Pub Date : 2024-01-26DOI: 10.3847/1538-4357/ad235d
B. Chhotaray, G. K. Jaisawal, P. Nandi, S. Naik, N. Kumari, M. Ng, K. Gendreau
We present the results obtained from detailed X-ray timing and spectral studies of X-ray pulsar Swift J0243.6+6124 during its giant and normal X-ray outbursts between 2017 and 2023 observed by the Neutron star Interior Composition Explorer (NICER). We focused on a timing analysis of the normal outbursts. A distinct break is found in the power density spectra of the source. The corresponding break frequency and slopes of the power laws around the break vary with luminosity, indicating a change in the accretion dynamics with the mass accretion rate. Interestingly, we detected quasiperiodic oscillations within a specific luminosity range, providing further insights into the underlying physical processes. We also studied the neutron star spin period evolution and a luminosity variation in the pulse profile during the recent 2023 outburst. The spectral analysis was conducted comprehensively for the giant and all other normal outbursts. We identified a double transition at luminosities of ≈7.5 × 1037 and 2.1 × 1038 erg s−1 in the evolution of continuum parameters like the photon index and cutoff energy with luminosity. This indicates three distinct accretion modes experienced by the source, mainly during the giant X-ray outburst. A soft blackbody component with a temperature of 0.08–0.7 keV is also detected in the spectra. The observed temperature undergoes a discontinuous transition when the pulsar evolves from a sub- to super-Eddington state. Notably, in addition to an evolving 6–7 keV iron line complex, a 1 keV emission line was observed during the super-Eddington state of the source, implying X-ray reflection from the accretion disk or outflow material.
{"title":"Long-term Study of the First Galactic Ultraluminous X-Ray Source Swift J0243.6+6124 Using NICER","authors":"B. Chhotaray, G. K. Jaisawal, P. Nandi, S. Naik, N. Kumari, M. Ng, K. Gendreau","doi":"10.3847/1538-4357/ad235d","DOIUrl":"https://doi.org/10.3847/1538-4357/ad235d","url":null,"abstract":"\u0000 We present the results obtained from detailed X-ray timing and spectral studies of X-ray pulsar Swift J0243.6+6124 during its giant and normal X-ray outbursts between 2017 and 2023 observed by the Neutron star Interior Composition Explorer (NICER). We focused on a timing analysis of the normal outbursts. A distinct break is found in the power density spectra of the source. The corresponding break frequency and slopes of the power laws around the break vary with luminosity, indicating a change in the accretion dynamics with the mass accretion rate. Interestingly, we detected quasiperiodic oscillations within a specific luminosity range, providing further insights into the underlying physical processes. We also studied the neutron star spin period evolution and a luminosity variation in the pulse profile during the recent 2023 outburst. The spectral analysis was conducted comprehensively for the giant and all other normal outbursts. We identified a double transition at luminosities of ≈7.5 × 1037 and 2.1 × 1038 erg s−1 in the evolution of continuum parameters like the photon index and cutoff energy with luminosity. This indicates three distinct accretion modes experienced by the source, mainly during the giant X-ray outburst. A soft blackbody component with a temperature of 0.08–0.7 keV is also detected in the spectra. The observed temperature undergoes a discontinuous transition when the pulsar evolves from a sub- to super-Eddington state. Notably, in addition to an evolving 6–7 keV iron line complex, a 1 keV emission line was observed during the super-Eddington state of the source, implying X-ray reflection from the accretion disk or outflow material.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140494332","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 : 2024-01-25DOI: 10.3847/1538-4357/ad0f16
Ryan C. Fortenberry, V. J. Esposito
With the recent radioastronomical detection of cis-trans-carbonic acid (H2CO3) in a molecular cloud toward the Galactic center, the more stable but currently unobserved cis-cis conformer is shown here to have strong IR features. While the higher-energy cis-trans-carbonic acid was detected at millimeter and centimeter wavelengths, owing to its larger dipole moment, the vibrational structure of cis-cis-carbonic acid is more amenable to its observation at micron wavelengths. Even so, both conformers have relatively large IR intensities, and some of these fall in regions not dominated by polycyclic aromatic hydrocarbons. Water features may inhibit observation near the 2.75 μm hydride stretches, but other vibrational fundamentals and even overtones in the 5.5–6.0 μm range may be discernible with JWST data. This work has employed high-level, accurately benchmarked quantum chemical anharmonic procedures to compute exceptionally accurate rotational spectroscopic data compared to experiment. Such performance implies that the IR absorption and even cascade emission spectral features computed in this work should be accurate and will provide the needed reference for observation of either carbonic acid conformer in various astronomical environments.
{"title":"Toward the IR Detection of Carbonic Acid: Absorption and Emission Spectra","authors":"Ryan C. Fortenberry, V. J. Esposito","doi":"10.3847/1538-4357/ad0f16","DOIUrl":"https://doi.org/10.3847/1538-4357/ad0f16","url":null,"abstract":"\u0000 With the recent radioastronomical detection of cis-trans-carbonic acid (H2CO3) in a molecular cloud toward the Galactic center, the more stable but currently unobserved cis-cis conformer is shown here to have strong IR features. While the higher-energy cis-trans-carbonic acid was detected at millimeter and centimeter wavelengths, owing to its larger dipole moment, the vibrational structure of cis-cis-carbonic acid is more amenable to its observation at micron wavelengths. Even so, both conformers have relatively large IR intensities, and some of these fall in regions not dominated by polycyclic aromatic hydrocarbons. Water features may inhibit observation near the 2.75 μm hydride stretches, but other vibrational fundamentals and even overtones in the 5.5–6.0 μm range may be discernible with JWST data. This work has employed high-level, accurately benchmarked quantum chemical anharmonic procedures to compute exceptionally accurate rotational spectroscopic data compared to experiment. Such performance implies that the IR absorption and even cascade emission spectral features computed in this work should be accurate and will provide the needed reference for observation of either carbonic acid conformer in various astronomical environments.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"15 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139595497","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 : 2024-01-25DOI: 10.3847/1538-4357/acfca8
Catherine A. Witherspoon, E. Wilcots
The discovery of active galactic nuclei (AGNs) in low-mass (M * ≤ 5 × 109 M ⊙) galaxies has pushed forward the idea that AGN feedback may play a role in quenching star formation in the low-mass regime. In order to test whether AGNs can be a dominant quenching mechanism, we must first disentangle the effects of internal and external processes caused by a galaxy’s environment. We have used the Sloan Digital Sky Survey IV Mapping Nearby Galaxies at Apache Point Observatory survey to produce resolved Baldwin, Phillips, & Terlevich diagrams, and we find 41 AGNs (∼1.3%) in low-mass galaxies. We have studied the group richness (the number of group members) of our AGN and non-AGN samples as a proxy for determining the possible effect of the environment on the gas reservoir in these galaxies. We find that low-mass galaxies hosting AGNs are more likely to be found in isolation or in low-mass groups than galaxies in the non-AGN samples. This preference is even more clear when we split our samples into star-forming and quiescent subsamples. This suggests that environment is not the main cause of quenching in these galaxies, though we cannot rule out the possibility of past mergers.
在低质量（M * ≤ 5 × 109 M ⊙）星系中发现的活动星系核（AGNs）推动了一种观点，即AGN反馈可能在低质量星系中起到淬灭恒星形成的作用。为了检验AGN是否是一种主要的淬火机制，我们必须首先区分星系环境所造成的内部和外部过程的影响。我们利用斯隆数字巡天IV "在阿帕奇角天文台绘制近邻星系 "巡天，绘制出了解析的鲍德温、菲利普斯和特列维奇图，在低质量星系中发现了41个AGN（∼1.3%）。我们研究了AGN和非AGN样本的群富集度（群成员的数量），以此来确定环境对这些星系中气体库可能产生的影响。我们发现，与非AGN样本中的星系相比，承载着AGN的低质量星系更有可能被孤立地发现，或者被发现在低质量的星系群中。当我们把样本分成恒星形成子样本和静止子样本时，这种偏好就更加明显了。这表明环境并不是造成这些星系淬火的主要原因，尽管我们不能排除过去合并的可能性。
{"title":"Environment of Quiescent Low-mass Galaxies Hosting AGNs in MaNGA","authors":"Catherine A. Witherspoon, E. Wilcots","doi":"10.3847/1538-4357/acfca8","DOIUrl":"https://doi.org/10.3847/1538-4357/acfca8","url":null,"abstract":"\u0000 The discovery of active galactic nuclei (AGNs) in low-mass (M\u0000 * ≤ 5 × 109\u0000 M\u0000 ⊙) galaxies has pushed forward the idea that AGN feedback may play a role in quenching star formation in the low-mass regime. In order to test whether AGNs can be a dominant quenching mechanism, we must first disentangle the effects of internal and external processes caused by a galaxy’s environment. We have used the Sloan Digital Sky Survey IV Mapping Nearby Galaxies at Apache Point Observatory survey to produce resolved Baldwin, Phillips, & Terlevich diagrams, and we find 41 AGNs (∼1.3%) in low-mass galaxies. We have studied the group richness (the number of group members) of our AGN and non-AGN samples as a proxy for determining the possible effect of the environment on the gas reservoir in these galaxies. We find that low-mass galaxies hosting AGNs are more likely to be found in isolation or in low-mass groups than galaxies in the non-AGN samples. This preference is even more clear when we split our samples into star-forming and quiescent subsamples. This suggests that environment is not the main cause of quenching in these galaxies, though we cannot rule out the possibility of past mergers.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"9 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139595842","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 : 2024-01-25DOI: 10.3847/1538-4357/ad0cbf
Sangjun Cha, K. HyeongHan, Zachary P. Scofield, Hyungjin Joo, M. J. Jee
We present a new high-resolution free-form mass model of A2744 that combines both weak-lensing (WL) and strong-lensing (SL) data sets from JWST. The SL data set comprises 286 multiple images, presenting the most extensive SL constraint to date for a single cluster. The WL data set, employing photo-z selection, yields a source density of ∼ 350 arcmin − 2 , marking the densest WL constraint ever. The combined mass reconstruction enables the highest-resolution mass map of A2744 within the ∼1.8 Mpc × 1.8 Mpc reconstruction region to date, revealing an isosceles triangular structure with two legs of ∼1 Mpc and a base of ∼0.6 Mpc. Although our algorithm, which is called MAximum-entropy ReconStruction (MARS), is entirely blind to the cluster galaxy distribution, the resulting mass reconstruction traces the brightest cluster galaxies remarkably well. The five strongest mass peaks coincide with the five most luminous cluster galaxies within ≲2″. We do not detect any unusual mass peaks that are not traced by the cluster galaxies, unlike the findings in previous studies. Our mass model shows the smallest scatter of SL multiple images in both source (∼0.″05) and image (∼0.″1) planes, which is lower than in previous studies by a factor of ∼4. Although MARS represents the mass field with an extremely large number of free parameters (∼300,000), it converges to a solution within a few hours because we use a deep-learning technique. We make our mass and magnification maps publicly available.
{"title":"Precision MARS Mass Reconstruction of A2744: Synergizing the Largest Strong-lensing and Densest Weak-lensing Data Sets from JWST","authors":"Sangjun Cha, K. HyeongHan, Zachary P. Scofield, Hyungjin Joo, M. J. Jee","doi":"10.3847/1538-4357/ad0cbf","DOIUrl":"https://doi.org/10.3847/1538-4357/ad0cbf","url":null,"abstract":"\u0000 We present a new high-resolution free-form mass model of A2744 that combines both weak-lensing (WL) and strong-lensing (SL) data sets from JWST. The SL data set comprises 286 multiple images, presenting the most extensive SL constraint to date for a single cluster. The WL data set, employing photo-z selection, yields a source density of \u0000 \u0000\u0000\u0000 \u0000 ∼\u0000 350\u0000 \u0000 \u0000 \u0000 arcmin\u0000 \u0000 \u0000 −\u0000 2\u0000 \u0000 \u0000 \u0000 \u0000 , marking the densest WL constraint ever. The combined mass reconstruction enables the highest-resolution mass map of A2744 within the ∼1.8 Mpc × 1.8 Mpc reconstruction region to date, revealing an isosceles triangular structure with two legs of ∼1 Mpc and a base of ∼0.6 Mpc. Although our algorithm, which is called MAximum-entropy ReconStruction (MARS), is entirely blind to the cluster galaxy distribution, the resulting mass reconstruction traces the brightest cluster galaxies remarkably well. The five strongest mass peaks coincide with the five most luminous cluster galaxies within ≲2″. We do not detect any unusual mass peaks that are not traced by the cluster galaxies, unlike the findings in previous studies. Our mass model shows the smallest scatter of SL multiple images in both source (∼0.″05) and image (∼0.″1) planes, which is lower than in previous studies by a factor of ∼4. Although MARS represents the mass field with an extremely large number of free parameters (∼300,000), it converges to a solution within a few hours because we use a deep-learning technique. We make our mass and magnification maps publicly available.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"24 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139598491","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 : 2024-01-25DOI: 10.3847/1538-4357/ad165a
Thomas K. Waters, Colton Peterson, Razieh Emami, Xuejian Shen, L. Hernquist, Randall Smith, M. Vogelsberger, Charles Alcock, Grant Tremblay, Matthew Liska, John C. Forbes, Jorge Moreno
We present an in-depth analysis of gas morphologies for a sample of 25 Milky Way–like galaxies from the IllustrisTNG TNG50 simulation. We constrain the morphology of cold, warm, hot gas, and gas particles as a whole using a local shell iterative method and explore its observational implications by computing the hard-to-soft X-ray ratio, which ranges between 10−3 and 10−2 in the inner ∼50 kpc of the distribution and 10−5–10−4 at the outer portion of the hot gas distribution. We group galaxies into three main categories: simple, stretched, and twisted. These categories are based on the radial reorientation of the principal axes of the reduced inertia tensor. We find that a vast majority (77%) of the galaxies in our sample exhibit twisting patterns in their radial profiles. Additionally, we present detailed comparisons between (i) the gaseous distributions belonging to individual temperature regimes, (ii) the cold gas distributions and stellar distributions, and (iii) the gaseous distributions and dark matter (DM) halos. We find a strong correlation between the morphological properties of the cold gas and stellar distributions. Furthermore, we find a correlation between gaseous distributions with a DM halo that increases with gas temperature, implying that we may use the warm–hot gaseous morphology as a tracer to probe the DM morphology. Finally, we show gaseous distributions exhibit significantly more prolate morphologies than the stellar distributions and DM halos, which we hypothesize is due to stellar and active galactic nucleus feedback.
我们对来自 IllustrisTNG TNG50 模拟的 25 个类银河系样本的气体形态进行了深入分析。我们使用局部壳迭代法对冷气体、暖气体、热气体和气体粒子的形态进行了整体约束，并通过计算硬-软 X 射线比来探索其观测意义，硬-软 X 射线比在星系分布的内侧 ∼ 50 kpc 范围内介于 10-3 和 10-2 之间，而在热气体分布的外侧则介于 10-5-10-4 之间。我们将星系分为三大类：简单星系、拉伸星系和扭曲星系。这些分类的依据是还原惯性张量主轴的径向重新定向。我们发现，样本中绝大多数（77%）星系的径向剖面都呈现出扭曲模式。此外，我们还详细比较了(i)属于不同温度机制的气体分布，(ii)冷气体分布和恒星分布，以及(iii)气体分布和暗物质（DM）晕之间的关系。我们发现冷气体分布和恒星分布的形态特性之间有很强的相关性。此外，我们还发现气态分布与DM晕之间的相关性随着气体温度的升高而增强，这意味着我们可以利用暖-热气态形态作为探测DM形态的示踪剂。最后，我们发现气态分布的形态明显比恒星分布和DM光环的形态更突出，我们假设这是恒星和活动星系核反馈造成的。
{"title":"Gas Morphology of Milky Way–like Galaxies in the TNG50 Simulation: Signals of Twisting and Stretching","authors":"Thomas K. Waters, Colton Peterson, Razieh Emami, Xuejian Shen, L. Hernquist, Randall Smith, M. Vogelsberger, Charles Alcock, Grant Tremblay, Matthew Liska, John C. Forbes, Jorge Moreno","doi":"10.3847/1538-4357/ad165a","DOIUrl":"https://doi.org/10.3847/1538-4357/ad165a","url":null,"abstract":"\u0000 We present an in-depth analysis of gas morphologies for a sample of 25 Milky Way–like galaxies from the IllustrisTNG TNG50 simulation. We constrain the morphology of cold, warm, hot gas, and gas particles as a whole using a local shell iterative method and explore its observational implications by computing the hard-to-soft X-ray ratio, which ranges between 10−3 and 10−2 in the inner ∼50 kpc of the distribution and 10−5–10−4 at the outer portion of the hot gas distribution. We group galaxies into three main categories: simple, stretched, and twisted. These categories are based on the radial reorientation of the principal axes of the reduced inertia tensor. We find that a vast majority (77%) of the galaxies in our sample exhibit twisting patterns in their radial profiles. Additionally, we present detailed comparisons between (i) the gaseous distributions belonging to individual temperature regimes, (ii) the cold gas distributions and stellar distributions, and (iii) the gaseous distributions and dark matter (DM) halos. We find a strong correlation between the morphological properties of the cold gas and stellar distributions. Furthermore, we find a correlation between gaseous distributions with a DM halo that increases with gas temperature, implying that we may use the warm–hot gaseous morphology as a tracer to probe the DM morphology. Finally, we show gaseous distributions exhibit significantly more prolate morphologies than the stellar distributions and DM halos, which we hypothesize is due to stellar and active galactic nucleus feedback.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"45 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139598094","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 : 2024-01-25DOI: 10.3847/1538-4357/ad235b
Xin Zhang, Hengjie Lin, Meng Zhang, Bin Yue, Yan Gong, Yidong Xu, Xuelei Chen
We investigate the feasibility of using the velocity acoustic oscillations (VAO) features on the Cosmic Dawn 21 cm power spectrum to probe small-scale density fluctuations. In the standard cold dark matter (CDM) model, Population III stars form in minihalos and affect the 21 cm signal through Lyα and X-ray radiation. Such a process is modulated by the relative motion between dark matter and baryons, generating the VAO wiggles on the 21 cm power spectrum. In the fuzzy or warm dark matter models for which the number of minihalos is reduced, the VAO wiggles are weaker or even fully invisible. We investigate the wiggle features in the CDM with different astrophysical models and in different dark matter models. We find that (1) in the CDM model the relative streaming velocities can generate the VAO wiggles for broad ranges of parameters f *, ζ X , and f esc,LW ζ LW, though for different parameters the wiggles would appear at different redshifts and have different amplitudes. (2) For the axion model with m a ≲ 10−19 eV, the VAO wiggles are negligible. In the mixed model, the VAO signal is sensitive to the axion fraction. For example, the wiggles almost disappear when f a ≳ 10% for m a = 10−21 eV. Therefore, the VAO signal can be an effective indicator for small-scale density fluctuations and a useful probe of the nature of dark matter. The Square Kilometre Array-low with ∼2000 hr observation time has the ability to detect the VAO signal and constrain dark matter models.
我们研究了利用宇宙黎明 21 厘米功率谱上的速度声振荡（VAO）特征来探测小尺度密度波动的可行性。在标准的冷暗物质（CDM）模型中，III族恒星在小星系中形成，并通过Lyα和X射线辐射影响21厘米信号。这一过程受到暗物质和重子之间相对运动的调制，在 21 厘米功率谱上产生 VAO 摆动。在模糊暗物质或暖暗物质模型中，由于微哈罗粒子的数量减少，VAO摆动会减弱甚至完全看不见。我们研究了不同天体物理模型和不同暗物质模型中 CDM 的摆动特征。我们发现：(1) 在 CDM 模型中，相对流速度可以在参数 f *, ζ X 和 f esc,LW ζ LW 的宽范围内产生 VAO 扭摆，尽管对于不同的参数，扭摆会出现在不同的红移和不同的振幅上。(2) 对于 m a ≲ 10-19 eV 的轴子模型，VAO 摆动可以忽略不计。在混合模型中，VAO 信号对轴心分数很敏感。例如，当 m a = 10-21 eV 的 f a ≳ 10% 时，踌躇几乎消失。因此，VAO 信号可以成为小尺度密度波动的有效指标，也是暗物质性质的有用探针。平方公里阵列-低观测时间为2000小时，具有探测VAO信号和约束暗物质模型的能力。
{"title":"Velocity Acoustic Oscillations on Cosmic Dawn 21 cm Power Spectrum as a Probe of Small-scale Density Fluctuations","authors":"Xin Zhang, Hengjie Lin, Meng Zhang, Bin Yue, Yan Gong, Yidong Xu, Xuelei Chen","doi":"10.3847/1538-4357/ad235b","DOIUrl":"https://doi.org/10.3847/1538-4357/ad235b","url":null,"abstract":"\u0000 We investigate the feasibility of using the velocity acoustic oscillations (VAO) features on the Cosmic Dawn 21 cm power spectrum to probe small-scale density fluctuations. In the standard cold dark matter (CDM) model, Population III stars form in minihalos and affect the 21 cm signal through Lyα and X-ray radiation. Such a process is modulated by the relative motion between dark matter and baryons, generating the VAO wiggles on the 21 cm power spectrum. In the fuzzy or warm dark matter models for which the number of minihalos is reduced, the VAO wiggles are weaker or even fully invisible. We investigate the wiggle features in the CDM with different astrophysical models and in different dark matter models. We find that (1) in the CDM model the relative streaming velocities can generate the VAO wiggles for broad ranges of parameters f\u0000 *, ζ\u0000 \u0000 X\u0000 , and f\u0000 esc,LW\u0000 ζ\u0000 LW, though for different parameters the wiggles would appear at different redshifts and have different amplitudes. (2) For the axion model with m\u0000 a ≲ 10−19 eV, the VAO wiggles are negligible. In the mixed model, the VAO signal is sensitive to the axion fraction. For example, the wiggles almost disappear when f\u0000 a ≳ 10% for m\u0000 a = 10−21 eV. Therefore, the VAO signal can be an effective indicator for small-scale density fluctuations and a useful probe of the nature of dark matter. The Square Kilometre Array-low with ∼2000 hr observation time has the ability to detect the VAO signal and constrain dark matter models.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"15 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140495816","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 : 2024-01-25DOI: 10.3847/1538-4357/ad206a
Ofer Cohen, Alex Glocer, C. Garraffo, J. Alvarado‐Gómez, Jeremy J. Drake, Kristina Monsch, Farah Fauth Puigdomenech
Exoplanets with short orbit periods reside very close to their host stars. They transition very rapidly between different sectors of the circumstellar space environment along their orbit, leading to large variations of the magnetic field in the vicinity of the planet on short timescales. This rapid change of the magnetic flux through the conducting and resistive layer of the planetary upper atmosphere may drive currents that dissipate in the form of Joule heating (JH). Here, we estimate the amount of JH dissipation in the upper atmosphere of Trappist-1e, and two hypothetical planets orbiting the Sun in close-in orbits. We find that the rapid orbital motion could drive a significant amount of atmospheric heating and could significantly affect the planetary atmosphere escape rate. Thus, the process should be accounted for when studying the long-term evolution of exoplanetary atmospheres.
{"title":"Heating of the Atmospheres of Short-orbit Exoplanets by Their Rapid Orbital Motion through an Extreme Space Environment","authors":"Ofer Cohen, Alex Glocer, C. Garraffo, J. Alvarado‐Gómez, Jeremy J. Drake, Kristina Monsch, Farah Fauth Puigdomenech","doi":"10.3847/1538-4357/ad206a","DOIUrl":"https://doi.org/10.3847/1538-4357/ad206a","url":null,"abstract":"\u0000 Exoplanets with short orbit periods reside very close to their host stars. They transition very rapidly between different sectors of the circumstellar space environment along their orbit, leading to large variations of the magnetic field in the vicinity of the planet on short timescales. This rapid change of the magnetic flux through the conducting and resistive layer of the planetary upper atmosphere may drive currents that dissipate in the form of Joule heating (JH). Here, we estimate the amount of JH dissipation in the upper atmosphere of Trappist-1e, and two hypothetical planets orbiting the Sun in close-in orbits. We find that the rapid orbital motion could drive a significant amount of atmospheric heating and could significantly affect the planetary atmosphere escape rate. Thus, the process should be accounted for when studying the long-term evolution of exoplanetary atmospheres.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"145 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140495233","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 : 2024-01-25DOI: 10.3847/1538-4357/ad118e
Daniel Wrench, Tulasi N. Parashar, S. Oughton, Kevin de Lange, Marcus Frean
The Reynolds number, Re, is an important quantity for describing a turbulent flow. It tells us about the bandwidth over which energy can cascade from large scales to smaller ones, prior to the onset of dissipation. However, calculating it for nearly collisionless plasmas like the solar wind is challenging. Previous studies have used formulations of an “effective” Reynolds number, expressing Re as a function of the correlation scale and either the Taylor scale or a proxy for the dissipation scale. We find that the Taylor scale definition of the Reynolds number has a sizable prefactor of approximately 27, which has not been employed in previous works. Drawing from 18 years of data from the Wind spacecraft at 1 au, we calculate the magnetic Taylor scale directly and use both the ion inertial length and the magnetic spectrum break scale as approximations for the dissipation scale, yielding three distinct Re estimates for each 12 hr interval. Average values of Re range between 116,000 and 3,406,000 within the general distribution of past work. We also find considerable disagreement between the methods, with linear associations of between 0.38 and 0.72. Although the Taylor scale method is arguably more physically motivated, due to its dependence on the energy cascade rate, more theoretical work is needed in order to identify the most appropriate way of calculating effective Reynolds numbers for kinetic plasmas. As a summary of our observational analysis, we make available a data product of 28 years of 1 au solar wind and magnetospheric plasma measurements from Wind.
雷诺数 Re 是描述湍流的一个重要参数。它告诉我们在耗散开始之前，能量可以从大尺度级联到小尺度的带宽。然而，对于像太阳风这样几乎没有碰撞的等离子体来说，计算它是一项挑战。之前的研究使用了 "有效 "雷诺数的公式，将雷诺数表示为相关尺度和泰勒尺度或耗散尺度的函数。我们发现，泰勒尺度定义的雷诺数有一个相当大的前置因子，大约为 27，这在以前的研究中没有被采用过。根据风飞船在 1 au 处 18 年的数据，我们直接计算了磁泰勒尺度，并使用离子惯性长度和磁谱断裂尺度作为耗散尺度的近似值，得出了每个 12 小时间隔的三个不同的 Re 估计值。Re 的平均值在 116,000 到 3,406,000 之间，与过去工作的总体分布一致。我们还发现这些方法之间存在相当大的分歧，线性关联度在 0.38 到 0.72 之间。虽然泰勒尺度方法由于依赖于能量级联率，可以说更具有物理动机，但要确定计算动力学等离子体有效雷诺数的最合适方法，还需要更多的理论工作。作为我们观测分析的总结，我们提供了 28 年来来自 Wind 的 1 au 太阳风和磁层等离子体测量数据产品。
{"title":"What is the Reynolds Number of the Solar Wind?","authors":"Daniel Wrench, Tulasi N. Parashar, S. Oughton, Kevin de Lange, Marcus Frean","doi":"10.3847/1538-4357/ad118e","DOIUrl":"https://doi.org/10.3847/1538-4357/ad118e","url":null,"abstract":"\u0000 The Reynolds number, Re, is an important quantity for describing a turbulent flow. It tells us about the bandwidth over which energy can cascade from large scales to smaller ones, prior to the onset of dissipation. However, calculating it for nearly collisionless plasmas like the solar wind is challenging. Previous studies have used formulations of an “effective” Reynolds number, expressing Re as a function of the correlation scale and either the Taylor scale or a proxy for the dissipation scale. We find that the Taylor scale definition of the Reynolds number has a sizable prefactor of approximately 27, which has not been employed in previous works. Drawing from 18 years of data from the Wind spacecraft at 1 au, we calculate the magnetic Taylor scale directly and use both the ion inertial length and the magnetic spectrum break scale as approximations for the dissipation scale, yielding three distinct Re estimates for each 12 hr interval. Average values of Re range between 116,000 and 3,406,000 within the general distribution of past work. We also find considerable disagreement between the methods, with linear associations of between 0.38 and 0.72. Although the Taylor scale method is arguably more physically motivated, due to its dependence on the energy cascade rate, more theoretical work is needed in order to identify the most appropriate way of calculating effective Reynolds numbers for kinetic plasmas. As a summary of our observational analysis, we make available a data product of 28 years of 1 au solar wind and magnetospheric plasma measurements from Wind.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"24 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139596183","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 : 2024-01-25DOI: 10.3847/1538-4357/ad1dd6
P. Scherbak, Jim Fuller
Double white dwarf (WD) binaries are increasingly being discovered at short orbital periods where strong tidal effects and significant tidal heating signatures may occur. We assume that the tidal potential of the companion excites outgoing gravity waves within the WD primary, the dissipation of which leads to an increase in the WD’s surface temperature. We compute the excitation and dissipation of the waves in cooling WD models in evolving MESA binary simulations. Tidal heating is self-consistently computed and added to the models at every time step. As a binary inspirals to orbital periods less than ∼20 minutes, the WD’s behavior changes from cooling to heating, with temperature enhancements that can exceed 10,000 K compared with nontidally heated models. We compare a grid of tidally heated WD models to observed short-period systems with hot WD primaries. While tidal heating affects their T eff, it is likely not the dominant luminosity. Instead, these WDs are probably intrinsically young and hot, implying that the binaries formed at short orbital periods. The binaries are consistent with undergoing common envelope evolution with a somewhat low efficiency α CE. We delineate the parameter space where the traveling wave assumption is most valid, noting that it breaks down for WDs that cool sufficiently, where standing waves may instead be formed.
{"title":"Ultra–short-period WD Binaries Are Not Undergoing Strong Tidal Heating","authors":"P. Scherbak, Jim Fuller","doi":"10.3847/1538-4357/ad1dd6","DOIUrl":"https://doi.org/10.3847/1538-4357/ad1dd6","url":null,"abstract":"\u0000 Double white dwarf (WD) binaries are increasingly being discovered at short orbital periods where strong tidal effects and significant tidal heating signatures may occur. We assume that the tidal potential of the companion excites outgoing gravity waves within the WD primary, the dissipation of which leads to an increase in the WD’s surface temperature. We compute the excitation and dissipation of the waves in cooling WD models in evolving MESA binary simulations. Tidal heating is self-consistently computed and added to the models at every time step. As a binary inspirals to orbital periods less than ∼20 minutes, the WD’s behavior changes from cooling to heating, with temperature enhancements that can exceed 10,000 K compared with nontidally heated models. We compare a grid of tidally heated WD models to observed short-period systems with hot WD primaries. While tidal heating affects their T\u0000 eff, it is likely not the dominant luminosity. Instead, these WDs are probably intrinsically young and hot, implying that the binaries formed at short orbital periods. The binaries are consistent with undergoing common envelope evolution with a somewhat low efficiency α\u0000 CE. We delineate the parameter space where the traveling wave assumption is most valid, noting that it breaks down for WDs that cool sufficiently, where standing waves may instead be formed.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"68 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140496719","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 : 2024-01-25DOI: 10.3847/1538-4357/ad0b7b
J. DerKacy, C. Ashall, P. Hoeflich, E. Baron, M. Shahbandeh, B. Shappee, J. Andrews, D. Baade, E. F. Balangan, K. Bostroem, P. Brown, C. Burns, A. Burrow, A. Cikota, T. de Jaeger, A. Do, Y. Dong, I. Dominguez, O. Fox, L. Galbany, E. Hoang, E. Hsiao, D. Janzen, J. Jencson, K. Krisciunas, S. Kumar, J. Lu, M. Lundquist, T. M. Evans, J. Maund, P. Mazzali, K. Medler, N. Retamal, N. Morrell, F. Patat, J. Pearson, M. Phillips, M. Shrestha, S. Stangl, C. Stevens, M. Stritzinger, N. Suntzeff, C. Telesco, M. Tucker, S. Valenti, L. Wang, Y. Yang
We present a JWST mid-infrared (MIR) spectrum of the underluminous Type Ia Supernova (SN Ia) 2022xkq, obtained with the medium-resolution spectrometer on the Mid-Infrared Instrument (MIRI) ∼130 days post-explosion. We identify the first MIR lines beyond 14 μm in SN Ia observations. We find features unique to underluminous SNe Ia, including the following: isolated emission of stable Ni, strong blends of [Ti ii], and large ratios of singly ionized to doubly ionized species in both [Ar] and [Co]. Comparisons to normal-luminosity SNe Ia spectra at similar phases show a tentative trend between the width of the [Co iii] 11.888 μm feature and the SN light-curve shape. Using non-LTE-multi-dimensional radiation hydro simulations and the observed electron capture elements, we constrain the mass of the exploding WD. The best-fitting model shows that SN 2022xkq is consistent with an off-center delayed-detonation explosion of a near-Chandrasekhar mass WD ( M WD ≈1.37 M ⊙) of high central density (ρ c ≥ 2.0 × 109 g cm−3) seen equator-on, which produced M(56Ni) =0.324 M ⊙ and M(58Ni) ≥0.06 M ⊙. The observed line widths are consistent with the overall abundance distribution; and the narrow stable Ni lines indicate little to no mixing in the central regions, favoring central ignition of subsonic carbon burning followed by an off-center deflagration-to-detonation transition beginning at a single point. Additional observations may further constrain the physics revealing the presence of additional species including Cr and Mn. Our work demonstrates the power of using the full coverage of MIRI in combination with detailed modeling to elucidate the physics of SNe Ia at a level not previously possible.
我们展示了 JWST 中红外（MIR）光谱，这是利用中红外仪器（MIRI）上的中分辨率光谱仪在爆发后 130 天获得的发光不足的 Ia 型超新星（SN Ia）2022xkq 的光谱。我们在SN Ia的观测中首次发现了14 μm以上的中红外光谱线。我们发现了亮度不足的SNe Ia所独有的特征，包括：稳定Ni的孤立发射、[Ti ii]的强混合以及[Ar]和[Co]中单电离与双电离物种的大比例。与类似阶段的正常亮度 SNe Ia 光谱比较显示，[Co iii] 11.888 μm 特征的宽度与 SN 光曲线形状之间存在一种初步趋势。利用非 LTE 多维辐射水模拟和观测到的电子俘获元素，我们确定了爆炸 WD 的质量。最佳拟合模型显示，SN 2022xkq与一个中心密度较高（ρ c ≥ 2.0 × 109 g cm-3）的近钱德拉塞卡质量WD（M WD ≈1.37 M ⊙）的偏心延迟爆燃爆炸一致，它在赤道上产生了M(56Ni) =0.324 M ⊙和M(58Ni) ≥0.06 M ⊙。观测到的线宽与总体丰度分布一致；窄的稳定镍线表明中心区域几乎没有混合，这有利于亚音速碳燃烧的中心点火，然后在单点开始偏离中心的爆燃到爆燃转变。更多的观测结果可能会进一步约束物理学，揭示包括铬和锰在内的其他物种的存在。我们的工作展示了利用全覆盖的 MIRI 与详细的建模相结合，在以前不可能实现的水平上阐释 SNe Ia 物理的威力。
{"title":"JWST MIRI/Medium Resolution Spectrograph (MRS) Observations and Spectral Models of the Underluminous Type Ia Supernova 2022xkq","authors":"J. DerKacy, C. Ashall, P. Hoeflich, E. Baron, M. Shahbandeh, B. Shappee, J. Andrews, D. Baade, E. F. Balangan, K. Bostroem, P. Brown, C. Burns, A. Burrow, A. Cikota, T. de Jaeger, A. Do, Y. Dong, I. Dominguez, O. Fox, L. Galbany, E. Hoang, E. Hsiao, D. Janzen, J. Jencson, K. Krisciunas, S. Kumar, J. Lu, M. Lundquist, T. M. Evans, J. Maund, P. Mazzali, K. Medler, N. Retamal, N. Morrell, F. Patat, J. Pearson, M. Phillips, M. Shrestha, S. Stangl, C. Stevens, M. Stritzinger, N. Suntzeff, C. Telesco, M. Tucker, S. Valenti, L. Wang, Y. Yang","doi":"10.3847/1538-4357/ad0b7b","DOIUrl":"https://doi.org/10.3847/1538-4357/ad0b7b","url":null,"abstract":"\u0000 We present a JWST mid-infrared (MIR) spectrum of the underluminous Type Ia Supernova (SN Ia) 2022xkq, obtained with the medium-resolution spectrometer on the Mid-Infrared Instrument (MIRI) ∼130 days post-explosion. We identify the first MIR lines beyond 14 μm in SN Ia observations. We find features unique to underluminous SNe Ia, including the following: isolated emission of stable Ni, strong blends of [Ti ii], and large ratios of singly ionized to doubly ionized species in both [Ar] and [Co]. Comparisons to normal-luminosity SNe Ia spectra at similar phases show a tentative trend between the width of the [Co iii] 11.888 μm feature and the SN light-curve shape. Using non-LTE-multi-dimensional radiation hydro simulations and the observed electron capture elements, we constrain the mass of the exploding WD. The best-fitting model shows that SN 2022xkq is consistent with an off-center delayed-detonation explosion of a near-Chandrasekhar mass WD (\u0000 \u0000\u0000\u0000 \u0000 \u0000 M\u0000 \u0000 WD\u0000 \u0000 \u0000 \u0000 \u0000 ≈1.37 M\u0000 ⊙) of high central density (ρ\u0000 \u0000 c\u0000 ≥ 2.0 × 109 g cm−3) seen equator-on, which produced M(56Ni) =0.324 M\u0000 ⊙ and M(58Ni) ≥0.06 M\u0000 ⊙. The observed line widths are consistent with the overall abundance distribution; and the narrow stable Ni lines indicate little to no mixing in the central regions, favoring central ignition of subsonic carbon burning followed by an off-center deflagration-to-detonation transition beginning at a single point. Additional observations may further constrain the physics revealing the presence of additional species including Cr and Mn. Our work demonstrates the power of using the full coverage of MIRI in combination with detailed modeling to elucidate the physics of SNe Ia at a level not previously possible.","PeriodicalId":504209,"journal":{"name":"The Astrophysical Journal","volume":"3 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139595877","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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