Do you know the extinction in your young massive cluster?

TL;DR

This paper introduces a method to determine the local extinction law in young massive clusters using multi-band photometry of red giant stars, revealing the unique extinction properties of the Tarantula nebula.

Contribution

The authors develop a novel, uniform approach to measure the extinction law across a cluster field using red clump stars, applicable to complex environments like 30 Dor.

Findings

Derived the extinction law for 30 Dor using Hubble data.

Established a self-consistent extinction curve over multiple wavelengths.

Demonstrated the method's effectiveness in a dense, dusty cluster environment.

Abstract

Up to ages of ~100 Myr, massive clusters are still swamped in large amounts of gas and dust, with considerable and uneven levels of extinction. At the same time, large grains (ices?) produced by type II supernovae profoundly alter the interstellar medium (ISM), thus resulting in extinction properties very different from those of the diffuse ISM. To obtain physically meaningful parameters of stars, from basic luminosities and effective temperatures to masses and ages, we must understand and measure the local extinction law. This problem affects all the massive young clusters discussed in his volume. We have developed a powerful method to unambiguously determine the extinction law in an uniform way across a cluster field, using multi-band photometry of red giant stars belonging to the red clump (RC). In the Large Magellanic Cloud, with about 20 RC stars per arcmin^2, we can easily derive a solid and self-consistent absolute extinction curve over the entire wavelength range of the photometry. Here, we present the extinction law of the Tarantula nebula (30 Dor) based on thousands of stars observed as part of the Hubble Tarantula Treasury Project.