Astrophysical Journal最新文献_第5页

Hunting Gamma-Ray-emitting FR0 Radio Galaxies in Wide-field Sky Surveys 在广域天空巡天中寻找发射伽马射线的FR0射电星系

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/ad00b5

Meghana Pannikkote, Vaidehi S. Paliya, D. J. Saikia

{"title":"Hunting Gamma-Ray-emitting FR0 Radio Galaxies in Wide-field Sky Surveys","authors":"Meghana Pannikkote, Vaidehi S. Paliya, D. J. Saikia","doi":"10.3847/1538-4357/ad00b5","DOIUrl":"https://doi.org/10.3847/1538-4357/ad00b5","url":null,"abstract":"Abstract The latest entry in the jetted active galactic nuclei (AGN) family is the Fanaroff–Riley type 0 (FR0) radio galaxies. They share several observational characteristics, e.g., nuclear emission and host galaxy morphology, with FR I sources; however, they lack extended, kiloparsec-scale radio structures, which are the defining features of canonical FR I and II sources. Here we report the identification of seven γ -ray-emitting AGN as FR0 radio sources by utilizing the high-quality observations delivered by ongoing multiwavelength wide-field sky surveys, e.g., Very Large Array Sky Survey. The broadband observational properties of these objects are found to be similar to their γ -ray undetected counterparts. In the γ -ray band, FR0 radio galaxies exhibit spectral features similar to more common FR I and II radio galaxies, indicating a common γ -ray production mechanism and the presence of misaligned jets. Although the parsec-scale radio structure of FR0s generally exhibits a wide range, with about half having emission on opposite sides of the core, the γ -ray-detected FR0s tend to have dominant cores with core-jet structures. We conclude that dedicated, high-resolution observations are needed to unravel the origin of relativistic jets in this enigmatic class of faint yet numerous population of compact radio sources.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"31 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135270693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Generation of Subion Scale Magnetic Holes from Electron Shear Flow Instabilities in Plasma Turbulence 等离子体湍流中电子剪切流不稳定性产生亚亚尺度磁空穴

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/acf12e

Giuseppe Arrò, Francesco Pucci, Francesco Califano, Maria Elena Innocenti, Giovanni Lapenta

{"title":"Generation of Subion Scale Magnetic Holes from Electron Shear Flow Instabilities in Plasma Turbulence","authors":"Giuseppe Arrò, Francesco Pucci, Francesco Califano, Maria Elena Innocenti, Giovanni Lapenta","doi":"10.3847/1538-4357/acf12e","DOIUrl":"https://doi.org/10.3847/1538-4357/acf12e","url":null,"abstract":"Abstract Magnetic holes (MHs) are coherent structures associated with strong magnetic field depressions in magnetized plasmas. They are observed in many astrophysical environments at a wide range of scales, but their origin is still under debate. In this work, we investigate the formation of subion scale MHs using a fully kinetic 2D simulation of plasma turbulence initialized with parameters typical of the Earth’s magnetosheath. Our analysis shows that the turbulence is capable of generating subion scale MHs from large scale fluctuations via the following mechanism: first, the nonlinear large scale dynamics spontaneously leads to the development of thin and elongated electron velocity shears; these structures then become unstable to the electron Kelvin–Helmholtz instability and break up into small scale electron vortices; the electric current carried by these vortices locally reduces the magnetic field, inducing the formation of subion scale MHs. The MHs thus produced exhibit features consistent with satellite observations and with previous numerical studies. We finally discuss the kinetic properties of the observed subion scale MHs, showing that they are characterized by complex non-Maxwellian electron velocity distributions exhibiting anisotropic and agyrotropic features.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"12 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135510390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Searching for C ii Emission from the First Sample of z ∼ 6 O i Absorption-associated Galaxies with the Atacama Large Millimeter/submillimeter Array 用阿塔卡马大型毫米/亚毫米阵列搜索z ~ 6 O i吸收相关星系首个样本的C ii发射

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/ad00b8

Yunjing Wu, Zheng Cai, Jianan Li, Kristian Finlator, Marcel Neeleman, J. Xavier Prochaska, Bjorn H. C. Emonts, Shiwu Zhang, Feige Wang, Jinyi Yang, Ran Wang, Xiaohui Fan, Dandan Xu, Emmet Golden-Marx, Laura C. Keating, Joseph F. Hennawi

{"title":"Searching for C ii Emission from the First Sample of z ∼ 6 O i Absorption-associated Galaxies with the Atacama Large Millimeter/submillimeter Array","authors":"Yunjing Wu, Zheng Cai, Jianan Li, Kristian Finlator, Marcel Neeleman, J. Xavier Prochaska, Bjorn H. C. Emonts, Shiwu Zhang, Feige Wang, Jinyi Yang, Ran Wang, Xiaohui Fan, Dandan Xu, Emmet Golden-Marx, Laura C. Keating, Joseph F. Hennawi","doi":"10.3847/1538-4357/ad00b8","DOIUrl":"https://doi.org/10.3847/1538-4357/ad00b8","url":null,"abstract":"Abstract We report the first statistical analyses of [C ii ] and dust continuum observations in six strong O i absorber fields at the end of the reionization epoch obtained by the Atacama Large Millimeter/submillimeter Array (ALMA). Combined with one [C ii ] emitter reported in Wu et al., we detect one O i -associated [C ii ] emitter in six fields. At redshifts of O i absorbers in nondetection fields, no emitters are brighter than our detection limit within impact parameters of 50 kpc and velocity offsets between ±200 km s −1 . The averaged [C ii ]-detection upper limit is <0.06 Jy km s −1 (3 σ ), corresponding to the [C ii ] luminosity of L [C II ] < 5.8 × 10 7 L ⊙ and the [C ii ]-based star formation rate of SFR [C II ] <5.5 M ⊙ yr −1 . Cosmological simulations suggest that only ∼10 −2.5 [C ii ] emitters around O i absorbers have comparable SFR to our detection limit. Although the detection in one out of six fields is reported, an order of magnitude number excess of emitters obtained from our ALMA observations supports that the contribution of massive galaxies that caused the metal enrichment cannot be ignored. Further, we also found 14 tentative galaxy candidates with a signal-to-noise ratio of ≈4.3 at large impact parameters (>50 kpc) and having larger outflow velocities within ±600 km s −1 . If these detections are confirmed in the future, then the mechanism of pushing metals at larger distances with higher velocities needs to be further explored from the theoretical side.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"53 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135564678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Calibrating VLBI Polarization Data Using GPCAL. I. Frequency-dependent Calibration 用GPCAL标定VLBI偏振数据。1 .频率相关校准

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/acfd2f

Jongho Park, Keiichi Asada, Do-Young Byun

{"title":"Calibrating VLBI Polarization Data Using GPCAL. I. Frequency-dependent Calibration","authors":"Jongho Park, Keiichi Asada, Do-Young Byun","doi":"10.3847/1538-4357/acfd2f","DOIUrl":"https://doi.org/10.3847/1538-4357/acfd2f","url":null,"abstract":"Abstract In this series of papers, we present new methods of frequency- and time-dependent instrumental polarization calibration for very long baseline interferometry (VLBI). In most existing calibration tools and pipelines, it has been assumed that instrumental polarization is constant over frequency within the instrument bandwidth and over time. The assumption is not always true and may prevent an accurate calibration, which can result in degradation of the quality of linear polarization images. In this paper, we present a method of frequency-dependent instrumental polarization calibration that is implemented in GPCAL, a recently developed polarization calibration pipeline. The method is tested using simulated data sets generated from real Very Long Baseline Array (VLBA) data. We present the results of applying the method to real VLBA data sets observed at 15 and 43 GHz. We were able to eliminate significant variability in cross-hand visibilities over frequency that is caused by frequency-dependent instrumental polarization. As a result of the calibration, linear polarization images were slightly to modestly improved as compared to those obtained without frequency-dependent instrumental polarization calibration. We discuss the reason for the minor impact of frequency-dependent instrumental polarization calibration on existing VLBA data sets and prospects for applying the method to future VLBI data sets, which are expected to provide very large bandwidths.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"283 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135566340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 1

Global Deceleration and Inward Movements of X-Ray Knots and Rims of RCW 103 rcw103的x射线节和环的整体减速和向内运动

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/ad00ae

Hiromasa Suzuki, Takaaki Tanaka, Tsuyoshi Inoue, Hiroyuki Uchida, Takuto Narita

引用次数: 0

Updated Reference Wavelengths for Si vii and Mg vii Lines in the 272–281 Å Range 更新参考波长的Si vii和Mg vii线在272-281 Å范围

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/ad0548

Peter R. Young

引用次数: 0

Morphology of Star-forming Clumps in Ram-pressure Stripped Galaxies as Seen by HST HST观测的ram压力剥离星系中恒星形成团块的形态

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/acfed6

Eric Giunchi, Bianca M. Poggianti, Marco Gullieuszik, Alessia Moretti, Ariel Werle, Anita Zanella, Benedetta Vulcani, Stephanie Tonnesen, Daniela Calzetti, Callum Bellhouse, Claudia Scarlata, Cecilia Bacchini

{"title":"Morphology of Star-forming Clumps in Ram-pressure Stripped Galaxies as Seen by HST","authors":"Eric Giunchi, Bianca M. Poggianti, Marco Gullieuszik, Alessia Moretti, Ariel Werle, Anita Zanella, Benedetta Vulcani, Stephanie Tonnesen, Daniela Calzetti, Callum Bellhouse, Claudia Scarlata, Cecilia Bacchini","doi":"10.3847/1538-4357/acfed6","DOIUrl":"https://doi.org/10.3847/1538-4357/acfed6","url":null,"abstract":"Abstract We characterize the morphological properties of a statistically relevant sample of H α and UV young star-forming clumps and optical complexes, observed with the Hubble Space Telescope in six galaxies of the GASP sample undergoing ram pressure stripping. The catalogs comprise 2406 (323 in the tails) H α clumps, 3750 (899) UV clumps, and 424 tail optical complexes. About 15%–20% of the clumps and 50% of the complexes are resolved in size. We find that more than half of the complexes contain no H α clumps, while most of them contain at least one UV clump. The clump number and size increase with the complex size, while the median complex filling factor is larger for UV clumps (0.27) than that for H α clumps (0.10) and does not correlate with almost any morphological property. This suggests that the clumps' number and size grow with the complex keeping the filling factor constant. When studying the position of the clumps inside their complexes, H α clumps, and UV clumps to a lesser extent, show a displacement from the complex center of 0.1–1 kpc, and in ∼60% of the cases, they are displaced away from the galactic disk. This is in accordance with the fireball configuration, already observed in the tails of stripped galaxies. Finally, the filling factor and the clump radius increase with the distance from the galactic disk, suggesting that the reciprocal displacement of the different stellar generations increases as a consequence of the velocity gradient caused by ram pressure.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"140 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135714764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Constraining Baryon Loading Efficiency of Active Galactic Nuclei with Diffuse Neutrino Flux from Galaxy Clusters 星系团散射中微子通量对活动星系核重子加载效率的约束

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/acfa79

Xin-Yue Shi, Ruo-Yu Liu, Chong Ge, Xiang-Yu Wang

{"title":"Constraining Baryon Loading Efficiency of Active Galactic Nuclei with Diffuse Neutrino Flux from Galaxy Clusters","authors":"Xin-Yue Shi, Ruo-Yu Liu, Chong Ge, Xiang-Yu Wang","doi":"10.3847/1538-4357/acfa79","DOIUrl":"https://doi.org/10.3847/1538-4357/acfa79","url":null,"abstract":"Abstract Active galactic nuclei (AGNs) are widely believed to be one of the promising acceleration sites of ultrahigh-energy cosmic rays (CRs). Essentially, AGNs are powered by the gravitational energy of matter falling into supermassive black holes. However, the conversion efficiency of gravitational to kinetic energy of CRs in AGNs, which is defined as the baryon loading factor η p , is not well known yet. After being accelerated, high-energy CRs could escape the host galaxy and enter the intracluster medium (ICM). These CRs can be confined within the galaxy cluster and produce γ -rays and neutrinos through proton–proton collisions with the ICM. In this paper, we study the diffusion of CRs in galaxy clusters and calculate the diffuse neutrino flux from the galaxy cluster population. Using the latest upper limits on the cumulative unresolved TeV–PeV neutrino flux from galaxy clusters posed by the IceCube Neutrino Observatory, we derive the upper limit of the average baryon loading factor as η p ,grav ≲ 2 × 10 −3 − 0.1 for the population of galaxy clusters. This constraint is more stringent than the one obtained from γ -ray observation on the Coma cluster.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"7 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Toward Interpreting the IBEX Ribbon with Mirror Diffusion in Interstellar Turbulent Magnetic Fields 星际湍流磁场中镜像扩散对IBEX带的解释

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/acfca5

Siyao 思遥 Xu 徐, Hui 晖 Li 李

{"title":"Toward Interpreting the IBEX Ribbon with Mirror Diffusion in Interstellar Turbulent Magnetic Fields","authors":"Siyao 思遥 Xu 徐, Hui 晖 Li 李","doi":"10.3847/1538-4357/acfca5","DOIUrl":"https://doi.org/10.3847/1538-4357/acfca5","url":null,"abstract":"Abstract We investigate the role of the magnetohydrodynamic (MHD) turbulence measured by Voyager in the very local interstellar medium (VLISM) in modeling the Interstellar Boundary Explorer ribbon. We demonstrate that the mirroring by compressible modes of MHD turbulence dominates over that by the mean magnetic field. Based on the new mirror diffusion mechanism identified by Lazarian & Xu for particles with large pitch angles in MHD turbulence, we find that the mirror diffusion can both confine pickup ions and preserve their initial pitch angles, and thus it accounts for the enhanced intensity of energetic neutral atoms that return to the heliosphere. The ribbon width is determined by both the range of pitch angles for effective turbulent mirroring and the field line wandering induced by Alfvénic modes. It in turn provides a constraint on the amplitude of magnetic fluctuations of fast modes. The field line wandering also affects the coherence of the ribbon structure across the sky. By extrapolating the magnetic energy spectrum measured by Voyager, we find that the injection scale of the turbulence in the VLISM must be less than ∼500 au for the ribbon structure to be coherent.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 1

Understanding the Duration of Solar and Stellar Flares at Various Wavelengths 了解不同波长太阳和恒星耀斑的持续时间

2区物理与天体物理

Astrophysical Journal Pub Date : 2023-11-01 DOI: 10.3847/1538-4357/acf45a

Jeffrey W. Reep, Vladimir S. Airapetian

{"title":"Understanding the Duration of Solar and Stellar Flares at Various Wavelengths","authors":"Jeffrey W. Reep, Vladimir S. Airapetian","doi":"10.3847/1538-4357/acf45a","DOIUrl":"https://doi.org/10.3847/1538-4357/acf45a","url":null,"abstract":"Abstract Recent irradiance measurements from numerous heliophysics and astrophysics missions including Solar Dynamics Observatory (SDO), GOES, Kepler, TESS, Chandra, the X-ray Multi-Mirror Mission, and NICER have provided critical input into understanding the physics of the most powerful transient events on the Sun and magnetically active stars:solar and stellar flares. The light curves of flare events from the Sun and stars show remarkably similar shapes, typically with a sharp rise and protracted decay phase. The duration of solar and stellar flares has been found to be correlated with the intensity of the event in some wavelengths, such as white light, but not in other wavelengths, such as soft X-rays, but it is not evident why this is the case. In this study, we use a radiative hydrodynamics code to examine factors affecting the duration of flare emission at various wavelengths. The duration of a light curve depends on the temperature of the plasma, the height in the atmosphere at which the emission forms, and the relative importance of cooling due to radiation, thermal conduction, and enthalpy flux. We find that there is a clear distinction between emission that forms low in the atmosphere and responds directly to heating, and emission that forms in the corona, indirectly responding to heating-induced chromospheric evaporation, a facet of the Neupert effect. We discuss the implications of our results for a wide range of flare energies.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135510571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0