Pub Date : 2024-10-17DOI: 10.3847/1538-4357/ad6ddb
Shing-Chi Leung and Ken’ichi Nomoto
The spectra of several galaxies, including extremely metal-poor galaxies from EMPRESS, have shown that the abundances of some Si-group elements differ from “spherical” explosion models of massive stars. This leads to the speculation that these galaxies have experienced supernova explosions with high asphericity, where mixing and fallback of the inner ejecta with the outer material lead to the distinctive chemical compositions. In this paper, we consider the jet-driven supernova models by direct 2D hydrodynamics simulations using progenitors of about 20–25 M⊙ at zero metallicity. We investigate how the abundance patterns depend on the progenitor mass, mass cut, and asphericity of the explosion. We compare the observable with available supernova and galaxy catalogs based on 56Ni, ejecta mass, and individual element ratios. The proximity of our results with the observational data signifies the importance of aspherical supernova explosions in chemical evolution of these galaxies. Our models will provide the theoretical counterpart for understanding the chemical abundances of high-z galaxies measured by the James Webb Space Telescope.
{"title":"Hydrodynamics and Nucleosynthesis of Jet-driven Supernovae. II. Comparisons with Abundances of Extremely Metal-poor Galaxies and Constraints on Supernova Progenitors","authors":"Shing-Chi Leung and Ken’ichi Nomoto","doi":"10.3847/1538-4357/ad6ddb","DOIUrl":"https://doi.org/10.3847/1538-4357/ad6ddb","url":null,"abstract":"The spectra of several galaxies, including extremely metal-poor galaxies from EMPRESS, have shown that the abundances of some Si-group elements differ from “spherical” explosion models of massive stars. This leads to the speculation that these galaxies have experienced supernova explosions with high asphericity, where mixing and fallback of the inner ejecta with the outer material lead to the distinctive chemical compositions. In this paper, we consider the jet-driven supernova models by direct 2D hydrodynamics simulations using progenitors of about 20–25 M⊙ at zero metallicity. We investigate how the abundance patterns depend on the progenitor mass, mass cut, and asphericity of the explosion. We compare the observable with available supernova and galaxy catalogs based on 56Ni, ejecta mass, and individual element ratios. The proximity of our results with the observational data signifies the importance of aspherical supernova explosions in chemical evolution of these galaxies. Our models will provide the theoretical counterpart for understanding the chemical abundances of high-z galaxies measured by the James Webb Space Telescope.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448726","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 : 2024-10-17DOI: 10.3847/1538-4357/ad7393
Gal Birenbaum, Ramandeep Gill, Omer Bromberg, Paz Beniamini and Jonathan Granot
Gamma-ray bursts (GRBs) are powered by ultrarelativistic jets. The launching sites of these jets are surrounded by dense media, which the jets must cross before they can accelerate and release high-energy emission. Interaction with the medium leads to the formation of a mildly relativistic sheath around the jet, resulting in an angular structure to the jet’s asymptotic Lorentz factor and energy per solid angle, which modifies the afterglow emission. We build a semi-analytical tool to analyze the afterglow light curve and polarization signatures of jets observed from a wide range of viewing angles, and focus on ones with slowly declining energy profiles known as shallow jets. We find overall lower polarization compared to the classical top hat jet model. We provide an analytical expression for the peak polarization degree as a function of the energy profile power-law index, magnetic field configuration, and viewing angle, and show that it occurs near the light-curve break time for all viewers. When applying our tool to GRB 221009A, suspected to originate from a shallow jet, we find that the suggested jet structures for this event agree with the upper limits placed on the afterglow polarization in the optical and X-ray bands. We also find that at early times the polarization levels may be significantly higher, allowing for a potential distinction between different jet structure models and possibly constraining the magnetization in both forward and reverse shocks at that stage.
伽马射线暴（GRB）由超相对论射流驱动。这些喷流的发射地点周围都是致密介质，喷流必须穿过这些介质才能加速并释放出高能量。与介质的相互作用导致在喷流周围形成轻度相对论鞘，从而使喷流的渐近洛伦兹系数和每固角能量的角度结构发生变化，从而改变了余辉发射。我们建立了一个半分析工具，用于分析从各种视角观测到的喷流的余辉光曲线和偏振特征，并重点关注能量曲线缓慢下降的喷流，即浅喷流。与经典的 "顶帽 "喷流模型相比，我们发现其偏振程度总体较低。我们提供了峰值偏振度与能量剖面幂律指数、磁场配置和观测角度的函数关系的分析表达式，并表明它出现在所有观测者的光曲线断裂时间附近。当把我们的工具应用于怀疑源自浅喷流的 GRB 221009A 时，我们发现该事件的喷流结构与光学和 X 射线波段中余辉偏振的上限一致。我们还发现，在早期，极化水平可能要高得多，从而有可能区分出不同的喷流结构模型，并有可能在这一阶段对正向和反向冲击中的磁化进行约束。
{"title":"Afterglow Linear Polarization Signatures from Shallow GRB Jets: Implications for Energetic GRBs","authors":"Gal Birenbaum, Ramandeep Gill, Omer Bromberg, Paz Beniamini and Jonathan Granot","doi":"10.3847/1538-4357/ad7393","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7393","url":null,"abstract":"Gamma-ray bursts (GRBs) are powered by ultrarelativistic jets. The launching sites of these jets are surrounded by dense media, which the jets must cross before they can accelerate and release high-energy emission. Interaction with the medium leads to the formation of a mildly relativistic sheath around the jet, resulting in an angular structure to the jet’s asymptotic Lorentz factor and energy per solid angle, which modifies the afterglow emission. We build a semi-analytical tool to analyze the afterglow light curve and polarization signatures of jets observed from a wide range of viewing angles, and focus on ones with slowly declining energy profiles known as shallow jets. We find overall lower polarization compared to the classical top hat jet model. We provide an analytical expression for the peak polarization degree as a function of the energy profile power-law index, magnetic field configuration, and viewing angle, and show that it occurs near the light-curve break time for all viewers. When applying our tool to GRB 221009A, suspected to originate from a shallow jet, we find that the suggested jet structures for this event agree with the upper limits placed on the afterglow polarization in the optical and X-ray bands. We also find that at early times the polarization levels may be significantly higher, allowing for a potential distinction between different jet structure models and possibly constraining the magnetization in both forward and reverse shocks at that stage.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448745","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 : 2024-10-17DOI: 10.3847/1538-4357/ad77d4
A. Hassanin, Amira Shimeis, Hadeer F. Sabeha and F. N. Minta
In this study, we have conducted an analysis of space weather disruptions that occurred on 19 January 2012. Our analysis identified three coronal mass ejections (CMEs), CME1, CME2, and CME3—which were ejected at 09:48:05 universal time (UT), 14:36:05 UT, and 16:12:06 UT, respectively. Nonrecurrent disturbances in space weather, such as geomagnetic storms, result from CMEs originating from the Sun and traveling toward Earth. We assess the contribution of CME–CME interactions on 2012 January 19 and the volume emission rate of nitric oxide (NO) near the Earth's upper atmosphere in prolonging the geomagnetic disturbances observed on 2012 January 23. The findings suggest an increase in intensity at the interacting boundaries of CME1 and CME2, indicating an increase in pressure and density, leading to the compression of the magnetosphere. The 3D reconstructions of the CMEs provide evidence of unequal expansion and rotations within coronagraphic frames attributed to structural variability in the background solar wind during the eruptions. Furthermore, highlights from the in situ observations suggest that the impact of the recurrent CMEs on the geomagnetic disturbance was more pronounced within the auroral region synchronizing with a significant increase in NO volume emission rate on 2012 January 23, near the upper Earth's atmosphere. Our focus is on exploring the interactions between these CMEs to understand their potential contribution to the extended duration of the observed geomagnetic disturbance.
{"title":"Recurrent Coronal Mass Ejections and Their Geomagnetic Storms Association on 2012 January 19: Solar Surface to Upper Earth’s Atmosphere Analyses","authors":"A. Hassanin, Amira Shimeis, Hadeer F. Sabeha and F. N. Minta","doi":"10.3847/1538-4357/ad77d4","DOIUrl":"https://doi.org/10.3847/1538-4357/ad77d4","url":null,"abstract":"In this study, we have conducted an analysis of space weather disruptions that occurred on 19 January 2012. Our analysis identified three coronal mass ejections (CMEs), CME1, CME2, and CME3—which were ejected at 09:48:05 universal time (UT), 14:36:05 UT, and 16:12:06 UT, respectively. Nonrecurrent disturbances in space weather, such as geomagnetic storms, result from CMEs originating from the Sun and traveling toward Earth. We assess the contribution of CME–CME interactions on 2012 January 19 and the volume emission rate of nitric oxide (NO) near the Earth's upper atmosphere in prolonging the geomagnetic disturbances observed on 2012 January 23. The findings suggest an increase in intensity at the interacting boundaries of CME1 and CME2, indicating an increase in pressure and density, leading to the compression of the magnetosphere. The 3D reconstructions of the CMEs provide evidence of unequal expansion and rotations within coronagraphic frames attributed to structural variability in the background solar wind during the eruptions. Furthermore, highlights from the in situ observations suggest that the impact of the recurrent CMEs on the geomagnetic disturbance was more pronounced within the auroral region synchronizing with a significant increase in NO volume emission rate on 2012 January 23, near the upper Earth's atmosphere. Our focus is on exploring the interactions between these CMEs to understand their potential contribution to the extended duration of the observed geomagnetic disturbance.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448750","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 : 2024-10-17DOI: 10.3847/1538-4357/ad701b
Yolanda Jiménez-Teja, Antonio Gimenez-Alcazar, Renato A. Dupke, Patrick Prado-Santos, Jose M. Viĺchez, Nícolas O. L. de Oliveira, Paola Dimauro, Anton M. Koekemoer, Patrick Kelly, Jens Hjorth and Wenlei Chen
We present the most detailed spectrum of intracluster light (ICL) in an individual cluster to date, the relaxed system RX J2129.7+0005, at z ∼ 0.234. Using 15 broadband, deep images observed with the Hubble Space Telescope and JWST in the optical and the infrared, plus deep integral field spectroscopy from MUSE, we computed a total of 3696 ICL maps spanning the spectral range ∼0.4−5 μm with our algorithm CICLE, a method that is extremely well suited to analyzing large samples of data in a fully automated way. We used both parametric and nonparametric approaches to fit the spectral energy distribution of the ICL and infer its physical properties, yielding a stellar mass between 11.5 and 12.7 and an average age between 9.7 and 10.5 Gyr, from CIGALE and Prospector results. This implies that the ICL in RX J2129.7+0005 is, on average, older than that of disturbed clusters, suggesting that the contribution from different stellar populations to the ICL is at play depending on the cluster’s dynamical state. Coupled with X-ray observations of the hot gas distribution, we confirm the relaxed state of RX J2129.7+0005, showing clear signs of sloshing after a last major merger with a high-mass-ratio satellite that could have happened ∼6.6 Gyr ago in a relatively radial orbit. The presence of substructure in the ICL, such as shells, clouds with different densities and a certain degree of boxyness, and a clump, supports this scenario.
{"title":"First Joint MUSE, Hubble Space Telescope, and JWST Spectrophotometric Analysis of the Intracluster Light: The Case of the Relaxed Cluster RX J2129.7+0005","authors":"Yolanda Jiménez-Teja, Antonio Gimenez-Alcazar, Renato A. Dupke, Patrick Prado-Santos, Jose M. Viĺchez, Nícolas O. L. de Oliveira, Paola Dimauro, Anton M. Koekemoer, Patrick Kelly, Jens Hjorth and Wenlei Chen","doi":"10.3847/1538-4357/ad701b","DOIUrl":"https://doi.org/10.3847/1538-4357/ad701b","url":null,"abstract":"We present the most detailed spectrum of intracluster light (ICL) in an individual cluster to date, the relaxed system RX J2129.7+0005, at z ∼ 0.234. Using 15 broadband, deep images observed with the Hubble Space Telescope and JWST in the optical and the infrared, plus deep integral field spectroscopy from MUSE, we computed a total of 3696 ICL maps spanning the spectral range ∼0.4−5 μm with our algorithm CICLE, a method that is extremely well suited to analyzing large samples of data in a fully automated way. We used both parametric and nonparametric approaches to fit the spectral energy distribution of the ICL and infer its physical properties, yielding a stellar mass between 11.5 and 12.7 and an average age between 9.7 and 10.5 Gyr, from CIGALE and Prospector results. This implies that the ICL in RX J2129.7+0005 is, on average, older than that of disturbed clusters, suggesting that the contribution from different stellar populations to the ICL is at play depending on the cluster’s dynamical state. Coupled with X-ray observations of the hot gas distribution, we confirm the relaxed state of RX J2129.7+0005, showing clear signs of sloshing after a last major merger with a high-mass-ratio satellite that could have happened ∼6.6 Gyr ago in a relatively radial orbit. The presence of substructure in the ICL, such as shells, clouds with different densities and a certain degree of boxyness, and a clump, supports this scenario.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448944","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 : 2024-10-17DOI: 10.3847/1538-4357/ad4d85
Andrew G. Sullivan and Roger W. Romani
PSR J2215+5135 (J2215) is a “redback” spider pulsar, where the intrabinary shock (IBS) wraps around the pulsar rather than the stellar-mass companion. Spider orbital light curves are modulated, dominated by their binary companion thermal emission in the optical bands and by IBS synchrotron emission in the X-rays. We report on new XMM-Newton X-ray and U-band observations of J2215. We produce orbital light curves and use them to model the system properties. Our best-fit optical light model gives a neutron star mass MNS = 1.98 ± 0.08 M⊙, lower than previously reported. However, uncertainty in the stellar atmosphere metallicity, a parameter to which J2215 is unusually sensitive, requires us to consider an acceptable systematic plus statistical range of MNS ∼ 1.85–2.3 M⊙. From the X-ray analysis, we find that the IBS wraps around the pulsar but with a pulsar-wind-to-companion-wind-momentum ratio unusually close to unity, implying a flatter IBS geometry than seen in other spiders. Estimating the companion wind momentum and speed from the X-ray light curve, we find a companion mass-loss rate of yr−1 so that J2215 may become an isolated millisecond pulsar in ∼1 Gyr. Our X-ray analyses place constraints on the magnetization and particle density of the pulsar wind and support models of magnetic reconnection and particle acceleration in the highly magnetized relativistic IBS.
PSR J2215+5135 (J2215)是一颗 "红背 "蜘蛛脉冲星，其中的双星内冲击（IBS）包裹着脉冲星，而不是恒星质量的伴星。蜘蛛轨道光曲线是调制的，在光学波段主要受其双星伴星热辐射的影响，在 X 射线波段主要受 IBS 同步辐射的影响。我们报告了 XMM-Newton X 射线和 U 波段对 J2215 的最新观测结果。我们制作了轨道光曲线，并利用它们建立了系统特性模型。我们的最佳拟合光学光模型给出了中子星质量 MNS = 1.98 ± 0.08 M⊙，比以前报告的要低。然而，J2215 对恒星大气金属性这个参数异常敏感，它的不确定性要求我们考虑一个可接受的系统加统计范围，即 MNS ∼ 1.85-2.3 M⊙。通过 X 射线分析，我们发现 IBS 包裹着脉冲星，但脉冲星风与伴星风动量比异常接近于 1，这意味着 IBS 的几何形状比在其他蜘蛛星上看到的更扁平。根据X射线光曲线估算伴星风的动量和速度，我们发现伴星的质量损失率为年-1，因此J2215可能会在∼1 Gyr内成为一颗孤立的毫秒脉冲星。我们的X射线分析为脉冲星风的磁化和粒子密度提供了约束条件，并支持高磁化相对论IBS中的磁重联和粒子加速模型。
{"title":"The Intrabinary Shock and Companion Star of Redback Pulsar J2215+5135","authors":"Andrew G. Sullivan and Roger W. Romani","doi":"10.3847/1538-4357/ad4d85","DOIUrl":"https://doi.org/10.3847/1538-4357/ad4d85","url":null,"abstract":"PSR J2215+5135 (J2215) is a “redback” spider pulsar, where the intrabinary shock (IBS) wraps around the pulsar rather than the stellar-mass companion. Spider orbital light curves are modulated, dominated by their binary companion thermal emission in the optical bands and by IBS synchrotron emission in the X-rays. We report on new XMM-Newton X-ray and U-band observations of J2215. We produce orbital light curves and use them to model the system properties. Our best-fit optical light model gives a neutron star mass MNS = 1.98 ± 0.08 M⊙, lower than previously reported. However, uncertainty in the stellar atmosphere metallicity, a parameter to which J2215 is unusually sensitive, requires us to consider an acceptable systematic plus statistical range of MNS ∼ 1.85–2.3 M⊙. From the X-ray analysis, we find that the IBS wraps around the pulsar but with a pulsar-wind-to-companion-wind-momentum ratio unusually close to unity, implying a flatter IBS geometry than seen in other spiders. Estimating the companion wind momentum and speed from the X-ray light curve, we find a companion mass-loss rate of yr−1 so that J2215 may become an isolated millisecond pulsar in ∼1 Gyr. Our X-ray analyses place constraints on the magnetization and particle density of the pulsar wind and support models of magnetic reconnection and particle acceleration in the highly magnetized relativistic IBS.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448942","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 : 2024-10-17DOI: 10.3847/1538-4357/ad74f1
Charity Woodrum, Christina C. Williams, Marcia Rieke, Kevin N. Hainline, Raphael E. Hviding, Zhiyuan Ji, Robert Kennicutt and Christopher N. A. Willmer
We present near-infrared (NIR) spectroscopy using the MMT and Magellan infrared spectrograph for a sample of 29 massive galaxies ( ) at z ∼ 0.7 with optical spectroscopy from the Large Early Galaxy Astrophysics Census (LEGA-C) survey. Having both optical and NIR spectroscopy at this redshift allows us to measure the full suite of rest-optical strong emission lines, enabling the study of ionization sources and the rest-optical selection of active galactic nuclei (AGN), as well as the measurement of dust-corrected Hα-based star formation rates (SFRs). We find that 11 out of 29 galaxies host AGN. We infer the nonparametric star formation histories with the spectral energy distribution fitting code Prospector and classify galaxies as star-forming, green valley, or quiescent based on their most recent specific SFRs. We explore the connection between AGN activity and suppressed star formation, and find that 89% ± 15% of galaxies in the green valley or below host AGN, while only 15% ± 8% of galaxies above the green valley host AGN. We construct the star-forming main sequence (SFMS) and find that the AGN host galaxies are 0.37 dex below the SFMS, while galaxies without detectable AGN are consistent with being on the SFMS. However, when compared to a bootstrapped mass-matched sample, the SFRs of our sample of AGN host galaxies are consistent with the full LEGA-C sample. Based on this mass-matched analysis, we cannot rule out that this suppression of star formation is driven by other processes associated with the higher mass of the AGN sample. We therefore cannot link the presence of AGN activity to the quenching of star formation.
{"title":"Active Galactic Nuclei in the Green Valley at z ∼ 0.7","authors":"Charity Woodrum, Christina C. Williams, Marcia Rieke, Kevin N. Hainline, Raphael E. Hviding, Zhiyuan Ji, Robert Kennicutt and Christopher N. A. Willmer","doi":"10.3847/1538-4357/ad74f1","DOIUrl":"https://doi.org/10.3847/1538-4357/ad74f1","url":null,"abstract":"We present near-infrared (NIR) spectroscopy using the MMT and Magellan infrared spectrograph for a sample of 29 massive galaxies ( ) at z ∼ 0.7 with optical spectroscopy from the Large Early Galaxy Astrophysics Census (LEGA-C) survey. Having both optical and NIR spectroscopy at this redshift allows us to measure the full suite of rest-optical strong emission lines, enabling the study of ionization sources and the rest-optical selection of active galactic nuclei (AGN), as well as the measurement of dust-corrected Hα-based star formation rates (SFRs). We find that 11 out of 29 galaxies host AGN. We infer the nonparametric star formation histories with the spectral energy distribution fitting code Prospector and classify galaxies as star-forming, green valley, or quiescent based on their most recent specific SFRs. We explore the connection between AGN activity and suppressed star formation, and find that 89% ± 15% of galaxies in the green valley or below host AGN, while only 15% ± 8% of galaxies above the green valley host AGN. We construct the star-forming main sequence (SFMS) and find that the AGN host galaxies are 0.37 dex below the SFMS, while galaxies without detectable AGN are consistent with being on the SFMS. However, when compared to a bootstrapped mass-matched sample, the SFRs of our sample of AGN host galaxies are consistent with the full LEGA-C sample. Based on this mass-matched analysis, we cannot rule out that this suppression of star formation is driven by other processes associated with the higher mass of the AGN sample. We therefore cannot link the presence of AGN activity to the quenching of star formation.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448748","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 : 2024-10-17DOI: 10.3847/1538-4357/ad7587
Haifan Zhu, Wei Wang and Ziyuan Zhu
We present the results of bicoherence analysis for Swift J1727.8−1613 during its 2023 outburst, using data from Insight-HXMT. Our analysis focused on observations with quasiperiodic oscillations (QPOs) of frequencies greater than 1 Hz, revealing that all of them belong to type-C QPOs. We found a strong correlation between the QPO frequency and the hardness ratio, as well as a linear relationship between the QPO rms and the hardness ratio. The bicoherence analysis revealed a transition from a “web” pattern to a “hypotenuse” pattern in the low-energy (LE) and high-energy (HE) bands. In the bicoherence patterns, there are correlations between horizontal and vertical bicoherence at f1 = f2 = fQPO with count rates. The diagonal structure at f1 + f2 = fQPO becomes more prominent with increasing energy. Additionally, we discovered a new bicoherence pattern in the medium energy band from 10 to 20 keV; the diagonal structure at f1 + f2 = fhar is prominent only in this energy band, which we refer to as the “parallel” pattern. The bicoherence analysis indicates that the source is likely a low-inclination source.
{"title":"The Bicoherence Analysis of Type-C Quasiperiodic Oscillations in Swift J1727.8−1613","authors":"Haifan Zhu, Wei Wang and Ziyuan Zhu","doi":"10.3847/1538-4357/ad7587","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7587","url":null,"abstract":"We present the results of bicoherence analysis for Swift J1727.8−1613 during its 2023 outburst, using data from Insight-HXMT. Our analysis focused on observations with quasiperiodic oscillations (QPOs) of frequencies greater than 1 Hz, revealing that all of them belong to type-C QPOs. We found a strong correlation between the QPO frequency and the hardness ratio, as well as a linear relationship between the QPO rms and the hardness ratio. The bicoherence analysis revealed a transition from a “web” pattern to a “hypotenuse” pattern in the low-energy (LE) and high-energy (HE) bands. In the bicoherence patterns, there are correlations between horizontal and vertical bicoherence at f1 = f2 = fQPO with count rates. The diagonal structure at f1 + f2 = fQPO becomes more prominent with increasing energy. Additionally, we discovered a new bicoherence pattern in the medium energy band from 10 to 20 keV; the diagonal structure at f1 + f2 = fhar is prominent only in this energy band, which we refer to as the “parallel” pattern. The bicoherence analysis indicates that the source is likely a low-inclination source.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448751","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 : 2024-10-17DOI: 10.3847/1538-4357/ad79fd
H. Dottori and R. J. Díaz
We analyze data from the IRAS, Wide-field Infrared Survey Explorer, and Planck satellites, revealing an unresolved dust condensation at the center of the Fourcade–Figueroa galaxy (ESO270-G017), which may correspond to a forming nucleus. We model the condensation’s continuum spectrum in the spectral range from 3 to 1300 μm using the DUSTY code. The best-fit model, based on the chi-square test, indicates that the condensation is a shell with an outer temperature of Tout ≈ 12 K and an inner boundary temperature of Ti ≈ 500 K. The shell’s outer radius is ro = 86.2 pc, and the inner cavity radius is ri = 0.082 pc. The condensation produces an extinction AV = 50 mag, and its luminosity is Lc = 1.08 × 1034 W, which would correspond to a burst of massive star formation approximately similar to the central 5 pc of R 136 in the LMC and NGC 3603, the ionizing cluster of a giant Carina arm H ii region. The comparison with normal, luminous, and ultraluminous IR galaxies leads us to consider this obscured nucleus as the nearest and weakest object of this category.
我们分析了来自IRAS、宽视场红外巡天探测器和普朗克卫星的数据，发现在福克多-费格罗亚星系（ESO270-G017）的中心有一个未解决的尘埃凝聚体，它可能相当于一个正在形成的星系核。我们利用 DUSTY 代码在 3 到 1300 μm 光谱范围内建立了这个凝聚体的连续光谱模型。基于卡方检验的最佳拟合模型表明，凝结体是一个外壳，其外部温度为 Tout ≈ 12 K，内部边界温度为 Ti ≈ 500 K。冷凝产生的消光为 AV = 50 mag，光度为 Lc = 1.08 × 1034 W，这相当于一次大质量恒星形成的爆发，与 LMC 中 R 136 的中心 5 pc 和巨型卡丽娜臂 H ii 区域的电离团 NGC 3603 大致相似。通过与正常、发光和超发光红外星系的比较，我们认为这个被遮挡的星核是这一类星系中最接近也是最弱的天体。
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Pub Date : 2024-10-16DOI: 10.3847/1538-4357/ad71cc
Wenyuan Yu, Nada Al-Haddad, Charles J. Farrugia, Noé Lugaz, Bin Zhuang, Florian Regnault and Antoinette B. Galvin
The aim of this study is to use multispacecraft measurements of interplanetary magnetic clouds (MCs) to better constrain and understand the effect of expansion on their magnetic field properties. We develop a parameter (γ) for comparing magnetic field components measured at multiple spacecraft. We use the minimum variance technique on the magnetic field data to obtain the axial and azimuthal components. The parameter γ acts at the front boundary as a measure of the global difference in the evolution with heliospheric distance of the axial and azimuthal magnetic field components of MCs. Our goal is to determine whether the studied MCs exhibit self-similar expansion and, if so, whether this expansion is predominantly isotropic or radial, based on the estimated γ. Through our analysis of data from multiple spacecraft, we observe a notable consistency in the γ values across the examples examined. We find that the overall expansion of these MCs tends to be isotropic, while the local expansion of MCs, derived from the γ values measured at the rear boundary of MCs, usually shows anisotropic behavior, particularly when the distances between the observations from the two spacecraft are relatively short. This discovery offers insights for refining flux rope models and advancing our comprehension of the expansion processes associated with coronal mass ejections.
本研究的目的是利用多航天器对行星际磁云（MC）的测量，更好地约束和理解膨胀对其磁场特性的影响。我们开发了一个参数（γ），用于比较多个航天器测量到的磁场成分。我们利用磁场数据的最小方差技术来获得轴向和方位角分量。参数γ作用于前边界，衡量 MC 的轴向和方位角磁场分量随日光层距离演变的总体差异。我们的目标是确定所研究的 MC 是否呈现自相似膨胀，如果是，则根据估算的 γ 值确定这种膨胀主要是各向同性的还是径向的。我们发现，这些 MCs 的整体膨胀趋于各向同性，而 MCs 的局部膨胀（根据 MCs 后边界测量的 γ 值推导）通常表现为各向异性，尤其是当两个航天器的观测距离相对较短时。这一发现为完善通量绳模型和推进我们对与日冕物质抛射相关的膨胀过程的理解提供了启示。
{"title":"Measurements of Magnetic Cloud Expansion through Multiple Spacecraft in Radial Conjunction","authors":"Wenyuan Yu, Nada Al-Haddad, Charles J. Farrugia, Noé Lugaz, Bin Zhuang, Florian Regnault and Antoinette B. Galvin","doi":"10.3847/1538-4357/ad71cc","DOIUrl":"https://doi.org/10.3847/1538-4357/ad71cc","url":null,"abstract":"The aim of this study is to use multispacecraft measurements of interplanetary magnetic clouds (MCs) to better constrain and understand the effect of expansion on their magnetic field properties. We develop a parameter (γ) for comparing magnetic field components measured at multiple spacecraft. We use the minimum variance technique on the magnetic field data to obtain the axial and azimuthal components. The parameter γ acts at the front boundary as a measure of the global difference in the evolution with heliospheric distance of the axial and azimuthal magnetic field components of MCs. Our goal is to determine whether the studied MCs exhibit self-similar expansion and, if so, whether this expansion is predominantly isotropic or radial, based on the estimated γ. Through our analysis of data from multiple spacecraft, we observe a notable consistency in the γ values across the examples examined. We find that the overall expansion of these MCs tends to be isotropic, while the local expansion of MCs, derived from the γ values measured at the rear boundary of MCs, usually shows anisotropic behavior, particularly when the distances between the observations from the two spacecraft are relatively short. This discovery offers insights for refining flux rope models and advancing our comprehension of the expansion processes associated with coronal mass ejections.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443966","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 : 2024-10-16DOI: 10.3847/1538-4357/ad778b
Anna-Christina Eilers, Ruari Mackenzie, Elia Pizzati, Jorryt Matthee, Joseph F. Hennawi, Haowen Zhang, Rongmon Bordoloi, Daichi Kashino, Simon J. Lilly, Rohan P. Naidu, Robert A. Simcoe, Minghao Yue, Carlos S. Frenk, John C. Helly, Matthieu Schaller and Joop Schaye
We expect luminous (M1450 ≲ −26.5) high-redshift quasars to trace the highest-density peaks in the early Universe. Here, we present observations of four z ≳ 6 quasar fields using JWST/NIRCam in the imaging and wide-field slitless spectroscopy mode and report a wide range in the number of detected [O iii]-emitting galaxies in the quasars’ environments, ranging between a density enhancement of δ ≈ 65 within a 2 cMpc radius—one of the largest protoclusters during the Epoch of Reionization discovered to date—to a density contrast consistent with zero, indicating the presence of a UV-luminous quasar in a region comparable to the average density of the Universe. By measuring the two-point cross-correlation function of quasars and their surrounding galaxies, as well as the galaxy autocorrelation function, we infer a correlation length of quasars at 〈z〉 = 6.25 of , while we obtain a correlation length of the [O iii]-emitting galaxies of . By comparing the correlation functions to dark-matter-only simulations we estimate the minimum mass of the quasars’ host dark matter halos to be (and for the [O iii] emitters), indicating that (a) luminous quasars do not necessarily reside within the most overdense regions in the early Universe, and that (b) the UV-luminous duty cycle of quasar activity at these redshifts is fduty ≪ 1. Such short quasar activity timescales challenge our understanding of early supermassive black hole growth and provide evidence for highly dust-obscured growth phases or episodic, radiatively inefficient accretion rates.
{"title":"EIGER. VI. The Correlation Function, Host Halo Mass, and Duty Cycle of Luminous Quasars at z ≳ 6","authors":"Anna-Christina Eilers, Ruari Mackenzie, Elia Pizzati, Jorryt Matthee, Joseph F. Hennawi, Haowen Zhang, Rongmon Bordoloi, Daichi Kashino, Simon J. Lilly, Rohan P. Naidu, Robert A. Simcoe, Minghao Yue, Carlos S. Frenk, John C. Helly, Matthieu Schaller and Joop Schaye","doi":"10.3847/1538-4357/ad778b","DOIUrl":"https://doi.org/10.3847/1538-4357/ad778b","url":null,"abstract":"We expect luminous (M1450 ≲ −26.5) high-redshift quasars to trace the highest-density peaks in the early Universe. Here, we present observations of four z ≳ 6 quasar fields using JWST/NIRCam in the imaging and wide-field slitless spectroscopy mode and report a wide range in the number of detected [O iii]-emitting galaxies in the quasars’ environments, ranging between a density enhancement of δ ≈ 65 within a 2 cMpc radius—one of the largest protoclusters during the Epoch of Reionization discovered to date—to a density contrast consistent with zero, indicating the presence of a UV-luminous quasar in a region comparable to the average density of the Universe. By measuring the two-point cross-correlation function of quasars and their surrounding galaxies, as well as the galaxy autocorrelation function, we infer a correlation length of quasars at 〈z〉 = 6.25 of , while we obtain a correlation length of the [O iii]-emitting galaxies of . By comparing the correlation functions to dark-matter-only simulations we estimate the minimum mass of the quasars’ host dark matter halos to be (and for the [O iii] emitters), indicating that (a) luminous quasars do not necessarily reside within the most overdense regions in the early Universe, and that (b) the UV-luminous duty cycle of quasar activity at these redshifts is fduty ≪ 1. Such short quasar activity timescales challenge our understanding of early supermassive black hole growth and provide evidence for highly dust-obscured growth phases or episodic, radiatively inefficient accretion rates.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443973","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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