Supernova Remnants with Jets

Kesteven, Michael; Caswell, J. L.; Roger, R. S.; Milne, D. K.; Haynes, R. F.

doi:10.1071/ph870855

Cited by 53 publications

(60 citation statements)

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“…How can it be interpreted? SNR 4449‐1's observed morphology is similar to the barrel shape seen in some older Galactic SNRs (Kesteven & Caswell 1987; Gaensler 1998), which is thought to be due to interaction with the large‐scale Galactic magnetic field, with the symmetry axis being preferentially parallel to the Galactic plane (Gaensler 1998). In the case of SNR 4449‐1, which as we have shown is interacting with the CSM still, the influence of NGC 4449's large‐scale galactic field is likely to be small, especially given the fact that SNR 4449‐1 is over an order of magnitude smaller than the barrel‐shaped Galactic SNRs.…”

Section: Discussionmentioning

confidence: 54%

The first VLBI image of the young, oxygen-rich supernova remnant in NGC 4449

Bietenholz

Bartel

Milisavljevic

et al. 2010

Monthly Notices of the Royal Astronomical Society

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We report on sensitive 1.4‐GHz VLBI radio observations of the unusually luminous supernova remnant SNR 4449‐1 in the galaxy NGC 4449, which gave us the first well‐resolved image of this object. The remnant's radio morphology consists of two approximately parallel bright ridges, suggesting similarities to the barrel shape seen for many older Galactic supernova remnants or possibly to SN 1987A. The angular extent of the remnant is 65 × 40 mas, corresponding to (3.7 × 2.3) × 1018 (D/3.8 Mpc) cm. We also present a new, high signal‐to‐noise ratio optical spectrum. By comparing the remnant's linear size to the maximum velocities measured from optical lines, as well as using constraints from historical images, we conclude that the supernova explosion occurred between ∼1905 and 1961, likely around 1940. The age of the remnant is therefore likely ∼70 yr. We find that SNR 4449‐1's shock wave is likely still interacting with the circumstellar rather than interstellar medium.

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Section: Discussionmentioning

confidence: 54%

The first VLBI image of the young, oxygen-rich supernova remnant in NGC 4449

Bietenholz

Bartel

Milisavljevic

et al. 2010

Monthly Notices of the Royal Astronomical Society

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“…There are three names for the class of SNRs that have two opposite limbs in the literature: ‘barrel‐shaped’ (Kesteven & Caswell 1987), ‘bipolar’ (Fulbright & Reynolds 1990) and ‘bilateral’ (Gaensler 1998). They were introduced on the basis of two‐dimensional visual morphology.…”

Section: Resultsmentioning

confidence: 99%

Some properties of synchrotron radio and inverse-Compton gamma-ray images of supernova remnants

Petruk¹,

Beshley²,

Bocchino³

et al. 2009

Monthly Notices of the Royal Astronomical Society

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The synchrotron radio maps of supernova remnants (SNRs) in a uniform interstellar medium and interstellar magnetic field (ISMF) are analysed, allowing for different ‘sensitivity’ of the injection efficiency to the obliquity of the shock. The very‐high‐energy γ‐ray maps arising from inverse Compton processes are also synthesized. The properties of images in these different wavelength bands are compared, with particular emphasis on the location of the bright limbs in bilateral SNRs. Recent High‐Energy Stereoscopic System (HESS) observations of SN 1006 show that the radio and inverse Compton γ‐ray limbs coincide, and we found that this may happen if (i) injection is isotropic but the variation of the maximum energy of electrons is rather fast to compensate for differences in the magnetic field, or (ii) the obliquity dependence of injection (either quasi‐parallel or quasi‐perpendicular) and the electron maximum energy are strong enough to dominate the magnetic field variation. In the latter case, the obliquity dependences of the injection and the maximum energy should not be opposite. We argue that the position of the limbs alone, and even their coincidence in radio, X‐rays and γ‐rays, as discovered by HESS in SN 1006, cannot be conclusive as regards the dependence of the electron injection efficiency, the compression/amplification of the ISMF and the electron maximum energy on the obliquity angle.

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“…In many cases, the ISMF, galactic in origin, may be assumed to be rather uniform on the scales of SNR sizes. This is likely to be the case of the bilateral SNRs (hereafter BSNRs; Kesteven & Caswell 1987; Gaensler 1998; but see Orlando et al 2007, for implications of asymmetries in BSNRs), which are characterized by strong, opposite limbs. BSNRs with symmetric structure in radio images limit the orientation of the ISMF component in the plane of the sky.…”

Section: Introductionmentioning

confidence: 99%

Aspect angle for interstellar magnetic field in SN 1006

Petruk

Dubner

Castelletti

et al. 2009

Monthly Notices of the Royal Astronomical Society

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A number of important processes taking place around strong shocks in supernova remnants (SNRs) depend on the shock obliquity. The measured synchrotron flux is a function of the aspect angle between interstellar magnetic field (ISMF) and the line of sight. Thus, a model of non-thermal emission from SNRs should account for the orientation of the ambient magnetic field. We develop a new method for the estimation of the aspect angle, based on the comparison between observed and synthesized radio maps of SNRs, making different assumptions about the dependence of electron injection efficiency on the shock obliquity. The method uses the azimuthal profile of radio surface brightness as a probe for orientation of ambient magnetic field because it is almost insensitive to the downstream distribution of magnetic field and emitting electrons. We apply our method to a new radio image of SN 1006 produced on the basis of archival Very Large Array and Parkes data. The image recovers emission from all spatial structures with angular scales from a few arcsec to 15 arcmin. We explore different models of injection efficiency and find the following best-fitting values for the aspect angle of SN 1006: φo = 70o ± 4.2o if the injection is isotropic, φo = 64o ± 2.8o for quasi-perpendicular injection (SNR has an equatorial belt in both cases) and φo = 11o ± 0.8o for quasi-parallel injection (polar-cap model of SNR). In the last case, SN 1006 is expected to have a centrally peaked morphology contrary to what is observed. Therefore, our analysis provides some indication against the quasi-parallel injection model.Fil: Petruk, O.. Institute for Applied Problems in Mechanics and Mathematics; UcraniaFil: Dubner, Gloria Mabel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Castelletti, Gabriela Marta. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Bocchino, F.. Istituto Nazionale Di Astrofísica. Osservatorio Astronómico Di Palermo; ItaliaFil: Iakubovskyi, D.. Bogolyubov Institute for Theoretical Physics; UcraniaFil: Kirsch, M. G. F.. European Space Agency; AlemaniaFil: Miceli, M.. Istituto Nazionale Di Astrofísica. Osservatorio Astronómico Di Palermo; ItaliaFil: Orlando, S.. Istituto Nazionale Di Astrofísica. Osservatorio Astronómico Di Palermo; ItaliaFil: Telezhinsky, I.. Kiev National Taras Shevchenko University; Ucrani

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Supernova Remnants with Jets

Cited by 53 publications

References 1 publication

The first VLBI image of the young, oxygen-rich supernova remnant in NGC 4449

The first VLBI image of the young, oxygen-rich supernova remnant in NGC 4449

Some properties of synchrotron radio and inverse-Compton gamma-ray images of supernova remnants

Aspect angle for interstellar magnetic field in SN 1006

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