Abstract Details

Name: Himanshu Tyagi
Affiliation: Tata Institute of Fundamental Research
Conference ID: ASI2021_362
Title : Crystalline silicates in the Protostars
Authors and Co-Authors : Himanshu Tyagi(DAA, TIFR), Manoj Puravankara(DAA, TIFR)
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : The silicate dust in the interstellar medium from which stars and planetary systems form is predominantly in an amorphous state. However, young protoplanetary disks show evidence for the presence of a significant amount of crystalline dust. When and how crystallization happens during the formation of stars and planetary systems is only poorly understood. High crystallinity has recently been reported in a protostar, HOPS 68 (Poteet et al., 2011), suggesting the possibility of crystallization in the early protostellar phase. This is, however, surprising because protostars are cold (T_bol ~< 100 K) objects, and thermal annealing that can convert amorphous silicates into crystalline dust require temperatures above 1000 K. We have carried out a systematic search for crystalline silicates in embedded protostars in the nearby star-forming regions to investigate if crystallization of amorphous dust occurs early in the protostellar phase. We have analyzed the Spitzer mid-IR (5-40 micron) spectra of these protostars to quantify the mass fraction of crystalline dust in these systems. This is a preparatory study for the upcoming JWST. We will present our results and discuss the evidence for the crystallization of silicate dust in protostars.