Mapping Circumstellar Matter with Polarized Light: The Case of Supernova 2014J in M82

Chen

et al. 2019

ApJ

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Type Ia supernovae (SNe Ia) play key roles in revealing the accelerating expansion of the universe, but our knowledge about their progenitors is still very limited. Here we report the discovery of a rigid dichotomy in circumstellar (CS) environments around two subclasses of type Ia supernovae (SNe Ia) as defined by their distinct photospheric velocities. For the SNe Ia with high photospheric velocities (HV), we found a significant excess flux in blue light during 60-100 days past maximum, while this phenomenon is absent for SNe with normal photospheric velocity (Normal). This blue excess can be attributed to light echoes by circumstellar dust located at a distance of about 1-3×10 17 cm from the HV subclass. Moreover, we also found that the HV SNe Ia show systematically evolving Na I absorption line by performing a systematic search of variable Na I absorption lines in spectra of all SNe Ia, whereas this evolution is rarely seen in Normal ones. The evolving Na I absorption can be modeled in terms of photoionization model, with the location of the gas clouds at a distance of about 2×10 17 cm, in striking agreement with the location of CS dust inferred from B-band light curve excess. These observations show clearly that the progenitors of HV and Normal subclasses are systematically different, suggesting that they are likely from single and double degenerate progenitor systems, respectively.

Section: Discussionmentioning

confidence: 99%

The Cold and Dusty Circumstellar Matter around Fast-expanding Type Ia Supernovae

Chen

et al. 2019

ApJ

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Monthly Notices of the Royal Astronomical Society

“…However, observations by Patat et al (2015) and Kawabata et al (2014) were taken at relatively early epochs, between ∼ 10 d before and ∼ 35 d after peak brightness. A recent study by Yang et al (2018) analyses imaging polarimetry of SN 2014J at later epochs and claims a variation in the polarization signal occurring 277 d after maximum light. This is interpreted as due to ∼ 10 −6 M of CS dust located at ∼ 0.2 pc from the SN.…”

Section: Time-evolution Of Polarizationmentioning

confidence: 99%

Shedding light on the Type Ia supernova extinction puzzle: dust location found

Bulla

Goobar

Dhawan

2018

The colour evolution of reddened Type Ia supernovae can place strong constraints on the location of dust and help address the question of whether the observed extinction stems from the interstellar medium or from circumstellar material surrounding the progenitor. Here we analyse BV photometry of 48 reddened Type Ia supernovae from the literature and estimate the dust location from their B−V colour evolution. We find a time-variable colour excess E(B − V ) for 15 supernovae in our sample and constrain dust to distances between 0.013 and 45 pc (4 × 10 16 − 10 20 cm). For the remaining supernovae, we obtain a constant E(B − V ) evolution and place lower limits on the dust distance from the explosion. In all the 48 supernovae, the inferred dust location is compatible with an interstellar origin for the extinction. This is corroborated by the observation that supernovae with relatively nearby dust ( 1 pc) are located close to the center of their host galaxy, in high-density dusty regions where interactions between the supernova radiation and interstellar clouds close by are likely to occur. For supernovae showing time-variable E(B − V ), we identify a potential preference for low R V values, unusually strong sodium absorption and blue-shifted and timevariable absorption features. Within the interstellar framework, this brings evidence to a proposed scenario where cloud-cloud collisions induced by the supernova radiation pressure can shift the grain size distribution to smaller values and enhance the abundance of sodium in the gaseous phase.

“…The SN exploded relatively close to the galactic center and displays an extinction of 𝐸 (𝐵 −𝑉) = 1.37 ± 0.03 mag with 𝑅 𝑉 = 1.4 ± 0.1 (Amanullah et al 2014). The extinction can be explained by a combination of dust reddening and scattering (Foley et al 2014;Welty et al 2014;Yang et al 2017Yang et al , 2018. Patat et al (2014) obtained three spectropolarimetry epochs of SN 2014J (2014 January 28, February 3, and March 8), using the Calar Alto Faint Object Spectrograph (CAFOS) mounted at the 2.2 m telescope in Calar Alto, Spain (Patat & Taubenberger 2011).…”

Section: The Cases Of Sn 2006x and Sn 2014jmentioning

confidence: 99%

An imaging polarimetry survey of Type Ia supernovae: are peculiar extinction and polarization properties produced by circumstellar or interstellar matter?

Chu,

Cikota,

Baade

et al. 2021

Preprint

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Some highly reddened Type Ia supernovae (SNe Ia) display low total-to-selective extinction ratios (𝑅 𝑉 2) in comparison to that of typical Milky Way dust (𝑅 𝑉 ≈ 3.3), and polarization curves that rise steeply to blue wavelengths, with peak polarization values at short wavelengths (𝜆 max < 0.4 µm) in comparison to the typical Galactic values (𝜆 max ≈ 0.55 µm). Understanding the source of these properties could provide insight into the progenitor systems of SNe Ia. We aim to determine whether they are the result of the host galaxy's interstellar dust or circumstellar dust. This is accomplished by analysing the continuum polarization of 66 SNe Ia in dust-rich spiral galaxies and 13 SNe Ia in dust-poor elliptical galaxies as a function of normalised galactocentric distance. We find that there is a general trend of SNe Ia in spiral galaxies displaying increased polarization values when located closer to the host galaxies' centre, while SNe Ia in elliptical host galaxies display low polarization. Furthermore, all highly polarized SNe Ia in spiral host galaxies display polarization curves rising toward blue wavelengths, while no evidence of such polarization properties is shown in elliptical host galaxies. This indicates that the source of the peculiar polarization curves is likely the result of interstellar material as opposed to circumstellar material. The peculiar polarization and extinction properties observed toward some SNe Ia may be explained by the radiative torque disruption mechanism induced by the SN or the interstellar radiation field.