Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acfcbd
Mei Zhang, Haocheng Zhang
Abstract Although it is generally believed that the solar photosphere is not magnetically force-free owing to its high plasma β , the estimations of force-freeness using observed magnetograms have produced disputable results. Some studies confirmed that the photosphere is largely not force-free whereas some authors argued that the photosphere is not far away from being force-free. In a previous paper of ours we demonstrated that, due to the fact that the noise levels of the transverse field in the magnetograms are much larger than those of the vertical field, wrong judgments on the force-freeness could be made: a truly force-free field could be judged as being not-force-free and a truly not-force-free field could be judged as being force-free. Here in this Letter, we propose an approach to overcome this serious problem. By reducing the spatial resolution to lower the noise level, the heavy influence of the measurement noise on the force-freeness judgment can be significantly suppressed. We first use two analytical solutions to show the success and effectiveness of this approach. Then, we apply this new approach to two large data sets of active region magnetograms, obtained with the Helioseismic and Magnetic Imager/Solar Dynamics Observatory and Spectro-Polarimeter (SP)/Hinode, respectively. Our analysis shows that the photospheric magnetic fields are actually far away from being force-free. Particularly, and most notably, the mean value of F z / F p (where F z is the net Lorentz force in the vertical direction and F p the total Lorentz force) is as low as −0.47, with more than 98% of the active regions having ∣ F z / F p ∣ > 0.1 when using the SP/Hinode magnetograms of true field strength.
虽然人们普遍认为太阳光球由于其高等离子体β而不是无磁力的，但利用观测到的磁图估计无磁力的结果有争议。一些研究证实，光球层在很大程度上不是无力的，而一些作者认为光球层离无力不远了。在我们之前的一篇论文中，我们论证了由于磁图中横向场的噪声级比垂直场的噪声级大得多，因此可能会对无力性做出错误的判断:真正无力的场可能被判断为无力，而真正无力的场可能被判断为无力。在这封信中，我们提出了一个解决这个严重问题的方法。通过降低空间分辨率来降低噪声水平，可以有效地抑制测量噪声对自由力判断的严重影响。我们首先使用两个解析解来展示这种方法的成功和有效性。然后，我们将这种新方法应用于两个大数据集的活动区域磁图，分别由日震和磁成像仪/太阳动力学观测站和光谱偏振仪(SP)/Hinode获得。我们的分析表明，光球磁场实际上远非无力的。特别值得注意的是，F z / F p的平均值(其中F z为垂直方向的净洛伦兹力，F p为总洛伦兹力)低至- 0.47，超过98%的活动区域具有∣F z / F p∣>0.1当使用真场强的SP/Hinode磁图时。
{"title":"The Force-freeness of the Solar Photosphere: Revisit with New Approach and Large Data Sets","authors":"Mei Zhang, Haocheng Zhang","doi":"10.3847/2041-8213/acfcbd","DOIUrl":"https://doi.org/10.3847/2041-8213/acfcbd","url":null,"abstract":"Abstract Although it is generally believed that the solar photosphere is not magnetically force-free owing to its high plasma β , the estimations of force-freeness using observed magnetograms have produced disputable results. Some studies confirmed that the photosphere is largely not force-free whereas some authors argued that the photosphere is not far away from being force-free. In a previous paper of ours we demonstrated that, due to the fact that the noise levels of the transverse field in the magnetograms are much larger than those of the vertical field, wrong judgments on the force-freeness could be made: a truly force-free field could be judged as being not-force-free and a truly not-force-free field could be judged as being force-free. Here in this Letter, we propose an approach to overcome this serious problem. By reducing the spatial resolution to lower the noise level, the heavy influence of the measurement noise on the force-freeness judgment can be significantly suppressed. We first use two analytical solutions to show the success and effectiveness of this approach. Then, we apply this new approach to two large data sets of active region magnetograms, obtained with the Helioseismic and Magnetic Imager/Solar Dynamics Observatory and Spectro-Polarimeter (SP)/Hinode, respectively. Our analysis shows that the photospheric magnetic fields are actually far away from being force-free. Particularly, and most notably, the mean value of F z / F p (where F z is the net Lorentz force in the vertical direction and F p the total Lorentz force) is as low as −0.47, with more than 98% of the active regions having ∣ F z / F p ∣ > 0.1 when using the SP/Hinode magnetograms of true field strength.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135607002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2023-10-01DOI: 10.3847/2041-8213/acf7c7
Chiaki Kobayashi, Souradeep Bhattacharya, Magda Arnaboldi, Ortwin Gerhard
Abstract An outstanding question is whether the α /Fe bimodality exists in disk galaxies other than in the Milky Way. Here we present a bimodality using our state-of-the-art galactic chemical evolution models that can explain various observations in the Andromeda galaxy (M31) disks, namely, elemental abundances both of planetary nebulae and of red giant branch stars recently observed with the James Webb Space Telescope. We find that in M31 a high- α thicker-disk population out to 30 kpc formed by a more intense initial starburst than that in the Milky Way. We also find a young low- α thin disk within 14 kpc, which is formed by a secondary star formation M31 underwent about 2–4.5 Gyr ago, probably triggered by a wet merger. In the outer disk, however, the planetary nebula observations indicate a slightly higher- α young (∼2.5 Gyr) population at a given metallicity, possibly formed by secondary star formation from almost pristine gas. Therefore, an α /Fe bimodality is seen in the inner disk (≲14 kpc), while only a slight α /Fe offset of the young population is seen in the outer disk (≳18 kpc). The appearance of the α /Fe bimodality depends on the merging history at various galactocentric radii, and wide-field multiobject spectroscopy is required for unveiling the history of M31.
{"title":"On the α/Fe Bimodality of the M31 Disks","authors":"Chiaki Kobayashi, Souradeep Bhattacharya, Magda Arnaboldi, Ortwin Gerhard","doi":"10.3847/2041-8213/acf7c7","DOIUrl":"https://doi.org/10.3847/2041-8213/acf7c7","url":null,"abstract":"Abstract An outstanding question is whether the α /Fe bimodality exists in disk galaxies other than in the Milky Way. Here we present a bimodality using our state-of-the-art galactic chemical evolution models that can explain various observations in the Andromeda galaxy (M31) disks, namely, elemental abundances both of planetary nebulae and of red giant branch stars recently observed with the James Webb Space Telescope. We find that in M31 a high- α thicker-disk population out to 30 kpc formed by a more intense initial starburst than that in the Milky Way. We also find a young low- α thin disk within 14 kpc, which is formed by a secondary star formation M31 underwent about 2–4.5 Gyr ago, probably triggered by a wet merger. In the outer disk, however, the planetary nebula observations indicate a slightly higher- α young (∼2.5 Gyr) population at a given metallicity, possibly formed by secondary star formation from almost pristine gas. Therefore, an α /Fe bimodality is seen in the inner disk (≲14 kpc), while only a slight α /Fe offset of the young population is seen in the outer disk (≳18 kpc). The appearance of the α /Fe bimodality depends on the merging history at various galactocentric radii, and wide-field multiobject spectroscopy is required for unveiling the history of M31.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135656275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2023-10-01DOI: 10.3847/2041-8213/acf1a3
Sergiy S. Vasylyev, Yi 轶 Yang 杨, Alexei V. Filippenko, Kishore C. Patra, Thomas G. Brink, Lifan Wang, Ryan Chornock, Raffaella Margutti, Elinor L. Gates, Adam J. Burgasser, Preethi R. Karpoor, Natalie LeBaron, Emma Softich, Christopher A. Theissen, Eli Wiston, WeiKang Zheng
Abstract We present six epochs of optical spectropolarimetry of the Type II supernova (SN) 2023ixf ranging from ∼2 to 15 days after the explosion. Polarimetry was obtained with the Kast double spectrograph on the Shane 3 m telescope at Lick Observatory, representing the earliest such observations ever captured for an SN. We observe a high continuum polarization p cont ≈ 1% on days +1.4 and +2.5 before dropping to 0.5% on day +3.5, persisting at that level up to day +14.5. Remarkably, this change coincides temporally with the disappearance of highly ionized “flash” features. The decrease of the continuum polarization is accompanied by a ∼70° rotation of the polarization position angle (PA) as seen across the continuum. The early evolution of the polarization may indicate different geometric configurations of the electron-scattering atmosphere as seen before and after the disappearance of the emission lines associated with highly ionized species (e.g., He ii , C iv , and N iii ), which are likely produced by elevated mass loss shortly prior to the SN explosion. We interpret the rapid change of polarization and PA from days +2.5 to +4.5 as the time when the SN ejecta emerge from the dense asymmetric circumstellar material (CSM). The temporal evolution of the continuum polarization and the PA is consistent with an aspherical SN explosion that exhibits a distinct geometry compared to the CSM. The rapid follow-up spectropolarimetry of SN 2023ixf during the shock ionization phase reveals an exceptionally asymmetric mass-loss process leading up to the explosion.
摘要:我们研究了II型超新星(SN) 2023ixf在爆炸后2 ~ 15天内的6个光谱偏振谱。偏振测量是由利克天文台Shane 3米望远镜上的Kast双摄谱仪获得的，这是迄今为止对超新星进行的最早的观测。我们观察到，在+1.4和+2.5天，连续极化p = 1%，在+3.5天降至0.5%，并持续到+14.5天。值得注意的是，这种变化与高度电离的“闪光”特征的消失在时间上是一致的。连续介质极化的减小伴随着偏振位角(PA)的旋转~ 70°，在整个连续介质上可见。极化的早期演化可能表明，在与高电离物质(如He ii, C iv和N iii)相关的发射线消失前后，电子散射大气的几何构型不同，这可能是在SN爆炸前不久由于质量损失增加而产生的。我们认为从+2.5天到+4.5天的极化和PA的快速变化是SN喷射从致密的不对称星周物质(CSM)中出现的时间。连续极化和PA的时间演化与非球面SN爆炸相一致，与CSM相比具有明显的几何特征。SN 2023ixf在激波电离阶段的快速跟踪光谱偏振测量揭示了导致爆炸的异常不对称的质量损失过程。
{"title":"Early Time Spectropolarimetry of the Aspherical Type II Supernova SN 2023ixf","authors":"Sergiy S. Vasylyev, Yi 轶 Yang 杨, Alexei V. Filippenko, Kishore C. Patra, Thomas G. Brink, Lifan Wang, Ryan Chornock, Raffaella Margutti, Elinor L. Gates, Adam J. Burgasser, Preethi R. Karpoor, Natalie LeBaron, Emma Softich, Christopher A. Theissen, Eli Wiston, WeiKang Zheng","doi":"10.3847/2041-8213/acf1a3","DOIUrl":"https://doi.org/10.3847/2041-8213/acf1a3","url":null,"abstract":"Abstract We present six epochs of optical spectropolarimetry of the Type II supernova (SN) 2023ixf ranging from ∼2 to 15 days after the explosion. Polarimetry was obtained with the Kast double spectrograph on the Shane 3 m telescope at Lick Observatory, representing the earliest such observations ever captured for an SN. We observe a high continuum polarization p cont ≈ 1% on days +1.4 and +2.5 before dropping to 0.5% on day +3.5, persisting at that level up to day +14.5. Remarkably, this change coincides temporally with the disappearance of highly ionized “flash” features. The decrease of the continuum polarization is accompanied by a ∼70° rotation of the polarization position angle (PA) as seen across the continuum. The early evolution of the polarization may indicate different geometric configurations of the electron-scattering atmosphere as seen before and after the disappearance of the emission lines associated with highly ionized species (e.g., He ii , C iv , and N iii ), which are likely produced by elevated mass loss shortly prior to the SN explosion. We interpret the rapid change of polarization and PA from days +2.5 to +4.5 as the time when the SN ejecta emerge from the dense asymmetric circumstellar material (CSM). The temporal evolution of the continuum polarization and the PA is consistent with an aspherical SN explosion that exhibits a distinct geometry compared to the CSM. The rapid follow-up spectropolarimetry of SN 2023ixf during the shock ionization phase reveals an exceptionally asymmetric mass-loss process leading up to the explosion.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134935512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2023-10-01DOI: 10.3847/2041-8213/acf4fd
Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Emiko Gardiner, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Levi Schult, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sarah J. Vigeland, Haley M. Wahl, Caitlin A. Witt, Olivia Young
Abstract The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has reported evidence for the presence of an isotropic nanohertz gravitational-wave background (GWB) in its 15 yr data set. However, if the GWB is produced by a population of inspiraling supermassive black hole binary (SMBHB) systems, then the background is predicted to be anisotropic, depending on the distribution of these systems in the local Universe and the statistical properties of the SMBHB population. In this work, we search for anisotropy in the GWB using multiple methods and bases to describe the distribution of the GWB power on the sky. We do not find significant evidence of anisotropy. By modeling the angular power distribution as a sum over spherical harmonics (where the coefficients are not bound to always generate positive power everywhere), we find that the Bayesian 95% upper limit on the level of dipole anisotropy is ( C l =1 / C l =0 ) < 27%. This is similar to the upper limit derived under the constraint of positive power everywhere, indicating that the dipole may be close to the data-informed regime. By contrast, the constraints on anisotropy at higher spherical-harmonic multipoles are strongly prior dominated. We also derive conservative estimates on the anisotropy expected from a random distribution of SMBHB systems using astrophysical simulations conditioned on the isotropic GWB inferred in the 15 yr data set and show that this data set has sufficient sensitivity to probe a large fraction of the predicted level of anisotropy. We end by highlighting the opportunities and challenges in searching for anisotropy in pulsar timing array data.
北美纳赫兹引力波天文台(nanogravity)报告了在其15年的数据集中存在各向同性纳赫兹引力波背景(GWB)的证据。然而，如果GWB是由超大质量黑洞双星(SMBHB)系统产生的，那么根据这些系统在局部宇宙中的分布和SMBHB种群的统计特性，预计背景是各向异性的。在这项工作中，我们使用多种方法和基础来寻找GWB的各向异性，以描述GWB功率在天空中的分布。我们没有发现显著的各向异性证据。通过将角功率分布建模为球面谐波的和(其中系数并不一定总是在任何地方产生正功率)，我们发现偶极子各向异性水平上的贝叶斯95%上限为(C l =1 / C l =0) <27%。这与处处在正功率约束下导出的上限相似，表明偶极子可能接近于数据知情的状态。相比之下，高球谐多极的各向异性约束是强烈优先支配的。我们还利用15年数据集中推断的各向同性GWB的天体物理模拟，对SMBHB系统随机分布的各向异性进行了保守估计，并表明该数据集具有足够的灵敏度，可以探测预测的各向异性水平的很大一部分。最后，我们强调了在脉冲星定时阵列数据中寻找各向异性的机遇和挑战。
{"title":"The NANOGrav 15 yr Data Set: Search for Anisotropy in the Gravitational-wave Background","authors":"Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Emiko Gardiner, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Levi Schult, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sarah J. Vigeland, Haley M. Wahl, Caitlin A. Witt, Olivia Young","doi":"10.3847/2041-8213/acf4fd","DOIUrl":"https://doi.org/10.3847/2041-8213/acf4fd","url":null,"abstract":"Abstract The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has reported evidence for the presence of an isotropic nanohertz gravitational-wave background (GWB) in its 15 yr data set. However, if the GWB is produced by a population of inspiraling supermassive black hole binary (SMBHB) systems, then the background is predicted to be anisotropic, depending on the distribution of these systems in the local Universe and the statistical properties of the SMBHB population. In this work, we search for anisotropy in the GWB using multiple methods and bases to describe the distribution of the GWB power on the sky. We do not find significant evidence of anisotropy. By modeling the angular power distribution as a sum over spherical harmonics (where the coefficients are not bound to always generate positive power everywhere), we find that the Bayesian 95% upper limit on the level of dipole anisotropy is ( C l =1 / C l =0 ) < 27%. This is similar to the upper limit derived under the constraint of positive power everywhere, indicating that the dipole may be close to the data-informed regime. By contrast, the constraints on anisotropy at higher spherical-harmonic multipoles are strongly prior dominated. We also derive conservative estimates on the anisotropy expected from a random distribution of SMBHB systems using astrophysical simulations conditioned on the isotropic GWB inferred in the 15 yr data set and show that this data set has sufficient sensitivity to probe a large fraction of the predicted level of anisotropy. We end by highlighting the opportunities and challenges in searching for anisotropy in pulsar timing array data.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134937020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Abstract Accretion of magnetized gas on compact astrophysical objects such as black holes (BHs) has been successfully modeled using general relativistic magnetohydrodynamic (GRMHD) simulations. These simulations have largely been performed in the Kerr metric, which describes the spacetime of a vacuum and stationary spinning BH in general relativity (GR). The simulations have revealed important clues to the physics of accretion flows and jets near the BH event horizon and have been used to interpret recent Event Horizon Telescope images of the supermassive BHs M87* and Sgr A*. The GRMHD simulations require the spacetime metric to be given in horizon-penetrating coordinates such that all metric coefficients are regular at the event horizon. Only a few metrics, notably the Kerr metric and its electrically charged spinning analog, the Kerr–Newman metric, are currently available in such coordinates. We report here horizon-penetrating forms of a large class of stationary, axisymmetric, spinning metrics. These can be used to carry out GRMHD simulations of accretion on spinning, nonvacuum BHs and non-BHs within GR, as well as accretion on spinning objects described by non-GR metric theories of gravity.
{"title":"Toward General Relativistic Magnetohydrodynamics Simulations in Stationary Nonvacuum Spacetimes","authors":"Prashant Kocherlakota, Ramesh Narayan, Koushik Chatterjee, Alejandro Cruz-Osorio, Yosuke Mizuno","doi":"10.3847/2041-8213/acfd1f","DOIUrl":"https://doi.org/10.3847/2041-8213/acfd1f","url":null,"abstract":"Abstract Accretion of magnetized gas on compact astrophysical objects such as black holes (BHs) has been successfully modeled using general relativistic magnetohydrodynamic (GRMHD) simulations. These simulations have largely been performed in the Kerr metric, which describes the spacetime of a vacuum and stationary spinning BH in general relativity (GR). The simulations have revealed important clues to the physics of accretion flows and jets near the BH event horizon and have been used to interpret recent Event Horizon Telescope images of the supermassive BHs M87* and Sgr A*. The GRMHD simulations require the spacetime metric to be given in horizon-penetrating coordinates such that all metric coefficients are regular at the event horizon. Only a few metrics, notably the Kerr metric and its electrically charged spinning analog, the Kerr–Newman metric, are currently available in such coordinates. We report here horizon-penetrating forms of a large class of stationary, axisymmetric, spinning metrics. These can be used to carry out GRMHD simulations of accretion on spinning, nonvacuum BHs and non-BHs within GR, as well as accretion on spinning objects described by non-GR metric theories of gravity.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"209 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135606549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2023-10-01DOI: 10.3847/2041-8213/acf92a
K. Sowmya, A. I. Shapiro, L. H. M. Rouppe van der Voort, N. A. Krivova, S. K. Solanki
Abstract The S -index is a measure of emission in the Ca ii H and K lines and is a widely used proxy of stellar magnetic activity. It has been assumed until now that the S -index is mainly affected by bright plage regions in the chromosphere. In particular, the effect of starspots on the S -index has been neglected. In this study, we revisit this assumption. For this, we analyze high-resolution observations of sunspots recorded in the Ca ii H spectral line at the Swedish 1 m Solar Telescope and determine the contrast of spots with respect to the quiet surroundings. We find that the Ca ii H line core averaged over whole sunspots (including superpenumbrae) is brighter than in the quiet surroundings and that the spot contrast in the line core is comparable to the facular contrast. This allows us to get a first estimate of the influence of spots on the S -index. We show that spots increase the S -index. While this increase is quite small for the Sun, it becomes significantly larger for more active stars. Further, we show that the inclusion of the contribution of spots to the S -index strongly affects the relationship between the S -index and stellar disk area coverages by spots and faculae, and present the new relations.
S指数是测量Ca ii H和K线发射的指标，是广泛使用的恒星磁活动的代理。到目前为止，人们一直认为S指数主要受色球层中亮斑区域的影响。特别是，星黑子对S指数的影响一直被忽略。在这项研究中，我们重新审视了这一假设。为此，我们分析了瑞典1米太阳望远镜在Ca ii H光谱线上记录的太阳黑子的高分辨率观测结果，并确定了黑子与安静环境的对比。我们发现，在整个太阳黑子(包括超半影)上平均的Ca ii H线核心比在安静的环境中更亮，并且线核心的黑子对比度与斑对比度相当。这使我们能够初步估计点对S指数的影响。我们发现斑点增加了S指数。虽然这种增加对太阳来说相当小，但对于更活跃的恒星来说，它会变得更大。此外，我们还证明了黑子对S指数的贡献对S指数与黑子和光斑覆盖的星盘面积之间的关系有强烈的影响，并提出了新的关系。
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Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acfa98
Benjamin L. Davis, Zehao 泽灏 Jin 金
Abstract Supermassive black holes (SMBHs) are tiny in comparison to the galaxies they inhabit, yet they manage to influence and coevolve along with their hosts. Evidence of this mutual development is observed in the structure and dynamics of galaxies and their correlations with black hole mass ( M • ). For our study, we focus on relative parameters that are unique to only disk galaxies. As such, we quantify the structure of spiral galaxies via their logarithmic spiral-arm pitch angles ( ϕ ) and their dynamics through the maximum rotational velocities of their galactic disks ( v max ). In the past, we have studied black hole mass scaling relations between M • and ϕ or v max , separately. Now, we combine the three parameters into a trivariate M • – ϕ – v max relationship that yields best-in-class accuracy in prediction of black hole masses in spiral galaxies. Because most black hole mass scaling relations have been created from samples of the largest SMBHs within the most massive galaxies, they lack certainty when extrapolated to low-mass spiral galaxies. Thus, it is difficult to confidently use existing scaling relations when trying to identify galaxies that might harbor the elusive class of intermediate-mass black holes (IMBHs). Therefore, we offer our novel relationship as an ideal predictor to search for IMBHs and probe the low-mass end of the black hole mass function by utilizing spiral galaxies. Already with rotational velocities widely available for a large population of galaxies and pitch angles readily measurable from uncalibrated images, we expect that the M • – ϕ – v max fundamental plane will be a useful tool for estimating black hole masses, even at high redshifts.
与它们所在的星系相比，超大质量黑洞(SMBHs)很小，但它们设法影响并与宿主共同进化。这种相互发展的证据是在星系的结构和动力学以及它们与黑洞质量(M•)的相关性中观察到的。在我们的研究中，我们关注的是只有盘状星系才特有的相对参数。因此，我们通过对数螺旋臂俯仰角(ϕ)量化螺旋星系的结构，并通过其星系盘的最大旋转速度(vmax)量化其动力学。过去，我们分别研究了M•与φ或v max之间的黑洞质量缩放关系。现在，我们将这三个参数组合成一个三元变量M•- φ - v max关系，在预测螺旋星系中的黑洞质量方面产生一流的精度。因为大多数黑洞的质量尺度关系都是由最大质量星系中最大的SMBHs的样本建立的，所以当外推到低质量螺旋星系时，它们缺乏确定性。因此，在试图识别可能包含难以捉摸的中等质量黑洞(IMBHs)的星系时，很难自信地使用现有的缩放关系。因此，我们提供了新的关系，作为一个理想的预测器来搜索IMBHs，并利用螺旋星系探测黑洞质量函数的低质量端。由于大量星系的旋转速度已经广泛可用，并且俯仰角很容易从未经校准的图像中测量出来，我们预计M•- φ - v max基本平面将成为估计黑洞质量的有用工具，即使在高红移时也是如此。
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Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acfe7c
Hao Zhang, Lorenzo Sironi, Dimitrios Giannios, Maria Petropoulou
Abstract Magnetic reconnection is often invoked as a source of high-energy particles, and in relativistic astrophysical systems it is regarded as a prime candidate for powering fast and bright flares. We present a novel analytical model—supported and benchmarked with large-scale three-dimensional kinetic particle-in-cell simulations in electron–positron plasmas—that elucidates the physics governing the generation of power-law energy spectra in relativistic reconnection. Particles with Lorentz factor γ ≳ 3 σ (here, σ is the magnetization) gain most of their energy in the inflow region, while meandering between the two sides of the reconnection layer. Their acceleration time is <?CDATA ${t}_{mathrm{acc}}sim gamma ,{eta }_{mathrm{rec}}^{-1}{omega }_{{rm{c}}}^{-1}simeq 20,gamma ,{omega }_{{rm{c}}}^{-1}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>acc</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mi>γ</mml:mi> <mml:mspace width="0.25em" /> <mml:msubsup> <mml:mrow> <mml:mi>η</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>rec</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> <mml:msubsup> <mml:mrow> <mml:mi>ω</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">c</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> <mml:mo>≃</mml:mo> <mml:mn>20</mml:mn> <mml:mspace width="0.25em" /> <mml:mi>γ</mml:mi> <mml:mspace width="0.25em" /> <mml:msubsup> <mml:mrow> <mml:mi>ω</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">c</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> , where η rec ≃ 0.06 is the inflow speed in units of the speed of light and ω c = eB 0 / mc is the gyrofrequency in the upstream magnetic field. They leave the region of active energization after t esc , when they get captured by one of the outflowing flux ropes of reconnected plasma. We directly measure t esc in our simulations and find that t esc ∼ t acc for σ ≳ few. This leads to a universal (i.e., σ -independent) power-law spectrum <?CDATA ${{dN}}_{mathrm{free}}/dgamma propto {gamma }^{-1}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="italic">dN</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>free</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:mi>d</mml:mi> <mml:mi>γ</mml:mi> <mml:mo>∝</mml:mo> <mml:msup> <mml:mrow> <mml:mi>γ</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> for the particles undergoing active acceleration, and <?CDATA ${dN}/dgamma propto {gamma }^{-2}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="italic">dN</mml:mi> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <
磁重联通常被认为是高能粒子的来源，在相对论天体物理系统中，它被认为是驱动快速明亮耀斑的主要候选者。我们提出了一种新的分析模型，以电子-正电子等离子体中大规模三维动力学粒子在细胞内的模拟为基准，阐明了相对论重连中幂律能谱产生的物理规律。具有洛伦兹因子γ≥3 σ (σ为磁化强度)的粒子在流入区获得大部分能量，而在重联层的两侧之间徘徊。它们的加速时间为t acc ~ γ η rec−1 ω c−1≃20 γ ω c−1，其中η rec≈0.06为以光速为单位的流入速度，ω c = eB 0 / mc为上游磁场的陀螺频率。当它们被重新连接的等离子体的一条流出的通量绳捕获时，它们离开了主动通电区域。在我们的模拟中，我们直接测量了t esc，并发现t esc ~ t acc对于σ < 0。这导致了一个普遍的(即σ无关的)幂律谱dN free / d γ∝γ−1对于经历主动加速的粒子，和dN / d γ∝γ−2对于整个粒子群。我们的结果有助于阐明在天体物理非热源中普遍存在的幂律粒子和光子光谱。
{"title":"The Origin of Power-law Spectra in Relativistic Magnetic Reconnection","authors":"Hao Zhang, Lorenzo Sironi, Dimitrios Giannios, Maria Petropoulou","doi":"10.3847/2041-8213/acfe7c","DOIUrl":"https://doi.org/10.3847/2041-8213/acfe7c","url":null,"abstract":"Abstract Magnetic reconnection is often invoked as a source of high-energy particles, and in relativistic astrophysical systems it is regarded as a prime candidate for powering fast and bright flares. We present a novel analytical model—supported and benchmarked with large-scale three-dimensional kinetic particle-in-cell simulations in electron–positron plasmas—that elucidates the physics governing the generation of power-law energy spectra in relativistic reconnection. Particles with Lorentz factor γ ≳ 3 σ (here, σ is the magnetization) gain most of their energy in the inflow region, while meandering between the two sides of the reconnection layer. Their acceleration time is <?CDATA ${t}_{mathrm{acc}}sim gamma ,{eta }_{mathrm{rec}}^{-1}{omega }_{{rm{c}}}^{-1}simeq 20,gamma ,{omega }_{{rm{c}}}^{-1}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>acc</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mi>γ</mml:mi> <mml:mspace width=\"0.25em\" /> <mml:msubsup> <mml:mrow> <mml:mi>η</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>rec</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> <mml:msubsup> <mml:mrow> <mml:mi>ω</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant=\"normal\">c</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> <mml:mo>≃</mml:mo> <mml:mn>20</mml:mn> <mml:mspace width=\"0.25em\" /> <mml:mi>γ</mml:mi> <mml:mspace width=\"0.25em\" /> <mml:msubsup> <mml:mrow> <mml:mi>ω</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant=\"normal\">c</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> , where η rec ≃ 0.06 is the inflow speed in units of the speed of light and ω c = eB 0 / mc is the gyrofrequency in the upstream magnetic field. They leave the region of active energization after t esc , when they get captured by one of the outflowing flux ropes of reconnected plasma. We directly measure t esc in our simulations and find that t esc ∼ t acc for σ ≳ few. This leads to a universal (i.e., σ -independent) power-law spectrum <?CDATA ${{dN}}_{mathrm{free}}/dgamma propto {gamma }^{-1}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mi mathvariant=\"italic\">dN</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>free</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy=\"true\">/</mml:mo> </mml:mrow> <mml:mi>d</mml:mi> <mml:mi>γ</mml:mi> <mml:mo>∝</mml:mo> <mml:msup> <mml:mrow> <mml:mi>γ</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> for the particles undergoing active acceleration, and <?CDATA ${dN}/dgamma propto {gamma }^{-2}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mi mathvariant=\"italic\">dN</mml:mi> <mml:mrow> <mml:mo stretchy=\"true\">/</mml:mo> </mml:mrow> <","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135810327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2023-10-01DOI: 10.3847/2041-8213/acfee3
Yunjing Wu, Feige Wang, Zheng Cai, Xiaohui Fan, Kristian Finlator, Jinyi Yang, Joseph F. Hennawi, Fengwu Sun, Jaclyn B. Champagne, Xiaojing Lin, Zihao Li, Zuyi Chen, Eduardo Bañados, George D. Becker, Sarah E. I. Bosman, Gustavo Bruzual, Stephane Charlot, Hsiao-Wen Chen, Jacopo Chevallard, Anna-Christina Eilers, Emanuele Paolo Farina, Xiangyu Jin, Hyunsung D. Jun, Koki Kakiichi, Mingyu Li, Weizhe Liu, Maria A. Pudoka, Wei Leong Tee, Zhang-Liang Xie, Siwei Zou
Abstract The launch of JWST opens a new window for studying the connection between metal-line absorbers and galaxies at the end of the Epoch of Reionization. Previous studies have detected absorber–galaxy pairs in limited quantities through ground-based observations. To enhance our understanding of the relationship between absorbers and their host galaxies at z > 5, we utilized the NIRCam wide-field slitless spectroscopy to search for absorber-associated galaxies by detecting their rest-frame optical emission lines (e.g., [O III ] + H β ). We report the discovery of a Mg ii -associated galaxy at z = 5.428 using data from the JWST ASPIRE program. The Mg ii absorber is detected on the spectrum of quasar J0305–3150 with a rest-frame equivalent width of 0.74 Å. The associated galaxy has an [O III ] luminosity of 10 42.5 erg s −1 with an impact parameter of 24.9 pkpc. The joint Hubble Space Telescope–JWST spectral energy distribution (SED) implies a stellar mass and star formation rate of M * ≈ 10 8.8 M ⊙ , star-formation rate ≈ 10 M ⊙ yr −1 . Its [O III ] equivalent width and stellar mass are typical of [O III ] emitters at this redshift. Furthermore, connecting the outflow starting time to the SED-derived stellar age, the outflow velocity of this galaxy is ∼300 km s −1 , consistent with theoretical expectations. We identified six additional [O III ] emitters with impact parameters of up to ∼300 pkpc at similar redshifts (∣ dv ∣ < 1000 km s −1 ). The observed number is consistent with that in cosmological simulations. This pilot study suggests that systematically investigating the absorber–galaxy connection within the ASPIRE program will provide insights into the metal-enrichment history in the early Universe.
{"title":"A SPectroscopic Survey of Biased Halos in the Reionization Era (ASPIRE): JWST Discovers an Overdensity around a Metal Absorption-selected Galaxy at z ∼ 5.5","authors":"Yunjing Wu, Feige Wang, Zheng Cai, Xiaohui Fan, Kristian Finlator, Jinyi Yang, Joseph F. Hennawi, Fengwu Sun, Jaclyn B. Champagne, Xiaojing Lin, Zihao Li, Zuyi Chen, Eduardo Bañados, George D. Becker, Sarah E. I. Bosman, Gustavo Bruzual, Stephane Charlot, Hsiao-Wen Chen, Jacopo Chevallard, Anna-Christina Eilers, Emanuele Paolo Farina, Xiangyu Jin, Hyunsung D. Jun, Koki Kakiichi, Mingyu Li, Weizhe Liu, Maria A. Pudoka, Wei Leong Tee, Zhang-Liang Xie, Siwei Zou","doi":"10.3847/2041-8213/acfee3","DOIUrl":"https://doi.org/10.3847/2041-8213/acfee3","url":null,"abstract":"Abstract The launch of JWST opens a new window for studying the connection between metal-line absorbers and galaxies at the end of the Epoch of Reionization. Previous studies have detected absorber–galaxy pairs in limited quantities through ground-based observations. To enhance our understanding of the relationship between absorbers and their host galaxies at z > 5, we utilized the NIRCam wide-field slitless spectroscopy to search for absorber-associated galaxies by detecting their rest-frame optical emission lines (e.g., [O III ] + H β ). We report the discovery of a Mg ii -associated galaxy at z = 5.428 using data from the JWST ASPIRE program. The Mg ii absorber is detected on the spectrum of quasar J0305–3150 with a rest-frame equivalent width of 0.74 Å. The associated galaxy has an [O III ] luminosity of 10 42.5 erg s −1 with an impact parameter of 24.9 pkpc. The joint Hubble Space Telescope–JWST spectral energy distribution (SED) implies a stellar mass and star formation rate of M * ≈ 10 8.8 M ⊙ , star-formation rate ≈ 10 M ⊙ yr −1 . Its [O III ] equivalent width and stellar mass are typical of [O III ] emitters at this redshift. Furthermore, connecting the outflow starting time to the SED-derived stellar age, the outflow velocity of this galaxy is ∼300 km s −1 , consistent with theoretical expectations. We identified six additional [O III ] emitters with impact parameters of up to ∼300 pkpc at similar redshifts (∣ dv ∣ < 1000 km s −1 ). The observed number is consistent with that in cosmological simulations. This pilot study suggests that systematically investigating the absorber–galaxy connection within the ASPIRE program will provide insights into the metal-enrichment history in the early Universe.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135965106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2023-10-01DOI: 10.3847/2041-8213/acfedf
Shun-Yi Lan, Xiang-Cun Meng
Abstract A millisecond pulsar (MSP) is an old neutron star (NS) that has accreted material from its companion star, causing it to spin up, which is known as the recycling scenario. During the mass transfer phase, the system manifests itself as an X-ray binary. PSR J1402+13 is an MSP with a spin period of 5.89 ms and a spin period derivative of logṖspin=−16.32 . These properties make it a notable object within the pulsar population, as MSPs typically exhibit low spin period derivatives. In this paper, we aim to explain how an MSP can possess a high spin period derivative by binary evolution. By utilizing the stellar evolution code MESA , we examine the effects of irradiation on the companion star and the propeller effect on the NS during binary evolution. We demonstrate that irradiation can modify the spin period and mass of an MSP, resulting in a higher spin period derivative. These results suggest that the irradiation effect may serve as a key factor in explaining MSPs with high spin period derivatives.
毫秒脉冲星(MSP)是一颗古老的中子星(NS)，它从伴星中吸积物质，导致其旋转，这被称为再循环情景。在传质阶段，系统表现为x射线双星。PSR J1402+13的自旋周期为5.89 ms，自旋周期导数为log P (spin) =−16.32。这些特性使它成为脉冲星群中一个值得注意的对象，因为msp通常表现出低自旋周期导数。在本文中，我们的目的是通过二元演化来解释MSP如何具有高自旋周期导数。利用恒星演化代码MESA，研究了双星演化过程中辐照对伴星的影响和螺旋桨对NS的影响。我们证明了辐照可以改变MSP的自旋周期和质量，从而导致更高的自旋周期导数。这些结果表明，辐照效应可能是解释具有高自旋周期衍生物的MSPs的关键因素。
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