Abstract In this Letter, we report a potential candidate of recoiling supermassive black hole (rSMBH) in SDSS J1619 based on similar velocity shifts and line widths of the blue-shifted broad components in Hα and [O iii] doublet. The measured line width ratio between blue-shifted broad Hα and broad [O iii] line is 0.93, if compared with common values around 5.12 for normal Type-1 AGN, indicating different properties of the blue-shifted broad components in SDSS J1619 from those of normal QSOs. The virial BH mass MBHr derived from the broad Hα is consistent with the mass expected from the MBH − σ relation. The similar velocity shifts and line widths of the blue-shifted broad components in Hα and [O iii] and the virial BH mass derived from the Hα broad line emissions that is consistent with the mass expected from the MBH − σ relation, can be explained by a rSMBH scenario. Besides the rSMBH scenario, either the similar line widths of the blue-shifted broad components in Hα and in [O iii] or the consistency between the virial BH mass and the mass expected from the MBH − σ relation cannot be explained by the other proposed models in SDSS J1619.
{"title":"SDSS J1619 with blue-shifted broad components in Hα and in [O <scp>iii</scp>] having similar line width and velocity shifts: a recoiling SMBH candidate?","authors":"Xue-Guang Zhang","doi":"10.1093/mnrasl/slad161","DOIUrl":"https://doi.org/10.1093/mnrasl/slad161","url":null,"abstract":"Abstract In this Letter, we report a potential candidate of recoiling supermassive black hole (rSMBH) in SDSS J1619 based on similar velocity shifts and line widths of the blue-shifted broad components in Hα and [O iii] doublet. The measured line width ratio between blue-shifted broad Hα and broad [O iii] line is 0.93, if compared with common values around 5.12 for normal Type-1 AGN, indicating different properties of the blue-shifted broad components in SDSS J1619 from those of normal QSOs. The virial BH mass MBHr derived from the broad Hα is consistent with the mass expected from the MBH − σ relation. The similar velocity shifts and line widths of the blue-shifted broad components in Hα and [O iii] and the virial BH mass derived from the Hα broad line emissions that is consistent with the mass expected from the MBH − σ relation, can be explained by a rSMBH scenario. Besides the rSMBH scenario, either the similar line widths of the blue-shifted broad components in Hα and in [O iii] or the consistency between the virial BH mass and the mass expected from the MBH − σ relation cannot be explained by the other proposed models in SDSS J1619.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135169003","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}
Abstract Field-level inference is emerging as a promising technique for optimally extracting information from cosmological datasets. Previous analyses have shown field-based inference produces tighter parameter constraints than power spectrum analyses. However, estimates of the detailed quantitative gain in constraining power differ. Here, we demonstrate the gain in constraining power depends on the parameter space being constrained. As a specific example, we find that lognormal field-based analysis of an LSST Y1-like mock data set only marginally improves constraints relative to a 2-point function analysis in ΛCDM, yet it more than doubles the constraining power of the data in the context of wCDM models. This effect reconciles some, but not all, of the discrepant results found in the literature. Our results suggest the importance of using a full systematics model when quantifying the information gain for realistic field-level analyses of future data sets.
{"title":"Map-based cosmology inference with weak lensing – information content and its dependence on the parameter space","authors":"Supranta S Boruah, Eduardo Rozo","doi":"10.1093/mnrasl/slad160","DOIUrl":"https://doi.org/10.1093/mnrasl/slad160","url":null,"abstract":"Abstract Field-level inference is emerging as a promising technique for optimally extracting information from cosmological datasets. Previous analyses have shown field-based inference produces tighter parameter constraints than power spectrum analyses. However, estimates of the detailed quantitative gain in constraining power differ. Here, we demonstrate the gain in constraining power depends on the parameter space being constrained. As a specific example, we find that lognormal field-based analysis of an LSST Y1-like mock data set only marginally improves constraints relative to a 2-point function analysis in ΛCDM, yet it more than doubles the constraining power of the data in the context of wCDM models. This effect reconciles some, but not all, of the discrepant results found in the literature. Our results suggest the importance of using a full systematics model when quantifying the information gain for realistic field-level analyses of future data sets.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135414537","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}
Giovanni Montani, Mariaveronica De Angelis, Flavio Bombacigno, Nakia Carlevaro
Abstract We introduce a theoretical framework to interpret the Hubble tension, based on the combination of a metric f(R) gravity with a dynamical dark energy contribution. The modified gravity provides the non-minimally coupled scalar field responsible for the proper scaling of the Hubble constant, in order to accommodate for the local SNIa pantheon+ data and Planck measurements. The dynamical dark energy source, which exhibits a phantom divide line separating the low red-shift quintessence regime (−1 < w < −1/3) from the phantom contribution (w < −1) in the early Universe, guarantees the absence of tachyonic instabilities at low red-shift. The resulting H0(z) profile rapidly approaches the Planck value, with a plateau behaviour for z ≳ 5. In this scenario, the Hubble tension emerges as a low red-shift effect, which can be in principle tested by comparing SNIa predictions with far sources, like QUASARS and Gamma Ray Bursts.
{"title":"Metric <i>f</i>(<i>R</i>) gravity with dynamical dark energy as a scenario for the Hubble tension","authors":"Giovanni Montani, Mariaveronica De Angelis, Flavio Bombacigno, Nakia Carlevaro","doi":"10.1093/mnrasl/slad159","DOIUrl":"https://doi.org/10.1093/mnrasl/slad159","url":null,"abstract":"Abstract We introduce a theoretical framework to interpret the Hubble tension, based on the combination of a metric f(R) gravity with a dynamical dark energy contribution. The modified gravity provides the non-minimally coupled scalar field responsible for the proper scaling of the Hubble constant, in order to accommodate for the local SNIa pantheon+ data and Planck measurements. The dynamical dark energy source, which exhibits a phantom divide line separating the low red-shift quintessence regime (−1 &lt; w &lt; −1/3) from the phantom contribution (w &lt; −1) in the early Universe, guarantees the absence of tachyonic instabilities at low red-shift. The resulting H0(z) profile rapidly approaches the Planck value, with a plateau behaviour for z ≳ 5. In this scenario, the Hubble tension emerges as a low red-shift effect, which can be in principle tested by comparing SNIa predictions with far sources, like QUASARS and Gamma Ray Bursts.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135414401","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 population of binary stellar-mass black hole (BBH) mergers are believed to occur embedded in the accretion disk of active galactic nuclei (AGNs). In this Letter, we demonstrate that the jets from these BBH mergers can propagate collimatedly within the disk atmosphere along with a forward shock and a reverse shock forming at the jet head. Efficient proton acceleration by these shocks is usually expected before the breakout, leading to the production of TeV−PeV neutrinos through interactions between these protons and electron-radiating photons via photon-meson production. AGN BBH mergers occurring in the outer regions of the disk are more likely to produce more powerful neutrino bursts. Taking the host AGN properties of the potential GW190521 electromagnetic (EM) counterpart as an example, one expects ≳ 1 neutrino events detectable by IceCube if the jet is on-axis and the radial location of the merger is R ≳ 105Rg, where Rg is the gravitational radius of the supermassive BH. Neutrino bursts from AGN BBH mergers could be detected by IceCube following the observation of gravitational waves (GWs), serving as precursor signals before the detection of EM breakout signals. AGN BBH mergers are potential target sources for future joint GW, neutrino, and EM multi-messenger observations.
{"title":"High-energy neutrinos from merging stellar-mass black holes in active galactic nuclei accretion disk","authors":"Jin-Ping Zhu","doi":"10.1093/mnrasl/slad176","DOIUrl":"https://doi.org/10.1093/mnrasl/slad176","url":null,"abstract":"A population of binary stellar-mass black hole (BBH) mergers are believed to occur embedded in the accretion disk of active galactic nuclei (AGNs). In this Letter, we demonstrate that the jets from these BBH mergers can propagate collimatedly within the disk atmosphere along with a forward shock and a reverse shock forming at the jet head. Efficient proton acceleration by these shocks is usually expected before the breakout, leading to the production of TeV−PeV neutrinos through interactions between these protons and electron-radiating photons via photon-meson production. AGN BBH mergers occurring in the outer regions of the disk are more likely to produce more powerful neutrino bursts. Taking the host AGN properties of the potential GW190521 electromagnetic (EM) counterpart as an example, one expects ≳ 1 neutrino events detectable by IceCube if the jet is on-axis and the radial location of the merger is R ≳ 105Rg, where Rg is the gravitational radius of the supermassive BH. Neutrino bursts from AGN BBH mergers could be detected by IceCube following the observation of gravitational waves (GWs), serving as precursor signals before the detection of EM breakout signals. AGN BBH mergers are potential target sources for future joint GW, neutrino, and EM multi-messenger observations.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"107 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139315529","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}
Abstract Gravity drives the collapse of molecular clouds through which stars form, yet the exact role of gravity in cloud collapse remains a complex issue. Studies point to a picture where star formation occurs in clusters. In a typical, pc-sized cluster-forming region, the collapse is hierarchical, and the stars should be born from regions of even smaller sizes ($approx 0.1,,rm pc$). The origin of this spatial arrangement remains under investigation. Based on a high-quality surface density map towards the Perseus region, we construct a 3D density structure, compute the gravitational potential, and derive eigenvalues of the tidal tensor (λmin, λmid, λmax, λmin < λmid < λmax), analyze the behavior of gravity at every location and reveal its multiple roles in cloud evolution. We find that fragmentation is limited to several isolated, high-density “islands”. Surrounding them, is a vast amount of the gas ($75~{{%}}$ of the mass, $95~{{%}}$ of the volume) stays under the influence of extensive tides where fragmentation is suppressed. This gas will be transported towards these regions to fuel star formation. The spatial arrangement of regions under different tides explains the hierarchical and localized pattern of star formation inferred from the observations. Tides were first recognized by Newton, yet this is the first time its dominance in cloud evolution has been revealed. We expect this link between cloud density structure and role gravity to be strengthened by future studies, resulting in a clear view of the star formation process.
{"title":"Tides in clouds: control of star formation by long-range gravitational force","authors":"Guang-Xing Li","doi":"10.1093/mnrasl/slad149","DOIUrl":"https://doi.org/10.1093/mnrasl/slad149","url":null,"abstract":"Abstract Gravity drives the collapse of molecular clouds through which stars form, yet the exact role of gravity in cloud collapse remains a complex issue. Studies point to a picture where star formation occurs in clusters. In a typical, pc-sized cluster-forming region, the collapse is hierarchical, and the stars should be born from regions of even smaller sizes ($approx 0.1,,rm pc$). The origin of this spatial arrangement remains under investigation. Based on a high-quality surface density map towards the Perseus region, we construct a 3D density structure, compute the gravitational potential, and derive eigenvalues of the tidal tensor (λmin, λmid, λmax, λmin &lt; λmid &lt; λmax), analyze the behavior of gravity at every location and reveal its multiple roles in cloud evolution. We find that fragmentation is limited to several isolated, high-density “islands”. Surrounding them, is a vast amount of the gas ($75~{{%}}$ of the mass, $95~{{%}}$ of the volume) stays under the influence of extensive tides where fragmentation is suppressed. This gas will be transported towards these regions to fuel star formation. The spatial arrangement of regions under different tides explains the hierarchical and localized pattern of star formation inferred from the observations. Tides were first recognized by Newton, yet this is the first time its dominance in cloud evolution has been revealed. We expect this link between cloud density structure and role gravity to be strengthened by future studies, resulting in a clear view of the star formation process.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136033664","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}
Abstract Can information theory provide insights into whether exoplanets are habitable? Here we apply information theory to a range of simulated exoplanet transmission spectra as a diagnostic tool to search for potential signatures of life on Earth-analog planets. We test the algorithms on three epochs of evolution for Earth-like planets orbiting a range of host stars. The James Webb Space Telescope and upcoming ground- and space-based missions promise to achieve sufficient high-resolution data that information theory can be applied to assess habitability. This approach provides a framework and a tool for observers to assess whether an exoplanet shows signs of habitability.
{"title":"An Information Theory Approach to Identifying Signs of Life on Transiting Planets","authors":"Sara Vannah, Marcelo Gleiser, Lisa Kaltenegger","doi":"10.1093/mnrasl/slad156","DOIUrl":"https://doi.org/10.1093/mnrasl/slad156","url":null,"abstract":"Abstract Can information theory provide insights into whether exoplanets are habitable? Here we apply information theory to a range of simulated exoplanet transmission spectra as a diagnostic tool to search for potential signatures of life on Earth-analog planets. We test the algorithms on three epochs of evolution for Earth-like planets orbiting a range of host stars. The James Webb Space Telescope and upcoming ground- and space-based missions promise to achieve sufficient high-resolution data that information theory can be applied to assess habitability. This approach provides a framework and a tool for observers to assess whether an exoplanet shows signs of habitability.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"238 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136034041","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}
Ronan Legin, Matthew Ho, Pablo Lemos, Laurence Perreault-Levasseur, Shirley Ho, Yashar Hezaveh, Benjamin Wandelt
Abstract Reconstructing the initial conditions of the universe is a key problem in cosmology. Methods based on simulating the forward evolution of the universe have provided a way to infer initial conditions consistent with present-day observations. However, due to the high complexity of the inference problem, these methods either fail to sample a distribution of possible initial density fields or require significant approximations in the simulation model to be tractable, potentially leading to biased results. In this work, we propose the use of score-based generative models to sample realizations of the early universe given present-day observations. We infer the initial density field of full high-resolution dark matter N-body simulations from the present-day density field and verify the quality of produced samples compared to the ground truth based on summary statistics. The proposed method is capable of providing plausible realizations of the early universe density field from the initial conditions posterior distribution marginalized over cosmological parameters and can sample orders of magnitude faster than current state-of-the-art methods.
{"title":"Posterior Sampling of the Initial Conditions of the Universe from Non-linear Large Scale Structures using Score-Based Generative Models","authors":"Ronan Legin, Matthew Ho, Pablo Lemos, Laurence Perreault-Levasseur, Shirley Ho, Yashar Hezaveh, Benjamin Wandelt","doi":"10.1093/mnrasl/slad152","DOIUrl":"https://doi.org/10.1093/mnrasl/slad152","url":null,"abstract":"Abstract Reconstructing the initial conditions of the universe is a key problem in cosmology. Methods based on simulating the forward evolution of the universe have provided a way to infer initial conditions consistent with present-day observations. However, due to the high complexity of the inference problem, these methods either fail to sample a distribution of possible initial density fields or require significant approximations in the simulation model to be tractable, potentially leading to biased results. In this work, we propose the use of score-based generative models to sample realizations of the early universe given present-day observations. We infer the initial density field of full high-resolution dark matter N-body simulations from the present-day density field and verify the quality of produced samples compared to the ground truth based on summary statistics. The proposed method is capable of providing plausible realizations of the early universe density field from the initial conditions posterior distribution marginalized over cosmological parameters and can sample orders of magnitude faster than current state-of-the-art methods.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135805033","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}
Abstract In the search for life in the universe, Earth provides a template of evolution for the one habitable planet we know. Earth's atmospheric composition has changed significantly throughout its history. The last 500 million years -the Phanerozoic Eon, which includes the origins of animals, dinosaurs, and land plants- saw oxygen rise from ≤10% to 35%. But the resulting transmission spectra are a crucial missing piece in our search for signs of life in exoplanet atmospheres. Here, we simulate the atmosphere and transmission spectra of the Phanerozoic, using estimates from established climate models, and present the first high-resolution transmission spectra for Phanerozoic Earth. We demonstrate that the spectral biosignature pairs O2+CH4 and O3+CH4 in the atmosphere of a transiting Earth-like planet would indicate a biosphere, with O2 and O3 features potentially stronger than for modern Earth. The full model and high-resolution transmission spectra, covering 0.4–20 μm, are available online and provides a tool to plan and optimize observations, train retrieval methods, and interpret upcoming observations with ground- and space-based telescopes.
{"title":"Oxygen Bounty for Earth-like exoplanets: Spectra of Earth through the Phanerozoic","authors":"R C Payne, L Kaltenegger","doi":"10.1093/mnrasl/slad147","DOIUrl":"https://doi.org/10.1093/mnrasl/slad147","url":null,"abstract":"Abstract In the search for life in the universe, Earth provides a template of evolution for the one habitable planet we know. Earth's atmospheric composition has changed significantly throughout its history. The last 500 million years -the Phanerozoic Eon, which includes the origins of animals, dinosaurs, and land plants- saw oxygen rise from ≤10% to 35%. But the resulting transmission spectra are a crucial missing piece in our search for signs of life in exoplanet atmospheres. Here, we simulate the atmosphere and transmission spectra of the Phanerozoic, using estimates from established climate models, and present the first high-resolution transmission spectra for Phanerozoic Earth. We demonstrate that the spectral biosignature pairs O2+CH4 and O3+CH4 in the atmosphere of a transiting Earth-like planet would indicate a biosphere, with O2 and O3 features potentially stronger than for modern Earth. The full model and high-resolution transmission spectra, covering 0.4–20 μm, are available online and provides a tool to plan and optimize observations, train retrieval methods, and interpret upcoming observations with ground- and space-based telescopes.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135854760","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 his 2021 lecture to the Canadian Association of Physicists Congress, P.J.E. Peebles pointed out that the brightest extra-galactic radio sources tend to be aligned with the plane of the de Vaucouleur Local Supercluster up to redshifts of z = 0.02 ($d_{rm MW}approx 85~rm {Mpc}$). He then asked whether such an alignment of clusters is anomalous in the standard ΛCDM framework. In this letter, we employ an alternative, absolute orientation agnostic, measure of the anisotropy based on the inertia tensor axis ratio of these brightest sources and use a large cosmological simulation from the Flamingo suite to measure how common such an alignment of structures is. We find that only 3.5% of randomly selected regions display an anisotropy of their clusters more extreme than the one found in the local Universe’s radio data. This sets the region around the Milky Way as a 1.85σ outlier. Varying the selection parameters of the objects in the catalogue, we find that the clusters in the local Universe are never more than 2σ away from the simulations’ prediction for the same selection. We thus conclude that the reported anisotropy, whilst note-worthy, is not in tension with the ΛCDM paradigm.
{"title":"On the anisotropic distribution of clusters in the local Universe","authors":"Matthieu Schaller","doi":"10.1093/mnrasl/slad199","DOIUrl":"https://doi.org/10.1093/mnrasl/slad199","url":null,"abstract":"In his 2021 lecture to the Canadian Association of Physicists Congress, P.J.E. Peebles pointed out that the brightest extra-galactic radio sources tend to be aligned with the plane of the de Vaucouleur Local Supercluster up to redshifts of z = 0.02 ($d_{rm MW}approx 85~rm {Mpc}$). He then asked whether such an alignment of clusters is anomalous in the standard ΛCDM framework. In this letter, we employ an alternative, absolute orientation agnostic, measure of the anisotropy based on the inertia tensor axis ratio of these brightest sources and use a large cosmological simulation from the Flamingo suite to measure how common such an alignment of structures is. We find that only 3.5% of randomly selected regions display an anisotropy of their clusters more extreme than the one found in the local Universe’s radio data. This sets the region around the Milky Way as a 1.85σ outlier. Varying the selection parameters of the objects in the catalogue, we find that the clusters in the local Universe are never more than 2σ away from the simulations’ prediction for the same selection. We thus conclude that the reported anisotropy, whilst note-worthy, is not in tension with the ΛCDM paradigm.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139320574","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 microshot from FRB 20220912A (Hewitt et al. 2023) satisfies the uncertainty relation ΔωΔt ≥ 1 by a factor of only ⪅3. A Crab pulsar nanoshot (Hankins & Eilek 2007) exceeds this bound by a similar factor. The number of orthogonal plasma modes contributing to the coherent radiation is also ≈ΔωΔt, placing constraints on their excitation and growth.
{"title":"Radiation Modes in FRB 20220912A Microshots and a Crab PSR Nanoshot","authors":"J. I. Katz","doi":"10.1093/mnrasl/slad177","DOIUrl":"https://doi.org/10.1093/mnrasl/slad177","url":null,"abstract":"A microshot from FRB 20220912A (Hewitt et al. 2023) satisfies the uncertainty relation ΔωΔt ≥ 1 by a factor of only ⪅3. A Crab pulsar nanoshot (Hankins & Eilek 2007) exceeds this bound by a similar factor. The number of orthogonal plasma modes contributing to the coherent radiation is also ≈ΔωΔt, placing constraints on their excitation and growth.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139321531","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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