Score-matching neural networks for improved multi-band source separation

We present the implementation of a score-matching neural network that represents a data-driven prior for non-parametric galaxy morphologies. The gradients of this prior can be included in the optimization routine of the recently developed multi-band modeling framework Scarlet2, a redesign of the Scarlet method currently employed as deblender in the pipelines of the HyperSuprimeCam survey and the Rubin Observatory.

Feb 1, 2024

Turbulent diffusion of streaming cosmic rays in compressible, partially ionized plasma

Cosmic rays (CRs) are a dynamically important component of the interstellar medium (ISM) of galaxies. The ∼GeV CRs that carry most CR energy and pressure are likely confined by self-generated turbulence, leading them to stream along magnetic field lines at the ion Alfvén speed.

Aug 1, 2023

Spotting Hallucinations in Inverse Problems with Data-Driven Priors

Hallucinations are an inescapable consequence of solving inverse problems with deep neural networks. The expressiveness of recent generative models is the reason why they can yield results far superior to conventional regularizers; it can also lead to realistic-looking but incorrect features, potentially undermining the trust in important aspects of the reconstruction.

Aug 1, 2023

Cosmic ray interstellar propagation tool using Itô Calculus (criptic): software for simultaneous calculation of cosmic ray transport and observational signatures

We present criptic, the Cosmic Ray Interstellar Propagation Tool using Itô Calculus, a new open-source software package to simulate the propagation of cosmic rays through the interstellar medium and to calculate the resulting observable non-thermal emission.

Oct 1, 2022

Ion alfvén velocity fluctuations and implications for the diffusion of streaming cosmic rays

The interstellar medium (ISM) of star-forming galaxies is magnetized and turbulent. Cosmic rays (CRs) propagate through it, and those with energies from ∼ GeV − TeV are likely subject to the streaming instability, whereby the wave damping processes balances excitation of resonant ionic Alfvén waves by the CRs, reaching an equilibrium in which the propagation speed of the CRs is very close to the local ion Alfvén velocity.

Aug 1, 2022

The impact of pair-instability mass loss on the binary black hole mass distribution

A population of binary black hole mergers has now been observed in gravitational waves by Advanced LIGO and Virgo. The masses of these black holes appear to show evidence for a pileup between 30 and 45 M⊙ and a cutoff above ∼45 M⊙.

Aug 1, 2019