The Astrophysical Journal最新文献_第7页

Follow-up of Neutron Star Mergers with CTA and Prospects for Joint Detection with Gravitational-wave Detectors

The Astrophysical Journal Pub Date : 2025-04-02 DOI: 10.3847/1538-4357/adbd12

T. Mondal, S. Chakraborty, L. Resmi and D. Bose

{"title":"Follow-up of Neutron Star Mergers with CTA and Prospects for Joint Detection with Gravitational-wave Detectors","authors":"T. Mondal, S. Chakraborty, L. Resmi and D. Bose","doi":"10.3847/1538-4357/adbd12","DOIUrl":"https://doi.org/10.3847/1538-4357/adbd12","url":null,"abstract":"The joint gravitational wave (GW) and electromagnetic observations of the binary neutron star (BNS) merger GW170817 marked a giant leap in multimessenger astrophysics. The extensive observation campaign of the associated gamma-ray burst (GRB) and its afterglow has strengthened the hypothesis associating GRBs with BNS mergers and provided insights into mass ejection, particularly the relativistic outflow launched in BNS mergers. In this paper, we investigate the joint detection probabilities of BNS mergers by GW detectors and the upcoming ground-based very-high-energy (VHE) γ-ray instrument, the Cherenkov Telescope Array (CTA). Using an empirical relation that constrains the distance–inclination angle plane, we simulated BNS mergers detectable in the O5 run of the LIGO/Virgo/Kagra network with a 300 Mpc BNS horizon. Assuming Gaussian structured jets and ignoring the large sky localization challenges of GW detectors, we estimated probability of detection of the VHE afterglow by CTA. We have explored the afterglow parameter space to identify conditions favourable for detecting synchrotron self-Compton emission by CTA. Our study reveals that events viewed at angles ≲3 times the jet core angle are detectable by CTA when the initial bulk Lorentz factor at the jet axis ranges between 100 and 800. We find high kinetic energy (Ek > 1050 erg), ambient density (n0 > 10−1 cm−3), and energy content in nonthermal electrons significantly enhance the likelihood of CTA detection within 300 Mpc. The joint detection rate varies significantly with afterglow parameter distributions, ranging from 0.003 to 0.5 per year.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"107 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766402","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}

引用次数: 0

Subphotospheric Emission from Short Gamma-Ray Bursts. II. Signatures of Nonthermal Dissipation in the Multi-messenger Signals

The Astrophysical Journal Pub Date : 2025-04-02 DOI: 10.3847/1538-4357/adbd3e

Annika Rudolph, Irene Tamborra and Ore Gottlieb

{"title":"Subphotospheric Emission from Short Gamma-Ray Bursts. II. Signatures of Nonthermal Dissipation in the Multi-messenger Signals","authors":"Annika Rudolph, Irene Tamborra and Ore Gottlieb","doi":"10.3847/1538-4357/adbd3e","DOIUrl":"https://doi.org/10.3847/1538-4357/adbd3e","url":null,"abstract":"Building on a general relativistic magnetohydrodynamic simulation of a short gamma-ray burst (sGRB) jet with initial magnetization σ0 = 150, propagating through the dynamical ejecta from a binary neutron star merger, we identify regions of energy dissipation driven by magnetic reconnection and collisionless subshocks within different scenarios. We solve the transport equations for photons, electrons, protons, neutrinos, and intermediate particles up to the photosphere, accounting for all relevant radiative processes, including electron and proton acceleration, and investigate the potential impact of magnetic reconnection occurring in different regions along the jet. We find the photon spectra undergo nonthermal modifications below the photosphere, observable in both on-axis and off-axis emission directions, as well as across different scenarios of energy dissipation and subsequent particle acceleration. Interestingly, the spectral index of the photon energy distribution can vary at most by ∼20% across all different dissipation scenarios. Depending on the dissipation mechanism at play, neutrino signatures may accompany the photon signal, pointing to efficient proton acceleration and shedding light on jet physics. Although our findings are based on one jet simulation, they point to a potential universal origin of the nonthermal features of the Band spectrum observed in sGRBs.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"133 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766403","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}

引用次数: 0

Lagrangian Perturbation Theory for Biased Tracers: Significance of the Number Conservation 偏置示踪剂的拉格朗日扰动理论：数字守恒的意义

The Astrophysical Journal Pub Date : 2025-04-02 DOI: 10.3847/1538-4357/adbe69

Peter Espenshade and Jaiyul Yoo

{"title":"Lagrangian Perturbation Theory for Biased Tracers: Significance of the Number Conservation","authors":"Peter Espenshade and Jaiyul Yoo","doi":"10.3847/1538-4357/adbe69","DOIUrl":"https://doi.org/10.3847/1538-4357/adbe69","url":null,"abstract":"The Lagrangian perturbation theory provides a simple yet powerful way of computing the nonlinear matter power spectrum, and it has been applied to biased tracers such as halos and galaxies. The number conservation of matter particles allows a simple relation between the fluctuations at the initial and late times, which is essential in deriving the exact expression for the nonlinear matter power spectrum. Here, we investigate the significance of the number conservation in the Lagrangian perturbation theory for biased tracers. We use N-body simulations to test the significance of the number conservation, by tracing dark matter halo samples in time. For the mass-bin sample at z ≃ 3, the theoretical predictions for the halos overestimate the power spectrum at z = 0 by a factor of 3, while the simulation results match the theoretical predictions if the number conservation of halos is imposed in the simulations throughout the evolution. Starting with a halo sample at z = 0 as another test, we trace back in time the particles that belong to the halos at z = 0 and use their center-of-mass positions as halo positions at z > 0. The halo power spectra at z > 0 from the simulations agree with the theoretical predictions of the Lagrangian perturbation theory. This numerical experiment proves that the number conservation is crucial in the Lagrangian perturbation theory predictions. We discuss the implications for various applications of the Lagrangian perturbation theory for biased tracers.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766439","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}

引用次数: 0

The Distance of Quasar Outflows from the Central Source: The First Consistent Values from Emission and Absorption Determinations

The Astrophysical Journal Pub Date : 2025-04-02 DOI: 10.3847/1538-4357/adb9e1

Mayank Sharma, Nahum Arav, Qinyuan Zhao, Maryam Dehghanian, Doyee Byun, Gwen Walker, Luming Sun, Lu Shen, Yulong Gao, Guilin Liu and Junfeng Wang

{"title":"The Distance of Quasar Outflows from the Central Source: The First Consistent Values from Emission and Absorption Determinations","authors":"Mayank Sharma, Nahum Arav, Qinyuan Zhao, Maryam Dehghanian, Doyee Byun, Gwen Walker, Luming Sun, Lu Shen, Yulong Gao, Guilin Liu and Junfeng Wang","doi":"10.3847/1538-4357/adb9e1","DOIUrl":"https://doi.org/10.3847/1538-4357/adb9e1","url":null,"abstract":"Measuring the distance of quasar outflows from the central source (R) is essential for determining their importance for active galactic nucleus feedback. There are two methods to measure R: (1) a direct determination using spatially resolved integral field spectroscopy (IFS) of the outflow in emission and (2) an indirect method that uses the absorption troughs from ionic excited states. The column density ratio between the excited and resonance states yields the outflow number density. Combined with a knowledge of the outflow’s ionization parameter, R can be determined. Generally, the IFS method probes an R range of several kiloparsecs or more, while the absorption method usually yields R values of less than 1 kpc. There is no inconsistency between the two methods as the determinations come from different objects. Here we report the results of applying both methods to the same quasar outflow, where we derive consistent determinations of R ≈ 5 kpc. This is the first time that the indirect absorption R determination is verified by a direct spatially resolved IFS observation. In addition, the velocities (and energetics) from the IFS and absorption data are found to be consistent. Therefore, these are two manifestations of the same outflow. In this paper we concentrate on the absorption R determination for the outflow seen in quasar 3C 191 using Very Large Telescope/X-shooter observations. We also reanalyze an older absorption determination for the outflow based on Keck/High Resolution Echelle Spectrometer data and find the revised measurement to be consistent with ours. Our companion paper details the IFS analysis of the same object.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766395","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}

引用次数: 0

Radio Pulse Search from Aql X-1

The Astrophysical Journal Pub Date : 2025-04-02 DOI: 10.3847/1538-4357/adbd43

Long Peng, Zhaosheng Li, Yuanyue Pan, Shanshan Weng, Wenming Yan, Na Wang, Bo-Jun Wang and Shuangqiang Wang

引用次数: 0

Two Phases of Particle Acceleration of a Solar Flare Associated with In Situ Energetic Particles

The Astrophysical Journal Pub Date : 2025-04-02 DOI: 10.3847/1538-4357/adbdd0

Meiqi Wang, 美祺王, Bin Chen, 彬陈, Trevor Knuth, Christina Cohen, Jeongwoo Lee, Haimin Wang and Sijie Yu

{"title":"Two Phases of Particle Acceleration of a Solar Flare Associated with In Situ Energetic Particles","authors":"Meiqi Wang, 美祺王, Bin Chen, 彬陈, Trevor Knuth, Christina Cohen, Jeongwoo Lee, Haimin Wang and Sijie Yu","doi":"10.3847/1538-4357/adbdd0","DOIUrl":"https://doi.org/10.3847/1538-4357/adbdd0","url":null,"abstract":"How impulsive solar energetic particle (SEP) events are produced by magnetic-reconnection-driven processes during solar flares remains an outstanding question. Here we report a short-duration SEP event associated with an X-class eruptive flare on 2021 July 3, using a combination of remote sensing observations and in situ measurements. The in situ SEPs were recorded by multiple spacecraft including the Parker Solar Probe. The hard X-ray (HXR) light curve exhibits two impulsive periods. The first period is characterized by a single peak with a rapid rise and decay, while the second period features a more gradual HXR light curve with a harder spectrum. Such observation is consistent with in situ measurements: the energetic electrons were first released during the early impulsive phase when the eruption was initiated. The more energetic in situ electrons were released several minutes later during the second period of the impulsive phase when the eruption was well underway. This second period of energetic electron acceleration also coincides with the release of in situ energetic protons and the onset of an interplanetary type III radio burst. We conclude that these multimessenger observations favor a two-phase particle acceleration scenario: the first, less energetic electron population was produced during the initial reconnection that triggers the flare eruption, and the second, more energetic electron population was accelerated in the region above the loop-top below a well-developed, large-scale reconnection current sheet induced by the eruption.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766910","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}

引用次数: 0

The Birth of a Major Coronal Mass Ejection with Intricate Magnetic Structure from Multiple Active Regions 来自多个活动区的具有复杂磁结构的大日冕物质抛射的诞生

The Astrophysical Journal Pub Date : 2025-04-02 DOI: 10.3847/1538-4357/adb976

J. H. Guo, Y. W. Ni, B. Schmieder, Y. Guo, C. Xia, P. Devi, R. Chandra, S. Poedts, R. Joshi, Y. H. Zhou, H. T. Li and P. F. Chen

{"title":"The Birth of a Major Coronal Mass Ejection with Intricate Magnetic Structure from Multiple Active Regions","authors":"J. H. Guo, Y. W. Ni, B. Schmieder, Y. Guo, C. Xia, P. Devi, R. Chandra, S. Poedts, R. Joshi, Y. H. Zhou, H. T. Li and P. F. Chen","doi":"10.3847/1538-4357/adb976","DOIUrl":"https://doi.org/10.3847/1538-4357/adb976","url":null,"abstract":"Coronal mass ejections (CMEs) are the eruptions of magnetized plasma from the Sun and are considered the main driver of adverse space weather events. Hence, understanding their formation process, particularly the magnetic topology, is critical for accurate space weather prediction. Here, based on imaging observations and three-dimensional (3D) data-constrained thermodynamic magnetohydrodynamic (MHD) simulation in spherical coordinates, we exhibit the birth of a CME with intricate magnetic structure from multiple active regions (ARs) due to 3D magnetic reconnection. It is observed as a coronal jet between ARs, accompanied by the back-flowing of filament materials along the jet spine after the passage of the eruptive filament. This jet connects two dimming regions within different ARs. This is an observational proxy of 3D magnetic reconnection between the CME flux rope and the null-point magnetic field lines crossing ARs. Hereafter, the thermodynamic data-constrained MHD simulation successfully reproduces the observed jet and the reconnection process that flux ropes partake in, leading to a CME flux rope with a complex magnetic structure distinct from its progenitor. The generality of this scenario is then validated by data-inspired MHD simulations in a simple multipolar magnetic configuration. This work demonstrates the role of multiple ARs in forming CMEs with intricate magnetic structures. On the one hand, a noncoherent flux rope where not all twisted magnetic field lines wind around one common axis is naturally formed. On the other hand, our findings suggest that the topology of a real CME flux rope may not be solely determined by a single AR, particularly during periods of solar maximum.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"48 5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766394","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}

引用次数: 0

A Tale of Two Black Holes: Multiband Gravitational-wave Measurement of Recoil Kicks

The Astrophysical Journal Pub Date : 2025-04-01 DOI: 10.3847/1538-4357/adba4e

Shobhit Ranjan, Karan Jani, Alexander H. Nitz, Kelly Holley-Bockelmann and Curt Cutler

{"title":"A Tale of Two Black Holes: Multiband Gravitational-wave Measurement of Recoil Kicks","authors":"Shobhit Ranjan, Karan Jani, Alexander H. Nitz, Kelly Holley-Bockelmann and Curt Cutler","doi":"10.3847/1538-4357/adba4e","DOIUrl":"https://doi.org/10.3847/1538-4357/adba4e","url":null,"abstract":"The nonlinear dynamics of General Relativity leave their imprint on remnants of black hole mergers in the form of a recoil “kick.” The kick has profound astrophysical implications across the black hole mass spectrum, from stellar-mass to supermassive black holes. However, a direct measurement of the kick would require observing the binary from different orientations. Therefore, the kick is primarily inferred by constraining the premerger parameters, mainly the spin orientations and mass ratio of the black holes and fitting them with postmerger parameters. In this study, we demonstrate the prospects for such measurements of black hole kicks in a multiband gravitational-wave network consisting of space mission LISA, the current Earth-based detector network, and a third-generation detector. For two distinct cases of remnant black hole kick (68, 1006 km s−1) emerging from near identical premerger configuration of GW190521—the first confirmed intermediate-mass black hole—we find that the multiband network will recover with a 90% credible level of the projection of the kick vector relative to the orbital plane within tens of km s−1 accuracy. Such precise measurement of the kick offers a new set of multimessenger follow-ups and unprecedented tests of astrophysical formation channels.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758353","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}

引用次数: 0

Is the Central Compact Object in HESS J1731-347 a Hybrid Star with a Quark Core? An Analysis with the Constant Speed of Sound Parameterization

The Astrophysical Journal Pub Date : 2025-04-01 DOI: 10.3847/1538-4357/adbc6b

Suman Pal, Soumen Podder and Gargi Chaudhuri

{"title":"Is the Central Compact Object in HESS J1731-347 a Hybrid Star with a Quark Core? An Analysis with the Constant Speed of Sound Parameterization","authors":"Suman Pal, Soumen Podder and Gargi Chaudhuri","doi":"10.3847/1538-4357/adbc6b","DOIUrl":"https://doi.org/10.3847/1538-4357/adbc6b","url":null,"abstract":"In this work, we investigate the possibility of the compact object in HESS J1731-347 with and to be a hybrid star with quark matter in the inner core. The observation of this low-mass compact star dictates the use of a softer equation of state, which, on the contrary, cannot explain the massive compact stars. This poses a new challenge for astrophysicists in their search for the equation of state of compact objects. The hybrid equations of state are constructed using the IUFSU parameterization based on the relativistic mean field theory for the hadronic part and the generic constant speed of sound (CSS) parameterization for the phase transition to quark matter. The CSS framework is characterized by three key parameters, namely the transition density (ρtr), the energy jumps (Δε), and the speed of sound (Cs). Here, our primary aim is to investigate the influence of individual CSS parameters on the formation of an object of small mass and radius compatible with HESS J1731-347 parameters. We have also examined the effect of hadronic parameters such as effective mass, symmetry energy, and the slope of the symmetry energy at saturation densities on the formation of this compact object. Finally, our analysis suggests that, within a 1σ credible level, HESS J1731-347 aligns with the scenario of a stable hybrid star with early deconfinement and higher energy gap.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758357","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}

引用次数: 0

Reprocessing from Highly Ionized Gas in the Soft Spectral State of V4641 Sgr with NuSTAR

The Astrophysical Journal Pub Date : 2025-04-01 DOI: 10.3847/1538-4357/adbbdb

Riley M. T. Connors, Joey Neilsen, Aarran W. Shaw, James F. Steiner, Federico Vincentelli, Javier A. García, Phil Uttley, Ronald A. Remillard and Guglielmo Mastroserio

{"title":"Reprocessing from Highly Ionized Gas in the Soft Spectral State of V4641 Sgr with NuSTAR","authors":"Riley M. T. Connors, Joey Neilsen, Aarran W. Shaw, James F. Steiner, Federico Vincentelli, Javier A. García, Phil Uttley, Ronald A. Remillard and Guglielmo Mastroserio","doi":"10.3847/1538-4357/adbbdb","DOIUrl":"https://doi.org/10.3847/1538-4357/adbbdb","url":null,"abstract":"V4641 Sgr is a low-mass black hole X-ray binary system with somewhat puzzling spectral characteristics during its soft state. Recent high-resolution spectroscopic studies of V4641 Sgr have revealed strong ionized emission-line features in both the optical and X-ray bands, including P-Cygni signatures, and an unusually low soft-state luminosity, indicating that the central engine is obscured. Here, we present an analysis of five Nuclear Spectroscopic Telescope Array (NuSTAR) observations of V4641 Sgr taken during its recent outburst in 2021, when the source was in the soft state. We identify highly ionized Fe K emission lines—consistent with a combination of the near-neutral 6.4 keV Fe Kα line and the H-like and He-like Fe Kα and Fe Kβ transitions found at 6.7–7 keV and ∼8 keV—and find no evidence for strong relativistic broadening. The line fluxes correlate linearly with the observed disk continuum flux, implying a direct connection between the central engine and the reprocessing region. Most interestingly, all five spectra also show a persistent highly ionized Fe K continuum edge feature at ∼9 keV with a stable optical depth, which is likely smeared, implying a localized reprocessing zone. We find tentative supporting evidence for obscuration of the inner accretion disk based on its unusually low intrinsic luminosity, although the NuSTAR spectra do not require obscuration from cold, optically thick gas.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758385","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}

引用次数: 0