Accretion disc outbursts are re-occurring events observed in various astrophysical systems, including X-ray binaries and cataclysmic variables. These outbursts are characterized by a sudden increase in luminosity due to various instabilities in the accretion disc. We need to investigate the time-dependent accretion flow models to understand the mechanisms driving these outbursts. Time-dependent models incorporate the disc's time evolution and can capture the build-up of instabilities. This review aims to give a basic overview of accretion disc outburst and stability analysis. The paper highlights the necessity of considering the hierarchy of different timescales, dynamical, viscous, and thermal, when investigating the instabilities occurring in the accretion disc. The importance and observational implications of studying these accretion disc outbursts are also discussed.
吸积盘爆发是在各种物理系统（包括 X 射线双星和大灾变变星）中观测到的重复发生的事件。我们需要研究与时间相关的吸积流模型，以了解这些爆发的驱动机制。与时间相关的模型包含了圆盘的时间演化，可以捕捉到不稳定性的积累。本综述旨在介绍吸积盘爆发和稳定性分析的基本概况。本文强调了在研究吸积盘中发生的不稳定性时，考虑不同时间尺度（动力学、粘性和热学）层次的必要性。还讨论了研究这些吸积盘爆发的重要性和观测意义。
{"title":"Accretion Disc Outbursts and Stability Analysis","authors":"Liza Devi, Asish Jyoti Boruah, Biplob Sarkar","doi":"arxiv-2409.11708","DOIUrl":"https://doi.org/arxiv-2409.11708","url":null,"abstract":"Accretion disc outbursts are re-occurring events observed in various\u0000astrophysical systems, including X-ray binaries and cataclysmic variables.\u0000These outbursts are characterized by a sudden increase in luminosity due to\u0000various instabilities in the accretion disc. We need to investigate the\u0000time-dependent accretion flow models to understand the mechanisms driving these\u0000outbursts. Time-dependent models incorporate the disc's time evolution and can\u0000capture the build-up of instabilities. This review aims to give a basic\u0000overview of accretion disc outburst and stability analysis. The paper\u0000highlights the necessity of considering the hierarchy of different timescales,\u0000dynamical, viscous, and thermal, when investigating the instabilities occurring\u0000in the accretion disc. The importance and observational implications of\u0000studying these accretion disc outbursts are also discussed.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260070","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}
In this work, we performed a spectro-temporal investigation of the low-mass X-ray binary GX 9+9 using the Large Area X-ray Proportional Counter (LAXPC) and Soft X- ray Telescope (SXT) observation on board AstroSat. The source was detected in the soft state during the observation, which results in a disk dominating energy spectrum within the energy range of 0.7-25.0 keV. We carried out the analysis at different flux levels. In the temporal analysis, LAXPC data in all flux levels showed the presence of noise components, describing broad Lorentzian components. We modeled the energy-dependent temporal properties of the source in order to identify the radiative origin of the observed variability. This source is not a well-studied source; hence we attempt to estimate various source characteristics like inner-disk radius, flux, and inner-disk temperature.
在这项工作中，我们利用 AstroSat 上的大面积 X 射线比例计数器（LAXPC）和软 X 射线望远镜（SXT）观测，对低质量 X 射线双星 GX 9+9 进行了光谱时间调查。在观测过程中发现该源处于软态，这导致在 0.7-25.0 keV 的能量范围内出现了一个以圆盘为主的能谱。我们在不同的通量水平下进行了分析。在时间分析中，LAXPC 数据在所有通量水平上都显示出噪声成分的存在，描述了宽广的洛伦兹成分。我们模拟了该源随能量变化的时间特性，以确定观测到的可变性的辐射来源。这个源的研究并不深入，因此我们试图估算各种源特征，如内盘半径、通量和内盘温度。
{"title":"Spectro-temporal study of atoll source GX 9+9 observed with AstroSat","authors":"Sree Bhattacherjee, Arbind Pradhan, Biplob Sarkar","doi":"arxiv-2409.11721","DOIUrl":"https://doi.org/arxiv-2409.11721","url":null,"abstract":"In this work, we performed a spectro-temporal investigation of the low-mass\u0000X-ray binary GX 9+9 using the Large Area X-ray Proportional Counter (LAXPC) and\u0000Soft X- ray Telescope (SXT) observation on board AstroSat. The source was\u0000detected in the soft state during the observation, which results in a disk\u0000dominating energy spectrum within the energy range of 0.7-25.0 keV. We carried\u0000out the analysis at different flux levels. In the temporal analysis, LAXPC data\u0000in all flux levels showed the presence of noise components, describing broad\u0000Lorentzian components. We modeled the energy-dependent temporal properties of\u0000the source in order to identify the radiative origin of the observed\u0000variability. This source is not a well-studied source; hence we attempt to\u0000estimate various source characteristics like inner-disk radius, flux, and\u0000inner-disk temperature.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260068","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}
A. Anitra, C. Miceli, T. Di Salvo, R. Iaria, N. Degenaar, M. Jon Miller, F. Barra, W. Leone, L. Burderi
We propose a novel approach for determining the orbital inclination of low-mass X-ray binary systems by modelling the H$alpha$ and H$beta$ line profiles emitted by the accretion disc, with a Newtonian version of diskline. We applied the model to two sample sources, Swift J1357.2-0933 and MAXI J1305-704, which are both transient black hole systems, and analyse two observations that were collected during a quiescent state and one observation of an outburst. The line profile is well described by the diskline model, although we had to add a Gaussian line to describe the deep inner core of the double-peaked profile, which the diskline model was unable to reproduce. The H$beta$ emission lines in the spectrum of Swift J1357.2-0933 and the H$alpha$ emission lines in that of MAXI J1305-704 during the quiescent state are consistent with a scenario in which these lines originate from a disc ring between $(9.6-57) times 10^{3}, rm{R_{g}}$ and $(1.94-20) times 10^{4}, rm{R_{g}}$, respectively. We estimate an inclination angle of $81 pm 5$ degrees for Swift J1357.2-0933 and an angle of $73 pm 4$ degrees for MAXI J1305-704. This is entirely consistent with the values reported in the literature. In agreement with the recent literature, our analysis of the outburst spectrum of MAXI J1305-704 revealed that the radius of the emission region deviates from expected values. This outcome implies several potential scenarios, including alternative disc configuration or even a circumbinary disc. We caution that these results were derived from a simplistic model that may not fully describe the complicated physics of accretion discs. Despite these limitations, our results for the inclination angles are remarkably consistent with recent complementary studies, and the proposed description of the emitting region remains entirely plausible.
我们将该模型应用于两个样本源：Swift J1357.2-0933和MAXIJ1305-704，它们都是瞬态黑洞系统，并分析了两次静态观测和一次爆发观测。尽管我们不得不添加一条高斯线来描述双峰轮廓的深内核，而盘线模型却无法再现这一轮廓，但盘线模型很好地描述了线轮廓。Swift J1357.2-0933光谱中的H$beta$发射线和MAXI J1305-704静态光谱中的H$alpha$发射线都符合这样一种假设，即这些发射线起源于一个环绕在$(9.6-57) times 10^{3}, rm{R_{g}}$和 $(1.94-20) times 10^{4}, rm{R_{g}}$之间。我们估计 Swift J1357.2-0933 的倾角为 81 （pm 5）度，MAXIJ1305-704 的倾角为 73 （pm 4）度。这与文献报道的数值完全一致。与最近的文献一致，我们对MAXI J1305-704爆发光谱的分析表明，发射区的半径偏离了预期值。这一结果意味着几种可能的情况，包括另一种圆盘构造，甚至是环形圆盘。我们要提醒的是，这些结果是由一个简单的模型得出的，它可能无法完全描述吸积盘的复杂物理现象。尽管存在这些局限性，我们对倾角的研究结果与最近的补充研究结果非常一致，对发射区的描述仍然是完全可信的。
{"title":"X-ray view of emission lines in optical spectra: Spectral analysis of the two low-mass X-ray binary systems Swift J1357.2-0933 and MAXI J1305-704","authors":"A. Anitra, C. Miceli, T. Di Salvo, R. Iaria, N. Degenaar, M. Jon Miller, F. Barra, W. Leone, L. Burderi","doi":"arxiv-2409.11988","DOIUrl":"https://doi.org/arxiv-2409.11988","url":null,"abstract":"We propose a novel approach for determining the orbital inclination of\u0000low-mass X-ray binary systems by modelling the H$alpha$ and H$beta$ line\u0000profiles emitted by the accretion disc, with a Newtonian version of diskline.\u0000We applied the model to two sample sources, Swift J1357.2-0933 and MAXI\u0000J1305-704, which are both transient black hole systems, and analyse two\u0000observations that were collected during a quiescent state and one observation\u0000of an outburst. The line profile is well described by the diskline model,\u0000although we had to add a Gaussian line to describe the deep inner core of the\u0000double-peaked profile, which the diskline model was unable to reproduce. The\u0000H$beta$ emission lines in the spectrum of Swift J1357.2-0933 and the H$alpha$\u0000emission lines in that of MAXI J1305-704 during the quiescent state are\u0000consistent with a scenario in which these lines originate from a disc ring\u0000between $(9.6-57) times 10^{3}, rm{R_{g}}$ and $(1.94-20) times 10^{4},\u0000rm{R_{g}}$, respectively. We estimate an inclination angle of $81 pm 5$\u0000degrees for Swift J1357.2-0933 and an angle of $73 pm 4$ degrees for MAXI\u0000J1305-704. This is entirely consistent with the values reported in the\u0000literature. In agreement with the recent literature, our analysis of the\u0000outburst spectrum of MAXI J1305-704 revealed that the radius of the emission\u0000region deviates from expected values. This outcome implies several potential\u0000scenarios, including alternative disc configuration or even a circumbinary\u0000disc. We caution that these results were derived from a simplistic model that\u0000may not fully describe the complicated physics of accretion discs. Despite\u0000these limitations, our results for the inclination angles are remarkably\u0000consistent with recent complementary studies, and the proposed description of\u0000the emitting region remains entirely plausible.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260065","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}
F. Coti Zelati, D. de Martino, V. S. Dhillon, T. R. Marsh, F. Vincentelli, S. Campana, D. F. Torres, A. Papitto, M. C. Baglio, A. Miraval Zanon, N. Rea, J. Brink, D. A. H. Buckley, P. D'Avanzo, G. Illiano, A. Manca, A. Marino
CXOU J110926.4-650224 is a candidate transitional millisecond pulsar (tMSP) with X-ray and radio emission properties reminiscent of those observed in confirmed tMSPs in their X-ray 'subluminous' disc state. We present the results of observing campaigns that, for the first time, characterise the optical and near-infrared variability of this source and establish a connection with the mode-switching phenomenon observed in X-rays. The optical emission exhibited flickering activity, frequent dipping episodes where it appeared redder, and a multi-peaked flare where it was bluer. The variability pattern was strongly correlated with that of the X-ray emission. Each dip matched an X-ray low-mode episode, indicating that a significant portion of the optical emission originates from nearly the same region as the X-ray emission. The near-infrared emission also displayed remarkable variability, including a dip of 20 min in length during which it nearly vanished. Time-resolved optical spectroscopic observations reveal significant changes in the properties of emission lines from the disc and help infer the spectral type of the companion star to be between K0 and K5. We compare the properties of CXOU J110926.4-650224 with those of other tMSPs in the X-ray subluminous disc state and discuss our findings within the context of a recently proposed scenario that explains the phenomenology exhibited by the prototypical tMSP PSR J1023+0038.
CXOU J110926.4-650224是一颗候选的过渡毫秒脉冲星（tMSP），其X射线和无线电发射特性与在X射线 "亚光 "圆盘状态下观测到的已证实的tMSP的特性相似。我们介绍了观测活动的结果，这些结果首次描述了该星源的光学和近红外变率特征，并与在 X 射线中观测到的模式切换现象建立了联系。光学发射表现出闪烁活动、频繁的倾斜现象（在这种情况下它显得更红）和多峰耀斑（在这种情况下它显得更蓝）。这种变化模式与 X 射线辐射的变化模式密切相关。每次下沉都与 X 射线低模式事件相吻合，这表明光学发射的很大一部分几乎来自 X 射线发射的同一区域。近红外辐射也显示出显著的可变性，包括一次长达 20 分钟的衰减，在此期间，近红外辐射几乎消失。时间分辨光学光谱观测揭示了来自圆盘的发射线性质的显著变化，有助于推断伴星的光谱类型介于 K0 和 K5 之间。我们将CXOU J110926.4-650224的性质与其他处于X射线亚光圆盘状态的tMSP的性质进行了比较，并结合最近提出的一种解释原型tMSP PSR J1023+0038所表现出的现象学的方案来讨论我们的发现。
{"title":"Short-term variability of the transitional pulsar candidate CXOU J110926.4-650224 from X-rays to infrared","authors":"F. Coti Zelati, D. de Martino, V. S. Dhillon, T. R. Marsh, F. Vincentelli, S. Campana, D. F. Torres, A. Papitto, M. C. Baglio, A. Miraval Zanon, N. Rea, J. Brink, D. A. H. Buckley, P. D'Avanzo, G. Illiano, A. Manca, A. Marino","doi":"arxiv-2409.11719","DOIUrl":"https://doi.org/arxiv-2409.11719","url":null,"abstract":"CXOU J110926.4-650224 is a candidate transitional millisecond pulsar (tMSP)\u0000with X-ray and radio emission properties reminiscent of those observed in\u0000confirmed tMSPs in their X-ray 'subluminous' disc state. We present the results\u0000of observing campaigns that, for the first time, characterise the optical and\u0000near-infrared variability of this source and establish a connection with the\u0000mode-switching phenomenon observed in X-rays. The optical emission exhibited\u0000flickering activity, frequent dipping episodes where it appeared redder, and a\u0000multi-peaked flare where it was bluer. The variability pattern was strongly\u0000correlated with that of the X-ray emission. Each dip matched an X-ray low-mode\u0000episode, indicating that a significant portion of the optical emission\u0000originates from nearly the same region as the X-ray emission. The near-infrared\u0000emission also displayed remarkable variability, including a dip of 20 min in\u0000length during which it nearly vanished. Time-resolved optical spectroscopic\u0000observations reveal significant changes in the properties of emission lines\u0000from the disc and help infer the spectral type of the companion star to be\u0000between K0 and K5. We compare the properties of CXOU J110926.4-650224 with\u0000those of other tMSPs in the X-ray subluminous disc state and discuss our\u0000findings within the context of a recently proposed scenario that explains the\u0000phenomenology exhibited by the prototypical tMSP PSR J1023+0038.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260069","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}
Sijia Peng, Ru-Sen Lu, Ciriaco Goddi, Thomas P. Krichbaum, Zhiyuan Li, Ruo-Yu Liu, Jae-Young Kim, Masanori Nakamura, Feng Yuan, Liang Chen, Ivan Marti-Vidal, Zhiqiang Shen
Faraday rotation is an important probe of the magnetic fields and magnetized plasma around active galactic nuclei (AGN) jets. We present a Faraday rotation measure image of the M87 jet between 85.2 GHz and 101.3 GHz with a resolution of ~2" with the Atacama Large Millimeter/submillimeter Array (ALMA). We found that the rotation measure (RM) of the M87 core is $rm (4.5pm 0.4)times10^{4} rad m^{-2}$ with a low linear polarization fraction of $rm (0.88pm 0.08)%$. The spatial RM gradient in the M87 jet spans a wide range from $sim -2times10^4rm~rad m^{-2}$ to $sim 3times10^4rm~rad m^{-2}$ with a typical uncertainty of $0.3times10^4rm~rad m^{-2}$. A comparison with previous RM measurements of the core suggests that the Faraday rotation of the core may originate very close to the super massive black hole (SMBH). Both an internal origin and an external screen with a rapidly varying emitting source could be possible. As for the jet, the RM gradient indicates a helical configuration of the magnetic field that persists up to kpc scale. Combined with the kpc-scale RM measurements at lower frequencies, we found that RM is frequency-dependent in the jet. One possible scenario to explain this dependence is that the kpc-scale jet has a trumpet-like shape and the jet coil unwinds near its end.
{"title":"The Faraday rotation measure of the M87 jet at 3.5mm with the Atacama Large Millimeter/submillimeter Array","authors":"Sijia Peng, Ru-Sen Lu, Ciriaco Goddi, Thomas P. Krichbaum, Zhiyuan Li, Ruo-Yu Liu, Jae-Young Kim, Masanori Nakamura, Feng Yuan, Liang Chen, Ivan Marti-Vidal, Zhiqiang Shen","doi":"arxiv-2409.12028","DOIUrl":"https://doi.org/arxiv-2409.12028","url":null,"abstract":"Faraday rotation is an important probe of the magnetic fields and magnetized\u0000plasma around active galactic nuclei (AGN) jets. We present a Faraday rotation\u0000measure image of the M87 jet between 85.2 GHz and 101.3 GHz with a resolution\u0000of ~2\" with the Atacama Large Millimeter/submillimeter Array (ALMA). We found\u0000that the rotation measure (RM) of the M87 core is $rm (4.5pm\u00000.4)times10^{4} rad m^{-2}$ with a low linear polarization fraction of $rm\u0000(0.88pm 0.08)%$. The spatial RM gradient in the M87 jet spans a wide range\u0000from $sim -2times10^4rm~rad m^{-2}$ to $sim 3times10^4rm~rad m^{-2}$\u0000with a typical uncertainty of $0.3times10^4rm~rad m^{-2}$. A comparison with\u0000previous RM measurements of the core suggests that the Faraday rotation of the\u0000core may originate very close to the super massive black hole (SMBH). Both an\u0000internal origin and an external screen with a rapidly varying emitting source\u0000could be possible. As for the jet, the RM gradient indicates a helical\u0000configuration of the magnetic field that persists up to kpc scale. Combined\u0000with the kpc-scale RM measurements at lower frequencies, we found that RM is\u0000frequency-dependent in the jet. One possible scenario to explain this\u0000dependence is that the kpc-scale jet has a trumpet-like shape and the jet coil\u0000unwinds near its end.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260098","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}
Hitesh Tanenia, Akash Garg, Ranjeev Misra, Somasri Sen
We present a spectro-timing analysis of the black hole X-ray transient GX 339-4 using simultaneous observations from Astrosat and NICER during the 2021 outburst period. The combined spectrum obtained from NICER, LAXPC, and SXT data is effectively described by a model comprising a thermal disk component, hard Comptonization component, and reflection component with an edge. Our analysis of the Astrosat and NICER spectra indicates the source to be in a low/hard state, with a photon index of ~1.64. The Power Density Spectra (PDS) obtained from both Astrosat and NICER observations exhibit two prominent broad features at 0.22 Hz and 2.94 Hz. We generated energy-dependent time lag and fractional root mean square (frms) at both frequencies in a broad energy range of 0.5-30 keV and found the presence of hard lags along with a decrease in variability at higher energy levels. Additionally, we discovered that the correlated variations in accretion rate, inner disc radius, coronal heating rate, and the scattering fraction, along with a delay between them, can explain the observed frms and lag spectra for both features.
{"title":"Modelling the Energy-dependent broadband variability in the black-hole transient GX 339-4 using Astrosat and NICER","authors":"Hitesh Tanenia, Akash Garg, Ranjeev Misra, Somasri Sen","doi":"arxiv-2409.11875","DOIUrl":"https://doi.org/arxiv-2409.11875","url":null,"abstract":"We present a spectro-timing analysis of the black hole X-ray transient GX\u0000339-4 using simultaneous observations from Astrosat and NICER during the 2021\u0000outburst period. The combined spectrum obtained from NICER, LAXPC, and SXT data\u0000is effectively described by a model comprising a thermal disk component, hard\u0000Comptonization component, and reflection component with an edge. Our analysis\u0000of the Astrosat and NICER spectra indicates the source to be in a low/hard\u0000state, with a photon index of ~1.64. The Power Density Spectra (PDS) obtained\u0000from both Astrosat and NICER observations exhibit two prominent broad features\u0000at 0.22 Hz and 2.94 Hz. We generated energy-dependent time lag and fractional\u0000root mean square (frms) at both frequencies in a broad energy range of 0.5-30\u0000keV and found the presence of hard lags along with a decrease in variability at\u0000higher energy levels. Additionally, we discovered that the correlated\u0000variations in accretion rate, inner disc radius, coronal heating rate, and the\u0000scattering fraction, along with a delay between them, can explain the observed\u0000frms and lag spectra for both features.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269459","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}
Supernova remnants (SNRs) have long been suspected to be the primary sources of Galactic cosmic rays. Over the past decades, great strides have been made in the modelling of particle acceleration, magnetic field amplification, and escape from SNRs. Yet, while many SNRs have been observed in non-thermal emission in radio, X-rays, and gamma-rays, there is no evidence for any individual object contributing to the locally observed flux. Here, we propose a particular spectral signature from individual remnants that is due to the energy-dependent escape from SNRs. For young and nearby sources, we predict fluxes enhanced by tens of percent in narrow rigidity intervals; given the percent-level flux uncertainties of contemporary cosmic-ray data, such features should be readily detectable. We model the spatial and temporal distribution of sources and the resulting distribution of fluxes with a Monte Carlo approach. The decision tree that we have trained on simulated data is able to discriminate with very high significance between the null hypothesis of a smooth distribution of sources and the scenario with a stochastic distribution of individual sources. We suggest that this cosmic-ray energy-dependent injection time (CREDIT) scenario be considered in experimental searches to identify individual SNRs as cosmic-ray sources.
{"title":"Investigating the CREDIT history of supernova remnants as cosmic-ray sources","authors":"Anton Stall, Chun Khai Loo, Philipp Mertsch","doi":"arxiv-2409.11012","DOIUrl":"https://doi.org/arxiv-2409.11012","url":null,"abstract":"Supernova remnants (SNRs) have long been suspected to be the primary sources\u0000of Galactic cosmic rays. Over the past decades, great strides have been made in\u0000the modelling of particle acceleration, magnetic field amplification, and\u0000escape from SNRs. Yet, while many SNRs have been observed in non-thermal\u0000emission in radio, X-rays, and gamma-rays, there is no evidence for any\u0000individual object contributing to the locally observed flux. Here, we propose a\u0000particular spectral signature from individual remnants that is due to the\u0000energy-dependent escape from SNRs. For young and nearby sources, we predict\u0000fluxes enhanced by tens of percent in narrow rigidity intervals; given the\u0000percent-level flux uncertainties of contemporary cosmic-ray data, such features\u0000should be readily detectable. We model the spatial and temporal distribution of\u0000sources and the resulting distribution of fluxes with a Monte Carlo approach.\u0000The decision tree that we have trained on simulated data is able to\u0000discriminate with very high significance between the null hypothesis of a\u0000smooth distribution of sources and the scenario with a stochastic distribution\u0000of individual sources. We suggest that this cosmic-ray energy-dependent\u0000injection time (CREDIT) scenario be considered in experimental searches to\u0000identify individual SNRs as cosmic-ray sources.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260104","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}
Rahul Sharma, Manoj Mandal, Sabyasachi Pal, Biswajit Paul, G. K. Jaisawal, Ajay Ratheesh
The Be/X-ray binary pulsar RX J0440.9+4431 went through a giant outburst in December 2022 with a peak flux of $sim$2.3 Crab in 15--50 keV. We studied the broad-band timing and spectral properties of RX J0440.9+4431 using four $AstroSat$ observations, where the source transited between subcritical and supercritical accretion regimes. Pulsations were detected significantly above 100 keV. The pulse profiles were found to be highly luminosity- and energy-dependent. A significant evolution in the pulse profile shape near the peak of the outburst indicates a possible change in the accretion mode and beaming patterns of RX J0440.9+4431. The rms pulsed fraction was luminosity- and energy-dependent, with a concave-like feature around 20--30 keV. The depth of this feature varied with luminosity, indicating changes in the accretion column height and proportion of reflected photons. The broad-band continuum spectra were best fitted with a two-component Comptonization model with a blackbody component or a two-blackbody component model with a thermal Comptonization component. A quasi-periodic oscillation at 60 mHz was detected at a luminosity of $2.6 times 10^{37}$ erg s$^{-1}$, which evolved into 42 mHz at $1.5 times 10^{37}$ erg s$^{-1}$. The QPO rms were found to be energy dependent with an overall increasing trend with energy. For the first time, we found the QPO frequency varying with photon energy in an X-ray pulsar, which poses a challenge in explaining the QPO with current models such as the Keplarian and beat frequency model. Hence, more physically motivated models are required to understand the physical mechanism behind the mHz QPOs.
{"title":"Probing the energy and luminosity-dependent spectro-timing properties of RX J0440.9+4431 with AstroSat","authors":"Rahul Sharma, Manoj Mandal, Sabyasachi Pal, Biswajit Paul, G. K. Jaisawal, Ajay Ratheesh","doi":"arxiv-2409.11121","DOIUrl":"https://doi.org/arxiv-2409.11121","url":null,"abstract":"The Be/X-ray binary pulsar RX J0440.9+4431 went through a giant outburst in\u0000December 2022 with a peak flux of $sim$2.3 Crab in 15--50 keV. We studied the\u0000broad-band timing and spectral properties of RX J0440.9+4431 using four\u0000$AstroSat$ observations, where the source transited between subcritical and\u0000supercritical accretion regimes. Pulsations were detected significantly above\u0000100 keV. The pulse profiles were found to be highly luminosity- and\u0000energy-dependent. A significant evolution in the pulse profile shape near the\u0000peak of the outburst indicates a possible change in the accretion mode and\u0000beaming patterns of RX J0440.9+4431. The rms pulsed fraction was luminosity-\u0000and energy-dependent, with a concave-like feature around 20--30 keV. The depth\u0000of this feature varied with luminosity, indicating changes in the accretion\u0000column height and proportion of reflected photons. The broad-band continuum\u0000spectra were best fitted with a two-component Comptonization model with a\u0000blackbody component or a two-blackbody component model with a thermal\u0000Comptonization component. A quasi-periodic oscillation at 60 mHz was detected\u0000at a luminosity of $2.6 times 10^{37}$ erg s$^{-1}$, which evolved into 42 mHz\u0000at $1.5 times 10^{37}$ erg s$^{-1}$. The QPO rms were found to be energy\u0000dependent with an overall increasing trend with energy. For the first time, we\u0000found the QPO frequency varying with photon energy in an X-ray pulsar, which\u0000poses a challenge in explaining the QPO with current models such as the\u0000Keplarian and beat frequency model. Hence, more physically motivated models are\u0000required to understand the physical mechanism behind the mHz QPOs.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260101","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}
Kayhan Gültekin, Karl Gebhardt, John Kormendy, Adi Foord, Ralf Bender, Tod R. Lauer, Jason Pinkney, Douglas O. Richstone, Scott Tremaine
We present IR photometry and HST imaging and spectroscopy of Sab galaxy NGC 4826. Schwarzschild dynamical modeling is used to measure its central black hole mass $M$. Photometric decomposition is used to enable a comparison of $M$ to published scaling relations between black hole masses and properties of host bulges. This decomposition implies that NGC 4826 contains classical and pseudo bulges of approximately equal mass. The classical bulge has best-fit S'ersic index $n=3.27$. The pseudobulge is made up of three parts, an inner lens ($n=0.18$ at $rlesssim4^{primeprime}$), an outer lens ($n=0.17$ at $r lesssim 45^{primeprime}$), and a $n=0.58$ component required to match the surface brightness between the lens components. The total $V$-band luminosity of the galaxy is $M_{VT}=-21.07$, the ratio of classical bulge to total light is $B/Tsimeq0.12$, and the ratio of pseudobulge to total light is $PB/Tsimeq0.13$. The outer disk is exponential ($n=1.07$) and makes up $D/T=0.75$ of the light of the galaxy. Our best-fit Schwarzschild model has a black hole mass with $1sigma$ uncertainties of $M=8.4^{+1.7}_{-0.6}times10^6 M_odot$ and a stellar $K$-band mass-to-light ratio of $Upsilon_K=0.46pm0.03 M_{odot} mathrm{L}_{odot}^{-1}$ at the assumed distance of 7.27 Mpc. Our modeling is marginally consistent with $M=0$ at the $3sigma$ limit. These best-fit parameters were calculated assuming the black hole is located where the velocity dispersion is largest; this is offset from the maximum surface brightness, probably because of dust absorption. The black hole mass -- one of the smallest measured by modeling stellar dynamics -- satisfies the well known correlations of $M$ with the $K$-band luminosity, stellar mass, and velocity dispersion of the classical bulge only in contrast to total (classical plus pseudo) bulge luminosity.
我们展示了 Sab 星系 NGC4826 的红外测光和 HST 成像与光谱。我们利用施瓦兹柴尔德动力学模型来测量其中心黑洞质量$M$。通过光度分解，可以将$M$与已公布的黑洞质量和宿主星系性质之间的比例关系进行比较。这种分解方法意味着 NGC 4826 包含质量大致相同的经典隆起和伪隆起。经典隆起的最佳拟合S/'ersic指数为$n=3.27$。伪凸起由三部分组成，一个内透镜（$n=0.18$，rlesssim4^{primeprime}$），一个外透镜（$n=0.17$，rlesssim 45^{primeprime}$），以及一个$n=0.58$的部分，用来匹配透镜部分之间的表面亮度。星系的总$V$波段光度为$M_{VT}=-21.07$，经典隆起与总光度的比值为$B/T（simeq0.12$），伪隆起与总光度的比值为$PB/T（simeq0.13$）。外圆盘是指数型的（$n=1.07$），占星系光量的$D/T=0.75$。我们的最佳拟合施瓦兹柴尔德模型的黑洞质量（1sigma$不确定度）为$M=8.4^{+1.7}_{-0.6}times10^6M_odot$，恒星的$K$波段质量光比为$Upsilon_K=0.46pm0.03M_{odot}mathrm{L}_{odot}^{-1}$，假定距离为7.27 Mpc。我们的模型在3sigma$极限下与$M=0$略微一致。这些最佳拟合参数是假设黑洞位于速度弥散最大的地方计算出来的；这与最大表面亮度有偏差，可能是因为尘埃的吸收。黑洞质量--通过恒星动力学建模测得的最小质量之一--满足众所周知的$M$与$K$波段光度、恒星质量和经典暴凸的速度色散之间的相关性，只是与总（经典加伪）暴凸光度不同。
{"title":"The Black Hole Mass and Photometric Components of NGC 4826","authors":"Kayhan Gültekin, Karl Gebhardt, John Kormendy, Adi Foord, Ralf Bender, Tod R. Lauer, Jason Pinkney, Douglas O. Richstone, Scott Tremaine","doi":"arxiv-2409.11575","DOIUrl":"https://doi.org/arxiv-2409.11575","url":null,"abstract":"We present IR photometry and HST imaging and spectroscopy of Sab galaxy NGC\u00004826. Schwarzschild dynamical modeling is used to measure its central black\u0000hole mass $M$. Photometric decomposition is used to enable a comparison of $M$\u0000to published scaling relations between black hole masses and properties of host\u0000bulges. This decomposition implies that NGC 4826 contains classical and pseudo\u0000bulges of approximately equal mass. The classical bulge has best-fit S'ersic\u0000index $n=3.27$. The pseudobulge is made up of three parts, an inner lens\u0000($n=0.18$ at $rlesssim4^{primeprime}$), an outer lens ($n=0.17$ at $r\u0000lesssim 45^{primeprime}$), and a $n=0.58$ component required to match the\u0000surface brightness between the lens components. The total $V$-band luminosity\u0000of the galaxy is $M_{VT}=-21.07$, the ratio of classical bulge to total light\u0000is $B/Tsimeq0.12$, and the ratio of pseudobulge to total light is\u0000$PB/Tsimeq0.13$. The outer disk is exponential ($n=1.07$) and makes up\u0000$D/T=0.75$ of the light of the galaxy. Our best-fit Schwarzschild model has a\u0000black hole mass with $1sigma$ uncertainties of $M=8.4^{+1.7}_{-0.6}times10^6\u0000M_odot$ and a stellar $K$-band mass-to-light ratio of $Upsilon_K=0.46pm0.03\u0000M_{odot} mathrm{L}_{odot}^{-1}$ at the assumed distance of 7.27 Mpc. Our\u0000modeling is marginally consistent with $M=0$ at the $3sigma$ limit. These\u0000best-fit parameters were calculated assuming the black hole is located where\u0000the velocity dispersion is largest; this is offset from the maximum surface\u0000brightness, probably because of dust absorption. The black hole mass -- one of\u0000the smallest measured by modeling stellar dynamics -- satisfies the well known\u0000correlations of $M$ with the $K$-band luminosity, stellar mass, and velocity\u0000dispersion of the classical bulge only in contrast to total (classical plus\u0000pseudo) bulge luminosity.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260099","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}
The recent observations by the James Webb Space Telescope (JWST) have revealed a larger number of bright galaxies at $zgtrsim10$ than was expected. The origin of this excess is still under debate, although several possibilities have been presented. We propose that gamma-ray bursts (GRBs) are a powerful probe to explore the origin of the excess and, hence, the star and galaxy formation histories in the early universe. Focusing on the recently launched mission, Einstein Probe (EP), we find that EP can detect several GRBs annually at $zgtrsim10$, assuming the GRB formation rate calibrated by events at $zlesssim6$ can be extrapolated. Interestingly, depending on the excess scenarios, the GRB event rate may also show an excess at $zsimeq10$, and its detection will help to discriminate between the scenarios that are otherwise difficult to distinguish. Additionally, we discuss that the puzzling, red-color, compact galaxies discovered by JWST, the so-called ``little red dots'', could host dark GRBs if they are dust-obscured star forming galaxies. We are eager for unbiased follow-up of GRBs and encourage future missions such as high-z GUNDAM to explore the early universe.
{"title":"Probing the Origin of the Star Formation Excess Discovered by JWST through Gamma-Ray Bursts","authors":"Tatsuya Matsumoto, Yuichi Harikane, Keiichi Maeda, Kunihito Ioka","doi":"arxiv-2409.11468","DOIUrl":"https://doi.org/arxiv-2409.11468","url":null,"abstract":"The recent observations by the James Webb Space Telescope (JWST) have\u0000revealed a larger number of bright galaxies at $zgtrsim10$ than was expected.\u0000The origin of this excess is still under debate, although several possibilities\u0000have been presented. We propose that gamma-ray bursts (GRBs) are a powerful\u0000probe to explore the origin of the excess and, hence, the star and galaxy\u0000formation histories in the early universe. Focusing on the recently launched\u0000mission, Einstein Probe (EP), we find that EP can detect several GRBs annually\u0000at $zgtrsim10$, assuming the GRB formation rate calibrated by events at\u0000$zlesssim6$ can be extrapolated. Interestingly, depending on the excess\u0000scenarios, the GRB event rate may also show an excess at $zsimeq10$, and its\u0000detection will help to discriminate between the scenarios that are otherwise\u0000difficult to distinguish. Additionally, we discuss that the puzzling,\u0000red-color, compact galaxies discovered by JWST, the so-called ``little red\u0000dots'', could host dark GRBs if they are dust-obscured star forming galaxies.\u0000We are eager for unbiased follow-up of GRBs and encourage future missions such\u0000as high-z GUNDAM to explore the early universe.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260097","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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