Pub Date : 2024-11-18DOI: 10.3847/1538-4357/ad8343
Ana Acebron, Claudio Grillo, Sherry H. Suyu, Giuseppe Angora, Pietro Bergamini, Gabriel B. Caminha, Sebastian Ertl, Amata Mercurio, Mario Nonino, Piero Rosati, Han Wang, Andrea Bolamperti, Massimo Meneghetti, Stefan Schuldt and Eros Vanzella
Overcoming both modeling and computational challenges, we present, for the first time, the extended surface-brightness distribution model of a strongly lensed source in a complex galaxy-cluster-scale system. We exploit the high-resolution Hubble Space Telescope (HST) imaging and extensive Multi Unit Spectroscopic Explorer spectroscopy to build an extended strong-lensing model, in a full multiplane formalism, of SDSS J1029+2623, a lens cluster at z = 0.588 with three multiple images of a background quasar (z = 2.1992). Going beyond typical cluster strong-lensing modeling techniques, we include as observables both the positions of 26 pointlike multiple images from seven background sources, spanning a wide redshift range between 1.02 and 5.06, and the extended surface-brightness distribution of the strongly lensed quasar host galaxy, over ∼78,000 HST pixels. In addition, we model the light distribution of seven objects, angularly close to the strongly lensed quasar host, over ∼9300 HST pixels. Our extended lens model reproduces well both the observed intensity and morphology of the quasar host galaxy in the HST F160W band (with a 0.″03 pixel scale). The reconstructed source shows a single, compact, and smooth surface-brightness distribution, for which we estimate an intrinsic magnitude of 23.3 ± 0.1 in the F160W band and a half-light radius of (2.39 ± 0.03) kpc. The increased number of observables enables the accurate determination of the total mass of line-of-sight halos lying angularly close to the extended arc. This work paves the way for a new generation of galaxy cluster strong-lens models, where additional, complementary lensing observables are directly incorporated as model constraints.
{"title":"The Next Step in Galaxy Cluster Strong Lensing: Modeling the Surface Brightness of Multiply Imaged Sources*","authors":"Ana Acebron, Claudio Grillo, Sherry H. Suyu, Giuseppe Angora, Pietro Bergamini, Gabriel B. Caminha, Sebastian Ertl, Amata Mercurio, Mario Nonino, Piero Rosati, Han Wang, Andrea Bolamperti, Massimo Meneghetti, Stefan Schuldt and Eros Vanzella","doi":"10.3847/1538-4357/ad8343","DOIUrl":"https://doi.org/10.3847/1538-4357/ad8343","url":null,"abstract":"Overcoming both modeling and computational challenges, we present, for the first time, the extended surface-brightness distribution model of a strongly lensed source in a complex galaxy-cluster-scale system. We exploit the high-resolution Hubble Space Telescope (HST) imaging and extensive Multi Unit Spectroscopic Explorer spectroscopy to build an extended strong-lensing model, in a full multiplane formalism, of SDSS J1029+2623, a lens cluster at z = 0.588 with three multiple images of a background quasar (z = 2.1992). Going beyond typical cluster strong-lensing modeling techniques, we include as observables both the positions of 26 pointlike multiple images from seven background sources, spanning a wide redshift range between 1.02 and 5.06, and the extended surface-brightness distribution of the strongly lensed quasar host galaxy, over ∼78,000 HST pixels. In addition, we model the light distribution of seven objects, angularly close to the strongly lensed quasar host, over ∼9300 HST pixels. Our extended lens model reproduces well both the observed intensity and morphology of the quasar host galaxy in the HST F160W band (with a 0.″03 pixel scale). The reconstructed source shows a single, compact, and smooth surface-brightness distribution, for which we estimate an intrinsic magnitude of 23.3 ± 0.1 in the F160W band and a half-light radius of (2.39 ± 0.03) kpc. The increased number of observables enables the accurate determination of the total mass of line-of-sight halos lying angularly close to the extended arc. This work paves the way for a new generation of galaxy cluster strong-lens models, where additional, complementary lensing observables are directly incorporated as model constraints.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"228 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670971","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}
Pub Date : 2024-11-18DOI: 10.3847/1538-4357/ad84df
Jane Huang, Megan Ansdell, Tilman Birnstiel, Ian Czekala, Feng Long, Jonathan Williams, Shangjia Zhang and Zhaohuan Zhu
The Atacama Large Millimeter/submillimeter Array (ALMA) has detected substructures in numerous protoplanetary disks at radii from a few to over 100 au. These substructures are commonly thought to be associated with planet formation, either by serving as sites fostering planetesimal formation or by arising as a consequence of planet–disk interactions. Our current understanding of substructures, though, is primarily based on observations of nearby star-forming regions with mild UV environments, whereas stars are typically born in much harsher UV environments, which may inhibit planet formation in the outer disk through external photoevaporation. We present high-resolution (∼8 au) ALMA 1.3 mm continuum images of eight disks in σ Orionis, a cluster irradiated by an O9.5 star. Gaps and rings are resolved in the images of five disks. The most striking of these is SO 1274, which features five gaps that appear to be arranged nearly in a resonant chain. In addition, we infer the presence of gap or shoulder-like structures in the other three disks through visibility modeling. These observations indicate that substructures robustly form and survive at semimajor axes of several tens of au or less in disks exposed to intermediate levels of external UV radiation as well as in compact disks. However, our observations also suggest that disks in σ Orionis are mostly small, and thus millimeter continuum gaps beyond a disk radius of 50 au are rare in this region, possibly due to either external photoevaporation or age effects.
阿塔卡马大毫米波/亚毫米波阵列（ALMA）在许多原行星盘中探测到了半径从几au到超过100au的亚结构。这些亚结构通常被认为与行星的形成有关，或者是作为行星形成的场所，或者是行星与盘相互作用的结果。不过，我们目前对亚结构的理解主要基于对附近恒星形成区的观测，这些区域的紫外环境比较温和，而恒星通常诞生在更为严酷的紫外环境中，这可能会通过外部光蒸发来抑制外盘中行星的形成。我们展示了由一颗 O9.5 恒星辐照的星团 σ Orionis 中八个星盘的高分辨率（∼8 au）ALMA 1.3 mm 连续谱图像。其中五个星盘的图像可以分辨出间隙和星环。其中最引人注目的是 SO 1274，它有五个间隙，看起来几乎排列成一个共振链。此外，我们还通过能见度建模推断出其他三个星盘中存在间隙或类似肩的结构。这些观测结果表明，在暴露于中等水平外部紫外线辐射的磁盘以及紧凑磁盘中，亚结构在几十au或更小的半长轴上稳健地形成并存活。不过，我们的观测结果也表明，猎户座σ中的磁盘大多很小，因此在这一区域，可能由于外部光蒸发或年龄效应的影响，超过磁盘半径50au的毫米级连续相隙非常罕见。
{"title":"High-resolution ALMA Observations of Richly Structured Protoplanetary Disks in σ Orionis","authors":"Jane Huang, Megan Ansdell, Tilman Birnstiel, Ian Czekala, Feng Long, Jonathan Williams, Shangjia Zhang and Zhaohuan Zhu","doi":"10.3847/1538-4357/ad84df","DOIUrl":"https://doi.org/10.3847/1538-4357/ad84df","url":null,"abstract":"The Atacama Large Millimeter/submillimeter Array (ALMA) has detected substructures in numerous protoplanetary disks at radii from a few to over 100 au. These substructures are commonly thought to be associated with planet formation, either by serving as sites fostering planetesimal formation or by arising as a consequence of planet–disk interactions. Our current understanding of substructures, though, is primarily based on observations of nearby star-forming regions with mild UV environments, whereas stars are typically born in much harsher UV environments, which may inhibit planet formation in the outer disk through external photoevaporation. We present high-resolution (∼8 au) ALMA 1.3 mm continuum images of eight disks in σ Orionis, a cluster irradiated by an O9.5 star. Gaps and rings are resolved in the images of five disks. The most striking of these is SO 1274, which features five gaps that appear to be arranged nearly in a resonant chain. In addition, we infer the presence of gap or shoulder-like structures in the other three disks through visibility modeling. These observations indicate that substructures robustly form and survive at semimajor axes of several tens of au or less in disks exposed to intermediate levels of external UV radiation as well as in compact disks. However, our observations also suggest that disks in σ Orionis are mostly small, and thus millimeter continuum gaps beyond a disk radius of 50 au are rare in this region, possibly due to either external photoevaporation or age effects.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670337","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}
Pub Date : 2024-11-18DOI: 10.3847/1538-4357/ad85e2
Vaidehi S. Paliya, D. J. Saikia, Alberto Domínguez and C. S. Stalin
The extragalactic γ-ray sky is dominated by relativistic jets aligned to the observer’s line of sight, i.e., blazars. A few of their misaligned counterparts, e.g., radio galaxies, are also detected with the Fermi-Large Area Telescope (LAT), albeit in a small number (∼50), indicating the crucial role played by the jet viewing angle in detecting γ-ray emission from jets. These γ-ray emitting misaligned active galactic nuclei (AGN) provide us with a unique opportunity to understand the high-energy emission production mechanisms from a different viewpoint than the more common blazars. With this goal in mind, we have systematically studied the radio morphology of γ-ray emitting sources present in the fourth data release of the fourth catalog of Fermi-LAT detected γ-ray sources to identify misaligned AGN. By utilizing the high-resolution and sensitive MHz and GHz frequency observations delivered by the Very Large Array Sky Survey, Low-Frequency Array Two-metre Sky Survey, Faint Images of the Radio Sky at Twenty Centimeters, and Rapid ASKAP Continuum Survey, here we present a catalog of 149 γ-ray detected misaligned AGN, thus approximately tripling the number of known objects of this class. Our sample includes a variety of radio morphologies, e.g., edge-darkened and edge-brightened, hybrids, wide-angle-tailed, bent jets, and giants. Since the γ-ray emission is thought to be highly sensitive to the jet viewing angle, such an enlarged sample of γ-ray detected misaligned radio sources will permit us to explore the origin of high-energy emission in relativistic jets and radio lobes and study AGN unification, in general.
{"title":"Radio Morphology of Gamma-Ray Sources: Double-lobed Radio Sources","authors":"Vaidehi S. Paliya, D. J. Saikia, Alberto Domínguez and C. S. Stalin","doi":"10.3847/1538-4357/ad85e2","DOIUrl":"https://doi.org/10.3847/1538-4357/ad85e2","url":null,"abstract":"The extragalactic γ-ray sky is dominated by relativistic jets aligned to the observer’s line of sight, i.e., blazars. A few of their misaligned counterparts, e.g., radio galaxies, are also detected with the Fermi-Large Area Telescope (LAT), albeit in a small number (∼50), indicating the crucial role played by the jet viewing angle in detecting γ-ray emission from jets. These γ-ray emitting misaligned active galactic nuclei (AGN) provide us with a unique opportunity to understand the high-energy emission production mechanisms from a different viewpoint than the more common blazars. With this goal in mind, we have systematically studied the radio morphology of γ-ray emitting sources present in the fourth data release of the fourth catalog of Fermi-LAT detected γ-ray sources to identify misaligned AGN. By utilizing the high-resolution and sensitive MHz and GHz frequency observations delivered by the Very Large Array Sky Survey, Low-Frequency Array Two-metre Sky Survey, Faint Images of the Radio Sky at Twenty Centimeters, and Rapid ASKAP Continuum Survey, here we present a catalog of 149 γ-ray detected misaligned AGN, thus approximately tripling the number of known objects of this class. Our sample includes a variety of radio morphologies, e.g., edge-darkened and edge-brightened, hybrids, wide-angle-tailed, bent jets, and giants. Since the γ-ray emission is thought to be highly sensitive to the jet viewing angle, such an enlarged sample of γ-ray detected misaligned radio sources will permit us to explore the origin of high-energy emission in relativistic jets and radio lobes and study AGN unification, in general.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"197 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670357","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}
Pub Date : 2024-11-18DOI: 10.3847/1538-4357/ad8570
Adnane Osmane and Savvas Raptis
Super-Alfvénic jets, with kinetic energy densities significantly exceeding that of the solar wind, are commonly generated downstream of Earth's bow shock under both high- and low-beta plasma conditions. In this study, we present theoretical evidence that these enhanced kinetic energy flows can be driven by firehose-unstable fluctuations and compressive heating within collisionless plasma environments. Using a fluid formalism that incorporates pressure anisotropy, we estimate that the downstream flow of a collisionless plasma shock can be accelerated by a factor of 2–4 following the compression and saturation of firehose instability. By analyzing quasi-parallel magnetosheath jets observed in situ by the Magnetospheric Multiscale (MMS) mission, we find that approximately 11% of plasma measurements within these jets exhibit firehose-unstable fluctuations. Our findings offer an explanation for the distinctive generation of fast downstream flows in both low (β < 1) and high (β > 1) beta plasmas, and provide new evidence that kinetic processes are crucial for accurately describing the formation and evolution of magnetosheath jets.
{"title":"On the Formation of Super-Alfvénic Flows Downstream of Collisionless Shocks","authors":"Adnane Osmane and Savvas Raptis","doi":"10.3847/1538-4357/ad8570","DOIUrl":"https://doi.org/10.3847/1538-4357/ad8570","url":null,"abstract":"Super-Alfvénic jets, with kinetic energy densities significantly exceeding that of the solar wind, are commonly generated downstream of Earth's bow shock under both high- and low-beta plasma conditions. In this study, we present theoretical evidence that these enhanced kinetic energy flows can be driven by firehose-unstable fluctuations and compressive heating within collisionless plasma environments. Using a fluid formalism that incorporates pressure anisotropy, we estimate that the downstream flow of a collisionless plasma shock can be accelerated by a factor of 2–4 following the compression and saturation of firehose instability. By analyzing quasi-parallel magnetosheath jets observed in situ by the Magnetospheric Multiscale (MMS) mission, we find that approximately 11% of plasma measurements within these jets exhibit firehose-unstable fluctuations. Our findings offer an explanation for the distinctive generation of fast downstream flows in both low (β < 1) and high (β > 1) beta plasmas, and provide new evidence that kinetic processes are crucial for accurately describing the formation and evolution of magnetosheath jets.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670341","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}
Pub Date : 2024-11-18DOI: 10.3847/1538-4357/ad7b38
Alexander W. James and Hamish A. S. Reid
Quantifying the energy content of accelerated electron beams during solar eruptive events is a key outstanding objective that must be constrained to refine particle acceleration models and understand the electron component of space weather. Previous estimations have used in situ measurements near the Earth, and consequently suffer from electron-beam propagation effects. In this study, we deduce properties of a rapid sequence of escaping electron beams that were accelerated during a solar flare on 2013 May 22 and produced type III radio bursts, including the first estimate of energy density from remote-sensing observations. We use extreme-ultraviolet observations to infer the magnetic structure of the source active region NOAA 11745, and Nançay Radioheliograph imaging spectroscopy to estimate the speed and origin of the escaping electron beams. Using the observationally deduced electron-beam properties from the type III bursts and cotemporal hard X-rays, we simulate electron-beam properties to estimate the electron number density and energy in the acceleration region. We find an electron density (above 30 keV) in the acceleration region of 102.5 cm−3 and an energy density of 2 × 10−5 erg cm−3. Radio observations suggest the particles travelled a very short distance before they began to produce radio emission, implying a radially narrow acceleration region. A short but plausibly wide slab-like acceleration volume of 1026–1028 cm3 atop the flaring loop arcade could contain a total energy of 1023–1025 erg (∼100 beams), which is comparable to energy estimates from previous studies.
对太阳爆发事件期间加速电子束的能量含量进行量化是一个关键的未完成目标，必须对其进行约束，以完善粒子加速模型并了解空间天气的电子成分。以前的估算使用的是地球附近的现场测量，因此受到电子束传播效应的影响。在这项研究中，我们推断了在2013年5月22日太阳耀斑期间被加速并产生III型射电暴的快速逃逸电子束序列的特性，包括首次通过遥感观测估计能量密度。我们利用极紫外观测推断源活动区 NOAA 11745 的磁结构，并利用 Nançay 射电日像仪成像光谱估算逸散电子束的速度和来源。利用从 III 型爆发和同时间硬 X 射线观测推断出的电子束特性，我们模拟了电子束特性，以估计加速区的电子数量密度和能量。我们发现加速区的电子密度（30 千伏以上）为 102.5 厘米-3，能量密度为 2 × 10-5 尔格厘米-3。无线电观测结果表明，粒子在开始产生无线电辐射之前只飞行了很短的距离，这意味着加速区的径向范围很窄。在闪烁的环形弧顶上有一个1026-1028立方厘米的短而宽的板状加速体积，可能包含1023-1025尔格（∼100束）的总能量，这与以前研究估计的能量相当。
{"title":"Estimating the Total Energy Content in Escaping Accelerated Solar Electron Beams","authors":"Alexander W. James and Hamish A. S. Reid","doi":"10.3847/1538-4357/ad7b38","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7b38","url":null,"abstract":"Quantifying the energy content of accelerated electron beams during solar eruptive events is a key outstanding objective that must be constrained to refine particle acceleration models and understand the electron component of space weather. Previous estimations have used in situ measurements near the Earth, and consequently suffer from electron-beam propagation effects. In this study, we deduce properties of a rapid sequence of escaping electron beams that were accelerated during a solar flare on 2013 May 22 and produced type III radio bursts, including the first estimate of energy density from remote-sensing observations. We use extreme-ultraviolet observations to infer the magnetic structure of the source active region NOAA 11745, and Nançay Radioheliograph imaging spectroscopy to estimate the speed and origin of the escaping electron beams. Using the observationally deduced electron-beam properties from the type III bursts and cotemporal hard X-rays, we simulate electron-beam properties to estimate the electron number density and energy in the acceleration region. We find an electron density (above 30 keV) in the acceleration region of 102.5 cm−3 and an energy density of 2 × 10−5 erg cm−3. Radio observations suggest the particles travelled a very short distance before they began to produce radio emission, implying a radially narrow acceleration region. A short but plausibly wide slab-like acceleration volume of 1026–1028 cm3 atop the flaring loop arcade could contain a total energy of 1023–1025 erg (∼100 beams), which is comparable to energy estimates from previous studies.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670970","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}
Pub Date : 2024-11-18DOI: 10.3847/1538-4357/ad83ce
S. S. Ren, R. X. Zhou, Y. G. Zheng and S. J. Kang
We investigate the evolution of a changing-look blazar (CLB) on long timescales and expect to trace the state change of a CLB. Three morphological types, including a flat spectrum radio quasar (FSRQ) state, transition state, and BL Lacertae (BL Lac) state, are classified according to the criteria proposed by analyzing the relationship between the equivalent width of the emission line and the γ-ray photon spectral index Γγ. The multiwavelength light curves and spectral energy distributions corresponding to different epochs are obtained. The efforts found that Γγ satisfy the relationships with Γγ ≳ 2.2 for the FSRQ state, 2.0 < Γγ < 2.2 for the transition state, and Γγ ≲ 2.0 for the BL Lac state. We apply the criteria to the photon spectrum evolution of CLB OQ 334 during MJD 58678–60387. The evolution is subdivided into five FSRQ states, nine transition states, and four BL Lac states. Moreover, we use the model spectra parameters of each state epoch to test the reliability of subdivided morphological types. The result shows that: (1) the accretion rate parameter is consistent with our earlier research; and (2) there is an increasing trend in the epochs of the BL Lac states, even if there is not an obvious decreasing trend in epochs of the FSRQ states. We issue strong evidence that a CLB is an especial epoch in the evolution of blazars that could be obtained from the oscillation phenomenon in the CLB evolution.
{"title":"The Oscillation in Evolution of Changing-look Blazar OQ 334","authors":"S. S. Ren, R. X. Zhou, Y. G. Zheng and S. J. Kang","doi":"10.3847/1538-4357/ad83ce","DOIUrl":"https://doi.org/10.3847/1538-4357/ad83ce","url":null,"abstract":"We investigate the evolution of a changing-look blazar (CLB) on long timescales and expect to trace the state change of a CLB. Three morphological types, including a flat spectrum radio quasar (FSRQ) state, transition state, and BL Lacertae (BL Lac) state, are classified according to the criteria proposed by analyzing the relationship between the equivalent width of the emission line and the γ-ray photon spectral index Γγ. The multiwavelength light curves and spectral energy distributions corresponding to different epochs are obtained. The efforts found that Γγ satisfy the relationships with Γγ ≳ 2.2 for the FSRQ state, 2.0 < Γγ < 2.2 for the transition state, and Γγ ≲ 2.0 for the BL Lac state. We apply the criteria to the photon spectrum evolution of CLB OQ 334 during MJD 58678–60387. The evolution is subdivided into five FSRQ states, nine transition states, and four BL Lac states. Moreover, we use the model spectra parameters of each state epoch to test the reliability of subdivided morphological types. The result shows that: (1) the accretion rate parameter is consistent with our earlier research; and (2) there is an increasing trend in the epochs of the BL Lac states, even if there is not an obvious decreasing trend in epochs of the FSRQ states. We issue strong evidence that a CLB is an especial epoch in the evolution of blazars that could be obtained from the oscillation phenomenon in the CLB evolution.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670362","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}
Pub Date : 2024-11-15DOI: 10.3847/1538-4357/ad8441
Miriam Golubchik, Charles L. Steinhardt, Adi Zitrin, Ashish K. Meena, Lukas J. Furtak, Doron Chelouche and Shai Kaspi
Mass estimates of black holes (BHs) in the centers of active galactic nuclei (AGNs) often rely on the radius–luminosity relation. However, this relation, usually probed by reverberation mapping (RM), is poorly constrained in the high-luminosity and high-redshift ends due to the very long expected RM lag times. Multiply imaged AGNs may offer a unique opportunity to explore the radius–luminosity relation at these ends. In addition to comprising several magnified images enabling a more efficient light-curve sampling, the time delay between multiple images of strongly lensed quasars can also aid in making such RM measurements feasible on reasonable timescales: if the strong-lensing time delay is, for example, of the order of the expected RM time lag, changes in the emission lines in the leading image can be observed around the same time as the changes in the continuum in the trailing image. In this work we probe the typical time-delay distribution in galaxy-cluster lenses and estimate the number of both high-mass (∼109−1010M⊙) and high-redshift (z ≳ 4−12) quasars that are expected to be strongly lensed by clusters. We find that up to several tens of thousands of MBH ∼ 106–108M⊙ broad-line AGNs at z > 4 should be multiply imaged by galaxy clusters and detectable with JWST, hundreds with Euclid, and several thousand with the Roman Space Telescope, across the whole sky. These could supply an important calibration for the BH mass scaling in the early Universe.
{"title":"Reverberation Mapping of High-mass and High-redshift Quasars Using Gravitational Time Delays","authors":"Miriam Golubchik, Charles L. Steinhardt, Adi Zitrin, Ashish K. Meena, Lukas J. Furtak, Doron Chelouche and Shai Kaspi","doi":"10.3847/1538-4357/ad8441","DOIUrl":"https://doi.org/10.3847/1538-4357/ad8441","url":null,"abstract":"Mass estimates of black holes (BHs) in the centers of active galactic nuclei (AGNs) often rely on the radius–luminosity relation. However, this relation, usually probed by reverberation mapping (RM), is poorly constrained in the high-luminosity and high-redshift ends due to the very long expected RM lag times. Multiply imaged AGNs may offer a unique opportunity to explore the radius–luminosity relation at these ends. In addition to comprising several magnified images enabling a more efficient light-curve sampling, the time delay between multiple images of strongly lensed quasars can also aid in making such RM measurements feasible on reasonable timescales: if the strong-lensing time delay is, for example, of the order of the expected RM time lag, changes in the emission lines in the leading image can be observed around the same time as the changes in the continuum in the trailing image. In this work we probe the typical time-delay distribution in galaxy-cluster lenses and estimate the number of both high-mass (∼109−1010M⊙) and high-redshift (z ≳ 4−12) quasars that are expected to be strongly lensed by clusters. We find that up to several tens of thousands of MBH ∼ 106–108M⊙ broad-line AGNs at z > 4 should be multiply imaged by galaxy clusters and detectable with JWST, hundreds with Euclid, and several thousand with the Roman Space Telescope, across the whole sky. These could supply an important calibration for the BH mass scaling in the early Universe.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"98 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637204","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}
Pub Date : 2024-11-15DOI: 10.3847/1538-4357/ad822b
Mahmoud Gholipour and Amir Abbas Eslami Shafigh
This study examines the importance of the thermal effects of ambipolar diffusion (AD), by analyzing the governing properties in the middle and outer regions of a standard thin accretion disk with outflows. To accomplish this, we derive the nonideal magnetohydrodynamic equations, considering both the dynamical and thermal impacts of AD in these regions of the disk. In a stationary state, we utilize the self-similar technique to analyze the vertical structure of a disk with outflows and express the ambipolar diffusivity in terms of the Alfvén velocity and the Elsässer number. Our main focus is on the vertical temperature profile at large radii of the disk when the values of the Elsässer number are small. While the findings indicate that AD heating has minimal effects within the disk, it does play a critical role near the disk surface. When the Elsässer number is low, there is a notable rate of outflows and disk evaporation, resulting in angular momentum transport in these regions. This issue becomes important when we decrease the value of turbulent viscosity, as it leads to highlighting the AD heating effect. This allows the surface regions to become hotter and results in an increase in the drive of the outflows. The results of this research may be important for studying disk coronae and disk dispersal in the middle and outer regions of the thin accretion disk.
本研究通过分析带有外流的标准薄吸积盘的中层和外层区域的支配特性，研究了伏极扩散（AD）的热效应的重要性。为此，我们推导了非理想磁流体力学方程，同时考虑了 AD 在磁盘这些区域的动力学和热学影响。在静止状态下，我们利用自相似技术分析了带有外流的磁盘的垂直结构，并用阿尔弗韦恩速度和埃尔塞数表示了伏极扩散性。我们的主要研究重点是当埃尔塞数值较小时，圆盘大半径处的垂直温度曲线。研究结果表明，AD 加热对圆盘内部的影响微乎其微，但在圆盘表面附近却起着至关重要的作用。当埃尔塞数较低时，外流和磁盘蒸发的速度明显加快，从而导致这些区域的角动量传输。当我们降低湍流粘度值时，这个问题就变得很重要了，因为它会导致 AD 加热效应凸显。这使得表面区域变得更热，从而增加了外流的驱动力。这项研究的结果可能对研究薄吸积盘中部和外部区域的盘冠和盘散布具有重要意义。
{"title":"The Importance of Ambipolar Heating in the Standard Thin Accretion Disk with Outflows","authors":"Mahmoud Gholipour and Amir Abbas Eslami Shafigh","doi":"10.3847/1538-4357/ad822b","DOIUrl":"https://doi.org/10.3847/1538-4357/ad822b","url":null,"abstract":"This study examines the importance of the thermal effects of ambipolar diffusion (AD), by analyzing the governing properties in the middle and outer regions of a standard thin accretion disk with outflows. To accomplish this, we derive the nonideal magnetohydrodynamic equations, considering both the dynamical and thermal impacts of AD in these regions of the disk. In a stationary state, we utilize the self-similar technique to analyze the vertical structure of a disk with outflows and express the ambipolar diffusivity in terms of the Alfvén velocity and the Elsässer number. Our main focus is on the vertical temperature profile at large radii of the disk when the values of the Elsässer number are small. While the findings indicate that AD heating has minimal effects within the disk, it does play a critical role near the disk surface. When the Elsässer number is low, there is a notable rate of outflows and disk evaporation, resulting in angular momentum transport in these regions. This issue becomes important when we decrease the value of turbulent viscosity, as it leads to highlighting the AD heating effect. This allows the surface regions to become hotter and results in an increase in the drive of the outflows. The results of this research may be important for studying disk coronae and disk dispersal in the middle and outer regions of the thin accretion disk.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637234","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}
Pub Date : 2024-11-15DOI: 10.3847/1538-4357/ad81f4
Yu-Fei Li, Da-Bin Lin, Li Zhou, Jia Ren, Zhi-Lin Chen and En-Wei Liang
A rapidly rotating magnetar has long been assumed to inject energy into the ejecta through isotropic output energy in previous works. However, the output energy of a magnetar is anisotropic and a jet is generally presented in the rotational direction of a magnetar. In this paper, we present a consistent model of the energy injection from a magnetar, considering both the anisotropic magnetic dipole radiation and the jet’s ingredient (i.e., the late jet mentioned refers to the beamed magnetars wind). In the situation that the energy injection into the ejecta presents a significant effect on the ejecta’s emission, two facts are obtained. (1) For an observer in the equatorial direction, there is no significant difference between the light curves of the ejecta’s emission based on the consistent model and those obtained in previous works (i.e., based on the isotropic energy injection). (2) For an on jet-axis observer, however, the difference is significant, especially in the optical/U-band. If the jet is not present in the system, the rise of the optical/U-band light-curve is actually steeper than that in previous works because the output energy of the anisotropic magnetic dipole radiation is mainly in the equatorial direction. If the jet is present in the system, a bump from the cocoon (i.e., the late jet launch is expected to shock and heat-up the ejecta) may only appear in the optical/U-band light curve for a quasi-isotropic ejecta. Our results reveal that the anisotropic energy output of the magnetic dipole radiation and the jet’s ingredient should be well considered in modeling the ejecta emission by considering the energy injection from a magnetar. In addition, the optical/U-band light-curve may disclose the central engine of the burst.
{"title":"The Effect of Anisotropic Energy Injection on the Ejecta Emission","authors":"Yu-Fei Li, Da-Bin Lin, Li Zhou, Jia Ren, Zhi-Lin Chen and En-Wei Liang","doi":"10.3847/1538-4357/ad81f4","DOIUrl":"https://doi.org/10.3847/1538-4357/ad81f4","url":null,"abstract":"A rapidly rotating magnetar has long been assumed to inject energy into the ejecta through isotropic output energy in previous works. However, the output energy of a magnetar is anisotropic and a jet is generally presented in the rotational direction of a magnetar. In this paper, we present a consistent model of the energy injection from a magnetar, considering both the anisotropic magnetic dipole radiation and the jet’s ingredient (i.e., the late jet mentioned refers to the beamed magnetars wind). In the situation that the energy injection into the ejecta presents a significant effect on the ejecta’s emission, two facts are obtained. (1) For an observer in the equatorial direction, there is no significant difference between the light curves of the ejecta’s emission based on the consistent model and those obtained in previous works (i.e., based on the isotropic energy injection). (2) For an on jet-axis observer, however, the difference is significant, especially in the optical/U-band. If the jet is not present in the system, the rise of the optical/U-band light-curve is actually steeper than that in previous works because the output energy of the anisotropic magnetic dipole radiation is mainly in the equatorial direction. If the jet is present in the system, a bump from the cocoon (i.e., the late jet launch is expected to shock and heat-up the ejecta) may only appear in the optical/U-band light curve for a quasi-isotropic ejecta. Our results reveal that the anisotropic energy output of the magnetic dipole radiation and the jet’s ingredient should be well considered in modeling the ejecta emission by considering the energy injection from a magnetar. In addition, the optical/U-band light-curve may disclose the central engine of the burst.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637202","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}
Pub Date : 2024-11-15DOI: 10.3847/1538-4357/ad8446
Qi-Bin Sun, Sheng-Bang Qian, Li-Ying Zhu, Qin-Mei Li, Fu-Xing Li, Min-Yu Li and Ping Li
The IW And-type phenomenon in cataclysmic variables presents a significant challenge to the accretion disk instability model. Using photometric data from the All-Sky Automated Survey for Supernovae, the Zwicky Transient Facility, and the Transiting Exoplanet Survey Satellite, we identify Karachurin 12 as a new noneclipsing IW And-type object with a cycle period of 35.69(3) days. We also report for the first time that Karachurin 12 is a negative superhump (NSH) system featuring precessing tilted disks, with precession, orbital, and NSH periods of 4.9588(2) days, 0.3168895(13) days, and 0.2979861(8) days, respectively. Our analysis, using dips as the index and NSHs as the probe, reveals diverse cycle patterns in Karachurin 12, with NSH amplitude varying throughout the cycle. These findings offer new insights for studying tilted disks and the IW And-type phenomenon. The mass-transfer burst model has difficulty explaining the observed variations in NSH amplitude, especially given the uncertainty surrounding the origin of the mass-transfer burst. Meanwhile, the tilted thermally unstable disk model indicates a possible connection to the IW And-type phenomenon, but it also struggles to account for the detailed variations in Karachurin 12. Therefore, a wider range of factors must be considered to fully understand the complex changes in Karachurin 12.
{"title":"A New IW And-type Star: Karachurin 12 with Tilted Disks and Diverse Cycles","authors":"Qi-Bin Sun, Sheng-Bang Qian, Li-Ying Zhu, Qin-Mei Li, Fu-Xing Li, Min-Yu Li and Ping Li","doi":"10.3847/1538-4357/ad8446","DOIUrl":"https://doi.org/10.3847/1538-4357/ad8446","url":null,"abstract":"The IW And-type phenomenon in cataclysmic variables presents a significant challenge to the accretion disk instability model. Using photometric data from the All-Sky Automated Survey for Supernovae, the Zwicky Transient Facility, and the Transiting Exoplanet Survey Satellite, we identify Karachurin 12 as a new noneclipsing IW And-type object with a cycle period of 35.69(3) days. We also report for the first time that Karachurin 12 is a negative superhump (NSH) system featuring precessing tilted disks, with precession, orbital, and NSH periods of 4.9588(2) days, 0.3168895(13) days, and 0.2979861(8) days, respectively. Our analysis, using dips as the index and NSHs as the probe, reveals diverse cycle patterns in Karachurin 12, with NSH amplitude varying throughout the cycle. These findings offer new insights for studying tilted disks and the IW And-type phenomenon. The mass-transfer burst model has difficulty explaining the observed variations in NSH amplitude, especially given the uncertainty surrounding the origin of the mass-transfer burst. Meanwhile, the tilted thermally unstable disk model indicates a possible connection to the IW And-type phenomenon, but it also struggles to account for the detailed variations in Karachurin 12. Therefore, a wider range of factors must be considered to fully understand the complex changes in Karachurin 12.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637205","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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