Starlight-polarization-based tomography of the magnetized ISM: PASIPHAE's line-of-sight inversion method
Artikel i vetenskaplig tidskrift, 2023

We present the first Bayesian method for tomographic decomposition of the plane-of-sky orientation of the magnetic field with the use of stellar polarimetry and distance. This standalone tomographic inversion method presents an important step forward in reconstructing the magnetized interstellar medium (ISM) in three dimensions within dusty regions. We develop a model in which the polarization signal from the magnetized and dusty ISM is described by thin layers at various distances, a working assumption which should be satisfied in small-angular circular apertures. Our modeling makes it possible to infer the mean polarization (amplitude and orientation) induced by individual dusty clouds and to account for the turbulence-induced scatter in a generic way. We present a likelihood function that explicitly accounts for uncertainties in polarization and parallax. We develop a framework for reconstructing the magnetized ISM through the maximization of the log-likelihood using a nested sampling method. We test our Bayesian inversion method on mock data, representative of the high Galactic latitude sky, taking into account realistic uncertainties from Gaia and as expected for the optical polarization survey PASIPHAE according to the currently planned observing strategy. We demonstrate that our method is effective at recovering the cloud properties as soon as the polarization induced by a cloud to its background stars is higher than ~0.1% for the adopted survey exposure time and level of systematic uncertainty. The larger the induced polarization is, the better the method's performance, and the lower the number of required stars. Our method makes it possible to recover not only the mean polarization properties but also to characterize the intrinsic scatter, thus creating new ways to characterize ISM turbulence and the magnetic field strength. Finally, we apply our method to an existing data set of starlight polarization with known line-of-sight decomposition, demonstrating agreement with previous results and an improved quantification of uncertainties in cloud properties.

polarization

ISM: magnetic fields

Astrophysics - Astrophysics of Galaxies

ISM: structure

dust

extinction

methods: statistical

Astrophysics - Cosmology and Nongalactic Astrophysics

Författare

Vincent Pelgrims

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

Georgia Panopoulou

California Institute of Technology (Caltech)

Konstantinos Tassis

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

Vasiliki Pavlidou

Panepistimio Kritis

A. Basyrov

Universitetet i Oslo

Dmitriy Blinov

Panepistimio Kritis

E. Gjerlow

Universitetet i Oslo

S. Kiehlmann

Panepistimio Kritis

N. Mandarakas

Panepistimio Kritis

A. Papadaki

Panepistimio Kritis

Raphael Skalidis

Idryma Technologias kai Erevnas (FORTH)

Panepistimio Kritis

A. Tsouros

Panepistimio Kritis

R. M. Anche

Inter-University Centre for Astronomy and Astrophysics

H. K. Eriksen

Universitetet i Oslo

Tuhin Ghosh

National Institute of Science Education and Research

J. A. Kypriotakis

Panepistimio Kritis

Siddharth Maharana

Panepistimio Kritis

E. Ntormousi

Panepistimio Kritis

Idryma Technologias kai Erevnas (FORTH)

T. J. Pearson

California Institute of Technology (Caltech)

S. B. Potter

South African Astronomical Observatory

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 670 id.A164

Ämneskategorier

Beräkningsmatematik

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/202244625

Mer information

Senast uppdaterat

2024-04-05