CRYSTALLINE SILICATES IN EVOLVED STARS. I.<i>SPITZER</i>/INFRARED SPECTROGRAPH SPECTROSCOPY OF IRAS 16456–3542, 18354–0638, AND 23239+5754

Jiang, Biwei; Zhang, Ke; Li, Aigen; Lisse, C. M.

doi:10.1088/0004-637x/765/1/72

Cited by 19 publications

(21 citation statements)

References 45 publications

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“…It has been detected in many other sources in both ISO and Spitzer spectra of OH/IR and other evolved stars (e.g. Jiang et al (2013); Molster et al (2002)), predominantly as an emission feature, as well as in Herbig and/or T Tauri star disks (Juhász et al (2010); Watson et al (2009); Sargent et al (2009); Meeus et al (2001)).…”

Section: Crystalline Silicate Features At 20-30 µMmentioning

confidence: 94%

Absorption at 11 μm in the interstellar medium and embedded sources: evidence for crystalline silicates

Wright

Duy

Lawson

2016

Mon. Not. R. Astron. Soc.

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An absorption feature is occasionally reported around 11 µm in astronomical spectra, including those of forming stars. Candidate carriers include water ice, polycyclic aromatic hydrocarbons (PAHs), silicon carbide, crystalline silicates or even carbonates. All are known constituents of cosmic dust in one or more types of environments, though not necessarily together. In this paper we present new ground-based 8-13 µm spectra of one evolved star, several embedded young stellar objects (YSOs) and a background source lying behind a large column of the interstellar medium (ISM) toward the Galactic Centre. Our observations, obtained at a spectral resolution of ∼ 100, are compared with previous lower resolution data, as well as data obtained with the Infrared Space Observatory (ISO) on these and other targets. By presenting a subset of a larger sample our aim is to establish the reality of the feature and subsequently speculate on its carrier. All evidence points toward crystalline silicate. For instance, the 11 µm band profile is well matched with the emissivity of crystalline olivine. Furthermore, the apparent association of the absorption feature with a sharp polarisation signature in the spectrum of two previously reported cases suggests a carrier with a relatively high band strength compared to amorphous silicates. If true, this would either set back the evolutionary stage in which silicates are crystallised, either to the embedded phase or even before within the ISM, or else the silicates ejected from the outflows of evolved stars retain some of their crystalline identity during their long residence in the ISM.

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Section: Crystalline Silicate Features At 20-30 µMmentioning

confidence: 94%

Absorption at 11 μm in the interstellar medium and embedded sources: evidence for crystalline silicates

Wright

Duy

Lawson

2016

Mon. Not. R. Astron. Soc.

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“…However, a systematic determination of the crystalline fraction of AGB stars observed with spectrographs on board of ISO and Spitzer is still missing, and determinations of crystalline fractions remain anecdotal. Estimates in common use place the crystallinity of the AGB silicates around 10%, however some extremely crystalline sources have been reported (Jiang et al 2013). Jones et al (2012) has performed the most complete inventory into the presence of crystalline silicate features in AGB stars and Red Supergiants, in the Milky Way and both Magellanic Clouds, demonstrating a correlation with mass-loss rate; however, they did not measure the crystalline fractions.…”

Section: The Origin and Evolution Of Dust In Galaxiesmentioning

confidence: 99%

“…Accurate photometry with SPICA/SMI has the potential to disentangle the two different models. crystallinity of the AGB silicates around 10%, however some extremely crystalline sources have been reported (Jiang et al 2013). Jones et al (2012) has performed the most complete inventory into the presence of crystalline silicate features in AGB stars and Red Supergiants, in the Milky Way and both Magellanic Clouds, demonstrating a correlation with mass-loss rate; however, they did not measure the crystalline fractions.…”

Section: Grain Processing and Destructionmentioning

confidence: 99%

Probing the Baryon Cycle of Galaxies with SPICA Mid- and Far-Infrared Observations

Tak

Madden

Roelfsema

et al. 2018

Publ. Astron. Soc. Aust.

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The SPICA mid and far-infrared telescope will address fundamental issues in our understanding of star formation and ISM physics in galaxies. A particular hallmark of SPICA is the outstanding sensitivity enabled by the cold telescope, optimized detectors, and wide instantaneous bandwidth throughout the midand far-infrared. The spectroscopic, imaging and polarimetric observations that SPICA will be able to collect will help in clarifying the complex physical mechanisms which underlie the baryon cycle of galaxies. In particular: (i) The access to a large suite of atomic and ionic fine-structure lines for large samples of galaxies will shed light on the origin of the observed spread in star formation rates within and between galaxies. (ii) Observations of HD rotational lines (out to ∼10 Mpc) and fine structure lines such as [C ii] 158 µm (out to ∼100 Mpc) will clarify the main reservoirs of interstellar matter in galaxies, including phases where CO does not emit. (iii) Far-infrared spectroscopy of dust and ice features will address uncertainties in the mass and composition of dust in galaxies, and the contributions of supernovae to the interstellar dust budget will be quantified by photometry and monitoring of supernova remnants in nearby galaxies. (iv) Observations of far-infrared cooling lines such as [O i] 63 µm from star-forming molecular clouds in our Galaxy will evaluate the importance of shocks to dissipate turbulent energy. The paper concludes with requirements for the telescope and instruments, and recommendations for the observing strategy.

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“…where B(T amo , ν) is a blackbody radiation at the temperature T amo , and Q amo (ν) is the absorption efficiency of amorphous silicate. The absorption efficiency of amorphous silicate is based on the optical constants of Ossenkopf et al (1992) assuming the dust to be spherical with radii a = 0.1µm, following the numerals of Jiang et al (2013). The temperature of amorphous silicate is adjusted in the range of 40-1200 K at an interval of 10 K to achieve the best fitting.…”

Section: Intensity Of the Spectral Features Of Crystalline Silicatesmentioning

confidence: 99%

“…Crystalline silicates have been identified in various scales (solar system, stars, galaxies and quasars), such as comet, protoplanetary disk of Herbig Ae/Be stars and T Tauri stars, debris disks around the main sequence stars (Li & Greenberg 1998), circumstellar envelopes in post-main sequence stars (Water et al 1996;Sylvester et al 1999;Molster et al 2002a;Jiang et al 2013), very bright infrared galaxies (Markwick-Kemper et al 2007;Spoon et al 2006), quasars (Markwick-Kemper et al 2007;Aller et al 2012;Xie et al 2014), etc. In this work, we present a systematic search for the spectra with features of crystalline silicates from the Spitzer IRS Enhanced Products (Houck et al 2004). In Section 2, a brief description is presented about the Spitzer IRS Enhanced Products (Houck et al 2004).…”

Section: Introductionmentioning

confidence: 99%

A systematic search for the spectra with features of crystalline silicates in the Spitzer IRS Enhanced Products

Chen,

Luo,

Liu

et al. 2016

Preprint

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The crystalline silicates features are mainly reflected in infrared bands. The Spitzer Infrared Spectrograph (IRS) collected numerous spectra of various objects and provided a big database to investigate crystalline silicates in a wide range of astronomical environments. We apply the manifold ranking algorithm to perform a systematic search for the spectra with crystalline silicates features in the Spitzer IRS Enhanced Products available. In total, 868 spectra of 790 sources are found to show the features of crystalline silicate. These objects are cross-matched with the SIMBAD database as well as with the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST)/DR2. The average spectrum of young stellar objects show a variety of features dominated either by forsterite or enstatite or neither, while the average spectrum of evolved objects consistently present dominant features of forsterite in AGB, OH/IR, post-AGB and planetary nebulae. They are identified optically as early-type stars, evolved stars, galaxies and so on. In addition, the strength of spectral features in typical silicate complexes is calculated. The results are available through CDS for the astronomical community to further study crystalline silicate.

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CRYSTALLINE SILICATES IN EVOLVED STARS. I.SPITZER/INFRARED SPECTROGRAPH SPECTROSCOPY OF IRAS 16456–3542, 18354–0638, AND 23239+5754

Cited by 19 publications

References 45 publications

Absorption at 11 μm in the interstellar medium and embedded sources: evidence for crystalline silicates

Absorption at 11 μm in the interstellar medium and embedded sources: evidence for crystalline silicates

Probing the Baryon Cycle of Galaxies with SPICA Mid- and Far-Infrared Observations

A systematic search for the spectra with features of crystalline silicates in the Spitzer IRS Enhanced Products

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