Session
2024 Session 5
Location
Salt Lake Community College Westpointe Campus, Salt Lake City, UT
Start Date
5-6-2024 11:10 AM
Description
Black holes (BHs) are believed to reside at the center of every luminous galaxy. Increasingly accurate techniques are now seeking to expand the BH census. Most of these primary techniques account for extended masses by using a stellar luminosity profile derived from optical or near-IR imaging. About 10% of early type galaxies (ETGs) contain a circumnuclear, dusty disk that obscures much of the stellar light originating from behind this thin disk. Few studies have accurately accounted for dust obscuration, or even acknowledged its effect on a BH mass measurement. In this work, we introduce a sample of ETGs with wide HST wavelength coverage and present preliminary results from our straightforward dust attenuation model that aims to construct maps of the extinction. This analysis treats the dust as originating in a thin, embedded screen and uses a dust-masked stellar luminosity profile to estimate the fraction of stellar light that is obscured by dust on a pixel-by-pixel basis. We demonstrate the potential of this method using optical and near-IR imaging of symmetrical galaxies NGC 3258 and NGC 3268, solving for the 2D dust extinction using a standard Cardelli et al. [1] extinction law. Preliminary findings for galaxies that have strong stellar population gradients, active star formation, or a more face-on disk inclination angle do not result in as good agreement with the data. We conclude by discussing plans to generalize our model to account for these more difficult cases.
Discovering What Cannot Be Seen: Dust Attenuation Modeling in Early-Type Galactic Nuclei
Salt Lake Community College Westpointe Campus, Salt Lake City, UT
Black holes (BHs) are believed to reside at the center of every luminous galaxy. Increasingly accurate techniques are now seeking to expand the BH census. Most of these primary techniques account for extended masses by using a stellar luminosity profile derived from optical or near-IR imaging. About 10% of early type galaxies (ETGs) contain a circumnuclear, dusty disk that obscures much of the stellar light originating from behind this thin disk. Few studies have accurately accounted for dust obscuration, or even acknowledged its effect on a BH mass measurement. In this work, we introduce a sample of ETGs with wide HST wavelength coverage and present preliminary results from our straightforward dust attenuation model that aims to construct maps of the extinction. This analysis treats the dust as originating in a thin, embedded screen and uses a dust-masked stellar luminosity profile to estimate the fraction of stellar light that is obscured by dust on a pixel-by-pixel basis. We demonstrate the potential of this method using optical and near-IR imaging of symmetrical galaxies NGC 3258 and NGC 3268, solving for the 2D dust extinction using a standard Cardelli et al. [1] extinction law. Preliminary findings for galaxies that have strong stellar population gradients, active star formation, or a more face-on disk inclination angle do not result in as good agreement with the data. We conclude by discussing plans to generalize our model to account for these more difficult cases.