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Effect of irradiation on the spin of millisecond pulsars

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arXiv 2023年

作者： Lan, Shun-Yi Meng, Xiang-Cun Yunnan Observatories Chinese Academy of Sciences Kunming650011 China University of the Chinese Academy of Sciences 19A Yuquan Road Shijingshan District Beijing100049 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China

A millisecond pulsar (MSP) is an old neutron star (NS) that has accreted material from its companion star, causing it to spin up, which is known as the recycling scenario. During the mass transfer phase, the system manifests itself as an X-ray binary. PSR J1402+13 is an MSP with a spin period of 5.89 ms and a spin period derivative of log Pspin = −16.32. These properties make it a notable object within the pulsar population, as MSPs typically exhibit low spin period derivatives. In this paper, we aim to explain how an MSP can posses high spin period derivative by binary evolution. By utilizing the stellar evolution code MESA, we examine the effects of irradiation on the companion star and the propeller effect on the NS during binary evolution. We demonstrate that irradiation can modify the spin period and mass of an MSP, resulting in a higher spin period derivative. These results suggest that the irradiation effect may serve as a key factor in explaining MSPs with high spin period derivatives. © 2023, CC BY.

关键词： Mass transfer

Constraints on Common Envelope Ejection from Double Helium White Dwarfs

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arXiv 2024年

作者： Zhang, Yangyang Li, Zhenwei Chen, Xuefei Han, Zhanwen Zhoukou Normal University East Wenchang Street Chuanhui District Zhoukou466001 China Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Science China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China University of the Chinese Academy of Science Yuquan Road 19 Shijingshan Block Beijing100049 China

Double helium white dwarfs (He WDs) are one type of gravitational wave source and are greatly important in the studies of binary interaction, particularly in the common envelope (CE) ejection physics. Most double He WDs with mass ratios of q ∼ 1 are formed through a particular channel. In this channel, one He WD is initially produced from a red giant (RG) with a degenerate core via stable Roche lobe overflow, and another He WD is formed from an RG with a degenerate core via CE ejection. They may have significant implications for the binary evolution processes yet have not received specific studies, especially for the CE phase. This paper adopts a semi-analytic method and a detailed stellar evolution simulation to model the formation of double He WDs. We find that most double He WDs show mass ratios being slightly greater than 1, and their orbital periods and mass ratios relation are broadly consistent with observations. There is also a relation between the mass ratios and the progenitors’ masses of the He WDs produced via CE ejection for double He WDs with determined WD masses. Based on this relation, the mass of the He WD progenitor can be inferred from the mass ratio. Then, the CE ejection efficiency can be constrained with the orbital period. In addition, we constrain the CE ejection efficiency for two double He WDs, J1005-2249 and WD0957-666. The results show that the CE ejection efficiencies increase with the WD progenitor masses. Copyright © 2024, The Authors. All rights reserved.

关键词： White dwarfs

Early phase simultaneous multi-band observations of Type II supernova SN 2024ggi with Mephisto

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arXiv 2024年

作者： Chen, Xinlei Kumar, Brajesh Er, Xinzhong Guo, Helong Yang, Yuan-Pei Lin, Weikang Fang, Yuan Du, Guowang Liu, Chenxu Zhao, Jiewei Zhang, Tianyu Bao, Yuxi Zou, Xingzhu Pan, Yu Wang, Yu Zhu, Xufeng Chatterjee, Kaushik Liu, Xiangkun Liu, Dezi Lagioia, Edoardo P. Rangwal, Geeta Zhong, Shiyan Zhang, Jinghua Lian, Jianhui Cai, Yongzhi Zhang, Yangwei Liu, Xiaowei South-Western Institute for Astronomy Research Yunnan University Yunnan Kunming650504 China Department of Astronomy Yunnan University Yunnan Kunming650504 China Yunnan Observatories Chinese Academy of Sciences Yunnan Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Yunnan Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Yunnan Kunming650216 China

We present early-phase good cadence simultaneous multi-band (ugi, urz–bands) imaging of nearby supernova SN 2024ggi, which exploded in the nearby galaxy, NGC 3621. A quick follow-up was conducted within less than a day after the explosion and continued ∼23 days. The uvg-band light curves display a rapid rise (∼1.4 mag day−1) to maximum in ∼4 days and absolute magnitude mg ∼–17.75 mag. The post-peak decay rate in redder bands is ∼0.01 mag day−1. Different colors (e.g., u − g and v− r) of SN 2024ggi are slightly redder than SN 2023ixf. A significant rise (∼12.5 kK) in black-body temperature (optical) was noticed within ∼2 days after the explosion, which successively decreased, indicating shock break out inside a dense circumstellar medium (CSM) surrounding the progenitor. Using semi-analytical modeling, the ejecta mass and progenitor radius were estimated as 1.2 M☉ and ∼550 R☉, respectively. The archival deep images (g, r, i, z-bands) from the Dark Energy Camera Legacy Survey (DECaLS) were examined, and a possible progenitor was detected in each band (∼22–22.5 mag) and had a mass range of 14–17 M☉. Copyright © 2024, The Authors. All rights reserved.

关键词： Supernovae

Photometric Study and Period Investigation of Two Contact Binaries: Vw Boo And V1128 Tau

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SSRN

SSRN 2023年

作者： Han, Quan-Wang Jiang, Deng-Kai School of Physics and Electronics Qiannan Normal University for Nationalities Duyun558000 China Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China

We analyzed the TESS data of VW Boo and V1128 Tau by using the Wilson-Devinney code. The obtained solutions reveal that these two systems are shallow-contact binaries. The fill-out factors for VW Boo and V1128 Tau are 10.35% and 17.20%, respectively. Period investigations were conducted based on all available times of minimum. Our results show that the orbital period of VW Boo is decreasing at a rate of dP/dt = −1.52 × 10−7 days yr−1, together with a cyclic oscillation having a period of 27.179 yr and a semi-amplitude of 0.0063 d. Similarly, the orbital period of V1128 Tau also shows a secular decrease (dP/dt = −1.40 × 10−7 days yr−1), along with a cyclic oscillation (P3= 16.125 yr and K3 = 0.0011). The secular decrease might be caused by mass transfer, while the cyclic oscillation might be caused by the presence of a third body or magnetic activity. © 2023, The Authors. All rights reserved.

关键词： Mass transfer

On the rotation properties of a post-explosion helium-star companion in Type Iax supernovae

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arXiv 2022年

作者： Zeng, Yaotian Liu, Zheng-Wei Meng, Xiangcun Han, Zhanwen Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects CAS Kunming650216 China University of Chinese Academy of Science Beijing100012 China Center for Astronomical Mega-Science CAS Beijing100012 China

Recent studies have suggested that type Iax supernovae (SNe Iax) are likely to result from a weak deflagration explosion of a Chandrasekhar-mass white dwarf in a binary system with a helium (He)-star companion. Assuming that most SNe Iax are produced from this scenario, in this work we extend our previous work on the three-dimensional hydrodynamical simulation of ejecta-companion interaction by taking the orbital and spin velocities of the progenitor system into account. We then follow the post-impact evolution of a surviving He-star companion by using the one-dimensional stellar evolution code MESA. We aim to investigate the post-explosion rotation properties of a He-star companion in SNe Iax. We find that the He-star companion spins down after the impact due to the angular-momentum loss and expansion caused by the mass-stripping and shock heating during the interaction. This leads to the situation where the surface rotational speed of the surviving companion can drop to one-third of its pre-explosion value when it expands to a maximum radius a few years after the impact. Subsequently, the star shrinks and spins up again once the deposited energy is released. This spin-switching feature of the surviving He-star companions of SNe Iax may be useful for the identification of such objects in future observations. Copyright © 2022, The Authors. All rights reserved.

关键词： Helium

Black Hole Ultracompact X-Ray Binaries as Galactic Low-frequency Gravitational Wave Sources: the He Star Channel

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arXiv 2023年

作者： Qin, Ke Xu, Kun Liu, Dong-Dong Jiang, Long Wang, Bo Chen, Wen-Cong School of Science Qingdao University of Technology Qingdao266525 China School of Physics Zhengzhou University Zhengzhou450001 China Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories Chinese Academy of Sciences Kunming650216 China School of Physics and Electrical Information Shangqiu Normal University Shangqiu476000 China

Black hole (BH) ultracompact X-ray binaries (UCXBs) are potential Galactic low-frequency gravitational wave (GW) sources. As an alternative channel, BH UCXBs can evolve from BH+He star binaries. In this work, we perform a detailed stellar evolution model for the formation and evolution of BH UCXBs evolving from the He star channel to diagnose their detectability as low-frequency GW sources. Our calculations found that some nascent BH+He star binaries after the common-envelope (CE) phase could evolve into UCXB-LISA sources with a maximum GW frequency of ∼ 5 mHz, which can be detected in a distance of 10 kpc (or 100 kpc). Once BH+He star systems become UCXBs through mass transfer, they would emit X-ray luminosities of ∼ 1038 erg s−1, making them ideal multimessenger objects. If the initial He-star masses are ≥ 0.7M☉, those systems are likely to experience two Roche lobe overflows, and the X-ray luminosity can reach a maximum of 3.5 × 1039 erg s−1 in the second mass-transfer stage. The initial He-star masses and initial orbital periods of progenitors of Galactic BH UCXB-LISA sources are in the range of 0.32-2.9 M☉ and 0.02-0.19 days, respectively. Nearly all BH+He star binaries in the above parameter space can evolve into GW sources whose chirp masses can be accurately measured. Employing a population synthesis simulation, we predict the birthrate and detection number of Galactic BH UCXB-LISA source evolving from the He star channel are R = 2.2 × 10−6 yr−1 and 33 for an optimistic CE parameter, respectively. © 2023, CC0.

关键词： Gravity waves

A Scenario for Origin of Global 4 mHz Oscillations in Solar Corona

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arXiv 2025年

作者： Xue, Li Jiao, Chengliang Zhang, Lixin Department of Astronomy Xiamen Univesity Xiamen361005 China Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China

We establish a spherically symmetric model of solar atmosphere, which consists of the whole chromosphere and low corona below the 1.25 solar radius. It is a hydrodynamic model with heating in the chromosphere through an artificial energy flux. We performed a series of simulations with our model and found oscillations with a peak frequency of ∼4 mHz in the power spectrum. We confirmed that this resulted from the p-mode excited in the transition region and amplified in a resonant cavity situated in the height range ∼4 × 103-2 × 104 km. This result is consistent with global observations of Alfvénic waves in corona and can naturally explain the observational ubiquity of 4 mHz without the difficulty of the p-mode passing through the acoustic-damping chromosphere. We also confirmed that acoustic shock waves alone cannot heat the corona to the observed temperature, and found mass upflows in the height range ∼7 × 103-7 × 104 km in our model, which pumped the dense and cool plasma into the corona and might be the mass supplier for solar prominences. © 2025, CC BY.

关键词： Plasma shock waves

A new route to massive hot subdwarfs: common envelope ejection from asymptotic giant branch stars

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arXiv 2024年

作者： Li, Zhenwei Zhang, Yangyang Chen, Hailiang Ge, Hongwei Jiang, Dengkai Li, Jiangdan Chen, Xuefei Han, Zhanwen Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Science Taiwan International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China Zhoukou Normal University East Wenchang Street Chuanhui District Zhoukou466001 China University of the Chinese Academy of Science Yuquan Road 19 Shijingshan Block Beijing100049 China

The hot subdwarf O/B stars (sdO/Bs) are known as extreme horizontal branch stars, which is of great importance in stellar evolution theory. The sdO/Bs are generally thought to have a helium-burning core and a thin hydrogen envelope (Menv ☉). In the canonical binary evolution scenario, sdO/Bs are considered to be the stripped cores of red giants. However, such a scenario cannot explain the recently discovered sdO/B binary, SMSS J1920, where the strong Ca H&K lines in the spectrum are found. It suggests that this binary is likely originated from the recent ejection of common envelope (CE). In this work, we proposed a new formation channel of massive sdO/Bs, namely sdO/Bs produced from a CE ejection process with an asymptotic giant branch (AGB) star (hereafter AGB CE channel). We constructed the evolutionary model of sdO/Bs and successfully explained most of the important observed parameters of the sdO/B star in SMSS J1920, including the evolutionary age, sdO/B mass, effective temperature, surface gravity and surface helium abundance. The minimum sdO/B mass produced from the AGB CE channel is about 0.48M☉. The evolutionary tracks in log Teff −log g plane may explain a fraction of the observational samples with high-log Teff and low-log g. Considering wind mass-loss of sdO/Bs, the model could produce helium-rich hot subdwarfs with log(nHe/nH) −1. Copyright © 2024, The Authors. All rights reserved.

关键词： Helium

A spectral hardening in the Fermi-LAT Data of 1ES 0502+675

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arXiv 2022年

作者： Zeng, Yuhang Yan, Dahai Hu, Wen Wang, Jiancheng Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories Chinese Academy of Sciences Kunming650011 China University of Chinese Academy of Science Beijing100049 China Department of Physics Jinggangshan University Jiangxi Province Ji'An343009 China

The γ-ray spectral feature of the blazar 1ES 0502+675 is investigated by using Fermi Large Area Telescope (Fermi-LAT) Pass 8 data (between 100 MeV and 300 GeV) covering from 2008 August to 2021 April. A significant (∼ 4σ) hardening at ∼ 1 GeV is found in the γ-ray spectrum during a moderately flaring state (MJD 55050-55350). The photon index below and above the break energy is Γ1 = 2.36 ± 0.31 and Γ2 = 1.33 ± 0.11, respectively. In the rest of the observations, the γ-ray spectrum can be described by a power-law form with the photon index of ≈ 1.6. In the frame of a one-zone synchrotron self-Compton (SSC) model, the spectral hardening is interpreted as the transition between the synchrotron component and the SSC component. This could be the result of a slight increase of the break/maximum Lorentz factor of the electrons. Copyright © 2022, The Authors. All rights reserved.

关键词： Hardening