J/A+A/627/A16 Silicon K-edge dust absorption cross sections (Zeegers+, 2019) ================================================================================ Dust absorption and scattering in the silicon K-edge. Zeegers S.T., Costantini E., Rogantini D., de Vries C.P., Mutschke H., Mohr P., de Groot F., Tielens. A.G.G.M. =2019A&A...627A..16Z (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Interstellar medium ; Atomic physics Keywords: dust, extinction - X-rays: binaries - ISM: abundances Abstract: The composition and properties of interstellar silicate dust are not well understood. Inthe X-rays, interstellar dust can be studied in detail, by making use of the fine structure features inthe Si K-edge. The features in the Si K-edge offer a range of possibilities to study silicon-bearingdust, such as investigating the crystallinity, abundance and the chemical composition along a given line of sight. We present newly acquired laboratory measurements of the silicon K-edge of several silicate-compounds which complement our measurements from our earlier pilot study. The resulting dust extinction profiles serve as templates for the interstellar extinction that we observe. The extinction profiles were used to model the interstellar dust in the dense environments of the Galaxy. The laboratory measurements, taken at the Soleil synchrotron facility in Paris, were adapted for astrophysical data analysis and implemented in the SPEX spectral fitting program. The models were used to fit the spectra of nine low-mass X-ray binaries located in the Galactic center neighborhood in order to determine the dust properties along those lines of sight. In most lines of sight can be well fitted by amorphous olivine. We also established upper limits on the amount of crystalline material that the modeling allows. We obtained values of the total silicon abundance, silicon dust abundance and depletion along each of the sightlines. We find a possible gradient of 0.06+/-0.02dex/kpc for the total silicon abundance versus the Galactocentric distance. We do not find a relation between the depletion and the extinction along the line of sight. Description: We analysed a sample of 14 silicates. Samples 2, 3, 5, 6, 7 and 10 were synthesized for this analysis in laboratories at AIU Jena and Osaka University. More details about these samples can be found in this paper and in Zeegers et al. (2017A&A...599A.117Z). The data presented in this paper were measured at the Soleil synchrotron facility in Paris using Lucia beamline. The laboratory absorption cross-sections of these measurements are given here. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 63 14 Samples oliv1.dat 27 3001 *Laboratory absorption cross section of olivine, sample 1, [Mg1.56Fe0.4Si0.91O4] prox2.dat 27 3001 *Laboratory absorption cross section of pyroxene, sample 2, [Mg0.9Fe0.1SiO3] amorphous prox3.dat 27 3001 *Laboratory absorption cross section of pyroxene, sample 3, [Mg0.9Fe0.1SiO3] enst4.dat 27 3001 *Laboratory absorption cross section of enstatite, sample 4, [MgSiO3] prox5.dat 27 3001 *Laboratory absorption cross section of pyroxene, sample 5, [Mg0.6Fe0.4SiO3] amorphous prox6.dat 27 3001 *Laboratory absorption cross section of pyroxene, sample 6, [Mg0.6Fe0.4SiO3] oliv7.dat 27 3001 *Laboratory absorption cross section of olivine, sample 7, [(Mg0.5Fe0.5)2SiO_4] amorphous prox8.dat 27 3001 *Laboratory absorption cross section of pyroxene, sample 8, [Mg0.75Fe0.25SiO3] faya9.dat 27 3001 *Laboratory absorption cross section of fayalite, sample 9, [Fe2SiO4] enst10.dat 27 3001 *Laboratory absorption cross section of enstatite, sample 10, [MgSiO3] amorphous fors11.dat 27 3001 *Laboratory absorption cross section of forsterite, sample 11, [Mg2SiO4] quar12.dat 27 3001 *Laboratory absorption cross section of quartz, sample 12, [SiO2] quar13.dat 27 3001 *Laboratory absorption cross section of quartz, sample 13, [SiO2], amorphous quar14.dat 27 3001 *Laboratory absorption cross section of quartz, sample 14, [SiO2], amorphous -------------------------------------------------------------------------------- Note on [efopq]*.dat: Header included 3 rows: - Sample number, corresponding to table 1 in the paper - Chemical formula and crystallinity - Column labels -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 2 I2 --- No [1/14] Sample identification number 4- 13 A10 --- Name Name 15- 41 A27 --- Chem Chemical formula 43- 51 A9 --- Struct Structure 54- 63 A10 --- Table Name of the table with laboratory absorption cross section -------------------------------------------------------------------------------- Byte-by-byte Description of file (#): [efopq]*.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 2- 10 F9.7 keV E Energy around the Fe K-edge 14- 27 E14.7 Mbarn CR Laboratory absorption cross section -------------------------------------------------------------------------------- Acknowledgements: Sascha Zeegers, szeegers(at)asiaa.sinica.edu.tw ================================================================================ (End) Patricia Vannier [CDS] 03-May-2019