Near-Infrared Polarization Source Catalog of the Northeastern Regions of the Large Magellanic Cloud

TL;DR

This paper provides a comprehensive near-infrared polarization catalog of the northeastern Large Magellanic Cloud, revealing large-scale magnetic fields and their relation to interstellar dust and star-forming regions.

Contribution

It presents a new, extensive polarization catalog and analyzes magnetic field structures and their correlation with dust and star formation in the LMC.

Findings

Magnetic fields range from 3 to 25 μG in selected regions.

Polarization patterns align with molecular clouds and star-forming regions.

Large-scale magnetic fields exist on scales of about one hundred parsecs.

Abstract

We present a near-infrared band-merged photometric and polarimetric catalog for the 39$\arcmin$ $\times$ 69$\arcmin$ fields on the northeastern part of the Large Magellanic Cloud (LMC), which were observed using SIRPOL, an imaging polarimeter of the InfraRed Survey Facility (IRSF). This catalog lists 1,858 sources brighter than 14 mag at $H$ band with polarization signal-to-noise ratio greater than three in the $J$, $H$, or $K_s$ bands. Based on the relationship between the extinction and the polarization degree, we argue that the polarization mostly arises from dichroic extinctions caused by local interstellar dust in the LMC. This catalog allows us to map polarization structures to examine the global geometry of the local magnetic field, and to show a statistical analysis of polarization of each field to understand its polarization properties. At the selected fields with coherent polarization position angles, we estimate magnetic field strengths in the range of 3$-$25 $\mu$G using the Chandrasekhar-Fermi method. This implies the presence of large-scale magnetic fields on a scale of around one hundred parsecs. When comparing mid and far-infrared dust emission maps, we confirmed that the polarization patterns are well aligned with molecular clouds around the star-forming regions.