Dust effect on Tremaine-Weinberg measurements

TL;DR

This study examines how dust affects the measurement of stellar bar rotation speeds using the Tremaine-Weinberg method, finding dust causes a 20-40% change in observed pattern speeds, with star formation having minimal impact.

Contribution

It demonstrates through simulations that dust attenuation significantly influences TW measurements, supporting broader application across galaxy types.

Findings

Dust causes 20-40% change in pattern speed measurements.

Star formation does not significantly affect TW results.

Method can be extended to various Hubble types.

Abstract

We investigate the effect of dust on the observed rotation rate of a stellar bar as measured by application of the Tremaine & Weinberg (TW) method. As the method requires that the tracer satisfies the continuity equation, it has been applied largely to early-type barred galaxies. We show using numerical simulations of barred galaxies that dust attenuation factors typically found in these systems change the observed bar pattern speed by 20-40%. We also address the effect of star formation on the TW method and find that it does not change the results significantly. This suggests that applications of the TW method can be extended to include barred galaxies covering the full range of Hubble type.