The Changing Morphology and Increasing Deceleration of Supernova 1993J in M81

Bartel, N.; Bietenholz, M. F.; Rupen, M. P.; Beasley, A. J.; Graham, D. A.; Altunin, V. I.; Venturi, T.; Umana, G.; Cannon, W. H.; Conway, J.

doi:10.1126/science.287.5450.112

Cited by 71 publications

(79 citation statements)

References 24 publications

(13 reference statements)

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“…In any case, deformations of the radio shell, whether they are caused by a disklike or an irregular density distribution of the CSM, may need time to develop. The expansion velocity of the shock front had already slowed from about D18,000 km s~1 at the start of our observations to D8000 km s~1 by June 1998 (Bartel et al 2000a), indicating that the swept-up material of the CSM already dominates the evolution of the radio shell. It may be just a matter of time until signiÐcant protrusions and other asymmetries develop.…”

Section: Constraint On Asymmetry Of the Explosionmentioning

confidence: 90%

“…For the last several epochs, where the supernova was sufficiently resolved for the shell thickness to be estimated with useful accuracy, we further estimated the outer angular radius, and inner radius, separately. The mean of h out , h in , the ratio for these epochs was 1.27^0.02 and was h out /h in constant within the uncertainties (Bartel et al 2000a). Then, for all epochs, we Ðt only with Ðxed at It is h out h in h out /1.25.1 from this last consistent set of Ðts that the values of and x i y i used in this paper were determined.…”

Section: Model-ðttingmentioning

confidence: 99%

“…For the origin of the coordinate systems in this Ðgure, we choose the position of the geometric center of the Ðt radio shell (i.e., o †set at x i , y i from the phase center position). For a full sequence of images up to 2000 February, see Bietenholz et al (2001) ; see an earlier version until June 1998 in Bartel et al (2000a). A complete sequence of images at 8.4 and 5.0 GHz will be presented in a future paper.…”

Section: T He Degree Of Circularity In the Imagesmentioning

confidence: 99%

“…After Ðve years, the supernova has slowed down to half its original expansion velocity, suggesting that its evolution is now considerably inÑuenced by the swept-up CSM. These results were summarized by Bartel et al (2000a).…”

Section: Introductionmentioning

confidence: 99%

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SN 1993J VLBI. I. The Center of the Explosion and a Limit on Anisotropic Expansion

Bietenholz

Bartel

Rupen

2001

ApJ

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Phase-referenced VLBI observations of supernova 1993J at 24 epochs, from 50 days after shock breakout to the present, allowed us to determine the coordinates of the explosion center relative to the quasistationary core of the host galaxy M81 with an accuracy of 45 kas and to determine the nominal proper motion of the geometric center of the radio shell with an accuracy of 9 kas yr~1. The uncertainties correspond to 160 AU for the position and 160 km s~1 for the proper motion at the distance of the source of 3.63 Mpc. After correcting for the expected galactic proper motion of the supernova around the core of M81 using H I rotation curves, we obtain a peculiar proper motion of the radio shell center of only 320^160 km s~1 to the south, which limits any possible one-sided expansion of the shell. We also Ðnd that the shell is highly circular, the outer contours in fact being circular to within 3%. Combining our proper-motion values with the degree of circular symmetry, we Ðnd that the expansion of the shock front from the explosion center is isotropic to within 5.5% in the plane of the sky. This is a more fundamental result on isotropic expansion than can be derived from the circularity of the images alone. The brightness of the radio shell, however, varies along the ridge and systematically changes with time. The degree of isotropy in the expansion of the shock front contrasts with the asymmetries and polarization found in optical spectral lines. Asymmetric density distributions in the ejecta, or more likely in the circumstellar medium, are favored to reconcile the radio and optical results. We see no sign of any disklike density distribution of the circumstellar material, with the average axis ratio of the radio shell of SN 1993J being less than 1.04.

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Section: Constraint On Asymmetry Of the Explosionmentioning

confidence: 90%

Section: Model-ðttingmentioning

confidence: 99%

Section: T He Degree Of Circularity In the Imagesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

SN 1993J VLBI. I. The Center of the Explosion and a Limit on Anisotropic Expansion

Bietenholz

Bartel

Rupen

2001

ApJ

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“…The radio and X-ray emission of SN1993J [11,129,142] have been attributed to circumstellar interaction [54]. Another indication comes from the boxy shape of the emission lines of late time optical spectra [77,94].…”

Section: Type Iibmentioning

confidence: 99%

Classification of Supernovae

Turatto

2003

Supernovae and Gamma-Ray Bursters

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Abstract. The current classification scheme for supernovae is presented. The main observational features of the supernova types are described and the physical implications briefly addressed. Differences between the homogeneous thermonuclear type Ia and similarities among the heterogeneous core collapse type Ib, Ic and II are highlighted. Transforming type IIb, narrow line type IIn, supernovae associated with GRBs and few peculiar objects are also discussed.

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Laboratory simulations of astrophysical blast waves with high energy lasers

Ditmire¹,

Edens

2008

Laser & Photonics Reviews

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We review recent efforts to simulate aspects of supernova remnants in laboratory experiments by creating energetic explosions with high energy lasers. High energy pulsed lasers are uniquely suited for these kinds of studies. By focusing a laser with pulse energy of a few joules to many hundreds of joules onto a solid target or into a dense gas target, explosive shock waves of very high Mach number can be created. With a well chosen set of laser and target parameters it has been shown by a number of groups that radiative blast waves can be produced. Such blast waves have dynamics dominated by radiation transport and exhibit unusual characteristics, the most important of which include hydrodynamic instabilities which may play an important role in the structure of the interstellar medium. As a result there are now prospects for gaining new insights into astronomical observations of supernova remnants by studying laboratory laser driven plasma systems.Image of a blast wave in nitrogen driven by focusing a 1 kJ laser pulse onto a pin immersed in nitrogen gas.

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The Changing Morphology and Increasing Deceleration of Supernova 1993J in M81

Cited by 71 publications

References 24 publications

SN 1993J VLBI. I. The Center of the Explosion and a Limit on Anisotropic Expansion

SN 1993J VLBI. I. The Center of the Explosion and a Limit on Anisotropic Expansion

Classification of Supernovae

Laboratory simulations of astrophysical blast waves with high energy lasers

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