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Markov Chain Monte Carlo methods for Bayesian data analysis in Astronomy

ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, VOL 55 2017年第1期55卷 213-259页

作者： Sharma, Sanjib Univ Sydney Sch Phys Sydney Inst Astron Sydney NSW 2006 Australia

Markov chain Monte Carlo-based Bayesian data analysis has now become the method of choice for analyzing and interpreting data in almost all disciplines of science. In astronomy, over the past decade, we have also seen a steady increase in the number of papers that employ Monte Carlo-based Bayesian analysis. New, efficient Monte Carlo-based methods are continuously being developed and explored. In this review, we first explain the basics of Bayesian theory and discuss how to set up data analysis problems within this framework. Next, we provide an overview of various Monte Carlobased methods for performing Bayesian data analysis. Finally, we discuss advanced ideas that enable us to tackle complex problems and thus hold great promise for the future. We also distribute downloadable computer software (https://***/sanjibs/bmcmc) Python that implements some of the algorithms and examples discussed here.

关键词： methods: data analysis numerical statistical

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An analysis of the effect of data processing methods on magnetic propeller models in short GRBs

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MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 2023年第1期519卷 418-431页

作者： Meredith, Tomos R. L. Wynn, Graham A. Evans, Philip A. Univ Leicester Sch Phys & Astron Leicester LE17RH England Northumbria Univ Dept Math Phys & Elect Engn Newcastle upon Tyne NE1 8ST England

We present analysis of observational data from the Swift Burst Analyser for a sample of 15 short gamma-ray bursts with extended emission (SGRBEEs) which have been processed such that error propagation from Swift's count-rate-to-flux conversion factor is applied to the flux measurements. We apply this propagation to data presented by the Burst Analyser at 0.3-10 keV and also at 15-50 keV, and identify clear differences in the morphologies of the light curves in the different bands. In performing this analysis with data presented at both 0.3-10 keV, at 15-50 keV, and also at a combination of both bands, we highlight the impact of extrapolating data from their native bandpasses on the light curve. We then test these data by fitting to them a magnetar-powered model for SGRBEEs, and show that while the model is consistent with the data in both bands, the model's derived physical parameters are generally very loosely constrained when this error propagation is included and are inconsistent across the two bands. In this way, we highlight the importance of the Swift data processing methodology to the details of physical model fits to SGRBEEs.

关键词： methods: data analysis stars: magnetars gamma-ray bursts

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LOFAR Deep Fields: Probing the sub-mJy regime of polarized extragalactic sources in ELAIS-N1: II. analysis

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ASTRONOMY & ASTROPHYSICS 2025年 693卷

作者： Piras, S. Horellou, C. Conway, J. E. Thomasson, M. Shimwell, T. W. O'Sullivan, S. P. Carretti, E. Vacca, V. Bonafede, A. Prandoni, I. Chalmers Univ Technol Dept Space Earth & Environm S-41296 Gothenburg Sweden Chalmers Univ Technol Dept Space Earth & Environm Onsala Space Observ S-43992 Onsala Sweden Netherlands Inst Radio Astron ASTRON Oude Hoogeveensedijk 4 NL-7991 PD Dwingeloo Netherlands Leiden Univ Leiden Observ POB 9513 NL-2300 RA Leiden Netherlands Univ Complutense Madrid Dept Fis Tierra & Astrofis Madrid 28040 Spain Univ Complutense Madrid IPARCOS UCM Madrid 28040 Spain INAF Ist Radioastron Via Gobetti 101 I-40129 Bologna Italy INAF Osservatorio Astron Cagliari Via Sci 5 I-09047 Selargius CA Italy Univ Bologna DIFA Via Gobetti 93-2 I-40129 Bologna Italy

Context. Deep polarization surveys at low radio frequencies are key to cosmic magnetism studies: Larger catalogs of polarized extra-galactic sources and increased precision on Faraday rotation measures (RMs) make it possible to probe the magneto-ionic medium along the lines of sight of the sources and to construct denser RM grids. In a first paper, we presented a search for polarized sources in deep observations of the 25-square-degree area of the European Large Area ISO Survey-North 1 (ELAIS-N1) field with the LOw Frequency ARray (LOFAR) at 114.9-177.4 MHz. Aims. In this paper, we investigate the properties of the polarized radio galaxies and use the catalog to produce an RM grid of the field. methods. After identifying the host galaxies and collecting redshift information, we characterized the radio galaxies in terms of their radio morphologies, rest-frame radio luminosities, and linear sizes. We calculated residual rotation measures (RRMs) by removing the Galactic RM and studied the variation in the RRMs with redshift and degree of polarization. We produced an RRM grid of the field and compared the positions of the polarized sources with those of galaxy clusters and superclusters. Results. The radio galaxies show a variety of morphologies, including diffuse emission;Fanaroff Riley type II sources make up about half of the sample. Using available multiband catalogs, we found redshifts for the hosts of all polarized sources in the range of 0.06-1.9. Polarized emission is detected mainly from large radio galaxies. The RRM values have a median close to zero, and they appear to be independent of redshift and degree of polarization. The sources in the lines of sight of clusters of galaxies and of a supercluster are indistinguishable in their polarization and RRM properties from the population of sources that are not behind these structures.

关键词： polarization methods: data analysis methods: observational galaxies: individual: ELAIS-N1

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FRB 20230708A, a quasi-periodic FRB with unique temporal-polarimetric morphology

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MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 2025年第4期536卷 3220-3231页

作者： Dial, T. Deller, A. T. Uttarkar, P. A. Lower, M. E. Shannon, R. M. Gourdji, Kelly Marnoch, Lachlan Bera, A. Ryder, Stuart D. Glowacki, Marcin Prochaska, J. Xavier Swinburne Univ Technol Ctr Astrophys & Supercomp POB 218 Hawthorn Vic 3122 Australia ARC Ctr Excellence All Sky Astrophys 3 Dimens ASTR Stromlo Australia Macquarie Univ Sch Math & Phys Sci Sydney NSW 2109 Australia Macquarie Univ Astrophys & Space Technol Res Ctr Sydney NSW 2109 Australia Curtin Univ Int Ctr Radio Astron Res Bentley WA 6102 Australia CSIRO Space & Astron Australia Telescope Natl Facil Box 76 Epping NSW 1710 Australia Univ Calif Santa Cruz Dept Astron & Astrophys Santa Cruz CA 95064 USA Kavli Inst Phys & Math Universe 5-1-5 Kashiwanoha Kashiwa 2778583 Japan Natl Astron Observ Japan Div Sci 2-21-1 Osawa Mitaka Tokyo 1818588 Japan

There has been a rapid increase in the known fast radio burst (FRB) population, yet the progenitor(s) of these events have remained an enigma. A small number of FRBs have displayed some level of quasi-periodicity in their burst profile, which can be used to constrain their plausible progenitors. However, these studies suffer from the lack of polarization data which can greatly assist in constraining possible FRB progenitors and environments. Here, we report on the detection and characterisation of FRB 20230708A by the Australian Square Kilometre Array Pathfinder (ASKAP), a burst which displays a rich temporal and polarimetric morphology. We model the burst time series to test for the presence of periodicity, scattering and scintillation. We find a potential period of T = 7.267 ms within the burst, but with a low statistical significance of 1.77 sigma. Additionally, we model the burst's time- and frequency-dependent polarization to search for the presence of (relativistic and non-relativistic) propagation effects. We find no evidence to suggest that the high circular polarization seen in FRB 20230708A is generated by Faraday conversion. The majority of the properties of FRB 20230708A are broadly consistent with a (non-millisecond) magnetar model in which the quasi-periodic morphology results from microstructure in the beamed emission, but other explanations are not excluded.

关键词： methods: data analysis stars: neutron radio continuum: transients fast radio bursts

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Separating deterministic and stochastic gravitational wave signals in realistic pulsar timing array datasets

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ASTRONOMY & ASTROPHYSICS 2025年 694卷

作者： Ferranti, Irene Shaifullah, Golam Chalumeau, Aurelien Sesana, Alberto Univ Milano Bicocca Dipartimento Fis G Occhialini Piazza Sci 3 I-20126 Milan Italy INFN Sez Milano Bicocca Piazza Sci 3 I-20126 Milan Italy INAF Osservatorio Astron Cagliari Via Sci 5 I-09047 Selargius CA Italy INAF Osservatorio Astron Brera Via Brera 20 I-20121 Milan Italy Netherlands Inst Radio Astron ASTRON Oude Hoogeveensedijk 4 NL-7991 PD Dwingeloo Netherlands

Recent observations by pulsar timing arrays (PTAs) suggest the presence of gravitational wave (GW) signals that potentially originate from supermassive black hole binaries (SMBHBs). These binaries can generate two kinds of signals: a stochastic gravitational wave background (GWB) or a deterministic continuous gravitational wave (CGW). The ability to correctly recognize and separate them is crucial for accurate signal recovery and astrophysical interpretation. This paper is aimed at investigating the interaction between stochastic GWB and deterministic CGW signals with the analysis pipelines currently available. We focus on understanding potential misinterpretations and biases in the parameter estimation when these signals are analysed separately or altogether. To this end, we performed several realistic simulations based on the European PTA 24.8 yr dataset. We first injected either a GWB or a CGW into five datasets (of three GWB realisations and two CGW realisations) with identical noise. We analysed each signal type independently and then we analysed data sets containing both a stochastic GWB and a single resolvable CGW. We compared the parameter estimations using different search models, including Earth term (ET) only or combined Earth and pulsar term (ET + PT) CGW templates, along with correlated or uncorrelated power law GWB templates. We show that when searched for independently, the GWB and CGW signals can be misinterpreted (i.e. they can be confused with each other) and only a combined search is able to recover the true signal present. For datasets containing both a GWB and a CGW, failure to account for the latter biases the recovery of the GWB;however, when we perform a combined search, both GWB and CGW parameters can be recovered without any strong bias. Care must be taken with the method used to perform combined searches on these multi-component datasets, as the CGW PT can be misinterpreted as a common uncorrelated red noise. However, this can be avoided b

关键词： black hole physics gravitational waves methods: data analysis pulsars: general

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Toward the fabric of the Milky Way: I. The density of disk streams from a local 250³ pc³ volume

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ASTRONOMY & ASTROPHYSICS 2025年 694卷

作者： Ratzenboeck, Sebastian Alves, Joao Hunt, Emily L. Miret-Roig, Nuria Meingast, Stefan Moeller, Torsten Univ Vienna Dept Astrophys Turkenschanzstr 17 A-1180 Vienna Austria Univ Vienna Res Network Data Sci Uni Vienna Kolingasse 14-16 A-1090 Vienna Austria Univ Vienna Fac Comp Sci Wahringer Str 29-S6 A-1090 Vienna Austria Heidelberg Univ Landessternwarte Zentrum Astron Konigstuhl 12 D-69117 Heidelberg Germany

We studied 12 disk streams found in a 250(3) pc(3) volume in the solar neighborhood, which we define as coeval and comoving stellar structures with aspect ratios greater than 3:1. Using Gaia data Release 3 data and the advanced clustering algorithms SigMA and Uncover, we identified and characterized these streams beyond the search volume, doubling, on average, their known populations. We estimate the number density of disk streams to be approximate to 820 objects/kpc(3) (for |Z| < 100 pc), or surface densities of approximate to 160 objects/kpc(2). These estimates surpass N-body estimates by one to two orders of magnitude and challenge the prevailing understanding of their destruction mechanisms. Our analysis reveals that these 12 disk streams are dynamically cold with 3D velocity dispersions between 2 and 5 km s(-1), exhibit narrow sequences in the Hertzsprung-Russell diagram, and are highly elongated with average aspect ratios of 7:1, extending up to several hundred parsecs. We find evidence suggesting that one of the disk streams, currently embedded in the Scorpius-Centaurus association, is experiencing disruption, likely due to the primordial gas mass of the association.

关键词： methods: data analysis methods: statistical open clusters and associations: general solar neighborhood Galaxy: structure

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Constraining the shape of dark matter haloes using only starlight I. A new technique and its application to the galaxy Nube

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ASTRONOMY & ASTROPHYSICS 2025年 694卷

作者： Sanchez Almeida, Jorge Trujillo, Ignacio Montes, Mireia Plastino, Angel R. Inst Astrofis Canarias Laguna E-38200 San Cristobal la Laguna Tenerife Spain Univ Laguna Dept Astrofis San Cristobal la Laguna Tenerife Spain CSIC Inst Space Sci ICE Campus UABCarrer Can Magrans S-N Barcelona 08193 Spain Univ Nacl Noroeste Prov Buenos Aires CeBio UNNOBA CONICET Roque Saenz Pena 456 Junin Argentina Univ Nacl Noroeste Prov Buenos Aires Dept Ciencias Bas UNNOBA CONICET Roque Saenz Pena 456 Junin Argentina

We present a new technique to constrain the gravitational potential of a galaxy from the observed stellar mass surface density alone under a number of assumptions. It uses the classical Eddington inversion method to compute the phase-space distribution function (DF) needed for stars to reside in a given gravitational potential. In essence, each potential defines a set of density profiles, and it is the expansion of the observed profile in this database that provides the DF. If the required DF becomes negative, then the potential is inconsistent with the observed stars and can be discarded. It is particularly well suited for analyzing low-mass low surface brightness galaxies, where photometric but not spectroscopic data can be obtained. The recently discovered low surface brightness galaxy Nube was used to showcase its application. For Nube's observed stellar core to be reproduced with a non-negative DF, cuspy NFW (Navarro, Frenk, and White) potentials are highly disfavored compared with potentials that have cores (Schuster-Plummer or rho 230). The method assumes the stellar system to have spherical symmetry and isotropic velocity distribution;however, we discuss simple extensions that relax the need for isotropy and may help to drop the spherical symmetry assumption.

关键词： methods: data analysis galaxies: dwarf galaxies: fundamental parameters galaxies: halos galaxies: individual: Nube galaxies: structure

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Distinguishing between light curves of ellipsoidal variables with massive dark companions, contact binaries, and semidetached binaries using principal component analysis

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ASTRONOMY & ASTROPHYSICS 2025年 696卷

作者： Pesta, Milan Pejcha, Ondrej Charles Univ Prague Inst Theoret Phys Fac Math & Phys 5 Holesovickach 2 Prague 8 Czech Republic

Photometric methods for identifying dark companion binaries - binary systems hosting quiescent black holes (BHs) and neutron stars (NSs) - operate by detecting ellipsoidal variations caused by tidal interactions. The limitation of this approach is that contact and semidetached binaries can produce similarly looking light curves. In this work, we address the degeneracy of ellipsoidal light curves by studying the differences between synthetically generated light curves of dark companion, semidetached, and contact binary systems. We inject the light curves with various levels of uncorrelated and correlated Gaussian noise to simulate the effects of instrumental noise and stellar spots. Using principal component analysis (PCA) and Fourier decomposition, we construct low-dimensional representations of the light curves. We find that the first three to five PCA components are sufficient to explain 99% of variance in the data. The PCA representations are generally more informative than the Fourier representation for the same number of coefficients as measured by both the silhouette scores of the representations and the macro recalls of random forest classifiers trained on the representations. The random forest classifiers reach macro recalls from 0.97 in the complete absence of noise to 0.67 in the presence of spots and strong instrumental noise, indicating that the classes remain largely separable even under adverse conditions. We find that instrumental noise significantly impacts the class separation only when its standard deviation exceeds 10(-3) mag, whereas the presence of spots can markedly reduce the class separation even when they contribute as little as 1% of the light curve amplitude. We discuss the application of our method to real ellipsoidal samples, and we show that we can increase the purity of a sample of dark companion candidates by a factor of up to 25 if we assume a prior purity of 1%, significantly improving the cost efficiency of follow-up observations.

关键词： methods: data analysis techniques: photometric binaries: close stars: black holes stars: neutron

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CMB low multipole alignments across WMAP and Planck data releases

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MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 2025年第1期539卷 542-556页

作者： Patel, Sanjeet Kumar Aluri, Pavan Kumar Ralston, John P. Indian Inst Technol BHU Dept Phys Varanasi 221005 UP India Univ Kansas Dept Phys & Astron Lawrence KS 66045 USA

The first observations of the cosmic microwave background (CMB) from NASA's Wilkinson Microwave Anisotropy Probe (WMAP) led to finding 'alignment' anomalies not expected from fluctuations in the isotropic cosmological model. We study the data of all 8 full-sky public releases since then to test for anomalous alignments and shapes of the first 60 multipoles, i.e. over the range 2 <= l <= 61. We use rotationally invariant and covariant statistics to test isotropy of all subsequent WMAP data releases, along with those from the ESA's Planck mission. Anomalous alignments among the multipoles l = 1 , 2 , 3 are very consistent and robust. More alignments are detected, some of them new, while significance is diluted by the large range of the search. Power entropy, a measure of the randomness of the multipoles, is consistently anomalous at about 2cr level or better across all data releases. It appears that the CMB is not as random as the cosmological principle predicts on large angular scales.

关键词： methods: data analysis methods: statistical cosmic background radiation

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A new method for determining the onset times of solar energetic particles and their uncertainties: Poisson-CUSUM bootstrap hybrid method

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ASTRONOMY & ASTROPHYSICS 2025年 694卷

作者： Palmroos, C. Dresing, N. Gieseler, J. Gutierrez, C. P. Vainio, R. Univ Turku Dept Phys & Astron Space Res Lab Turku 20014 Finland Inst Estudis Espacials Catalunya IEEC Edifici RDITCampus UPC Castelldefels 08860 Barcelona Spain CSIC Inst Space Sci ICE Campus UABCarrer Can Magrans S-N Barcelona 08193 Spain

Context. Solar energetic particle (SEP) events are a type of space weather phenomena in which highly energetic charged particles are released from the Sun into interplanetary space by violent and eruptive phenomena, such as solar flares and coronal mass ejections. In order to assess the origin of SEPs, an accurate timing of their arrival at spacecraft is of utmost importance. Several methods for determining the starting time of an SEP event at an observer exist, but the uncertainty of this starting time is not assessed in a systematic way by the vast majority of studies. Aims. Employing a newly developed hybrid method of Poisson-CUSUM combined with bootstrapping, we show that the uncertainty related to the onset of an event in any particular energy range is often more than the mere time resolution of the measuring apparatus, and furthermore, it is not necessarily symmetric with respect to the past and future of the determined onset. In addition, we provide a software tool to the scientific community that applies the presented method and automates the determination of SEP event onset times and their related uncertainties, and it finally allows one to easily perform a velocity dispersion analysis. methods. By applying the Poisson-CUSUM method coupled with statistical bootstrapping to SEP event observations, we demonstrate the effectiveness of the method on synthetic and real data, and we compare them to an analysis conducted using a classical approach in which the uncertainty is assumed based on the time resolution of the data. Results. In the example case, the inferred SEP path length and injection time related to the event, acquired by the velocity dispersion analysis, differ from what is obtained without properly assessing the uncertainty related to the onset times in varying energies. We also present the software package, PyOnset, that automates many steps of the method along with providing powerful data-visualization methods and analysis tools. We release the cod

关键词： methods: data analysis methods: observational methods: statistical Sun: particle emission

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