Mid-Infrared Polarization of the Diffuse Interstellar Medium toward CygOB2-12
arXiv:2210.12708 · doi:10.3847/2041-8213/ac9b56
Abstract
We present the first mid-IR detection of the linear polarization toward the star CygOB2-12, a luminous blue hypergiant that, with Av of ~10 mag of foreground extinction, is a benchmark in the study of the properties of dust in the diffuse interstellar medium. The 8-13 micrometer spectropolarimetry, obtained with the CanariCam multi-mode camera at the Gran Telescopio Canarias (GTC), shows clear trends with wavelength characteristic of silicate grains aligned in the interstellar magnetic field. The maximum polarization, detected with 7.8 statistical significance near 10.2 micrometers, is (1.24 +/- 0.28) % with position angle (126 +/- 8) deg. We comment on these measurements in the context of recent models for the dust composition in the diffuse interstellar medium.
arXiv commentAccepted Astrophysical Journal Letters, October 9, 2022
References in corpus (8)
- Error Analysis for Dual-Beam Optical Linear Polarimetry
- A novel estimator of the polarization amplitude from normally distributed Stokes parameters
- Milky Way Mid-Infrared Spitzer Spectroscopic Extinction Curves: Continuum and Silicate Features
- On the nature of the galactic early-B hypergiants
- The Dielectric Function of "Astrodust" and Predictions for Polarization in the 3.4m and 10m Features
- Detection of PAH Absorption and Determination of the Mid-Infrared Diffuse Interstellar Extinction Curve from the Sightline Toward Cyg OB2-12
- Silicate Composition of the Interstellar Medium
- Using the Starlight Polarization Efficiency Integral to Constrain Shapes and Porosities of Interstellar Grains
Cited by in corpus (4)
- The Astrodust+PAH Model: A Unified Description of the Extinction, Emission, and Polarization from Dust in the Diffuse Interstellar Medium
- THEMIS 2.0: A self-consistent model for dust extinction, emission, and polarisation
- Sensitivity of Polarization to Grain Shape: I. Convex Shapes
- Sensitivity of Polarization to Grain Shape: II. Aggregates