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The magnetic field strength in interstellar clouds can be estimated indirectly by using the spread of dust polarization angles ($\delta \theta$). The method developed by Davis 1951 and by Chandrasekhar and Fermi 1953 (DCF) assumes that…

Astrophysics of Galaxies · Physics 2021-12-11 R. Skalidis , J. Sternberg , J. R. Beattie , V. Pavlidou , K. Tassis

Polarimeric maps have been used on the characterization of the magnetic field in molecular clouds. However, it is difficult to determine the 3-dimensional properties of these regions from the projected maps. In that case, numerical…

Astrophysics · Physics 2008-12-23 D. Falceta-Goncalves , A. Lazarian , G. Kowal

We introduce two new ways of obtaining the strength of plane-of-sky (POS) magnetic field by simultaneous use of spectroscopic Doppler-shifted lines and the information on magnetic field direction. The latter can be obtained either through…

Astrophysics of Galaxies · Physics 2020-02-20 Alex Lazarian , Ka Ho Yuen , Dmitri Pogosyan

Denoising diffusion probabilistic models (DDPM) are a class of generative models which have recently been shown to produce excellent samples. We show that with a few simple modifications, DDPMs can also achieve competitive log-likelihoods…

Machine Learning · Computer Science 2021-02-22 Alex Nichol , Prafulla Dhariwal

Advances in microscopy imaging enable researchers to visualize structures at the nanoscale level thereby unraveling intricate details of biological organization. However, challenges such as image noise, photobleaching of fluorophores, and…

Image and Video Processing · Electrical Eng. & Systems 2024-09-19 Pamela Osuna-Vargas , Maren H. Wehrheim , Lucas Zinz , Johanna Rahm , Ashwin Balakrishnan , Alexandra Kaminer , Mike Heilemann , Matthias Kaschube

We observe the magnetic field morphology towards a nearby star-forming filamentary cloud, G202.3+2.5, by the JCMT/POL-2 850 {\mu}m thermal dust polarization observation with an angular resolution of 14.4" (~0.053 pc). The average magnetic…

Analysis of galaxy--galaxy strong lensing systems is strongly dependent on any prior assumptions made about the appearance of the source. Here we present a method of imposing a data-driven prior / regularisation for source galaxies based on…

Instrumentation and Methods for Astrophysics · Physics 2022-11-09 Konstantin Karchev , Noemi Anau Montel , Adam Coogan , Christoph Weniger

We discuss an extension to the Chandrasekhar-Fermi method for the evaluation of the mean magnetic field strength in molecular clouds to cases where the spatial orientation of the field is known. We apply the results to M17, using previously…

Astrophysics · Physics 2009-11-10 Martin Houde

The dynamical state of star-forming molecular clouds cannot be understood without determining the structure and strength of their magnetic fields. Measurements of polarized far-infrared radiation from thermally aligned dust grains are used…

Astrophysics · Physics 2009-11-06 F. Heitsch , E. G. Zweibel , M. -M. Mac Low , P. S. Li , M. L. Norman

Far-infrared (FIR) dust polarimetry enables the study of interstellar magnetic fields via tracing of the polarized emission from dust grains that are partially aligned with the direction of the field. The advent of high quality polarimetric…

Denoising diffusion probabilistic models (DDPMs) (Ho et al. 2020) have shown impressive results on image and waveform generation in continuous state spaces. Here, we introduce Discrete Denoising Diffusion Probabilistic Models (D3PMs),…

Machine Learning · Computer Science 2023-02-23 Jacob Austin , Daniel D. Johnson , Jonathan Ho , Daniel Tarlow , Rianne van den Berg

Linearly polarized emission from dust grains and molecular spectroscopy is an effective probe of the magnetic field topology in the interstellar medium and molecular clouds. The longstanding Davis-Chandrasekhar-Fermi (DCF) method and the…

Astrophysics of Galaxies · Physics 2022-09-13 Junhao Liu , Qizhou Zhang , Keping Qiu

3D Galactic magnetic fields are critical for understanding the interstellar medium, Galactic foreground polarization, and the propagation of ultra-high-energy cosmic rays. Leveraging recent theoretical insights into anisotropic…

Astrophysics of Galaxies · Physics 2025-07-23 Yue Hu

Diffusion models have emerged as a popular family of deep generative models (DGMs). In the literature, it has been claimed that one class of diffusion models -- denoising diffusion probabilistic models (DDPMs) -- demonstrate superior image…

Image and Video Processing · Electrical Eng. & Systems 2023-09-20 Rucha Deshpande , Muzaffer Özbey , Hua Li , Mark A. Anastasio , Frank J. Brooks

Out-of-distribution detection is crucial to the safe deployment of machine learning systems. Currently, unsupervised out-of-distribution detection is dominated by generative-based approaches that make use of estimates of the likelihood or…

We expand on the dispersion analysis of polarimetry maps toward applications to interferometry data. We show how the filtering of low-spatial frequencies can be accounted for within the idealized Gaussian turbulence model, initially…

Astrophysics of Galaxies · Physics 2016-03-23 Martin Houde , Charles L. H. Hull , Richard L. Plambeck , John E. Vaillancourt , Roger H. Hildebrand

Recent studies of the diffuse parts of molecular clouds have revealed the presence of parallel, ordered low-density filaments termed striations. Flows along magnetic field lines, Kelvin-Helmholtz instabilities and hydromagnetic waves are…

Astrophysics of Galaxies · Physics 2018-10-17 Aris Tritsis , Christoph Federrath , Nicola Schneider , Konstantinos Tassis

The currently most viable methods to estimate magnetic field strengths in molecular cloud cores are Zeeman measurements and the Chandrasekhar-Fermi (CF) method. The CF-method estimates magnetic field strengths from polarimetry and relies on…

Astrophysics · Physics 2007-05-23 F. Heitsch , P. S. Li

Methods for out-of-distribution (OOD) detection that scale to 3D data are crucial components of any real-world clinical deep learning system. Classic denoising diffusion probabilistic models (DDPMs) have been recently proposed as a robust…

This Letter introduces an approach for precisely designing surface friction properties using a conditional generative machine learning model, specifically a diffusion denoising probabilistic model (DDPM). We created a dataset of synthetic…

Computational Physics · Physics 2024-01-11 Even Marius Nordhagen , Henrik Andersen Sveinsson , Anders Malthe-Sørenssen