Spectropolarimetry of Galactic stars with anomalous extinction sightlines

Abstract

Highly reddened type Ia Supernovae (SNe Ia) with low total-to-selective visual extinction ratio values, $R_V$, also show peculiar linear polarization wavelength dependencies with peak polarizations at short wavelengths (${\lambda }_{max}\lesssim 0.4\mu m$). It is not clear why sightlines to SNe Ia display such different continuum polarization profiles from interstellar sightlines in the Milky Way with similar $R_V$ values. We investigate polarization profiles of a sample of Galactic stars with low $R_V$ values, along anomalous extinction sightlines, with the aim to find similarities to the polarization profiles that we observe in SN Ia sightlines. We undertook spectropolarimetry of 14 stars, and used archival data for three additional stars, and run dust extinction and polarization simulations to infer a simple dust model that can reproduce the observed extinction and polarization curves. Our sample of Galactic stars with low $R_V$ values and anomalous extinction sightlines displays normal polarization profiles with an average ${\lambda }_{max}\sim 0.53\mu m$, and is consistent within 3$\sigma$ to a larger coherent sample of Galactic stars from literature. Despite the low $R_V$ values of dust towards the stars in our sample, the polarization curves do not show any similarity to the continuum polarization curves observed towards SNe Ia with low $R_V$ values. There is a correlation between the best-fit Serkowski parameters $K$ and ${\lambda }_{max}$, but we did not find any significant correlation between $R_V$ and ${\lambda }_{max}$. Our simulations show that the $K-{\lambda }_{max}$ relationship is an intrinsic property of polarization. Furthermore, we have shown that in order to reproduce polarization curves with normal ${\lambda }_{max}$ and low $R_V$ values, a population of large (a $\ge 0.1\mu m$) interstellar silicate grains must be contained in the dust's composition.

arXiv commentaccepted for publication in A&A

References in corpus (45)

• Correcting for the Effects of Interstellar Extinction
• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• Interstellar Dust Grains
• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• Improved Dark Energy Constraints from ~100 New CfA Supernova Type Ia Light Curves
• The Reddening-Free Decline Rate Versus Luminosity Relationship for Type Ia Supernovae
• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• First-year Sloan Digital Sky Survey-II (SDSS-II) Supernova Results: Hubble Diagram and Cosmological Parameters
• SB9: The Ninth Catalogue of Spectroscopic Binary Orbits
• Spectropolarimetry of Supernovae
• The Carnegie Supernova Project: Analysis of the First Sample of Low-Redshift Type-Ia Supernovae
• The Effect of Host Galaxies on Type Ia Supernovae in the SDSS-II Supernova Survey
• On the Source of the Dust Extinction in Type Ia Supernovae and the Discovery of Anomalously Strong Na I Absorption
• Type Ia Supernova Light Curve Inference: Hierarchical Models in the Optical and Near Infrared
• Polarized Far-Infrared and Submillimeter Emission from Interstellar Dust
• Low R_v from circumstellar dust around supernovae
• Is there Evidence for a Hubble bubble? The Nature of Type Ia Supernova Colors and Dust in External Galaxies
• Error Analysis for Dual-Beam Optical Linear Polarimetry
• A unified model of grain alignment: radiative alignment of interstellar grains with magnetic inclusions
• Cepheid calibration of type Ia Supernovae and the Hubble constant
• Extensive HST Ultraviolet Spectra and Multi-wavelength Observations of SN 2014J in M82 Indicate Reddening and Circumstellar Scattering by Typical Dust
• Dust around Type Ia supernovae
• Dust Grain-Size Distributions From MRN to MEM
• Reddening, Absorption, and Decline Rate Corrections for a Complete Sample of Type Ia Supernovae leading to a Fully Corrected Hubble Diagram to v<30,000kms-1
• The colour-lightcurve shape relation of Type Ia supernovae and the reddening law
• The Detection of a Light Echo from the Type Ia Supernova 2006X in M100
• Spectropolarimetry of the 3.4 micron Feature in the Diffuse ISM toward the Galactic Center Quintuplet Cluster
• Determination of the Hubble constant, the intrinsic scatter of luminosities of Type Ia SNe, and evidence for non-standard dust in other galaxies
• Properties of extragalactic dust inferred from linear polarimetry of Type Ia Supernovae
• Constraint on the Polarization of Electric Dipole Emission from Spinning Dust
• Linear spectropolarimetry of polarimetric standard stars with VLT/FORS2
• Interstellar extinction and interstellar polarization: old and new models
• Large Interstellar Polarisation Survey. LIPS I: FORS2 spectropolarimetry in the Southern Hemisphere
• VLT Spectropolarimetry of the optical transient in NGC300. Evidence for asymmetry in the circumstellar dust
• Dust Formation in the Ejecta of Common Envelope Systems
• X-Ray Scattering by Nonspherical Grains. I. Oblate Spheroids
• Paramagnetic alignment of small grains: a novel method for measuring interstellar magnetic fields
• Properties and alignment of interstellar dust grains toward Type Ia Supernovae with anomalous polarization curves
• Interstellar-Medium Mapping in M82 Through Light Echoes Around Supernova 2014J
• Common continuum polarization properties: a possible link between proto-planetary nebulae and Type Ia Supernovae progenitors
• Determining Type Ia Supernovae Host galaxy extinction probabilities and a statistical approach to estimating the absorption-to-reddening ratio $R_V$
• Continuum Foreground Polarization and Na~I Absorption in Type Ia SNe
• Characterisation of the CAFOS linear spectro-polarimeter
• Chemical composition of evolved stars of high galactic latitude
• Dust properties along anomalous extinction sightlines. II. Studying extinction curves with dust models

Cited by in corpus (14)

• Linear spectropolarimetry of 35 Type Ia Supernovae with VLT/FORS: An analysis of the Si II line polarization
• Physical Model of Dust Polarization by Radiative Torque Alignment and Disruption and Implications for Grain Internal Structures
• UNCOVER: 404 Error -- Models Not Found for the Triply Imaged Little Red Dot A2744-QSO1
• Multiepoch VLT-FORS spectro-polarimetric observations of supernova 2012aw reveal an asymmetric explosion
• Probing the Progenitors of Type Ia Supernovae using Circumstellar Material Interaction Signatures
• 3D ISM structure challenges the Serkowski relation
• Spectropolarimetry of Type II supernovae (I) Sample, observational data and interstellar polarization
• The shape of SN 1993J re-analyzed
• Diversity of dust properties in external galaxies confirmed by polarization signals from Type II supernovae
• $R_V$ from multi-waveband galaxy polarimetry in supernovae vicinity
• Polarization position angle standard stars: a reassessment of $\theta$ and its variability for seventeen stars based on a decade of observations
• Time-Varying Extinction, Polarization, and Colors of Type Ia Supernovae due to Rotational Disruption of Dust Grains
• A High-Velocity Scatterer Revealed in the Thinning Ejecta of a Type II Supernova
• An imaging polarimetry survey of Type Ia supernovae: are peculiar extinction and polarization properties produced by circumstellar or interstellar matter?