Truncated stellar discs in the near infrared. II. Statistical properties and interpretation

TL;DR

This paper investigates the statistical properties of stellar disc truncations in the near-infrared, revealing relationships with galaxy brightness, rotation velocity, and wavelength, supporting a magnetically driven truncation scenario.

Contribution

It provides a detailed analysis of the correlations between NIR truncation radii and galaxy structural parameters, advancing understanding of disc truncation mechanisms.

Findings

Truncation radius scales with galaxy brightness and rotation velocity.

Truncation radius is lower at higher wavelengths.

Correlations support magnetically driven truncation models.

Abstract

The results obtained in paper I are used to study possible relationships between the truncation radius of stellar discs in the NIR and structural parameters of the galaxies. The NIR truncation radius is larger for brighter galaxies, being proportional to $V_m^c$ with $c \approx 3/2$, and with $V_m$ being the asymptotic rotation velocity at large radii (when the rotation curve becomes flat), and is lower for higher wavelengths. When it is normalized to the scalelength, the truncation is an increasing function of the central surface brightness and is lower for late type galaxies, although these correlations are weaker. These relations are in agreement with the scenario of magnetically driven truncations.