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Related papers: Silicate features in Galactic and extragalactic po…

200 papers

The unification theory of active galactic nuclei (AGNs) hypothesizes that all AGNs are surrounded by an anisotropic dust torus and are essentially the same objects but viewed from different angles. However, little is known about the dust…

Astrophysics of Galaxies · Physics 2017-01-18 Yanxia Xie , Aigen Li , Lei Hao

We have carried out a quantitative trend analysis of the crystalline silicates observed in the ISO spectra of a sample of 14 stars with different evolutionary backgrounds. We have modeled the spectra using a simple dust radiative transfer…

Astrophysics · Physics 2009-11-07 F. J. Molster , L. B. F. M. Waters , A. G. G. M. Tielens , C. Koike , H. Chihara

Second-generation circumbinary discs around evolved binary stars, such as post-Asymptotic Giant Branch (post-AGB) binaries, provide insights into poorly understood mechanisms of dust processing and disc evolution across diverse stellar…

Solar and Stellar Astrophysics · Physics 2025-10-01 Kateryna Andrych , Devika Kamath , Hans Van Wincke , Akke Corporaa , Toon De Prins , Daniel Price , Steve Ertel , Jacques Kluska

The AKARI and Spitzer satellites provided an unique opportunity to observe a variety of stars, which are considered as departing from the Asymptotic Giant Branch (AGB) and have started their post-AGB evolution recently. Most of these stars…

Solar and Stellar Astrophysics · Physics 2009-04-28 D. Engels , P. García-Lario , F. Bunzel , D. A. García-Hernández , J. V. Perea-Calderón

Infrared (IR) emission spectra are calculated for dust composed of mixtures of amorphous silicate and graphitic grains, including varying amounts of polycyclic aromatic hydrocarbon (PAH) particles. The models are constrained to reproduce…

Astrophysics · Physics 2008-11-26 B. T. Draine , Aigen Li

We present a new SMA survey of 47 Class II sources in the Taurus-Auriga region. Our observations made 12 independent samples of flux densities over the 200-400 GHz frequency range. We tightly constrained the spectral indices of most sources…

Earth and Planetary Astrophysics · Physics 2024-05-31 Chia-Ying Chung , Sean M. Andrews , Mark A. Gurwell , Melvyn Wright , Feng Long , Wenrui Xu , Hauyu Baobab Liu

Mid-infrared spectra of planet-forming discs commonly show prominent silicate emission, whose spectral shape is sensitive to the disc temperature distribution as well as its mineralogical composition. We report new James Webb Space…

We observed mid-infrared (7.5-22 mum) spectra of AGB stars in the globular cluster 47 Tuc with the Spitzer telescope and find significant dust features of various types. Comparison of the characteristics of the dust spectra with the…

Astrophysics · Physics 2009-11-11 T. Lebzelter , T. Posch , K. Hinkle , P. R. Wood , J. Bouwman

The relative abundance of the dust grain types in the interstellar medium (ISM) is directly linked to physical quantities that trace the evolution of galaxies. We study the dust properties of the whole disc of M33 at spatial scales of ~170…

This letter reports 12 novel spectroscopic detections of warm circumstellar dust orbiting polluted white dwarfs using JWST MIRI. The disks span two orders of magnitude in fractional infrared brightness and more than double the number of…

Earth and Planetary Astrophysics · Physics 2025-01-31 J. Farihi , K. Y. L. Su , C. Melis , S. J. Kenyon , A. Swan , S. Redfield , M. C. Wyatt , J. H. Debes

In this paper, the first of a series of two devoted to modelling the spectra of galaxies of different morphological type in presence of dust, we present our description of the dust both in the diffuse ISM and the molecular clouds. Our model…

Astrophysics · Physics 2009-11-13 L. Piovan , R. Tantalo , C. Chiosi

We investigate the dust growth in oxygen-rich stellar outflows for a set of nine well-observed massive supergiants with optically thin dust shells. Models of the infrared emission from their circumstellar dust shells are compared to their…

Solar and Stellar Astrophysics · Physics 2021-01-04 Hans-Peter Gail , Akemi Tamanai , Annemarie Pucci , Ralf Dohmen

This is the second paper in a series of three in which we present an exhaustive inventory of the 49 solid state emission bands observed in a sample of 17 oxygen-rich dust shells surrounding evolved stars. Most of these emission bands are…

Astrophysics · Physics 2009-11-07 F. J. Molster , L. B. F. M. Waters , A. G. G. M. Tielens

We present Spitzer IRS spectra of four carbon stars located in the Galactic Halo and the thick disc. The spectra display typical features of carbon stars with SiC dust emission and C$_2$H$_2$ molecular absorption. Dust radiative transfer…

Solar and Stellar Astrophysics · Physics 2015-06-11 Eric Lagadec , Greg. C. Sloan , Albert. A. Zijlstra , Nicolas Mauron , J. R. Houck

In a multi-wavelength study of thermal emission and scattered light images we analyse the dust properties and structure of the debris disc around the A1-type main sequence star 49~Cet. As a basis for this study, we present new scattered…

Absorption lines in the spectra of distant quasars whose sightlines pass through foreground galaxies provide a valuable tool to probe the dust and gas compositions of the interstellar medium (ISM) in galaxies. The first evidence of silicate…

Astrophysics of Galaxies · Physics 2014-05-05 Monique C. Aller , Varsha P. Kulkarni , Donald G. York , Daniel E. Welty , Giovanni Vladilo , Debopam Som

We use mid-infrared spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space…

Astrophysics of Galaxies · Physics 2010-01-15 G. D. Thompson , N. A. Levenson , S. A. Uddin , M. M. Sirocky

We present a model for the diffuse interstellar dust that explains the observed wavelength-dependence of extinction, emission, linear and circular polarisation of light. The model is set-up with a small number of parameters. It consists of…

Astrophysics of Galaxies · Physics 2015-06-16 R. Siebenmorgen , N. V. Voshchinnikov , S. Bagnulo

We investigate the composition and shape distribution of silicate dust grains in the interstellar medium. The effect of the amount of magnesium in the silicate lattice is studied. We fit the spectral shape of the interstellar 10 mu…

We characterize the crystalline silicate content and spatial distribution of small dust grains in a large sample of protoplanetary disks in the Taurus-Auriga young cluster, using Spitzer Space Telescope mid-infrared spectra. In turn we use…