RECORD
A distorted radio shell in the young supernova SN1986J
Astrophysics · Submitted 28 Feb 2002
abstract compiled · 2026-09-23 · no language-model review
The authors' main claim Thus, the supernova progenitor must have kept intact most of its hydrogen-rich envelope by the time of explosion, which favours a single, massive star progenitor scenario.
The compiled record
The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
Open the compiled record
The abstract, sentence by sentence
We report here on 5 GHz global very-long-baseline interferometry (VLBI) observations of SN 1986J, 16 yr after its explosion. We obtained a high-resolution image of the supernova, which shows a distorted shell of radio emission, indicative of a deformation of the shock front. The angular size of the shell is $\sim4.7 {\rm mas}$, corresponding to a linear size of $\sim6.8 \times 10^{17} {\rm cm}$ for a distance of 9.6 Mpc to NGC 891. The average speed of the shell has decreased from $\sim$7400 \kms in 1988.74 down to about $6300 {\rm km s^{-1}}$ in 1999.14, indicative of a mild deceleration in the expansion of SN 1986J. Assuming a standard density profile for the progenitor wind ($\rho_{\rm cs} \propto r^{-s}, s=2$), the swept-up mass by the shock front is $\sim$2.2\Ms. This large swept-up mass, coupled with the mild deceleration suffered by the supernova, suggests that the mass of the hydrogen-rich envelope ejected at explosion was $\ga12$ \Ms. Thus, the supernova progenitor must have kept intact most of its hydrogen-rich envelope by the time of explosion, which favours a single, massive star progenitor scenario. We find a flux density for SN 1986J of $\sim$7.2 mJy at the observing frequency of 5 GHz, which results in a radio luminosity of $\sim1.4 \times 10^{37} {\rm erg s^{-1}}$ for the frequency range $10^7$--$10^{10}$ Hz ($\alpha =-0.69; S_\nu \propto \nu^{\alpha})$. We detect four bright knots that delineate the shell structure, and an absolute minimum of emission, which we tentatively identify with the centre of the supernova explosion. If this is the case, SN 1986J has then suffered an asymmetric expansion. We suggest that this asymmetry is due to the collision of the supernova ejecta with an anisotropic, clumpy (or filamentary) medium.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We report here on 5 GHz global very-long-baseline interferometry (VLBI) observations of SN 1986J, 16 yr after its explosion. | contribution 0.82 | 0.96 | 0.02 | asserted 0.99 |
| s1 | We obtained a high-resolution image of the supernova, which shows a distorted shell of radio emission, indicative of a deformation of the shock front. | result 0.93 | 0.96 | 0.11 | asserted 0.59 |
| s2 | The angular size of the shell is $\sim4.7 {\rm mas}$, corresponding to a linear size of $\sim6.8 \times 10^{17} {\rm cm}$ for a distance of 9.6 Mpc to NGC 891. | result 1.00 | 0.92 | 0.04 | asserted 0.99 |
| s3 | The average speed of the shell has decreased from $\sim$7400 \kms in 1988.74 down to about $6300 {\rm km s^{-1}}$ in 1999.14, indicative of a mild deceleration in the expansion of SN 1986J. Assuming a standard density profile for the progenitor wind ($\rho_{\rm cs} \propto r^{-s}, s=2$), the swept-up mass by the shock front is $\sim$2.2\Ms. | result 0.98 | 0.93 | 0.09 | asserted 0.84 |
| s4 | This large swept-up mass, coupled with the mild deceleration suffered by the supernova, suggests that the mass of the hydrogen-rich envelope ejected at explosion was $\ga12$ \Ms. | interpretation 0.99 | 0.83 | 0.30 | hedged possibility 0.99 |
| s5 | Thus, the supernova progenitor must have kept intact most of its hydrogen-rich envelope by the time of explosion, which favours a single, massive star progenitor scenario. | interpretation 1.00 | 0.68 | 0.63 | hedged possibility 0.68 |
| s6 | We find a flux density for SN 1986J of $\sim$7.2 mJy at the observing frequency of 5 GHz, which results in a radio luminosity of $\sim1.4 \times 10^{37} {\rm erg s^{-1}}$ for the frequency range $10^7$--$10^{10}$ Hz ($\alpha =-0.69; S_\nu \propto \nu^{\alpha})$. | result 1.00 | 0.97 | 0.04 | asserted 1.00 |
| s7 | We detect four bright knots that delineate the shell structure, and an absolute minimum of emission, which we tentatively identify with the centre of the supernova explosion. | result 1.00 | 0.97 | 0.05 | asserted 0.82 |
| s8 | If this is the case, SN 1986J has then suffered an asymmetric expansion. | interpretation 0.94 | 0.58 | 0.09 | hedged possibility 0.79 |
| s9 | We suggest that this asymmetry is due to the collision of the supernova ejecta with an anisotropic, clumpy (or filamentary) medium. | interpretation 1.00 | 0.59 | 0.24 | hedged possibility 0.51 |
What was examined, and what was not
- arXiv listing abstract v2
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
The paper
Original abstract
We report here on 5 GHz global very-long-baseline interferometry (VLBI) observations of SN 1986J, 16 yr after its explosion. We obtained a high-resolution image of the supernova, which shows a distorted shell of radio emission, indicative of a deformation of the shock front. The angular size of the shell is $\sim4.7 {\rm mas}$, corresponding to a linear size of $\sim6.8 \times 10^{17} {\rm cm}$ for a distance of 9.6 Mpc to NGC 891. The average speed of the shell has decreased from $\sim$7400 \kms in 1988.74 down to about $6300 {\rm km s^{-1}}$ in 1999.14, indicative of a mild deceleration in the expansion of SN 1986J. Assuming a standard density profile for the progenitor wind ($\rho_{\rm cs} \propto r^{-s}, s=2$), the swept-up mass by the shock front is $\sim$2.2\Ms. This large swept-up mass, coupled with the mild deceleration suffered by the supernova, suggests that the mass of the hydrogen-rich envelope ejected at explosion was $\ga12$ \Ms. Thus, the supernova progenitor must have kept intact most of its hydrogen-rich envelope by the time of explosion, which favours a single, massive star progenitor scenario. We find a flux density for SN 1986J of $\sim$7.2 mJy at the observing frequency of 5 GHz, which results in a radio luminosity of $\sim1.4 \times 10^{37} {\rm erg s^{-1}}$ for the frequency range $10^7$--$10^{10}$ Hz ($\alpha =-0.69; S_\nu \propto \nu^{\alpha})$. We detect four bright knots that delineate the shell structure, and an absolute minimum of emission, which we tentatively identify with the centre of the supernova explosion. If this is the case, SN 1986J has then suffered an asymmetric expansion. We suggest that this asymmetry is due to the collision of the supernova ejecta with an anisotropic, clumpy (or filamentary) medium.
Human review
Discussion
Know something about this paper? Leave a comment, or highlight any passage above to comment on it.