Mid-infrared spectra of the shocked Murchison CM chondrite: Comparison with astronomical observations of dust in debris disks

Abstract

We present laboratory mid-infrared transmission/absorption spectra obtained from matrix of the hydrated Murchison CM meteorite experimentally shocked at peak pressures of 10 to 49 GPa, and compare them to astronomical observations of circumstellar dust in different stages of the formation of planetary systems. The laboratory spectra of the Murchison samples exhibit characteristic changes in the infrared features. A weakly shocked sample (shocked at 10 GPa) shows almost no changes from the unshocked sample dominated by hydrous silicate (serpentine). Moderately shocked samples (21 to 34 GPa) have typical serpentine features gradually replaced by bands of amorphous material and olivine with increasing shock pressure. A strongly shocked sample (36 GPa) shows major changes due to decomposition of the serpentine and due to devolatilization. A shock melted sample (49 GPa) shows features of olivine recrystallized from melted material. The spectra of highly shocked Murchison samples (36 and 49 GPa) are similar to those of dust in the debris disks of HD113766 and HD69830, and the transitional disk of HD100546. The moderately shocked samples (21 to 34 GPa) exhibit spectra similar to those of dust in the debris disks of Beta Pictoris and BD+20307, and the transitional disk of GM Aur. An average of the spectra of all Murchison samples (0 to 49 GPa) has a similarity to the spectrum of the older protoplanetary disk of SU Auriga. In the gas-rich transitional and protoplanetary disks, the abundances of amorphous silicates and gases have widely been considered to be a primary property. However, our study suggests that impact processing may play a significant role in generating secondary amorphous silicates and gases in those disks. Infrared spectra of the shocked Murchison samples are also suggesting that the comets also contain shocked Murchison-like material.

References in corpus (6)

• Spitzer IRS Spectroscopy of IRAS-Discovered Debris Disks
• Crystalline silicates and dust processing in the protoplanetary disks of the Taurus young cluster
• On the Nature of the Dust in the Debris Disk Around HD69830
• Circumstellar Dust Created by Terrestrial Planet Formation in HD 113766
• The Dust and Gas Around beta Pictoris
• Analysis of the dust evolution in the circumstellar disks of TTauri stars

Cited by in corpus (8)

• The evolved circumbinary disk of AC Her: a radiative transfer, interferometric and mineralogical study
• Dust from collisions: A way to probe the composition of exo-planets?
• Location and sizes of forsterite grains in protoplanetary disks: interpretation from the Herschel DIGIT programme
• Mid-Infrared Spectroscopy of Components in Chondrites: Search for Processed Materials in Young Solar Systems and Comets
• Mid-infrared spectra of differentiated meteorites (achondrites): Comparison with astronomical observations of dust in protoplanetary and debris disks
• Mid-Infrared spectroscopy of impactites from the Noerdlinger Ries impact crater
• Laboratory mid-IR spectra of equilibrated and igneous meteorites. Searching for observables of planetesimal debris
• Mid-infrared absorption spectra and mass absorption coefficients for 23 chondrites: dependence on composition and grain size