The Dielectric Function of "Astrodust" and Predictions for Polarization in the 3.4$\mu$m and 10$\mu$m Features

Abstract

The dielectric function of interstellar dust material is modeled using observations of extinction and polarization in the infrared, together with estimates for the mass of interstellar dust. The "astrodust" material is assumed to be a mix of amorphous silicates and other materials, including hydrocarbons producing an absorption feature at 3.4$\mu$m. The detailed shape of the 10$\mu$m polarization profile depends on the assumed porosity and grain shape, but the 10$\mu$m spectropolarimetric data are not yet good enough to clearly favor one shape over another, nor to constrain the porosity. The expected 3.4$\mu$m feature polarization is consistent with existing upper limits, provided the 3.4$\mu$m absorption is preferentially located in grain surface layers; a separate population of non-aligned carbonaceous grains is not required. We predict the 3.4$\mu$m polarization feature to be $(\Delta p{)}_{3.4\mu \mathrm{m}}/p(10\mu \mathrm{m})\approx 0.016$, just below current upper limits. Polarization by the same grains at submm wavelengths is also calculated.

arXiv comment32 pages, 10 figures. Submitted to Ap.J

References in corpus (43)

• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• Infrared Emission from Interstellar Dust. II. The Diffuse Interstellar Medium
• A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
• The Wavelength Dependence of Interstellar Extinction from 1.25 to 8.0 microns Using GLIMPSE Data
• New Interstellar Dust Models Consistent with Extinction, Emission, and Abundance Constraints
• The evolution of amorphous hydrocarbons in the ISM: dust modelling from a new vantage point
• Scattering by Interstellar Dust Grains. II. X-Rays
• Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust
• The global dust SED: Tracing the nature and evolution of dust with DustEM
• Radiative Torques on Interstellar Grains: I. Superthermal Spinup
• The Composition and Distribution of Dust Along the Line of Sight Towards the Galactic Center
• Pixie Dust: The Silicate Features in the Diffuse Interstellar Medium
• The Optical-Infrared Extinction Curve and its Variation in the Milky Way
• The shape and composition of interstellar silicate grains
• Planck 2018 results. XII. Galactic astrophysics using polarized dust emission
• Planck intermediate results. XXII. Frequency dependence of thermal emission from Galactic dust in intensity and polarization
• The Diffuse Interstellar Clouds toward 23 Orionis
• Polarized Far-Infrared and Submillimeter Emission from Interstellar Dust
• The Efficiency of Grain Alignment in Dense Interstellar Clouds: A Reassessment of Constraints from Near Infrared Polarization
• Magnetic Nanoparticles in the Interstellar Medium: Emission Spectrum and Polarization
• Planck intermediate results. XXIX. All-sky dust modelling with Planck, IRAS, and WISE observations
• Oxygen Depletion in the Interstellar Medium: Implications for Grain Models and the Distribution of Elemental Oxygen
• A new, large-scale map of interstellar reddening derived from HI emission
• Dust Grain-Size Distributions From MRN to MEM
• Observational Constraints on the Physical Properties of Interstellar Dust in the Post-Planck Era
• Dust in the diffuse interstellar medium: Extinction, emission, linear and circular polarisation
• Dust models compatible with Planck intensity and polarization data in translucent lines of sight
• Spectropolarimetry of the 3.4 micron Feature in the Diffuse ISM toward the Galactic Center Quintuplet Cluster
• Dust-Gas Scaling Relations and OH Abundance in the Galactic ISM
• The infrared emission spectra of compositionally inhomogeneous aggregates composed of irregularly shaped constituents
• Detection of PAH Absorption and Determination of the Mid-Infrared Diffuse Interstellar Extinction Curve from the Sightline Toward Cyg OB2-12
• The Composition of Interstellar Grains Toward Zeta Ophiuchi: Constraining the Elemental Budget Near the Diffuse-Dense Cloud Transition
• Grain size limits derived from 3.6 μm and 4.5 μm coreshine
• Silicate Composition of the Interstellar Medium
• First Observation of the Submillimeter Polarization Spectrum in a Translucent Molecular Cloud
• Mid-Infrared Spectropolarimetric Constraints on the Core-Mantle Interstellar Dust Model
• Submillimeter Polarization Spectrum of the Carina Nebula
• Absorption at 11 microns in the interstellar medium and embedded sources: evidence for crystalline silicates
• Interplay of dust alignment, grain growth and magnetic fields in polarization: lessons from the emission-to-extinction ratio
• Spectropolarimetric Constraints on the Nature of Interstellar Grains
• Constraints on interstellar dust models from extinction and spectro-polarimetry

Cited by in corpus (53)

• Water in star-forming regions (WISH): Physics and chemistry from clouds to disks as probed by Herschel spectroscopy
• The Astrodust+PAH Model: A Unified Description of the Extinction, Emission, and Polarization from Dust in the Diffuse Interstellar Medium
• Excitation of Polycyclic Aromatic Hydrocarbon (PAH) Emission: Dependence on Size Distribution, Ionization, and Starlight Spectrum and Intensity
• CCAT-prime Collaboration: Science Goals and Forecasts with Prime-Cam on the Fred Young Submillimeter Telescope
• Dust, CO and [CI]: Cross-calibration of molecular gas mass tracers in metal-rich galaxies across cosmic time
• On Internal and External Alignment of Dust Grains in Protostellar Environments
• THEMIS 2.0: A self-consistent model for dust extinction, emission, and polarisation
• JWST Observations of Young protoStars (JOYS): overview of program and early results
• Using the Starlight Polarization Efficiency Integral to Constrain Shapes and Porosities of Interstellar Grains
• Oxygen and iron in interstellar dust: an X-ray investigation
• The Simons Observatory: Galactic Science Goals and Forecasts
• Alignment of irregular grains by radiative torques: efficiency study
• Effects of grain alignment with magnetic fields on grain growth and the structure of dust aggregates
• On the Shapes of Interstellar Grains: Modeling Extinction and Polarization by Spheroids and Continuous Distributions of Ellipsoids
• Physical Modeling of Dust Polarization from Magnetically Enhanced Radiative Torque (MRAT) Alignment in Protostellar Cores with POLARIS
• Low-temperature optical constants of amorphous silicate dust analogues
• Benchmarking Dust Emission Models in M101
• Dark dust II: Properties in the general field of the diffuse ISM
• Evolution of dust porosity through coagulation and shattering in the interstellar medium
• On the Simultaneous Modelling of Dust and Stellar Populations for Interpretation of Galaxy Properties
• Joint Modelling of Dust Scattering and Thermal Emission: The Spider Complex
• The magnetic fields of starburst galaxies. I. Identification and characterization of the thermal polarization in the galactic disk and outflow
• Variation of dust properties with cosmic time implied by radiative torque disruption
• Characterizing line-of-sight variability of polarized dust emission with future CMB experiments
• Refractory carbon depletion by photolysis through dust collisions and vertical mixing
• On the origin of radio-loudness in active galactic nuclei using far-infrared polarimetric observations
• Evolution of dust grain size distribution and grain porosity in galaxies
• Evolution of grain size distribution with enhanced abundance of small carbonaceous grains in galactic environments
• On Far-Infrared and Submm Circular Polarization
• SOFIA/HAWC+ observations of the Crab Nebula: dust properties from polarised emission
• Physical conditions for dust grain alignment in Class 0 protostellar cores II. The role of the radiation field in models aligning/disrupting dust grains
• Sensitivity of Polarization to Grain Shape: I. Convex Shapes
• Ultraviolet Spectropolarimetry with Polstar: Interstellar Medium Science
• Synthetic Modelling of Polarized Dust Emission in Intermediate-Mass YSOs: I: Constraining the Role of Iron Inclusions and Inelastic Relaxation on Grain Alignment with ALMA Polarization
• The origin of dust polarization in the Orion Bar
• Mitigating Bias in CMB B-modes from Foreground Cleaning Using a Moment Expansion
• Mapping the aliphatic hydrocarbon content of interstellar dust in the Galactic plane
• Generation of high circular polarization of interstellar Lyman $\alpha$ radiation triggering biological homochirality
• The rotational disruption of porous dust aggregates from ab-initio kinematic calculations
• Mid-Infrared Polarization of the Diffuse Interstellar Medium toward CygOB2-12
• The Spheroidal Analog Method for Modeling Irregular Porous Aggregates
• The End of the Road for Far-infrared Reddening Maps? Evidence for Reddening Errors Driven by Changes in PAH Abundance
• Sensitivity of Polarization to Grain Shape: II. Aggregates
• Spitzer/IRS full spectral modeling to characterize mineralogical properties of silicate dust in heavily obscured AGNs
• Ray Tracing Through Absorbing Dielectric Media in the Schwarzschild Spacetime
• Limitations of the modified blackbody fit method for determining molecular cloud properties
• The Binding Energies of Atoms on Amorphous Silicate Dust: A Computational Study
• Grain alignment and dust evolution physics with polarisation (GRADE-POL). I. Dust polarisation modelling for isolated starless cores
• Photometric Mapping of Carbonaceous/Siliceous Dust and Water Ice in the ISM with JWST: Applications to the Dense Sightlines
• Effect of dust rotational disruption by radiative torques on radiation pressure feedback from massive protostars
• Large Interstellar Polarisation Survey. III. Observational constraints on the structure of grains
• The optical constants and grain sizes of interstellar dust measured directly using the dust scattered x-ray halo of GRB 221009A
• Earth's carbon deficit caused by early loss through irreversible sublimation