Pub Date : 2024-12-23DOI: 10.3847/2041-8213/ad9aa7
Wangzheng Zhang, Ming-chung Chu, Shihong Liao, Shek Yeung and Hui-Jie Hu
The Hubble constant H0, the current expansion rate of the Universe, is one of the most important parameters in cosmology. The cosmic expansion regulates the mutually approaching motion of a pair of celestial objects due to their gravity. Therefore, the mean pairwise peculiar velocity of celestial objects, which quantifies their relative motion, is sensitive to both H0 and the dimensionless total matter density Ωm. Based on this, using the Cosmicflows-4 data, we measured H0 for the first time via the galaxy pairwise velocity in the nonlinear and quasi-linear range. Our results yield H0 = 75.5 ± 1.4 km s−1 Mpc−1 and . The uncertainties of H0 and Ωm can be improved to around 0.6% and 2%, respectively, if the statistical errors become negligible in the future.
哈勃常数H0，宇宙当前的膨胀速率，是宇宙学中最重要的参数之一。由于引力作用，宇宙膨胀调节着一对天体相互接近的运动。因此，量化天体相对运动的平均对偶奇异速度对H0和无因次总物质密度Ωm都很敏感。在此基础上，利用Cosmicflows-4数据，我们首次在非线性和准线性范围内通过星系对向速度测量了H0。我们的结果得到H0 = 75.5±1.4 km s−1 Mpc−1和。如果将来统计误差可以忽略不计，H0和Ωm的不确定性可以分别提高到0.6%和2%左右。
{"title":"Measuring the Hubble Constant through the Galaxy Pairwise Peculiar Velocity","authors":"Wangzheng Zhang, Ming-chung Chu, Shihong Liao, Shek Yeung and Hui-Jie Hu","doi":"10.3847/2041-8213/ad9aa7","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9aa7","url":null,"abstract":"The Hubble constant H0, the current expansion rate of the Universe, is one of the most important parameters in cosmology. The cosmic expansion regulates the mutually approaching motion of a pair of celestial objects due to their gravity. Therefore, the mean pairwise peculiar velocity of celestial objects, which quantifies their relative motion, is sensitive to both H0 and the dimensionless total matter density Ωm. Based on this, using the Cosmicflows-4 data, we measured H0 for the first time via the galaxy pairwise velocity in the nonlinear and quasi-linear range. Our results yield H0 = 75.5 ± 1.4 km s−1 Mpc−1 and . The uncertainties of H0 and Ωm can be improved to around 0.6% and 2%, respectively, if the statistical errors become negligible in the future.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"83 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142879796","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 : 2024-12-23DOI: 10.3847/2041-8213/ad9bb4
Daniel C. M. Palumbo
The Event Horizon Telescope has released polarized images of the supermassive black holes Messier 87* (M87*) and Sagittarius A* accretion disks. As more images are produced, our understanding of the average polarized emission from near the event horizon improves. In this Letter, we use a semianalytic model for optically thin, equatorial emission near a Kerr black hole to study how spin constraints follow from measurements of the average polarization spiral pitch angle. We focus on the case of M87* and explore how the direct, weakly lensed image spiral is coupled to the strongly lensed indirect image spiral, and how a precise measurement of both provides a powerful spin tracer. We find a generic result that the spin twists the direct and indirect image polarization in opposite directions. Using a grid search over model parameters, we find a strong dependence of the resulting spin constraint on plasma properties near the horizon. Grid constraints suggest that, under reasonable assumptions for the accretion disk, a measurement of the direct and indirect image spiral pitch angles to ±5° yields a dimensionless spin amplitude measurement with uncertainty for radially infalling models but otherwise provides only weak constraints; an error of 1∘ can reach . We also find that a well-constrained rotation measure greatly improves spin measurements. Assuming that equatorial velocity and magnetic field are oppositely oriented, we find that the observed M87* polarization pattern favors models with strong radial velocity components, which are close to optimal for future spin measurements.
{"title":"Supermassive Black Hole Spin Constraints from Polarimetry in an Equatorial Disk Model","authors":"Daniel C. M. Palumbo","doi":"10.3847/2041-8213/ad9bb4","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9bb4","url":null,"abstract":"The Event Horizon Telescope has released polarized images of the supermassive black holes Messier 87* (M87*) and Sagittarius A* accretion disks. As more images are produced, our understanding of the average polarized emission from near the event horizon improves. In this Letter, we use a semianalytic model for optically thin, equatorial emission near a Kerr black hole to study how spin constraints follow from measurements of the average polarization spiral pitch angle. We focus on the case of M87* and explore how the direct, weakly lensed image spiral is coupled to the strongly lensed indirect image spiral, and how a precise measurement of both provides a powerful spin tracer. We find a generic result that the spin twists the direct and indirect image polarization in opposite directions. Using a grid search over model parameters, we find a strong dependence of the resulting spin constraint on plasma properties near the horizon. Grid constraints suggest that, under reasonable assumptions for the accretion disk, a measurement of the direct and indirect image spiral pitch angles to ±5° yields a dimensionless spin amplitude measurement with uncertainty for radially infalling models but otherwise provides only weak constraints; an error of 1∘ can reach . We also find that a well-constrained rotation measure greatly improves spin measurements. Assuming that equatorial velocity and magnetic field are oppositely oriented, we find that the observed M87* polarization pattern favors models with strong radial velocity components, which are close to optimal for future spin measurements.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142879798","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 : 2024-12-23DOI: 10.3847/2041-8213/ad9aa8
Tom Broadhurst, Sung Kei Li, Amruth Alfred, Jose M. Diego, Paloma Morilla, Patrick L. Kelly, Fengwu Sun, Masamune Oguri, Hayley Williams, Rogier Windhorst, Adi Zitrin, Katsuya T. Abe, Wenlei Chen, Liang Dai, Yoshinobu Fudamoto, Hiroki Kawai, Jeremy Lim, Tao Liu, Ashish K. Meena, Jose M. Palencia, George F. Smoot and Liliya L.R. Williams
Many microlensed stars discovered by JWST closely follow the winding critical curve of A370 along the “Dragon Arc” with mAB > 26.5, which we show comprises asymptotic giant branch stars microlensed by the observed level of diffuse cluster stars, corresponding to ≃1% of the dark matter density. Most events appear along the inner edge of the critical curve, following an asymmetric band of width ≃4.5 kpc that is skewed by −0.7 ± 0.2 kpc. This asymmetry, we argue, follows from the parity difference in caustic structure inherent to microlensing that extends to higher magnification in the negative parity regions. This parity difference predicts a modest net shift of −0.04 kpc to the inside of the cluster critical curve within a narrower band of ≃1.4 kpc than observed. Adding cold-dark-matter-like subhalos of 106−8M⊙ doubles the width, but detections are predicted to favor the outside of the critical curve, where the subhalos generate local Einstein rings, and subhalos inside the critical curve depress the magnification, reducing microlensing. Instead, the density perturbations of “wave dark matter” as a Bose–Einstein condensate (ψDM) can generate a wide band of corrugated critical curves with a large negative asymmetry. We find that a de Broglie wavelength of ≃10 pc reproduces the observed width of 4.5 kpc, with a negative skewness ≃−0.6 kpc, like the data, corresponding to a boson mass of ≃10−22 eV, in agreement with dwarf galaxy dynamical estimates. Independently, we also find clear asymmetry in the Jupiter Arc, with 12 microlensed stars lying along the inside of the critical curve, like the Dragon Arc.
{"title":"Dark Matter Distinguished by Skewed Microlensing in the “Dragon Arc”","authors":"Tom Broadhurst, Sung Kei Li, Amruth Alfred, Jose M. Diego, Paloma Morilla, Patrick L. Kelly, Fengwu Sun, Masamune Oguri, Hayley Williams, Rogier Windhorst, Adi Zitrin, Katsuya T. Abe, Wenlei Chen, Liang Dai, Yoshinobu Fudamoto, Hiroki Kawai, Jeremy Lim, Tao Liu, Ashish K. Meena, Jose M. Palencia, George F. Smoot and Liliya L.R. Williams","doi":"10.3847/2041-8213/ad9aa8","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9aa8","url":null,"abstract":"Many microlensed stars discovered by JWST closely follow the winding critical curve of A370 along the “Dragon Arc” with mAB > 26.5, which we show comprises asymptotic giant branch stars microlensed by the observed level of diffuse cluster stars, corresponding to ≃1% of the dark matter density. Most events appear along the inner edge of the critical curve, following an asymmetric band of width ≃4.5 kpc that is skewed by −0.7 ± 0.2 kpc. This asymmetry, we argue, follows from the parity difference in caustic structure inherent to microlensing that extends to higher magnification in the negative parity regions. This parity difference predicts a modest net shift of −0.04 kpc to the inside of the cluster critical curve within a narrower band of ≃1.4 kpc than observed. Adding cold-dark-matter-like subhalos of 106−8M⊙ doubles the width, but detections are predicted to favor the outside of the critical curve, where the subhalos generate local Einstein rings, and subhalos inside the critical curve depress the magnification, reducing microlensing. Instead, the density perturbations of “wave dark matter” as a Bose–Einstein condensate (ψDM) can generate a wide band of corrugated critical curves with a large negative asymmetry. We find that a de Broglie wavelength of ≃10 pc reproduces the observed width of 4.5 kpc, with a negative skewness ≃−0.6 kpc, like the data, corresponding to a boson mass of ≃10−22 eV, in agreement with dwarf galaxy dynamical estimates. Independently, we also find clear asymmetry in the Jupiter Arc, with 12 microlensed stars lying along the inside of the critical curve, like the Dragon Arc.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884186","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 : 2024-12-23DOI: 10.3847/2041-8213/ad841f
Jeong-Eun Lee, Neal J. Evans, Giseon Baek, Chul-Hwan Kim, Jinyoung Noh and Yao-Lun Yang
Emission lines from complex organic molecules in B335 were observed in four epochs, spanning a luminosity burst of about 10 yr duration. The emission lines increased dramatically in intensity as the luminosity increased, but they have decreased only slightly as the luminosity has decreased. This behavior agrees with expectations of rapid sublimation as the dust temperature increases, and of slower freeze-out after the dust temperature drops. Further monitoring of this source, along with detailed chemical models, will exploit this natural laboratory for astrochemistry.
{"title":"A Natural Laboratory for Astrochemistry: The Variable Protostar B335","authors":"Jeong-Eun Lee, Neal J. Evans, Giseon Baek, Chul-Hwan Kim, Jinyoung Noh and Yao-Lun Yang","doi":"10.3847/2041-8213/ad841f","DOIUrl":"https://doi.org/10.3847/2041-8213/ad841f","url":null,"abstract":"Emission lines from complex organic molecules in B335 were observed in four epochs, spanning a luminosity burst of about 10 yr duration. The emission lines increased dramatically in intensity as the luminosity increased, but they have decreased only slightly as the luminosity has decreased. This behavior agrees with expectations of rapid sublimation as the dust temperature increases, and of slower freeze-out after the dust temperature drops. Further monitoring of this source, along with detailed chemical models, will exploit this natural laboratory for astrochemistry.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873898","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 : 2024-12-20DOI: 10.3847/2041-8213/ad9a4f
Ling Zhang, Xindong Meng, Yuqi Qian, Yi Xu, Xiaoping Zhang, Zhipeng Liu, Jialong Lai and Rui Gao
Impact cratering is the most common geological process occurring on terrestrial planets. The morphologies of impact craters reflect not only the impact conditions but the target properties as well. They have been widely used as subsurface probes into regolith thickness and mechanical properties. A population of paleo-buried impact craters has been discovered by recent geophysical investigations of the Moon; however, their morphologies have never been constrained. The lunar penetrating radar onboard the Chang’e-4 rover has offered an unprecedented opportunity to study the morphology of those paleo-buried craters and reveal obscured depositing history. In this study, we have identified a flat-bottomed paleocrater (450 m in diameter; 11.5 m in depth) on an extraterrestrial world and reconstructed its morphology. This discovery reinforces how impacts would modify layered structures, providing additional evidence regarding subsurface interfaces between the paleoregolith layers and the final-stage lava layers, shedding light on similar processes on all planets.
{"title":"A Flat-bottomed Buried Crater and Paleo-layered Structures Revealed at the Von Kármán Crater Using Lunar Penetrating Radar","authors":"Ling Zhang, Xindong Meng, Yuqi Qian, Yi Xu, Xiaoping Zhang, Zhipeng Liu, Jialong Lai and Rui Gao","doi":"10.3847/2041-8213/ad9a4f","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9a4f","url":null,"abstract":"Impact cratering is the most common geological process occurring on terrestrial planets. The morphologies of impact craters reflect not only the impact conditions but the target properties as well. They have been widely used as subsurface probes into regolith thickness and mechanical properties. A population of paleo-buried impact craters has been discovered by recent geophysical investigations of the Moon; however, their morphologies have never been constrained. The lunar penetrating radar onboard the Chang’e-4 rover has offered an unprecedented opportunity to study the morphology of those paleo-buried craters and reveal obscured depositing history. In this study, we have identified a flat-bottomed paleocrater (450 m in diameter; 11.5 m in depth) on an extraterrestrial world and reconstructed its morphology. This discovery reinforces how impacts would modify layered structures, providing additional evidence regarding subsurface interfaces between the paleoregolith layers and the final-stage lava layers, shedding light on similar processes on all planets.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867183","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 : 2024-12-20DOI: 10.3847/2041-8213/ad99da
Xinyi Hong, Ning-Chen Sun, Zexi Niu, Junjie Wu, Qiang Xi and Jifeng Liu
The progenitors of Type II-P supernovae (SN) have been confirmed to be red supergiants. However, the upper mass limit of the directly probed progenitors is much lower than that predicted by current theories, and the accurate determination of the progenitor masses is key to understand the final fate of massive stars. Located at a distance of only 6.72 Mpc, the Type II-P SN 2024ggi is one of the closest SNe in the last decade. Previous studies have analyzed its progenitor by direct detection, but the derived progenitor mass may be influenced by the very uncertain circumstellar extinction and pulsational brightness variability. In this work, we try to constrain the progenitor mass with an environmental analysis based on images from the Hubble Space Telescope. We found that stars in the progenitor environment have a uniform spatial distribution without significant clumpiness, and we derived the star formation history of the environment with a hierarchical Bayesian method. The progenitor is associated with the youngest population in the SN environment with an age of log(t/yr) = 7.41 (i.e., 25.7 Myr), which corresponds to an initial mass of M⊙. Our work provides an independent measurement of the progenitor mass, which is not affected by circumstellar extinction and pulsational brightness variability.
{"title":"Constraining the Progenitor of the Nearby Type II-P SN 2024ggi with Environmental Analysis","authors":"Xinyi Hong, Ning-Chen Sun, Zexi Niu, Junjie Wu, Qiang Xi and Jifeng Liu","doi":"10.3847/2041-8213/ad99da","DOIUrl":"https://doi.org/10.3847/2041-8213/ad99da","url":null,"abstract":"The progenitors of Type II-P supernovae (SN) have been confirmed to be red supergiants. However, the upper mass limit of the directly probed progenitors is much lower than that predicted by current theories, and the accurate determination of the progenitor masses is key to understand the final fate of massive stars. Located at a distance of only 6.72 Mpc, the Type II-P SN 2024ggi is one of the closest SNe in the last decade. Previous studies have analyzed its progenitor by direct detection, but the derived progenitor mass may be influenced by the very uncertain circumstellar extinction and pulsational brightness variability. In this work, we try to constrain the progenitor mass with an environmental analysis based on images from the Hubble Space Telescope. We found that stars in the progenitor environment have a uniform spatial distribution without significant clumpiness, and we derived the star formation history of the environment with a hierarchical Bayesian method. The progenitor is associated with the youngest population in the SN environment with an age of log(t/yr) = 7.41 (i.e., 25.7 Myr), which corresponds to an initial mass of M⊙. Our work provides an independent measurement of the progenitor mass, which is not affected by circumstellar extinction and pulsational brightness variability.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867177","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 : 2024-12-20DOI: 10.3847/2041-8213/ad9bb5
Alexander E. Thelen, Katherine de Kleer, Martin A. Cordiner, Imke de Pater, Arielle Moullet and Statia Luszcz-Cook
We present spatially resolved measurements of SO2 and NaCl winds on Io at several unique points in its orbit: before and after eclipse and at maximum eastern and western elongation. The derived wind fields represent a unique case of meteorology in a rarified, volcanic atmosphere. Through the use of Doppler shift measurements in emission spectra obtained with the Atacama Large Millimeter/submillimeter Array between ~346 and 430 GHz (~0.70–0.87 mm), line-of-sight winds up to ~−100 m s−1 in the approaching direction and >250 m s−1 in the receding direction were derived for SO2 at altitudes of ~10–50 km, while NaCl winds consistently reached ~∣150–200∣ m s−1 in localized regions up to ~30 km above the surface. The wind distributions measured at maximum east and west Jovian elongations and on the sub-Jovian hemisphere pre- and posteclipse were found to be significantly different and complex, corroborating the results of simulations that include surface temperature and frost distribution, volcanic activity, and interactions with the Jovian magnetosphere. Further, the wind speeds of SO2 and NaCl are often inconsistent in direction and magnitude, indicating that the processes that drive the winds for the two molecular species are different and potentially uncoupled; while the SO2 wind field can be explained through a combination of sublimation-driven winds, plasma torus interactions, and plume activity, the NaCl winds appear to be primarily driven by the plasma torus.
我们展示了木卫一轨道上几个独特点的SO2和NaCl风的空间分辨率测量结果：日食前后和最大东伸长和最大西伸长。衍生的风场代表了稀薄的火山大气中气象学的一个独特案例。通过对阿塔卡马大型毫米/亚毫米阵列在~346 ~ 430 GHz （~0.70 ~ 0.87 mm）范围内获得的发射光谱进行多普勒频移测量，得出了在~10 ~ 50 km高度上，SO2接近方向的视距风速可达~−100 m s−1，后退方向的视距风速可达~ 250 m s−1，而在距离地面~30 km的局部区域，NaCl风速始终达到~∣150 ~ 200∣m s−1。在日蚀前后，在木星最大的东、西延伸处和次木星半球上测量到的风分布明显不同且复杂，证实了模拟结果，包括表面温度和霜冻分布、火山活动以及与木星磁层的相互作用。此外，SO2和NaCl的风速在方向和量级上往往不一致，这表明驱动这两种分子物种的风的过程是不同的，可能是不耦合的；SO2风场可以通过升华驱动风、等离子体环面相互作用和羽流活动的组合来解释，而NaCl风似乎主要是由等离子体环面驱动的。
{"title":"Io’s SO2 and NaCl Wind Fields from ALMA","authors":"Alexander E. Thelen, Katherine de Kleer, Martin A. Cordiner, Imke de Pater, Arielle Moullet and Statia Luszcz-Cook","doi":"10.3847/2041-8213/ad9bb5","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9bb5","url":null,"abstract":"We present spatially resolved measurements of SO2 and NaCl winds on Io at several unique points in its orbit: before and after eclipse and at maximum eastern and western elongation. The derived wind fields represent a unique case of meteorology in a rarified, volcanic atmosphere. Through the use of Doppler shift measurements in emission spectra obtained with the Atacama Large Millimeter/submillimeter Array between ~346 and 430 GHz (~0.70–0.87 mm), line-of-sight winds up to ~−100 m s−1 in the approaching direction and >250 m s−1 in the receding direction were derived for SO2 at altitudes of ~10–50 km, while NaCl winds consistently reached ~∣150–200∣ m s−1 in localized regions up to ~30 km above the surface. The wind distributions measured at maximum east and west Jovian elongations and on the sub-Jovian hemisphere pre- and posteclipse were found to be significantly different and complex, corroborating the results of simulations that include surface temperature and frost distribution, volcanic activity, and interactions with the Jovian magnetosphere. Further, the wind speeds of SO2 and NaCl are often inconsistent in direction and magnitude, indicating that the processes that drive the winds for the two molecular species are different and potentially uncoupled; while the SO2 wind field can be explained through a combination of sublimation-driven winds, plasma torus interactions, and plume activity, the NaCl winds appear to be primarily driven by the plasma torus.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867192","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 : 2024-12-19DOI: 10.3847/2041-8213/ad9917
Juan-Juan Luo, Liang Zhang, Li-Yun Zhang, Yong-Feng Huang, Jia-Quan Lin, Jun-Wang Lu and Xiao-Fei Dong
Gamma-ray bursts (GRBs) are usually classified into long/short categories according to their durations, but controversy still exists in this aspect. Here we reexamine the long/short classification of GRBs and further compare the cosmological distribution and evolution of each potential subclass. A large number of Swift Burst Alert Telescope (BAT) GRBs are analyzed in this study. The Gaussian mixture model is used to fit the duration distribution as well as the joint distribution of duration and hardness ratio, and the Akaike and Bayesian information criteria are adopted to assess the goodness of fit. It is found that three Gaussian components can better fit both the univariate and bivariate distributions, indicating that there are three subclasses in the Swift/BAT GRBs, namely, short, intermediate, and long subclasses. The nonparametric Efron–Petrosian and Lynden-Bell's c− methods are used to derive the luminosity function and formation rate from the truncated data of bursts with known redshift in each subclass. It is found that the luminosity distributions and birth rates of the three subclasses are different, further supporting the existence of the intermediate subclass in the Swift/BAT GRBs.
{"title":"The Classification and Formation Rate of Swift/BAT Gamma-Ray Bursts","authors":"Juan-Juan Luo, Liang Zhang, Li-Yun Zhang, Yong-Feng Huang, Jia-Quan Lin, Jun-Wang Lu and Xiao-Fei Dong","doi":"10.3847/2041-8213/ad9917","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9917","url":null,"abstract":"Gamma-ray bursts (GRBs) are usually classified into long/short categories according to their durations, but controversy still exists in this aspect. Here we reexamine the long/short classification of GRBs and further compare the cosmological distribution and evolution of each potential subclass. A large number of Swift Burst Alert Telescope (BAT) GRBs are analyzed in this study. The Gaussian mixture model is used to fit the duration distribution as well as the joint distribution of duration and hardness ratio, and the Akaike and Bayesian information criteria are adopted to assess the goodness of fit. It is found that three Gaussian components can better fit both the univariate and bivariate distributions, indicating that there are three subclasses in the Swift/BAT GRBs, namely, short, intermediate, and long subclasses. The nonparametric Efron–Petrosian and Lynden-Bell's c− methods are used to derive the luminosity function and formation rate from the truncated data of bursts with known redshift in each subclass. It is found that the luminosity distributions and birth rates of the three subclasses are different, further supporting the existence of the intermediate subclass in the Swift/BAT GRBs.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858312","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 : 2024-12-18DOI: 10.3847/2041-8213/ad823b
Eduardo Bañados, Yana Khusanova, Roberto Decarli, Emmanuel Momjian, Fabian Walter, Thomas Connor, Christopher L. Carilli, Chiara Mazzucchelli, Sofía Rojas-Ruiz and Bram P. Venemans
We present millimeter observations of the host galaxy of the most distant blazar known, VLASS J041009.05−013919.88 (hereafter J0410–0139) at z = 7, using Atacama Large Millimeter/submillimeter Array (ALMA) and NOrthern Extended Millimeter Array (NOEMA) observations. The ALMA data reveal a (2.02 ± 0.36) × 1042 erg s−1 [C ii] 158 μm emission line at z = 6.9964 with a [C ii]-inferred star formation rate (SFR) of 58 ± 9 M⊙ yr−1. We estimate a dynamical mass of Mdyn,[C ii] = (4.6 ± 2.0) × 109M⊙, implying a black hole mass to host a dynamical mass ratio of . The 238 GHz continuum (rest-frame IR) decreased by ∼33% from the NOEMA to the ALMA observations taken ∼10 months apart. The Very Large Array 3–10 GHz radio flux densities showed a ∼37% decrease in a similar time frame, suggesting a causal connection. At face value, J0410–0139 would have the lowest [C ii]-to-IR luminosity ratio of a z > 5.7 quasar reported to date (∼10−4). However, if only <20% of the measured IR luminosity was due to thermal emission from dust, the [C ii]-to-IR luminosity ratio would be typical of (U)LIRGs, and the SFRs derived from [C ii] and IR luminosities would be consistent. These results provide further evidence that synchrotron emission significantly contributes to the observed rest-frame IR emission of J0410–0139, similar to what has been reported in some radio-loud active galactic nuclei at z < 1.
{"title":"[C ii] Properties and Far-infrared Variability of a z = 7 Blazar","authors":"Eduardo Bañados, Yana Khusanova, Roberto Decarli, Emmanuel Momjian, Fabian Walter, Thomas Connor, Christopher L. Carilli, Chiara Mazzucchelli, Sofía Rojas-Ruiz and Bram P. Venemans","doi":"10.3847/2041-8213/ad823b","DOIUrl":"https://doi.org/10.3847/2041-8213/ad823b","url":null,"abstract":"We present millimeter observations of the host galaxy of the most distant blazar known, VLASS J041009.05−013919.88 (hereafter J0410–0139) at z = 7, using Atacama Large Millimeter/submillimeter Array (ALMA) and NOrthern Extended Millimeter Array (NOEMA) observations. The ALMA data reveal a (2.02 ± 0.36) × 1042 erg s−1 [C ii] 158 μm emission line at z = 6.9964 with a [C ii]-inferred star formation rate (SFR) of 58 ± 9 M⊙ yr−1. We estimate a dynamical mass of Mdyn,[C ii] = (4.6 ± 2.0) × 109M⊙, implying a black hole mass to host a dynamical mass ratio of . The 238 GHz continuum (rest-frame IR) decreased by ∼33% from the NOEMA to the ALMA observations taken ∼10 months apart. The Very Large Array 3–10 GHz radio flux densities showed a ∼37% decrease in a similar time frame, suggesting a causal connection. At face value, J0410–0139 would have the lowest [C ii]-to-IR luminosity ratio of a z > 5.7 quasar reported to date (∼10−4). However, if only <20% of the measured IR luminosity was due to thermal emission from dust, the [C ii]-to-IR luminosity ratio would be typical of (U)LIRGs, and the SFRs derived from [C ii] and IR luminosities would be consistent. These results provide further evidence that synchrotron emission significantly contributes to the observed rest-frame IR emission of J0410–0139, similar to what has been reported in some radio-loud active galactic nuclei at z < 1.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841443","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 : 2024-12-18DOI: 10.3847/2041-8213/ad991e
Michael M. Shara, Kenneth M. Lanzetta, Alexandra Masegian, James T. Garland, Stefan Gromoll, Joanna Mikolajewska, Mikita Misiura, David Valls-Gabaud, Frederick M. Walter and John K. Webb
A century or less separates the thermonuclear-powered eruptions of recurrent novae (RNe) in the hydrogen-rich envelopes of massive white dwarfs. The colliding ejecta of successive RN events are predicted to always generate very large (tens of parsecs) super-remnants; only two examples are currently known. T CrB offers an excellent opportunity to test this prediction. As it will almost certainly undergo its next, once in ∼80 yr RN event between 2024 and 2026, we carried out very deep narrowband and continuum imaging to search for the predicted, piled-up ejecta of the past millennia. While nothing is detected in continuum or narrowband [O iii] images, a ∼30 pc diameter, faint nebulosity surrounding T CrB is clearly present in deep Hα, [N ii], and [S ii] narrowband Condor Array Telescope imagery. We predict that these newly detected nebulosities, as well as the recent ejecta that have not yet reached the super-remnant, are far too optically thin to capture all but a tiny fraction of the photons emitted by RN flashes. We thus predict that fluorescent light echoes will not be detectable following the imminent nova flash of T CrB. Dust may be released by the T CrB red giant wind in preeruption outbursts, but we have no reliable estimates of its quantity or geometrical distribution. While we cannot predict the morphology or intensity of dust-induced continuum light echoes following the coming flash, we encourage multiepoch Hubble Space Telescope optical imaging as well as James Webb Space Telescope infrared imaging of T CrB during the year after it erupts.
{"title":"The Newly Discovered Nova Super-remnant Surrounding Recurrent Nova T Coronae Borealis: Will it Light Up during the Coming Eruption?","authors":"Michael M. Shara, Kenneth M. Lanzetta, Alexandra Masegian, James T. Garland, Stefan Gromoll, Joanna Mikolajewska, Mikita Misiura, David Valls-Gabaud, Frederick M. Walter and John K. Webb","doi":"10.3847/2041-8213/ad991e","DOIUrl":"https://doi.org/10.3847/2041-8213/ad991e","url":null,"abstract":"A century or less separates the thermonuclear-powered eruptions of recurrent novae (RNe) in the hydrogen-rich envelopes of massive white dwarfs. The colliding ejecta of successive RN events are predicted to always generate very large (tens of parsecs) super-remnants; only two examples are currently known. T CrB offers an excellent opportunity to test this prediction. As it will almost certainly undergo its next, once in ∼80 yr RN event between 2024 and 2026, we carried out very deep narrowband and continuum imaging to search for the predicted, piled-up ejecta of the past millennia. While nothing is detected in continuum or narrowband [O iii] images, a ∼30 pc diameter, faint nebulosity surrounding T CrB is clearly present in deep Hα, [N ii], and [S ii] narrowband Condor Array Telescope imagery. We predict that these newly detected nebulosities, as well as the recent ejecta that have not yet reached the super-remnant, are far too optically thin to capture all but a tiny fraction of the photons emitted by RN flashes. We thus predict that fluorescent light echoes will not be detectable following the imminent nova flash of T CrB. Dust may be released by the T CrB red giant wind in preeruption outbursts, but we have no reliable estimates of its quantity or geometrical distribution. While we cannot predict the morphology or intensity of dust-induced continuum light echoes following the coming flash, we encourage multiepoch Hubble Space Telescope optical imaging as well as James Webb Space Telescope infrared imaging of T CrB during the year after it erupts.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142848991","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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