consists of 70 new ssrAp stars, which mostly exhibit rotation periods of between 50 and 200 days. The object with the longest period has a rotation period of 2551.7 days. We present astrophysical parameters and a Hertzsprung-Russell diagram for the complete sample of known ssrAp stars. With very few exceptions, the ssrAp stars are grouped in the middle of the main sequence with ages in excess of 150 Myr. ZTF J021309.72+582827.7 was identified as a possible binary star harbouring an Ap star and a cool component, possibly shrouded in dust.Conclusions. With our study, we enlarge the sample of known ssrAp stars by about 150%, paving the way for more in-depth statistical studies.
{"title":"A new sample of super-slowly rotating Ap (ssrAp) stars from the Zwicky Transient Facility survey","authors":"S. Hümmerich, K. Bernhard, E. Paunzen","doi":"10.1051/0004-6361/202452075","DOIUrl":"https://doi.org/10.1051/0004-6361/202452075","url":null,"abstract":"<i>Context<i/>. The magnetic chemically peculiar Ap stars exhibit an extreme spread of rotational velocities, the cause of which is not clearly understood. Ap stars with rotation periods of 50 days or longer are know as super-slowly rotating Ap (ssrAp) stars. Photometrically variable Ap stars are commonly termed <i>α<i/><sup>2<sup/> Canum Venaticorum (ACV) variables.<i>Aims<i/>. Our study aims to enlarge the sample of known ssrAp stars using data from the <i>Zwicky<i/> Transient Facility (ZTF) survey to enable more robust and significant statistical studies of these objects.<i>Methods<i/>. Using selection criteria based on the known characteristics of ACV variables, candidate stars were gleaned from the ZTF catalogues of periodic and suspected variable stars and from ZTF raw data. ssrAp stars were identified from this list via their characteristic photometric properties, Δa photometry, and spectral classification.<i>Results<i/>. The final sample consists of 70 new ssrAp stars, which mostly exhibit rotation periods of between 50 and 200 days. The object with the longest period has a rotation period of 2551.7 days. We present astrophysical parameters and a Hertzsprung-Russell diagram for the complete sample of known ssrAp stars. With very few exceptions, the ssrAp stars are grouped in the middle of the main sequence with ages in excess of 150 Myr. ZTF J021309.72+582827.7 was identified as a possible binary star harbouring an Ap star and a cool component, possibly shrouded in dust.<i>Conclusions<i/>. With our study, we enlarge the sample of known ssrAp stars by about 150%, paving the way for more in-depth statistical studies.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"17 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202451017
Bertram Bitsch, Andre Izidoro
Migration is a key ingredient in the formation of close-in super-Earth and mini-Neptune systems. The migration rate sets the resonances in which planets can be trapped, where slower migration rates result in wider resonance configurations compared to higher migration rates. We investigate the influence of different migration rates – set by disc viscosity – on the structure of multi-planet systems via N-body simulations, where planets grow via pebble accretion. Planets in low-viscosity environments migrate slower due to partial gap opening compared to planets forming in high-viscosity environments. Consequently, systems formed in low-viscosity environments tend to have planets trapped in wider resonant configurations (typically 4:3, 3:2, and 2:1 configurations). Simulations of high-viscosity discs mostly produce planetary systems in 7:6, 5:4, and 4:3 resonances. After the gas disc dissipates, the damping forces of eccentricity and inclination cease to exist and the systems can undergo instities on timescales of a few tens of millions of years, rearranging their configurations and breaking the resonance chains. We show that low-viscosity discs naturally account for the configurations of resonant chains, such as Trappist-1, TOI-178, and Kepler-223, unlike high-viscosity simulations, which produce chains that are more compact. Following dispersal of the gas disc, about 95% of our low-viscosity resonant chains became unstable, experiencing a phase of giant impacts. Dynamical instabilities in our low-viscosity simulations are more violent than those of high-viscosity simulations due to the effects of leftover external perturbers (P>200 days). About 50% of our final systems end with no planets within 200 days, while all our systems harbour remaining outer planets. We speculate that this process could be qualitatively consistent with the lack of inner planets in a large fraction of the Sun-like stars. Systems produced in low-viscosity simulations alone do not match the overall period ratio distribution of observations, but give a better match to the period distributions of chains, which may suggest that systems of super-Earths and mini-Neptunes form in natal discs with a diversity of viscosities.
{"title":"Diversity of disc viscosities can explain the period ratios of resonant and non-resonant systems of hot super-Earths and mini-Neptunes","authors":"Bertram Bitsch, Andre Izidoro","doi":"10.1051/0004-6361/202451017","DOIUrl":"https://doi.org/10.1051/0004-6361/202451017","url":null,"abstract":"Migration is a key ingredient in the formation of close-in super-Earth and mini-Neptune systems. The migration rate sets the resonances in which planets can be trapped, where slower migration rates result in wider resonance configurations compared to higher migration rates. We investigate the influence of different migration rates – set by disc viscosity – on the structure of multi-planet systems via <i>N<i/>-body simulations, where planets grow via pebble accretion. Planets in low-viscosity environments migrate slower due to partial gap opening compared to planets forming in high-viscosity environments. Consequently, systems formed in low-viscosity environments tend to have planets trapped in wider resonant configurations (typically 4:3, 3:2, and 2:1 configurations). Simulations of high-viscosity discs mostly produce planetary systems in 7:6, 5:4, and 4:3 resonances. After the gas disc dissipates, the damping forces of eccentricity and inclination cease to exist and the systems can undergo instities on timescales of a few tens of millions of years, rearranging their configurations and breaking the resonance chains. We show that low-viscosity discs naturally account for the configurations of resonant chains, such as Trappist-1, TOI-178, and Kepler-223, unlike high-viscosity simulations, which produce chains that are more compact. Following dispersal of the gas disc, about 95% of our low-viscosity resonant chains became unstable, experiencing a phase of giant impacts. Dynamical instabilities in our low-viscosity simulations are more violent than those of high-viscosity simulations due to the effects of leftover external perturbers (P>200 days). About 50% of our final systems end with no planets within 200 days, while all our systems harbour remaining outer planets. We speculate that this process could be qualitatively consistent with the lack of inner planets in a large fraction of the Sun-like stars. Systems produced in low-viscosity simulations alone do not match the overall period ratio distribution of observations, but give a better match to the period distributions of chains, which may suggest that systems of super-Earths and mini-Neptunes form in natal discs with a diversity of viscosities.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"90 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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