The Astrophysical Journal Letters最新文献_第8页

Magnetic Reconnection–driven Energization of Protons up to ∼400 keV at the Near-Sun Heliospheric Current Sheet 在近太阳日球层电流片上，磁重联驱动的质子能量高达~ 400 keV

The Astrophysical Journal Letters Pub Date : 2025-05-28 DOI: 10.3847/2041-8213/ada697

M. I. Desai, J. F. Drake, T. Phan, Z. Yin, M. Swisdak, D. J. McComas, S. D. Bale, A. Rahmati, D. Larson, W. H. Matthaeus, M. A. Dayeh, M. J. Starkey, N. E. Raouafi, D. G. Mitchell, C. M. S. Cohen, J. R. Szalay, J. Giacalone, M. E. Hill, E. R. Christian, N. A. Schwadron, R. L. McNutt, O. Malandraki, P. Whittlesey, R. Livi and J. C. Kasper

{"title":"Magnetic Reconnection–driven Energization of Protons up to ∼400 keV at the Near-Sun Heliospheric Current Sheet","authors":"M. I. Desai, J. F. Drake, T. Phan, Z. Yin, M. Swisdak, D. J. McComas, S. D. Bale, A. Rahmati, D. Larson, W. H. Matthaeus, M. A. Dayeh, M. J. Starkey, N. E. Raouafi, D. G. Mitchell, C. M. S. Cohen, J. R. Szalay, J. Giacalone, M. E. Hill, E. R. Christian, N. A. Schwadron, R. L. McNutt, O. Malandraki, P. Whittlesey, R. Livi and J. C. Kasper","doi":"10.3847/2041-8213/ada697","DOIUrl":"https://doi.org/10.3847/2041-8213/ada697","url":null,"abstract":"We report observations of direct evidence of energetic protons being accelerated above ∼400 keV within the reconnection exhaust of a heliospheric current sheet (HCS) crossing by NASA’s Parker Solar Probe (PSP) at a distance of ∼16.25 solar radii (Rs) from the Sun. Inside the exhaust, both the reconnection-generated plasma jet and the accelerated protons up to ∼400 keV propagated toward the Sun, unambiguously establishing their origin from HCS reconnection sites located antisunward of PSP. Within the core of the exhaust, PSP detected stably trapped energetic protons up to ∼400 keV, which is ≈1000 times greater than the available magnetic energy per particle. The differential energy spectrum of the accelerated protons behaved as a pure power law with spectral index of ∼−5. Supporting simulations using the kglobal model suggest that the trapping and acceleration of protons up to ∼400 keV in the reconnection exhaust are likely facilitated by merging magnetic islands with a guide field between ∼0.2 and 0.3 of the reconnecting magnetic field, consistent with the observations. These new results, enabled by PSP’s proximity to the Sun, demonstrate that magnetic reconnection in the HCS is a significant new source of energetic particles in the near-Sun solar wind. Our findings of in situ particle acceleration via magnetic reconnection at the HCS provide valuable insights into this fundamental process, which frequently converts the large magnetic field energy density in the near-Sun plasma environment and may be responsible for heating the Sun’s atmosphere, accelerating the solar wind, and energizing charged particles to extremely high energies in solar flares.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"25 1","pages":"L38"},"PeriodicalIF":0.0,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144164913","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

Exploring the Link between Fast Radio Burst and Binary Neutron Star Origins with Spaceborne Gravitational Wave Observations 利用星载引力波观测探索快速射电暴与双中子星起源之间的联系

The Astrophysical Journal Letters Pub Date : 2025-05-28 DOI: 10.3847/2041-8213/add875

Yu-xuan Yin, 宇轩尹, En-kun Li, 恩坤李, Bing Zhang, 冰张, Yi-Ming Hu and 一鸣胡

{"title":"Exploring the Link between Fast Radio Burst and Binary Neutron Star Origins with Spaceborne Gravitational Wave Observations","authors":"Yu-xuan Yin, 宇轩尹, En-kun Li, 恩坤李, Bing Zhang, 冰张, Yi-Ming Hu and 一鸣胡","doi":"10.3847/2041-8213/add875","DOIUrl":"https://doi.org/10.3847/2041-8213/add875","url":null,"abstract":"The origin of repeating fast radio bursts (rFRBs) is an open question, with observations suggesting that at least some are associated with old stellar populations. It has been proposed that some rFRBs may be produced by interactions of the binary neutron star (BNS) magnetospheres decades to centuries before the coalescence. These systems would also emit centi-Hertz gravitational waves during this period, which can be detectable by spaceborne gravitational wave detectors. We explore the prospects of using current and future spaceborne gravitational wave detectors, such as TianQin, LISA, and DECIGO, to test this fast radio burst (FRB) formation hypothesis. Focusing on nearby galaxies like M81, which hosts an rFRB source in a globular cluster, we calculate the detection capabilities for BNS systems. Our analysis reveals that while missions like TianQin and LISA face limitations in horizon distance, changing the detector pointing direction could significantly enhance detection probabilities. Considering that the chance of a Milky Way–like galaxy coincidentally containing a BNS within 100 yr before merger is only 3 × 10−5–5 × 10−3, if a signal is detected originating from M81, we can establish the link between FRBs and BNSs with a significance level of at least 2.81σ. For TianQin and LISA, Bayes factors for rFRB–BNS associations range from 4 × 106 to 7 × 108 under ideal assumptions of uniform event distribution, dropping to 5 × 102–105 when accounting for the fact that the events are confined in galaxies. Next-generation detectors such as DECIGO offer enhanced capabilities compared to TianQin and LISA and should easily detect these systems in M81 and beyond. DECIGO can boost the Bayes factor by up to 4 orders of magnitude (1010–1012 ideally and 104–106 realistically). Our work highlights the critical role of spaceborne gravitational wave missions in unraveling FRB origins.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144164921","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

X-Ray Polarization of the Magnetar 1E 1841−045 磁星1e1841−045的x射线偏振

The Astrophysical Journal Letters Pub Date : 2025-05-27 DOI: 10.3847/2041-8213/adbffa

Rachael Stewart, George A. Younes, Alice K. Harding, Zorawar Wadiasingh, Matthew G. Baring, Michela Negro, Tod E. Strohmayer, Wynn C. G. Ho, Mason Ng, Zaven Arzoumanian, Hoa Dinh Thi, Niccolò Di Lalla, Teruaki Enoto, Keith Gendreau, Chin-Ping Hu, Alex van Kooten, Chryssa Kouveliotou and Alexander McEwen

{"title":"X-Ray Polarization of the Magnetar 1E 1841−045","authors":"Rachael Stewart, George A. Younes, Alice K. Harding, Zorawar Wadiasingh, Matthew G. Baring, Michela Negro, Tod E. Strohmayer, Wynn C. G. Ho, Mason Ng, Zaven Arzoumanian, Hoa Dinh Thi, Niccolò Di Lalla, Teruaki Enoto, Keith Gendreau, Chin-Ping Hu, Alex van Kooten, Chryssa Kouveliotou and Alexander McEwen","doi":"10.3847/2041-8213/adbffa","DOIUrl":"https://doi.org/10.3847/2041-8213/adbffa","url":null,"abstract":"We report on IXPE and NuSTAR observations beginning 40 days after the 2024 outburst onset of magnetar 1E 1841−045, marking the first IXPE observation of a magnetar in an enhanced state. Our spectropolarimetric analysis indicates that both a blackbody (BB) plus double power-law (PL) and a double blackbody plus power-law spectral model fit the phase-averaged intensity data well, with a hard PL tail (Γ = 1.19 and 1.35, respectively) dominating above ≈5 keV. For the former model, we find the soft PL (the dominant component at soft energies) exhibits a polarization degree (PD) of ≈30% while the hard PL displays a PD of ≈40%. Similarly, the cool BB of the 2BB+PL model possesses a PD of ≈15% and a hard PL PD of ≈57%. For both models, each component has a polarization angle (PA) compatible with celestial north. Model-independent polarization analysis supports these results, wherein the PD increases from ≈15% to ≈70% in the 2–3 keV and 6–8 keV ranges, respectively, while the PA remains nearly constant. We find marginal evidence for phase-dependent variability of the polarization properties, namely a higher PD at phases coinciding with the hard X-ray pulse peak. We compare the hard X-ray PL to the expectation from resonant inverse Compton scattering (RICS) and secondary pair cascade synchrotron radiation from primary high-energy RICS photons; both present reasonable spectropolarimetric agreement with the data, albeit the latter does so more naturally. We suggest that the soft PL X-ray component may originate from a Comptonized corona in the inner magnetosphere.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"152 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153611","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

Properties of “Lite” Intermediate-mass Black Hole Candidates in LIGO-Virgo’s Third Observing Run LIGO-Virgo第三次观测中“生命”中等质量黑洞候选者的特性

The Astrophysical Journal Letters Pub Date : 2025-05-27 DOI: 10.3847/2041-8213/adc5f8

Krystal Ruiz-Rocha, Anjali B. Yelikar, Jacob Lange, William Gabella, Robert A. Weller, Richard O’Shaughnessy, Kelly Holley-Bockelmann and Karan Jani

{"title":"Properties of “Lite” Intermediate-mass Black Hole Candidates in LIGO-Virgo’s Third Observing Run","authors":"Krystal Ruiz-Rocha, Anjali B. Yelikar, Jacob Lange, William Gabella, Robert A. Weller, Richard O’Shaughnessy, Kelly Holley-Bockelmann and Karan Jani","doi":"10.3847/2041-8213/adc5f8","DOIUrl":"https://doi.org/10.3847/2041-8213/adc5f8","url":null,"abstract":"Over a hundred gravitational-wave (GW) detections and candidates have been reported from the first three observing runs of the Advanced LIGO-Virgo-KAGRA (LVK) detectors. Among these, the most intriguing events are binary black hole mergers that result in a “lite” intermediate-mass black hole (IMBH) of ∼102M⊙, such as GW170502 and GW190521. In this study, we investigate 11 GW candidates from LVK’s third observing run with total detector-frame masses in the lite IMBH range. Using the Bayesian inference algorithm RIFT, we systematically analyze these candidates with three state-of-the-art waveform models that incorporate higher harmonics, which are crucial for resolving lite IMBHs in LVK data. For each candidate, we infer the premerger and postmerger black hole masses in the source frame, along with black hole spin projections across all three models. Under the assumption that these are binary black hole mergers, our analysis finds that five have a postmerger lite IMBH with masses ranging from 110 to 350 M⊙ with over 90% confidence interval. Additionally, we note that one of their premerger black holes is within the pair-instability supernova mass gap (60–120 M⊙), and two premerger black holes are above the mass gap. Furthermore, we report discrepancies among the three waveform models in intrinsic parameters, with at least three GW candidates showing deviations beyond accepted statistical limits. While the astrophysical certainty of these candidates cannot be established, our study provides a foundation to probe the lite IMBH population that emerge within the low-frequency noise spectrum of LVK detectors.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153608","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

On the Orbital Effects of Stellar Collisions in Galactic Nuclei: Tidal Disruption Events and Ejected Stars 星系核中恒星碰撞的轨道效应：潮汐破坏事件和抛射恒星

The Astrophysical Journal Letters Pub Date : 2025-05-27 DOI: 10.3847/2041-8213/add266

Sanaea C. Rose and Brenna Mockler

{"title":"On the Orbital Effects of Stellar Collisions in Galactic Nuclei: Tidal Disruption Events and Ejected Stars","authors":"Sanaea C. Rose and Brenna Mockler","doi":"10.3847/2041-8213/add266","DOIUrl":"https://doi.org/10.3847/2041-8213/add266","url":null,"abstract":"Dense stellar clusters surround the supermassive black holes (SMBH) in galactic nuclei. Interactions within the cluster can alter the stellar orbits, occasionally driving a star into the SMBH’s tidal radius, where it becomes ruptured, or expelling a star from the nuclear cluster. This proof-of-concept study examines the orbital effects of stellar collisions using a semianalytic model. Both low- and high-speed collisions occur in the SMBH’s sphere of influence. We find that collisions can place stars on nearly radial orbits. Depositing stars within the tidal radius, collisions may drive the disruption of stars with unusual masses and structures: depending on the nature of the collision, the star could be the product of a recent merger, or it could have lost its outer layers in a previous high-speed impact, appearing as a stripped star. We also find that high-speed collisions near the periapsis of an eccentric orbit can unbind stars from the SMBH. However, dissipation during these high-speed collisions can substantially reduce the number of unbound stars achieved in our simulations. We conclude that tidal disruption events and ejected stars, even in the hypervelocity regime, are plausible outcomes of stellar collisions, though their frequency in a three-dimensional nuclear star cluster is uncertain. Future work will address the rates and properties of these events.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"65 15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144164914","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

XRISM Reveals a Remnant Torus in the Low-luminosity AGN M81* XRISM揭示了低亮度AGN M81*的残余环面

The Astrophysical Journal Letters Pub Date : 2025-05-27 DOI: 10.3847/2041-8213/add262

Jon M. Miller, Ehud Behar, Hisamitsu Awaki, Ann Hornschemeier, Jesse Bluem, Luigi Gallo, Shogo B. Kobayashi, Richard Mushotzky, Masanori Ohno, Robert Petre, Kosuke Sato, Yuichi Terashima and Mihoko Yukita

{"title":"XRISM Reveals a Remnant Torus in the Low-luminosity AGN M81*","authors":"Jon M. Miller, Ehud Behar, Hisamitsu Awaki, Ann Hornschemeier, Jesse Bluem, Luigi Gallo, Shogo B. Kobayashi, Richard Mushotzky, Masanori Ohno, Robert Petre, Kosuke Sato, Yuichi Terashima and Mihoko Yukita","doi":"10.3847/2041-8213/add262","DOIUrl":"https://doi.org/10.3847/2041-8213/add262","url":null,"abstract":"Up to 40% of galaxies in the local Universe host a low-luminosity active galactic nucleus (LLAGN), making it vital to understand this mode of black hole accretion. However, the presence or absence of Seyfert-like geometries—an accretion disk close to the black hole, an optical broad-line region, and a molecular torus—remains uncertain owing to the low flux levels of sources within this class. Herein we present an analysis of an XRISM/Resolve spectrum of M81*, the LLAGN in the heart of the nearby spiral galaxy M81. A weak, neutral Fe K emission line is detected and resolved into Kα,1 and Kα,2 components. It shows a negligible velocity shift and weak broadening (FWHM ) that corresponds to an inner emission radius of r ≥ 2.7 × 104 GM c−2 for likely inclinations. The Fe Kα line likely traces a torus. The upper limit on additional splitting of the Fe Kα line components translates to a limit on the local magnetic field of B ≤ 3.5 × 108 G, assuming Zeeman splitting. The spectra also reveal ionized plasma(s) through He-like Fe xxv and H-like Fe xxvi emission lines. These can be fit equally well assuming photoionization and collisional excitation. The H-like Fe xxvi line is better described when a second component is included with a redshift of v = 1600 km s−1, but this addition is of marginal statistical significance. We discuss these results in the context of radiatively inefficient accretion flow models, magnetically arrested disks, and possible links to the Fermi bubbles in the Milky Way.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153610","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

IXPE Detection of Highly Polarized X-Rays from the Magnetar 1E 1841-045 磁星1e1841 -045高偏振x射线的IXPE探测

The Astrophysical Journal Letters Pub Date : 2025-05-27 DOI: 10.3847/2041-8213/adbffb

Michela Rigoselli, Roberto Taverna, Sandro Mereghetti, Roberto Turolla, Gian Luca Israel, Silvia Zane, Lorenzo Marra, Fabio Muleri, Alice Borghese, Francesco Coti Zelati, Davide De Grandis, Matteo Imbrogno, Ruth M. E. Kelly, Paolo Esposito and Nanda Rea

{"title":"IXPE Detection of Highly Polarized X-Rays from the Magnetar 1E 1841-045","authors":"Michela Rigoselli, Roberto Taverna, Sandro Mereghetti, Roberto Turolla, Gian Luca Israel, Silvia Zane, Lorenzo Marra, Fabio Muleri, Alice Borghese, Francesco Coti Zelati, Davide De Grandis, Matteo Imbrogno, Ruth M. E. Kelly, Paolo Esposito and Nanda Rea","doi":"10.3847/2041-8213/adbffb","DOIUrl":"https://doi.org/10.3847/2041-8213/adbffb","url":null,"abstract":"The Imaging X-ray Polarimetry Explorer (IXPE) observed for the first time highly polarized X-ray emission from the magnetar 1E 1841−045, targeted after a burst-active phase in 2024 August. To date, IXPE has observed four other magnetars during quiescent periods, highlighting substantially different polarization properties. 1E 1841−045 exhibits a high, energy-dependent polarization degree, which increases monotonically from ≈15% at 2–3 keV up to ≈55% at 5.5–8 keV, while the polarization angle, aligned with the celestial north, remains fairly constant. The broadband spectrum (2–79 keV) obtained by combining simultaneous IXPE and NuSTAR data is well modeled by a blackbody and two power-law components. The unabsorbed 2–8 keV flux (≈2 × 10−11 erg cm−2 s−1) is about 10% higher than that obtained from archival XMM-Newton and NuSTAR observations. The polarization of the soft, thermal component does not exceed ≈25%, and may be produced by a condensed surface or a bombarded atmosphere. The intermediate power law is polarized at around 30%, consistent with predictions for resonant Compton scattering in the star magnetosphere; meanwhile, the hard power law exhibits a polarization degree exceeding 65%, pointing to a synchrotron/curvature origin.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153632","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

Localizing Dynamically Formed Black Hole Binaries in Milky Way Globular Clusters with LISA 用LISA定位银河系球状星团中动态形成的黑洞双星

The Astrophysical Journal Letters Pub Date : 2025-05-27 DOI: 10.3847/2041-8213/add718

Zeyuan Xuan, Kyle Kremer and Smadar Naoz

{"title":"Localizing Dynamically Formed Black Hole Binaries in Milky Way Globular Clusters with LISA","authors":"Zeyuan Xuan, Kyle Kremer and Smadar Naoz","doi":"10.3847/2041-8213/add718","DOIUrl":"https://doi.org/10.3847/2041-8213/add718","url":null,"abstract":"The dynamical formation of binary black holes (BBHs) in globular clusters (GCs) may contribute significantly to the observed gravitational-wave (GW) merger rate. Furthermore, the Laser Interferometer Space Antenna (LISA) may detect many BBH sources from GCs at mHz frequencies, enabling the characterization of such systems within the Milky Way and nearby Universe. In this work, we use Monte Carlo N-body simulations to construct a realistic sample of Galactic clusters, thus estimating the population, detectability, and parameter measurement accuracy of BBHs hosted within them. In particular, we show that the GW signal from 0.7 ± 0.7, 2.0 ± 1.7, 3.6 ± 2.3, and 13.4 ± 4.7 BBHs in Milky Way GCs can exceed the signal-to-noise ratio (SNR) threshold of SNR = 30, 5, 3, and 1 for a 10 yr LISA observation, with ∼50% of detectable sources exhibiting high eccentricities (e ≳ 0.9). Moreover, the Fisher matrix and Bayesian analyses of the GW signals indicate that these systems typically feature highly resolved orbital frequencies (δforb/forb ∼ 10−7 to 10−5) and eccentricities (δe/e ∼ 10−3 to 0.1), as well as a measurable total mass when SNR exceeds ∼20. Notably, we show that high-SNR BBHs can be confidently localized to specific Milky Way GCs with a sky localization accuracy of δΩ ∼ 1 deg2, and we address the large uncertainties in their distance measurement (δR ∼ 0.3–20 kpc). The detection and localization of even a single BBH in a Galactic GC would allow accurate tracking of its long-term orbital evolution, enable a direct test of the role of GCs in BBH formation, and provide a unique probe into the evolutionary history of Galactic clusters.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"51 1","pages":"L42"},"PeriodicalIF":0.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144164915","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

Cosmology with Binary Neutron Stars: Does Mass–Redshift Correlation Matter? 双中子星宇宙学：质量红移相关是否重要？

The Astrophysical Journal Letters Pub Date : 2025-05-26 DOI: 10.3847/2041-8213/add34a

Soumendra Kishore Roy, Lieke A. C. van Son, Anarya Ray and Will M. Farr

{"title":"Cosmology with Binary Neutron Stars: Does Mass–Redshift Correlation Matter?","authors":"Soumendra Kishore Roy, Lieke A. C. van Son, Anarya Ray and Will M. Farr","doi":"10.3847/2041-8213/add34a","DOIUrl":"https://doi.org/10.3847/2041-8213/add34a","url":null,"abstract":"Next-generation gravitational-wave detectors are expected to detect millions of compact binary mergers across cosmological distances. The features of the mass distribution of these mergers, combined with gravitational-wave distance measurements, will enable precise cosmological inferences, even without the need for electromagnetic counterparts. However, achieving accurate results requires modeling the mass spectrum, particularly considering possible redshift evolution. Binary neutron star (BNS) mergers are thought to be less influenced by changes in metallicity compared to binary black holes or neutron star–black hole mergers. This stability in their mass spectrum over cosmic time reduces the chances of introducing biases in cosmological parameters caused by redshift evolution. In this study, we use the population synthesis code COMPAS to generate astrophysically motivated catalogs of BNS mergers and explore whether assuming a nonevolving BNS mass distribution with redshift could introduce biases in cosmological parameter inference. Our findings show that despite significant variations in the BNS mass distribution across binary physics assumptions and initial conditions in COMPAS, the joint mass–redshift population can be expressed as the product of the mass distribution marginalized over redshift and the redshift distribution marginalized over masses. This enables a 2% unbiased constraint on the Hubble constant—sufficient to address the Hubble tension. Additionally, we show that in the fiducial COMPAS setup, the bias from a nonevolving BNS mass model is less than 0.5% for the Hubble parameter measured at redshift 0.4. These results establish BNS mergers as strong candidates for spectral siren cosmology in the era of next-generation gravitational-wave detectors.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"152 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153612","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

Accurate Muonic Interactions in Neutron Star Mergers and Impact on Heavy-element Nucleosynthesis 中子星合并中的精确介子相互作用及其对重元素核合成的影响

The Astrophysical Journal Letters Pub Date : 2025-05-26 DOI: 10.3847/2041-8213/add324

Harry Ho-Yin Ng, Carlo Musolino, Samuel D. Tootle and Luciano Rezzolla

{"title":"Accurate Muonic Interactions in Neutron Star Mergers and Impact on Heavy-element Nucleosynthesis","authors":"Harry Ho-Yin Ng, Carlo Musolino, Samuel D. Tootle and Luciano Rezzolla","doi":"10.3847/2041-8213/add324","DOIUrl":"https://doi.org/10.3847/2041-8213/add324","url":null,"abstract":"The abundances resulting from r-process nucleosynthesis as predicted by simulations of binary neutron star (BNS) mergers remain an open question as the current state of the art is still restricted to three-species neutrino transport. We present the first BNS merger simulations employing a moment-based general-relativistic neutrino transport with five neutrino species, thus including (anti)muons and advanced muonic β-processes, and contrast them with traditional three-neutrino-species simulations. Our results show that a muonic trapped-neutrino equilibrium is established, forming a different trapped-neutrino hierarchy akin to the electronic equilibrium. The formation of (anti)muons and the muonization via muonic β-processes enhance neutrino luminosity, leading to a stronger cooling in the early postmerger phase. Since muonic processes redirect part of the energy otherwise used for protonization by electronic processes, they yield a cooler remnant and disk, together with neutrino-driven winds that are more neutron-rich. Importantly, the unbound ejected mass is smaller than in three-species simulations, and, because of its comparatively smaller temperature and proton fraction, it can enhance lanthanide production and reduce the overproduction of light r-process elements for softer equations of state. This finding underlines the importance of muonic interactions and five neutrino species in long-lived BNS remnants.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153647","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