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Main Authors: Alonso-Hernández, Jaime, Contreras, Carmen Sánchez, Sahai, Raghvendra, Sanz-Forcada, Jorge
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2603.19815
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author Alonso-Hernández, Jaime
Contreras, Carmen Sánchez
Sahai, Raghvendra
Sanz-Forcada, Jorge
author_facet Alonso-Hernández, Jaime
Contreras, Carmen Sánchez
Sahai, Raghvendra
Sanz-Forcada, Jorge
contents Aims. In a first study, we characterised the properties of the gas component in the circumstellar envelopes surrounding a sample of 29 AGB stars with UV excesses. Now we intend to complement this information with an analysis of the dust component and compare the estimated parameters with those previously inferred from larger samples of AGB stars. Methods. We modelled the spectral energy distributions of the sample using dust radiative transfer models. In some cases, we complemented the analysis with Herschel/PACS radial surface brightness profiles. Results. We derived mass-loss rates and gas-to-dust ratios, which are in the typical ranges for AGB stars. We found that the stellar and mass-loss parameters follow similar trends than those presented in the literature. There is an anticorrelation between the gas-to-dust ratio and the UV emission, although it is weaker than its correlations with pulsation and mass-loss. We also estimated the dust attenuation produced by the dust at UV wavelengths and describe its effects on the intrinsic UV emission. Conclusions. Stellar and mass-loss parameters of UV emitting AGB stars follow similar trends as found for larger samples of AGB stars. High-angular resolution observations are required to explore the dust forming regions and identify the presence of stellar companions. Circumstellar dust attenuation might play a dominant role in the observed UV emission, and needs to be accounted to estimate the intrinsic UV emission.
format Preprint
id arxiv_https___arxiv_org_abs_2603_19815
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The dusty envelopes of asymptotic giant branch stars with ultraviolet excesses
Alonso-Hernández, Jaime
Contreras, Carmen Sánchez
Sahai, Raghvendra
Sanz-Forcada, Jorge
Solar and Stellar Astrophysics
Aims. In a first study, we characterised the properties of the gas component in the circumstellar envelopes surrounding a sample of 29 AGB stars with UV excesses. Now we intend to complement this information with an analysis of the dust component and compare the estimated parameters with those previously inferred from larger samples of AGB stars. Methods. We modelled the spectral energy distributions of the sample using dust radiative transfer models. In some cases, we complemented the analysis with Herschel/PACS radial surface brightness profiles. Results. We derived mass-loss rates and gas-to-dust ratios, which are in the typical ranges for AGB stars. We found that the stellar and mass-loss parameters follow similar trends than those presented in the literature. There is an anticorrelation between the gas-to-dust ratio and the UV emission, although it is weaker than its correlations with pulsation and mass-loss. We also estimated the dust attenuation produced by the dust at UV wavelengths and describe its effects on the intrinsic UV emission. Conclusions. Stellar and mass-loss parameters of UV emitting AGB stars follow similar trends as found for larger samples of AGB stars. High-angular resolution observations are required to explore the dust forming regions and identify the presence of stellar companions. Circumstellar dust attenuation might play a dominant role in the observed UV emission, and needs to be accounted to estimate the intrinsic UV emission.
title The dusty envelopes of asymptotic giant branch stars with ultraviolet excesses
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2603.19815