Pub Date : 2024-10-14DOI: 10.3847/1538-4357/ad70ae
Eduard Salvador-Solé and Alberto Manrique
The Press–Schechter (PS) and excursion set (ES) models of structure formation fail in reproducing the halo bias found in simulations, while the ES-peaks' formalism built in the peak model reproduces it only at high masses and does not address in a fully satisfactory manner peak nesting, and the mass and time of ellipsoidal collapse of triaxial peaks in the Gaussian-smoothed density field. Here, we apply the confluent system of peak trajectories formalism fixing all these issues from first principles and with no free parameters to infer the Lagrangian local peak bias parameters, which adopt very simple analytic expressions similar to those found in the PS and ES models. The predicted Eulerian linear halo bias recovers the results of simulations. More specifically, we show that the only small departure observed at intermediate and low masses can be due to the spurious halo splitting and grouping caused by the spherical overdensity halo-finding algorithm used in simulations.
结构形成的 Press-Schechter （PS）和 excursion set （ES）模型无法再现模拟中发现的晕偏差，而建立在峰值模型中的 ES-peaks 形式主义只能在高质量下再现晕偏差，并且不能以完全令人满意的方式解决峰值嵌套问题，以及高斯平滑密度场中三轴峰值的椭圆坍缩质量和时间问题。在这里，我们应用峰轨迹汇合系统形式主义，从第一原理上解决了所有这些问题，并且没有自由参数，从而推断出了拉格朗日局部峰偏置参数，这些参数采用了非常简单的解析表达式，类似于 PS 和 ES 模型中的表达式。预测的欧拉线性光晕偏差恢复了模拟结果。更具体地说，我们表明在中低质量下观测到的唯一小偏离可能是由于模拟中使用的球面过密度光晕寻找算法造成的虚假光晕分裂和分组。
{"title":"Halo Bias in the Peak Model: A First-principles Nonparametric Approach","authors":"Eduard Salvador-Solé and Alberto Manrique","doi":"10.3847/1538-4357/ad70ae","DOIUrl":"https://doi.org/10.3847/1538-4357/ad70ae","url":null,"abstract":"The Press–Schechter (PS) and excursion set (ES) models of structure formation fail in reproducing the halo bias found in simulations, while the ES-peaks' formalism built in the peak model reproduces it only at high masses and does not address in a fully satisfactory manner peak nesting, and the mass and time of ellipsoidal collapse of triaxial peaks in the Gaussian-smoothed density field. Here, we apply the confluent system of peak trajectories formalism fixing all these issues from first principles and with no free parameters to infer the Lagrangian local peak bias parameters, which adopt very simple analytic expressions similar to those found in the PS and ES models. The predicted Eulerian linear halo bias recovers the results of simulations. More specifically, we show that the only small departure observed at intermediate and low masses can be due to the spurious halo splitting and grouping caused by the spherical overdensity halo-finding algorithm used in simulations.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.3847/1538-4357/ad6a5f
Xianjin Shen, Hong-Li Liu, Zhiyuan Ren, Anandmayee Tej, Di Li, Hauyu Baobab Liu, Gary A. Fuller, Jinjin Xie, Sihan Jiao, Aiyuan Yang, Patrick M. Koch, Fengwei Xu, Patricio Sanhueza, Pham Ngoc Diep, Nicolas Peretto, R. K. Yadav, Busaba H. Kramer, Koichiro Sugiyama, Mark G. Rawlings, Chang Won Lee, Ken’ichi Tatematsu, Daniel Harsono, David Eden, Woojin Kwon, Chao-Wei Tsai, Glenn J. White, Kee-Tae Kim, Tie Liu, Ke Wang, Siju Zhang, Wenyu Jiao, Dongting Yang, Swagat R. Das, Jingwen Wu and Chen Wang
Filaments are believed to play a key role in high-mass star formation. We present a systematic study of the filaments and their hosting clumps in the G35 molecular complex using James Clerk Maxwell Telescope SCUBA-2 850 μm continuum data. We identified five clouds in the complex and 91 filaments within them, some of which form 10 hub–filament systems (HFSs), each with at least three hub-composing filaments. We also compiled a catalog of 350 dense clumps, 183 of which are associated with the filaments. We investigated the physical properties of the filaments and clumps, such as mass, density, and size, and their relation to star formation. We find that the global mass–length trend of the filaments is consistent with a turbulent origin, while the hub-composing filaments of high line masses (ml > 230 M⊙ pc−1) in HFSs deviate from this relation, possibly due to feedback from massive star formation. We also find that the most massive and densest clumps (R > 0.2 pc, M > 35 M⊙, Σ > 0.05 g cm−2) are located in the filaments and in the hubs of HFSs, with the latter bearing a higher probability of the occurrence of high-mass star-forming signatures, highlighting the preferential sites of HFSs for high-mass star formation. We do not find significant variation in the clump mass surface density across different evolutionary environments of the clouds, which may reflect the balance between mass accretion and stellar feedback.
{"title":"JCMT 850 μm Continuum Observations of Density Structures in the G35 Molecular Complex","authors":"Xianjin Shen, Hong-Li Liu, Zhiyuan Ren, Anandmayee Tej, Di Li, Hauyu Baobab Liu, Gary A. Fuller, Jinjin Xie, Sihan Jiao, Aiyuan Yang, Patrick M. Koch, Fengwei Xu, Patricio Sanhueza, Pham Ngoc Diep, Nicolas Peretto, R. K. Yadav, Busaba H. Kramer, Koichiro Sugiyama, Mark G. Rawlings, Chang Won Lee, Ken’ichi Tatematsu, Daniel Harsono, David Eden, Woojin Kwon, Chao-Wei Tsai, Glenn J. White, Kee-Tae Kim, Tie Liu, Ke Wang, Siju Zhang, Wenyu Jiao, Dongting Yang, Swagat R. Das, Jingwen Wu and Chen Wang","doi":"10.3847/1538-4357/ad6a5f","DOIUrl":"https://doi.org/10.3847/1538-4357/ad6a5f","url":null,"abstract":"Filaments are believed to play a key role in high-mass star formation. We present a systematic study of the filaments and their hosting clumps in the G35 molecular complex using James Clerk Maxwell Telescope SCUBA-2 850 μm continuum data. We identified five clouds in the complex and 91 filaments within them, some of which form 10 hub–filament systems (HFSs), each with at least three hub-composing filaments. We also compiled a catalog of 350 dense clumps, 183 of which are associated with the filaments. We investigated the physical properties of the filaments and clumps, such as mass, density, and size, and their relation to star formation. We find that the global mass–length trend of the filaments is consistent with a turbulent origin, while the hub-composing filaments of high line masses (ml > 230 M⊙ pc−1) in HFSs deviate from this relation, possibly due to feedback from massive star formation. We also find that the most massive and densest clumps (R > 0.2 pc, M > 35 M⊙, Σ > 0.05 g cm−2) are located in the filaments and in the hubs of HFSs, with the latter bearing a higher probability of the occurrence of high-mass star-forming signatures, highlighting the preferential sites of HFSs for high-mass star formation. We do not find significant variation in the clump mass surface density across different evolutionary environments of the clouds, which may reflect the balance between mass accretion and stellar feedback.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.3847/1538-4357/ad7503
Shao-Peng Tang, Yong-Jia Huang, Ming-Zhe Han and Yi-Zhong Fan
Very recently, it has been shown that there is an upper bound on the squared sound speed of nuclear matter from the transport, which reads . In this work, we demonstrate that this upper bound is corroborated by the reconstructed equation of state (EOS; modeled with a nonparametric method) for ultradense matter. The reconstruction integrates multimessenger observation for neutron stars, in particular, the latest radius measurements for PSR J0437–4715 ( km), PSR J0030+0451 ( km, in the ST+PDT model), and PSR J0740+6620 ( km) by NICER have been adopted. The result shows in all cases, the upper limit for EOS will naturally yield the properties of matter near the center of the massive neutron star consistent with the causality-driven constraint from pQCD, where, in practice, the density in implementing the pQCD likelihood (nL) is applied at (where is the nuclear saturation density). We also note that there is a strong correlation for the maximum cs2 with nL, and is somehow violated when nL = nc,TOV. The result indicates that a higher nL, even considering the uncertainties from statistics, is more natural. Moreover, the remarkable agreement between the outcomes derived from these two distinct and independent constraints (i.e., the transport calculation and pQCD boundary) lends strong support to their validity. In addition, the latest joint constraint for R1.4, R2.0, R1.4 − R2.0, and MTOV are km, km, km, and (at 90% credible level), respectively.
{"title":"Upper Limit of Sound Speed in Nuclear Matter: A Harmonious Interplay of Transport Calculation and Perturbative Quantum Chromodynamic Constraint","authors":"Shao-Peng Tang, Yong-Jia Huang, Ming-Zhe Han and Yi-Zhong Fan","doi":"10.3847/1538-4357/ad7503","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7503","url":null,"abstract":"Very recently, it has been shown that there is an upper bound on the squared sound speed of nuclear matter from the transport, which reads . In this work, we demonstrate that this upper bound is corroborated by the reconstructed equation of state (EOS; modeled with a nonparametric method) for ultradense matter. The reconstruction integrates multimessenger observation for neutron stars, in particular, the latest radius measurements for PSR J0437–4715 ( km), PSR J0030+0451 ( km, in the ST+PDT model), and PSR J0740+6620 ( km) by NICER have been adopted. The result shows in all cases, the upper limit for EOS will naturally yield the properties of matter near the center of the massive neutron star consistent with the causality-driven constraint from pQCD, where, in practice, the density in implementing the pQCD likelihood (nL) is applied at (where is the nuclear saturation density). We also note that there is a strong correlation for the maximum cs2 with nL, and is somehow violated when nL = nc,TOV. The result indicates that a higher nL, even considering the uncertainties from statistics, is more natural. Moreover, the remarkable agreement between the outcomes derived from these two distinct and independent constraints (i.e., the transport calculation and pQCD boundary) lends strong support to their validity. In addition, the latest joint constraint for R1.4, R2.0, R1.4 − R2.0, and MTOV are km, km, km, and (at 90% credible level), respectively.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The star formation rate (SFR) is a fundamental parameter for describing galaxies and inferring their evolutionary course. H ii regions yield the best measure of instantaneous SFR in galaxies, although the derived SFR can have large uncertainties depending on tracers and assumptions. We present an SFR calibration for the entire molecular gas disk of the nearby Seyfert galaxy NGC 1068, based on our new high-sensitivity Atacama Large Millimeter/submillimeter Array 100 GHz continuum data at 55 pc (= 0.″8) resolution in combination with the Hubble Space Telescope Paα line data. In this calibration, we account for the spatial variations of dust extinction, electron temperature of H ii regions, AGN contamination, and diffuse ionized gas (DIG) based on publicly available multiwavelength data. Especially, given the extended nature and the possible nonnegligible contribution to the total SFR, a careful consideration of DIG is essential. With a cross-calibration between two corrected ionized gas tracers (free–free continuum and Paα), the total SFR of the NGC 1068 disk is estimated to be 3.2 ± 0.5 M⊙ yr−1, one-third of the SFR without accounting for DIG (9.1 ± 1.4 M⊙ yr−1). We confirmed a high SFR around the southern bar end and the corotation radius, which is consistent with the previous SFR measurements. In addition, our total SFR exceeds the total SFR based on 8 μm dust emission by a factor of 1.5. We attribute this discrepancy to the differences in the young stars at different stages of evolution traced by each tracer and their respective timescales. This study provides an example to address the various uncertainties in conventional SFR measurements and their potential to lead to significant SFR miscalculations.
{"title":"Measuring 60 pc-scale Star Formation Rate of the Nearby Seyfert Galaxy NGC 1068 with ALMA, HST, VLT/MUSE, and VLA","authors":"Yuzuki Nagashima, Toshiki Saito, Soh Ikarashi, Shuro Takano, Kouichiro Nakanishi, Nanase Harada, Taku Nakajima, Akio Taniguchi, Tomoka Tosaki and Kazuharu Bamba","doi":"10.3847/1538-4357/ad6312","DOIUrl":"https://doi.org/10.3847/1538-4357/ad6312","url":null,"abstract":"The star formation rate (SFR) is a fundamental parameter for describing galaxies and inferring their evolutionary course. H ii regions yield the best measure of instantaneous SFR in galaxies, although the derived SFR can have large uncertainties depending on tracers and assumptions. We present an SFR calibration for the entire molecular gas disk of the nearby Seyfert galaxy NGC 1068, based on our new high-sensitivity Atacama Large Millimeter/submillimeter Array 100 GHz continuum data at 55 pc (= 0.″8) resolution in combination with the Hubble Space Telescope Paα line data. In this calibration, we account for the spatial variations of dust extinction, electron temperature of H ii regions, AGN contamination, and diffuse ionized gas (DIG) based on publicly available multiwavelength data. Especially, given the extended nature and the possible nonnegligible contribution to the total SFR, a careful consideration of DIG is essential. With a cross-calibration between two corrected ionized gas tracers (free–free continuum and Paα), the total SFR of the NGC 1068 disk is estimated to be 3.2 ± 0.5 M⊙ yr−1, one-third of the SFR without accounting for DIG (9.1 ± 1.4 M⊙ yr−1). We confirmed a high SFR around the southern bar end and the corotation radius, which is consistent with the previous SFR measurements. In addition, our total SFR exceeds the total SFR based on 8 μm dust emission by a factor of 1.5. We attribute this discrepancy to the differences in the young stars at different stages of evolution traced by each tracer and their respective timescales. This study provides an example to address the various uncertainties in conventional SFR measurements and their potential to lead to significant SFR miscalculations.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.3847/1538-4357/ad713c
Samir Kušmić, Kristian Finlator, Ezra Huscher and Maya Steen
How do galaxies of different luminosities contribute to the metal absorber populations of varying species and strength? We present our analysis of the predicted metal contributions from galaxies as observed in quasar absorption line spectra during the end of the epoch of reionization (10 ≥ z ≥ 5.5). This was done by implementing on-the-fly particle tracking into the latest Technicolor Dawn simulation and then linking C ii, C iv, Si ii, Si iv, O i, and Mg ii absorbers to host galaxies in postprocessing. We define the host galaxy luminosity distribution (HGLD) as the rest-frame ultraviolet luminosity distribution of galaxies contributing ions to an absorber, weighted by the fractional contribution, and compute its dependence on ion and absorber strength. The HGLD shape is predicted to be indistinguishable from the field luminosity function, indicating that there is no relationship between the absorber strength or ion and the luminosity of the dominant contributing galaxy. Switching from galaxy luminosity to stellar mass, the predicted host galaxy mass distributions (HGMDs) indicate that more-massive galaxies contribute a higher fraction of metal ions to absorbers of each species, with the HGMDs of stronger absorbers extending out to higher masses. We conclude that the fraction of absorbing metal ions contributed by galaxies increases weakly with stellar mass, but the scatter in luminosity at fixed stellar mass obscures this relationship. For the same reason, we predict that observational analyses of the absorber–galaxy relationship will uncover stronger trends with stellar mass than with luminosity.
{"title":"Galaxy–Absorber Association in the Epoch of Reionization: Galactic Population Luminosity Distribution for Different Absorbers at 10 ≥ z ≥ 5.5","authors":"Samir Kušmić, Kristian Finlator, Ezra Huscher and Maya Steen","doi":"10.3847/1538-4357/ad713c","DOIUrl":"https://doi.org/10.3847/1538-4357/ad713c","url":null,"abstract":"How do galaxies of different luminosities contribute to the metal absorber populations of varying species and strength? We present our analysis of the predicted metal contributions from galaxies as observed in quasar absorption line spectra during the end of the epoch of reionization (10 ≥ z ≥ 5.5). This was done by implementing on-the-fly particle tracking into the latest Technicolor Dawn simulation and then linking C ii, C iv, Si ii, Si iv, O i, and Mg ii absorbers to host galaxies in postprocessing. We define the host galaxy luminosity distribution (HGLD) as the rest-frame ultraviolet luminosity distribution of galaxies contributing ions to an absorber, weighted by the fractional contribution, and compute its dependence on ion and absorber strength. The HGLD shape is predicted to be indistinguishable from the field luminosity function, indicating that there is no relationship between the absorber strength or ion and the luminosity of the dominant contributing galaxy. Switching from galaxy luminosity to stellar mass, the predicted host galaxy mass distributions (HGMDs) indicate that more-massive galaxies contribute a higher fraction of metal ions to absorbers of each species, with the HGMDs of stronger absorbers extending out to higher masses. We conclude that the fraction of absorbing metal ions contributed by galaxies increases weakly with stellar mass, but the scatter in luminosity at fixed stellar mass obscures this relationship. For the same reason, we predict that observational analyses of the absorber–galaxy relationship will uncover stronger trends with stellar mass than with luminosity.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.3847/1538-4357/ad6e83
Elena Bellomi, John A. ZuHone, Rainer Weinberger, Stephen A. Walker, Irina Zhuravleva, Mateusz Ruszkowski and Maxim Markevitch
The intracluster medium of the Perseus Cluster exhibits spiral-shaped X-ray surface brightness discontinuities known as “cold fronts,” which simulations indicate are caused by the sloshing motion of the gas after the passage of a subcluster. Recent observations of Perseus have shown that these fronts extend to large radii. In this work, we present simulations of the formation of sloshing cold fronts in Perseus using the AREPO magnetohydrodynamics code, to produce a plausible scenario for the formation of the large front at a radius of 700 kpc. Our simulations explore a range of subcluster masses and impact parameters. We find that low-mass subclusters cannot generate a cold front that can propagate to such a large radius, and that small impact parameters create too much turbulence, which leads to the disruption of the cold front before it reaches such a large distance. Subclusters that make only one core passage produce a stable initial front that expands to large radii, but without a second core passage of the subcluster, other fronts are not created at a later time in the core region. We find a small range of simulations with subclusters with mass ratios of R ∼ 1:5 and an initial impact parameter of θ ∼ 20°–25° that not only produce the large cold front but a second set in the core region at later times. These simulations indicate that the “ancient” cold front is ∼6–8.5 Gyr old. For the simulations providing the closest match with observations, the subcluster has completely merged into the main cluster.
英仙座星团的星团内介质呈现出螺旋形的 X 射线表面亮度不连续现象，这种现象被称为 "冷锋"，模拟结果表明它是由子星团通过后气体的滑动运动引起的。最近对英仙座的观测表明，这些冷锋的半径很大。在这项工作中，我们使用 AREPO 磁流体力学代码模拟了英仙座中荡漾冷锋的形成，为半径为 700 kpc 的大锋面的形成提出了一个合理的方案。我们的模拟探索了一系列亚星团质量和撞击参数。我们发现，低质量的亚星团无法产生能够传播到如此大半径的冷锋，而小的撞击参数会产生过多的湍流，导致冷锋在到达如此大的距离之前就被破坏。只通过一次核心的子团会产生一个稳定的初始锋面，并扩展到较大的半径，但如果没有子团的第二次核心通过，就不会在以后的核心区域产生其他锋面。我们发现在质量比为 R ∼ 1:5 和初始撞击参数为 θ ∼ 20°-25°的亚星团的小范围模拟中，不仅产生了大的冷锋，而且在后来的时间里在核心区域产生了第二组冷锋。这些模拟结果表明，"古老的 "冷锋的年龄为 ∼6-8.5 Gyr。在与观测结果最接近的模拟中，子星团完全并入了主星团。
{"title":"On the Origin of the Ancient, Large-scale Cold Front in the Perseus Cluster of Galaxies","authors":"Elena Bellomi, John A. ZuHone, Rainer Weinberger, Stephen A. Walker, Irina Zhuravleva, Mateusz Ruszkowski and Maxim Markevitch","doi":"10.3847/1538-4357/ad6e83","DOIUrl":"https://doi.org/10.3847/1538-4357/ad6e83","url":null,"abstract":"The intracluster medium of the Perseus Cluster exhibits spiral-shaped X-ray surface brightness discontinuities known as “cold fronts,” which simulations indicate are caused by the sloshing motion of the gas after the passage of a subcluster. Recent observations of Perseus have shown that these fronts extend to large radii. In this work, we present simulations of the formation of sloshing cold fronts in Perseus using the AREPO magnetohydrodynamics code, to produce a plausible scenario for the formation of the large front at a radius of 700 kpc. Our simulations explore a range of subcluster masses and impact parameters. We find that low-mass subclusters cannot generate a cold front that can propagate to such a large radius, and that small impact parameters create too much turbulence, which leads to the disruption of the cold front before it reaches such a large distance. Subclusters that make only one core passage produce a stable initial front that expands to large radii, but without a second core passage of the subcluster, other fronts are not created at a later time in the core region. We find a small range of simulations with subclusters with mass ratios of R ∼ 1:5 and an initial impact parameter of θ ∼ 20°–25° that not only produce the large cold front but a second set in the core region at later times. These simulations indicate that the “ancient” cold front is ∼6–8.5 Gyr old. For the simulations providing the closest match with observations, the subcluster has completely merged into the main cluster.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.3847/1538-4357/ad67e2
Bo Zhao, Ralph E. Pudritz, Rachel Pillsworth, Hector Robinson and James Wadsley
There is now abundant observational evidence that star formation is a highly dynamical process that connects filament hierarchies and supernova feedback from galaxy-scale kiloparsec filaments and superbubbles to giant molecular clouds (GMCs) on 100 pc scales and star clusters (1 pc). Here we present galactic multiscale MHD simulations that track the formation of structure from galactic down to subparsec scales in a magnetized, Milky Way–like galaxy undergoing supernova-driven feedback processes. We do this by adopting a novel zoom-in technique that follows the evolution of typical 3 kpc subregions without cutting out the surrounding galactic environment, allowing us to reach 0.28 pc resolution in the individual zoom-in regions. We find a wide range of morphologies and hierarchical structures, including superbubbles, turbulence, and kiloparsec atomic gas filaments hosting multiple GMC condensations that are often associated with superbubble compression, down to smaller-scale filamentary GMCs and star cluster regions within them. Gas accretion and compression ultimately drive filaments over a critical, scale-dependent line mass leading to gravitational instabilities that produce GMCs and clusters. In quieter regions, galactic shear can produce filamentary GMCs within flattened, rotating disklike structures on 100 pc scales. Strikingly, our simulations demonstrate the formation of helical magnetic fields associated with the formation of these disklike structures.
现在有大量的观测证据表明，恒星形成是一个高度动态的过程，它将星系尺度的千帕斯卡细丝和超级气泡到 100 pc 尺度的巨分子云（GMC）和星团（1 pc）的细丝层次结构和超新星反馈联系在一起。在这里，我们介绍银河系多尺度 MHD 模拟，在一个磁化的、类似银河系的、经历超新星驱动反馈过程的星系中，跟踪从银河系尺度到亚秒尺度的结构形成过程。为此，我们采用了一种新颖的放大技术，跟踪典型的 3 kpc 子区域的演变，而不切断周围的星系环境，从而使我们能够在单个放大区域达到 0.28 pc 的分辨率。我们发现了广泛的形态和层次结构，包括超泡泡、湍流、千波长原子气体丝（通常与超泡泡压缩有关）、小尺度丝状 GMC 和其中的星团区域。气体的吸积和压缩最终会驱使丝状气体超过临界线质量，从而导致引力不稳定性，产生 GMC 和星团。在较安静的区域，银河剪切会在 100 pc 尺度的扁平旋转盘状结构中产生丝状 GMC。令人震惊的是，我们的模拟证明了螺旋磁场的形成与这些盘状结构的形成有关。
{"title":"Filamentary Hierarchies and Superbubbles: Galactic Multiscale Magnetohydrodynamic Simulations of Giant Molecular Cloud to Star Cluster Formation","authors":"Bo Zhao, Ralph E. Pudritz, Rachel Pillsworth, Hector Robinson and James Wadsley","doi":"10.3847/1538-4357/ad67e2","DOIUrl":"https://doi.org/10.3847/1538-4357/ad67e2","url":null,"abstract":"There is now abundant observational evidence that star formation is a highly dynamical process that connects filament hierarchies and supernova feedback from galaxy-scale kiloparsec filaments and superbubbles to giant molecular clouds (GMCs) on 100 pc scales and star clusters (1 pc). Here we present galactic multiscale MHD simulations that track the formation of structure from galactic down to subparsec scales in a magnetized, Milky Way–like galaxy undergoing supernova-driven feedback processes. We do this by adopting a novel zoom-in technique that follows the evolution of typical 3 kpc subregions without cutting out the surrounding galactic environment, allowing us to reach 0.28 pc resolution in the individual zoom-in regions. We find a wide range of morphologies and hierarchical structures, including superbubbles, turbulence, and kiloparsec atomic gas filaments hosting multiple GMC condensations that are often associated with superbubble compression, down to smaller-scale filamentary GMCs and star cluster regions within them. Gas accretion and compression ultimately drive filaments over a critical, scale-dependent line mass leading to gravitational instabilities that produce GMCs and clusters. In quieter regions, galactic shear can produce filamentary GMCs within flattened, rotating disklike structures on 100 pc scales. Strikingly, our simulations demonstrate the formation of helical magnetic fields associated with the formation of these disklike structures.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.3847/1538-4357/ad7098
A. K. Maity, T. Inoue, Y. Fukui, L. K. Dewangan, H. Sano, R. I. Yamada, K. Tachihara, N. K. Bhadari and O. R. Jadhav
Massive star-forming regions (MSFRs) are commonly associated with hub-filament systems (HFSs) and sites of cloud–cloud collision (CCC). Recent observational studies of some MSFRs suggest a possible connection between CCC and the formation of HFSs. To understand this connection, we analyzed the magnetohydrodynamic simulation data from Inoue et al. This simulation involves the collision of a spherical turbulent molecular cloud with a plane-parallel sea of dense molecular gas at a relative velocity of about 10 km s−1. Following the collision, the turbulent and nonuniform cloud undergoes shock compression, rapidly developing filamentary structures within the compressed layer. We found that CCC can lead to the formation of HFSs, which is the combined effect of turbulence, shock compression, magnetic field, and gravity. The collision between the cloud components shapes the filaments into a cone and drives inward flows among them. These inward flows merge at the vertex of the cone, rapidly accumulating high-density gas, which can lead to the formation of massive star(s). The cone acts as a mass-collecting machine, involving a nongravitational early process of filament formation, followed by gravitational gas attraction to finalize the HFS. The gas distribution in the position–velocity (PV) and position–position spaces highlights the challenges in detecting two cloud components and confirming their complementary distribution if the colliding clouds have a large size difference. However, such CCC events can be confirmed by the PV diagrams presenting gas flow toward the vertex of the cone, which hosts gravitationally collapsing high-density objects, and by the magnetic field morphology curved toward the direction of the collision.
{"title":"Cloud–Cloud Collision: Formation of Hub-filament Systems and Associated Gas Kinematics. Mass-collecting Cone—A New Signature of Cloud–Cloud Collision","authors":"A. K. Maity, T. Inoue, Y. Fukui, L. K. Dewangan, H. Sano, R. I. Yamada, K. Tachihara, N. K. Bhadari and O. R. Jadhav","doi":"10.3847/1538-4357/ad7098","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7098","url":null,"abstract":"Massive star-forming regions (MSFRs) are commonly associated with hub-filament systems (HFSs) and sites of cloud–cloud collision (CCC). Recent observational studies of some MSFRs suggest a possible connection between CCC and the formation of HFSs. To understand this connection, we analyzed the magnetohydrodynamic simulation data from Inoue et al. This simulation involves the collision of a spherical turbulent molecular cloud with a plane-parallel sea of dense molecular gas at a relative velocity of about 10 km s−1. Following the collision, the turbulent and nonuniform cloud undergoes shock compression, rapidly developing filamentary structures within the compressed layer. We found that CCC can lead to the formation of HFSs, which is the combined effect of turbulence, shock compression, magnetic field, and gravity. The collision between the cloud components shapes the filaments into a cone and drives inward flows among them. These inward flows merge at the vertex of the cone, rapidly accumulating high-density gas, which can lead to the formation of massive star(s). The cone acts as a mass-collecting machine, involving a nongravitational early process of filament formation, followed by gravitational gas attraction to finalize the HFS. The gas distribution in the position–velocity (PV) and position–position spaces highlights the challenges in detecting two cloud components and confirming their complementary distribution if the colliding clouds have a large size difference. However, such CCC events can be confirmed by the PV diagrams presenting gas flow toward the vertex of the cone, which hosts gravitationally collapsing high-density objects, and by the magnetic field morphology curved toward the direction of the collision.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.3847/1538-4357/ad5bda
Mark J. Avara, Julian H. Krolik, Manuela Campanelli, Scott C. Noble, Dennis Bowen and Taeho Ryu
While supermassive binary black holes (SMBBHs) inspiral toward merger they may also accrete matter from a surrounding disk. To study the dynamics of this system requires simultaneously describing the evolving spacetime and the magnetized plasma. We present the first relativistic calculation simulating two equal-mass, nonspinning black holes as they inspiral from a 20 M (G = c = 1) initial separation almost to merger. Our results imply important observational consequences: for instance, the accretion rate onto the black holes first decreases and then plateaus, dropping by only a factor of ∼3 despite the rapid inspiral. An estimated bolometric light curve follows the same profile, suggesting some merging SMBBHs may be significantly luminous past the predicted circumbinary disk decoupling. The minidisks are nonstandard: Reynolds, not Maxwell, stresses dominate, and they oscillate between two states. In one part of the cycle, “sloshing” streams transfer mass between minidisks, carrying kinetic energy at a rate sometimes as high as the peak minidisk bolometric luminosity. We also discover that episodic accretion drives time-varying minidisk tilts. These complex dynamics all contribute to unique cyclical behavior in the light curves of late-time inspiraling SMBBHs. The poloidal magnetic flux on the black holes is roughly constant at a dimensionless level ϕ ∼ 2–3, but doubles just before merger; for significant black hole spin, this flux predicts powerful jets with variability driven by binary dynamics, another potentially unique electromagnetic signature. This simulation is the first to employ our multipatch infrastructure PatchworkMHD, decreasing the computational expense to ∼3% of conventional single-grid methods’ cost.
{"title":"Accretion onto a Supermassive Black Hole Binary before Merger","authors":"Mark J. Avara, Julian H. Krolik, Manuela Campanelli, Scott C. Noble, Dennis Bowen and Taeho Ryu","doi":"10.3847/1538-4357/ad5bda","DOIUrl":"https://doi.org/10.3847/1538-4357/ad5bda","url":null,"abstract":"While supermassive binary black holes (SMBBHs) inspiral toward merger they may also accrete matter from a surrounding disk. To study the dynamics of this system requires simultaneously describing the evolving spacetime and the magnetized plasma. We present the first relativistic calculation simulating two equal-mass, nonspinning black holes as they inspiral from a 20 M (G = c = 1) initial separation almost to merger. Our results imply important observational consequences: for instance, the accretion rate onto the black holes first decreases and then plateaus, dropping by only a factor of ∼3 despite the rapid inspiral. An estimated bolometric light curve follows the same profile, suggesting some merging SMBBHs may be significantly luminous past the predicted circumbinary disk decoupling. The minidisks are nonstandard: Reynolds, not Maxwell, stresses dominate, and they oscillate between two states. In one part of the cycle, “sloshing” streams transfer mass between minidisks, carrying kinetic energy at a rate sometimes as high as the peak minidisk bolometric luminosity. We also discover that episodic accretion drives time-varying minidisk tilts. These complex dynamics all contribute to unique cyclical behavior in the light curves of late-time inspiraling SMBBHs. The poloidal magnetic flux on the black holes is roughly constant at a dimensionless level ϕ ∼ 2–3, but doubles just before merger; for significant black hole spin, this flux predicts powerful jets with variability driven by binary dynamics, another potentially unique electromagnetic signature. This simulation is the first to employ our multipatch infrastructure PatchworkMHD, decreasing the computational expense to ∼3% of conventional single-grid methods’ cost.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-13DOI: 10.3847/1538-4357/ad71c9
Nicole M. Firestone, Eric Gawiser, Vandana Ramakrishnan, Kyoung-Soo Lee, Francisco Valdes, Changbom Park, Yujin Yang, Robin Ciardullo, María Celeste Artale, Barbara Benda, Adam Broussard, Lana Eid, Rameen Farooq, Caryl Gronwall, Lucia Guaita, Stephen Gwyn, Ho Seong Hwang, Sang Hyeok Im, Woong-Seob Jeong, Shreya Karthikeyan, Dustin Lang, Byeongha Moon, Nelson Padilla, Marcin Sawicki, Eunsuk Seo, Akriti Singh, Hyunmi Song and Paulina Troncoso Iribarren
Lyman-alpha-emitting galaxies (LAEs) are typically young, low-mass, star-forming galaxies with little extinction from interstellar dust. Their low dust attenuation allows their Lyα emission to shine brightly in spectroscopic and photometric observations, providing an observational window into the high-redshift Universe. Narrowband surveys reveal large, uniform samples of LAEs at specific redshifts that probe large-scale structure and the temporal evolution of galaxy properties. The One-hundred-deg2 DECam Imaging in Narrowbands (ODIN) utilizes three custom-made narrowband filters on the Dark Energy Camera (DECam) to discover LAEs at three equally spaced periods in cosmological history. In this paper, we introduce the hybrid-weighted double-broadband continuum estimation technique, which yields improved estimation of Lyα equivalent widths. Using this method, we discover 6032, 5691, and 4066 LAE candidates at z = 2.4, 3.1, and 4.5 in the extended COSMOS field (∼9 deg2). We find that [O ii] emitters are a minimal contaminant in our LAE samples, but that interloping Green Pea–like [O iii] emitters are important for our redshift 4.5 sample. We introduce an innovative method for identifying [O ii] and [O iii] emitters via a combination of narrowband excess and galaxy colors, enabling their study as separate classes of objects. We present scaled median stacked spectral energy distributions for each galaxy sample, revealing the overall success of our selection methods. We also calculate rest-frame Lyα equivalent widths for our LAE samples and find that the EW distributions are best fit by exponential functions with scale lengths of w0 = 53 ± 1, 65 ± 1, and 59 ± 1 Å, respectively.
{"title":"ODIN: Improved Narrowband Lyα Emitter Selection Techniques for z = 2.4, 3.1, and 4.5","authors":"Nicole M. Firestone, Eric Gawiser, Vandana Ramakrishnan, Kyoung-Soo Lee, Francisco Valdes, Changbom Park, Yujin Yang, Robin Ciardullo, María Celeste Artale, Barbara Benda, Adam Broussard, Lana Eid, Rameen Farooq, Caryl Gronwall, Lucia Guaita, Stephen Gwyn, Ho Seong Hwang, Sang Hyeok Im, Woong-Seob Jeong, Shreya Karthikeyan, Dustin Lang, Byeongha Moon, Nelson Padilla, Marcin Sawicki, Eunsuk Seo, Akriti Singh, Hyunmi Song and Paulina Troncoso Iribarren","doi":"10.3847/1538-4357/ad71c9","DOIUrl":"https://doi.org/10.3847/1538-4357/ad71c9","url":null,"abstract":"Lyman-alpha-emitting galaxies (LAEs) are typically young, low-mass, star-forming galaxies with little extinction from interstellar dust. Their low dust attenuation allows their Lyα emission to shine brightly in spectroscopic and photometric observations, providing an observational window into the high-redshift Universe. Narrowband surveys reveal large, uniform samples of LAEs at specific redshifts that probe large-scale structure and the temporal evolution of galaxy properties. The One-hundred-deg2 DECam Imaging in Narrowbands (ODIN) utilizes three custom-made narrowband filters on the Dark Energy Camera (DECam) to discover LAEs at three equally spaced periods in cosmological history. In this paper, we introduce the hybrid-weighted double-broadband continuum estimation technique, which yields improved estimation of Lyα equivalent widths. Using this method, we discover 6032, 5691, and 4066 LAE candidates at z = 2.4, 3.1, and 4.5 in the extended COSMOS field (∼9 deg2). We find that [O ii] emitters are a minimal contaminant in our LAE samples, but that interloping Green Pea–like [O iii] emitters are important for our redshift 4.5 sample. We introduce an innovative method for identifying [O ii] and [O iii] emitters via a combination of narrowband excess and galaxy colors, enabling their study as separate classes of objects. We present scaled median stacked spectral energy distributions for each galaxy sample, revealing the overall success of our selection methods. We also calculate rest-frame Lyα equivalent widths for our LAE samples and find that the EW distributions are best fit by exponential functions with scale lengths of w0 = 53 ± 1, 65 ± 1, and 59 ± 1 Å, respectively.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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