AGB and Post-AGB Stars versus Planetary Nebulae and Young Stellar Objects: Properties in Visual and IR Bands

TL;DR

This study compares the properties of AGB, post-AGB stars, planetary nebulae, and YSOs using visual and IR data, demonstrating effective classification methods and model-observation agreement.

Contribution

It introduces comprehensive color-magnitude and two-color diagrams combined with Gaia data and radiative transfer models to distinguish stellar classes.

Findings

AGB and PAGB stars are among the brightest in visual and IR bands.

YSOs are distinguishable from AGB stars by their fainter IR magnitudes.

Good agreement between theoretical models and observational data.

Abstract

We investigate the properties of AGB and post-AGB (PAGB) stars, planetary nebulae, and young stellar objects (YSOs) in our Galaxy through an analysis of observational data covering visual and infrared (IR) wavelengths. Utilizing datasets from IRAS, 2MASS, AllWISE, Gaia DR3, and the SIMBAD object database, we perform an in-depth comparison between observational data and theoretical models. For this comparison, we present various color-magnitude diagrams (CMDs) in visual and IR bands, as well as IR two-color diagrams (2CDs). Our results demonstrate that the CMDs, incorporating the latest distance and extinction data from Gaia DR3 for a majority of sample stars, are effective in distinguishing different classes of stars. To improve the precision of our analysis, we apply theoretical radiative transfer models for dust shells around AGB and PAGB stars. A thorough comparison of the theoretical models with observations across various IR 2CDs and CMDs shows a significant agreement. We find that AGB and PAGB stars are among the brightest classes in visual and IR bands. Furthermore, most YSOs are clearly distinguishable from AGB stars on various IR CMDs, exhibiting fainter absolute magnitudes in IR bands.