The vela supernova remnant: The unique morphological features of jittering jets
Noam Soker Dmitry Shishkin





0000-0003-0375-8987]Noam Soker
Department of Physics, Technion, Haifa, 3200003, Israel; s.dmitry@campus.technion.ac.il; soker@physics.technion.ac.il

0000-0002-9444-9460]Dmitry Shishkin
Department of Physics, Technion, Haifa, 3200003, Israel; s.dmitry@campus.technion.ac.il; soker@physics.technion.ac.il



§ ABSTRACT 
 We identify an S-shaped main-jet axis in the Vela core-collapse supernova (CCSN) remnant (CCSNR) that we attribute to a pair of precessing jets, one of the tens of pairs of jets that exploded the progenitor of Vela according to the jittering jets explosion mechanism (JJEM). A main-jet axis is a symmetry axis across the CCSNR and through the center. We identify the S-shaped main-jet axis by the high abundance of ejecta elements, oxygen, neon, and magnesium. We bring the number of identified pairs of clumps and ears in Vela to seven, two pairs shaped by the pair of precessing jets that formed the main-jet axis. The pairs and the main-jet axis form the point-symmetric wind-rose structure of Vela. The other five pairs of clumps/ears do not have signatures near the center, only on two opposite sides of the CCSNR.  We discuss different possible jet-less shaping mechanisms to form such a point-symmetric morphology and dismiss these processes because they cannot explain the point-symmetric morphology of Vela, the S-shaped high ejecta abundance pattern, and the enormous energy to shape the S-shaped structure. Our findings strongly support the JJEM and further severely challenge the neutrino-driven explosion mechanism. 





§ INTRODUCTION




Recent studies discuss two alternative theoretical explosion mechanisms of core-collapse supernovae (CCSNe), the delayed neutrino-driven mechanism and the jittering jets explosion mechanism (JJEM; for a most recent review, see ). Recent studies of the neutrino-driven mechanism focus on three-dimensional simulations, starting with the pre-collapse stellar core to seconds after the revival of the stalled shock at ≃ 100 from the newly born neutron star (NS; e.g., ). The magnetorotational explosion, which occurs when the progenitor core rotates rapidly and possesses strong magnetic fields (e.g., ), is included under the neutrino-driven as it still attributes most CCSNe to the neutrino-driven mechanism and only rare cases to jet-driven with a fixed axis. 

On the other hand, recent studies of the JJEM focus on finding signatures of jittering jets in CCSN remnants (CCSNRs; e.g., ). Last year's findings of such signatures in several CCSNRs and other expected signatures of the JJEM have led to a possible breakthrough in establishing the JJEM as the main, or even sole, explosion mechanism of CCSNe (review by  ). Neutrino heating plays a role in the JJEM but not the primary role. Namely, neutrino heating can help the launching of the jets from the intermittent accretion disks (or belts) around the newly born NS (but magnetic fields are also needed), and neutrino can boost the jet energy after they were launched <cit.>.

In the JJEM, pairs of jets with varying directions that the newly born NS, or black hole in some cases, launches explode the star (e.g., ). The source of the stochastic angular momentum of the gas that the NS accretes is the pre-collapse convective angular momentum fluctuations in the core (e.g., ) that instabilities above the newly born NS amplify, mainly instability modes of the spiral standing accretion shock instability (SASI; e.g.,  , for spiral-SASI). Envelope convection can be the seeds of the angular momentum fluctuations in electron-capture supernovae (), or if, for some reason, the accretion of core material does not explode the star and a black hole is formed (). 

According to the JJEM, a black hole is formed when, because of a rapidly rotating pre-collapse core, the central newly born NS (before collapsing to a black hole) launches the exploding jets along a fixed axis that implies inefficient jet feedback mechanism (e.g., ). A large amount of accreted mass can result in a super-energetic CCSN (e.g., ). There is a small jittering around the fixed axis. 

In the JJEM, there are several to a few tens jet-launching episodes. The stellar core material that did not collapse to the newly born NS chocks most of these jets acquires their energy and explodes. From that time, the explosion is similar in many aspects, but not all, to the neutrino-driven explosion mechanism; e.g., there are many instabilities, and the NS acquires a kick. However, the later jets expand more freely and can leave imprints on the ejecta; these jets are still part of the exploding jets and are not post-explosion jets. Each late jet pair can leave two opposite (relative to the center of the explosion) morphological features. If two or more pairs of jets are along different axes, the outcome is a point-symmetric morphology. The point-symmetric morphology of the Vela CCSNR is compatible with the JJEM (e.g., ).
In many cases, the two opposite jets in a pair will not be equal in their power and opening angle because of the short-lived launching accretion disk <cit.>. 
   
The JJEM allows for the last pair or two to be long-lived and hence have a sizeable morphological impact in forming a morphological feature from one side through the center to the other side of the CCSNR <cit.>. Such are the main jet-axis of SN 1987a, the keyhole structure <cit.>, the main jet-axis of SNR 0540-69.3 <cit.>, and the main jet-axis, the S-shaped hose of the Cygnus Loop <cit.>. In this study, we reveal the main-jet axis of the Vela SNR (section <ref>) and argue that only jets can shape it. The point-symmetric morphology of the Vela CCSNR leaves only the JJEM as a viable explanation for its explosion and shaping. We add this finding to earlier findings of other CCSNRs to compare the JJEM with possible alternatives for these morphological features; we find that only the JJEM can account for all morphological properties (Section <ref>). 
We summarize this study in Section <ref>. 






§ IDENTIFYING THE MAIN AXIS OF THE VELA CCSNR






 §.§ The point-symmetric wind-rose of Vela




Earlier studies of Vela identified several clumps of Vela; these are clumps A-L in Figure <ref>. <cit.> marked clumps A-F, <cit.> added clumps G and drew the line AG, <cit.> added more clumps' labeling, and <cit.> identified the possible clump L. <cit.> argued that clumps K and G are counter to clump A and are jet-like structure from the explosion process. <cit.> identified clump H2 from X-ray images by <cit.> and extended the point-symmetric wind-rose of Vela from <cit.> to include the symmetry lines (axes) AG, DE, FJ, and HH2. 




The high Si abundance of clumps A <cit.>, G, and K  <cit.> implies that they originate deep inside Vela's progenitor's core.  <cit.> found clump D to have ONeMg overabundance, indicating its origin from near the remnant's center, as previously <cit.> suggested. <cit.> took ears D and E to compose the main jet-axis of Vela and estimated the total energy of the two jets that inflated these ears to be ≈ 1 % of the Vela explosion energy, which is very low energy. We identify a new main-jet axis (section <ref>), which, together with the other jet pairs, can bring the total energy of the shaping jets to be tens of percent of the explosion energy. According to the JJEM, the rest of the explosion energy is due to earlier jets that did not leave an imprint on the point symmetric morphology because they exploded the core of the stellar progenitor. 

Although clumps B2 and C2, which we define in figure <ref> are small, they are (i) prominent in their surroundings, and (ii) not smaller than clumps A and L and not much smaller than clumps G that were identified in the past as clumps. The last property is shared by clump L2, which we also identify in Figure <ref>. When we connect B2 to B, C2 to C, and L2 to L (three dashed lines in Figure <ref>), the three lines cross the center defined by the other five symmetry lines (up to the uncertainty in the centers of the clumps at the ends of the lines). In section <ref>, we argue that pairs LL2 and HH2 belong to one pair of processing jets. 

Three crucial comments regarding the seven pairs of clumps composing Vela's point-symmetric wind-rose are in place here. (1) In the JJEM, the two jets in each pair of jets are expected to be unequal in their opening angle and power because the intermittent accretion disk that launches the pair of jets has no time to fully relax <cit.>.  Therefore, the centers of the symmetry lines, marked by blue dots, might miss the lines' cross-point, and not all lines will cross at precisely the same point. (2) Not each pair of clumps are necessarily the heads of two opposite jets. Dense clumps might be formed in compressed zones between jet-inflated bubbles. This is observed in the hot gas of clusters of galaxies, e.g., Abell 2597 <cit.>, and was found in the hydrodynamical simulations of the early phase of the JJEM <cit.>.  (3) The distance of the average centers of the lines (blue asterisk) from the NS location (red asterisk) and the distances of the cross points of the symmetry axes with each other from the NS location are similar to the distance the NS has moved from the explosion site to its present location. Considering the unequal jets in a pair (point 1), the center of the seven symmetry axes is sufficiently close to the present location of the NS and to the location of the NS at the explosion to be associated with the explosion. Namely, pairs of jets exploded the progenitor of the Vela SNR. 

We turn to identify Vela's main-jet axis. 




 §.§ The main-jet axis of Vela




In this section, we use the new results of the eROSITA X-ray telescope to identify Vela's main-jet axis. A main-jet axis is one across the diameter of the SNR, i.e., with a structure inside the main SNR shell in addition to the SNR outer zones. For example, in the most prominent pair of ears, the ears (clumps) D and E have prominent structures in the outer zones of the SNR. However, near the center, no signatures are related to the symmetry axis connecting ears D and E.  

<cit.> performed an extensive study of the Vela SNR in the X-ray, using the eROSITA DR1 data. Their results include some abundance distributions in the SNR as contrived from a spectral model fitted to the X-ray data. They identify enhanced abundances (relative to solar ratios) of oxygen, neon, and magnesium along a zone extending north to south and through the remnant's center. In Figure <ref>, we present the distribution of neon abundance. The region of enhanced neon abundance through the center has an S-shaped morphology (and so are oxygen and magnesium in the maps that  present). The S-shaped structure, which we identify as the main-jet axis and draw by a dotted line in Figure <ref>, includes on its northern end clumps H and L2, and its southern end clumps H2 with L further out. We attribute the pairs HH2 and LL2 to the same pair of jets, a precessing jet pair.  




In Figure <ref>, we present the Vela SNR X-ray image separated by energy ranges, soft, 0.2-0.7 (upper panel), combined, including the higher range in which the SNR is still visible, 1.1-2.3 (middle panel), and  0.7-1.1 (lower panel). In the upper and lower panels of Figure <ref>, we draw two symmetric sides of an S-shaped axis (dashed lines), different from the one that we draw in Figure <ref>. The difference between the two S-shaped axes conveys the uncertainty in the exact center of the north-south S-shaped structure.  




We identify another structure that we attribute to the pairs of pressing jets that formed the main-jet axis. The images in Figure <ref> reveal a sharp boundary between an inner elongated bright S-shaped structure and a fainter outer structure. We mark this boundary in the middle panel of Figure <ref>. In some segments of the closed boundary, the jump in brightness is clear, and in some, it is less clear. This boundary is around the S-shaped main-jet axis. We suggest that this boundary-enclosed material was shaped by the energetic jets of the main-jet axis. 

In Figure <ref>, we draw the point-symmetric wind-rose from Figure <ref>, the dotted S-shaped line from Figure <ref>, and the dashed-blue S-shaped line and the dashed-white boundary from Figure <ref> on the same X-ray image of Vela. The point symmetric structure appears here in its full glory. We emphasize that the two S-shaped lines (dotted and dashed) are not two jet pairs but one processing pair of jets with uncertain locations; this is the main-jet axis of Vela. The HH2 axis and LL2 axis do not represent separate jet pairs but rather clumps that belong to the same processing jet pair. 




Near the center, the direction of the S-shaped that we draw with the dashed blue line in figures <ref> and <ref> is parallel to the jets' direction of the pulsar of the Vela SNR, PSR B0833-45 (e.g., 
). Namely, to the accuracy in determining the S-shaped line, e.g., compare the dashed and dotted S-shaped lines in Figure <ref>, near the center, the S-shaped segment is more or less parallel to the spin of the pulsar. However, the symmetry axes HH2 and LL2 are almost perpendicular to the spin direction. 
 We also note that the pulsar wind nebula (PWN)  covers a small region of the sky, only ≃ 8^'' across (e.g., ). Therefore, the shaping of the S-shaped structure cannot be due to the PWN.




§ OBSERVATIONAL EVIDENCE FOR POINT-SYMMETRIC EXPLODING JETS




According to the JJEM, energetic jets, as expected to explode the star, can account for the properties of the point-symmetric structures of CCSNRs, including pairs of opposite clumps, filaments, ears, lobes, and nozzles. 
Other processes can also contribute to the shaping of CCSNRs but cannot explain the majority of observed point-symmetric morphologies. In Table <ref>, we list four shaping processes and whether they can or cannot account for specific morphologies of some CCSNRs. Although the interstellar medium (ISM) also influences the morphology of CCSNRs (e.g.,  for a very recent study), it cannot explain the basic morphological features we are studying here, in particular point symmetry. The ISM does poorer than the CSM in accounting for the CCSNR properties we are interested in. Only the JJEM can account for all the morphological structures we examine in the Table.  





We did not include shaping by a possible pulsar wind nebula because, in most CCSNRs we study, there is no indication of a pulsar wind nebula (e.g., SN 1987A). Also, in general, pulsar wind nebula power is insufficient to explain the shaping of large structures along the polar directions. Instead, the pulsar wind nebula's shocked material fills the CCSNR volume.  

According to the neutrino-driven explosion mechanism, post-explosion jets might shape CCSNRs, like Cassiopeia A (e.g., ). According to Table <ref>, shaping by post-explosion jets can take place in some cases (only in some cases) if the axes of pairs of jets change between jet launching episodes and the jets are energetic. This raises the question of why earlier jets could not be launched either; these early jets then explode the star. In some cases, the post-explosion jets cannot account for the observed properties. Only exploding jets with varying directions can account for all observed morphologies. 
Indeed, <cit.> discuss the formation of pairs of ears by fallback material (see also ), but comment that this outflow is not expected to be energetic. 
<cit.> also simulated post-explosion jets that can only shape the very inner zones of the ejecta; this also holds for jets launched by an NS companion (e.g., ). <cit.> show that very late jets, launched weeks after the explosion, can power a peak in the light curve. However, these jets cannot form large-scale point-symmetric morphologies.  
The famous case of SNR W50 is observed to be shaped by precessing jets that the central binary system SS433 launches. This is a different category of processes that do not belong to this study because it involves a post-explosion active binary system.    

We emphasize that all the processes we list can take place. In particular, we expect the interstellar medium (e.g.,  ), CSM (e.g., ) and instabilities (e.g., ) to play a role in shaping the majority of CCSNe (the CSM might influence only older CCSNRs, as the CSM of SN 1987A did not affect the inner massive ejecta yet).  Also, an NS natal kick is expected in the JJEM to be similar to the neutrino-driven explosion mechanism but to avoid small angles with the main-jet axis (e.g., ). 
However, instabilities and the ejecta-CSM interaction smear and dilute the point-symmetric morphology rather than produce it. 
Moreover, the hot ejecta itself expands and smears point-symmetrical features; hot ejecta results from the explosion itself, the decay of nickel (nickel bubbles; e.g., ), and the reverse shock (e.g., ).  
For these smearing processes, it is hard to identify point-symmetric morphological components in many cases. The NS kick, accompanied by asymmetrical mass ejection, adds to the smearing of point symmetry. The main properties of instabilities, ejecta-CSM interaction, and NS kick in the JJEM (e.g., ) are similar to those in the neutrino-driven explosion mechanism (e.g., NS kick, ). The JJEM may have another process to impart a natal kick to the NS, the kick by early asymmetrical pair (kick-BEAP) mechanism <cit.>. The JJEM has jets that carry more energy than instabilities. Hence, the jets can form point-symmetric morphological structures. Instabilities, nonetheless, somewhat smear the point symmetry.  


Other features further support the JJEM. 
Jittering in a plane. 
The ejecta of Cassiopeia A is concentrated around one plane <cit.>.  <cit.> speculated that the torus morphology of a tilted thick disc with multiple jets in Cassiopeia A, as observations find (e.g., ), results from the tendency of jittering jets in the JJEM to share a plane, up to the fluctuations that change jets' axes, and which can even avoid the planar jittering. <cit.> confirmed this speculation by identifying the point symmetry of Cassiopeia A; because dense clumps, which are concentrated in this plane, are much brighter than their surroundings, there might be bias in emission from this plane (e.g., ), implying the possible presence of massive ejecta also perpendicular to this plane.  A planar jittering might also shaped SNR 0540-69.3; this requires further study. 
Main-jet axis. This is the case with the `keyhole' structure of SN 1987A, the jet axis of SNR 0540-69.3, and the S-shaped hose that is the main jet-axis of the Cygnus loop <cit.>. The explanation in the frame of the JJEM <cit.> is that at the end of the accretion process onto the newly born NS, the mass accretion decreases so that the time scale of the fluctuations of the angular momentum increases, allowing long-lived jet-launching episodes; in particular the last one. This last pair of jets might form the main-jet axis. Note that this axis need not be along the pre-collapse rotation axis of the core in case the pre-collapse rotation is slow. 
An interaction with a CSM shapes the outskirts of the SNR; it cannot form a main jet-axis with imprints in the remnant's center, as with the Vela SNR (Section <ref>). Based on the above, we dismiss the suggestion of <cit.> that a CSM shaped the Vela SNR. 




§ SUMMARY




The main result of this study is the identification of a main-jet axis in the Vela CCSNR. This is the S-shaped structure we draw in Figures <ref> - <ref>. We based this identification on the high abundance of ejecta material, namely, O, Ne, and Mg, as the X-ray analysis of Vela by <cit.> reveals (Figure <ref>) and on the boundary of the X-ray bright inner zone that we draw on Figures <ref> and <ref>. 

In earlier studies (), we discussed The point-symmetric morphology of the Vela CCSNR and its formation in the JJEM based only on outer ears and clumps. Identifying the S-shaped ejecta-rich main-jet axis has two critical implications. (1) The high abundance of O, Ne, and Mg implies that the S-shaped material was ejected during the explosion, as these metals come from the deep core. (2) The large volume that the precessing jets that we take to have formed the S-shaped main-jet axis influenced (the boundary drawn on Figures <ref> and <ref>), implies that these jets were very energetic. <cit.>, who considered only the pair DE, found the energy in the jets that inflated these two ears to add up to only ≈ 1 % of the Vela explosion energy. Now, with the other pairs and the two precessing jets that shaped the main-jet axis, the energy adds up to a much more significant fraction of the explosion energy. This is compatible with the JJEM, as early jets in the explosion process that supplied the rest of the explosion energy did not leave marks in the morphology.   

As discussed in Section <ref>, other shaping processes can not explain the extension of the main-jet axis through the center, the ejecta abundance pattern, the large volume of the main-jet axis, and the point-symmetric wind-rose morphology (see Table <ref>). 

We consider the point-symmetric morphologies of CCSNRs to pose the most severe challenge to the neutrino-driven explosion mechanism, as Table <ref> shows. It might be that these point-symmetric CCSNRs even rule out the neutrino-driven explosion mechanism. We emphasize that neutrino heating does take place, but in boosting the energy of the jittering jets at launching and in their interaction with the inner core, rather than being the primary explosion process <cit.>. Studies have identified point-symmetric morphology in ten CCSNRs, some with clear point-symmetric wind-rose and some with more subtle point-symmetric morphologies; we expect to increase this number in 2025. 






§ ACKNOWLEDGEMENTS


 A grant from the Pazy Foundation supported this research. 


natexlab#1#1




[Akashi & Soker(2020)]AkashiSoker2020
Akashi, M., & Soker, N. 2020, , 901, 53, 10.3847/1538-4357/abad35

[Akashi & Soker(2021)]AkashiSoker2021
—. 2021, , 501, 4053, 10.1093/mnras/staa3897

[Akashi & Soker(2022)]AkashiSoker2022
—. 2022, , 930, 59, 10.3847/1538-4357/ac6102

[Andresen et al.(2019)Andresen, Müller, Janka, Summa, Gill, & Zanolin]Andresenetal2019
Andresen, H., Müller, E., Janka, H. T., et al. 2019, , 486, 2238, 10.1093/mnras/stz990

[Antoni & Quataert(2022)]AntoniQuataert2022
Antoni, A., & Quataert, E. 2022, , 511, 176, 10.1093/mnras/stab3776

[Antoni & Quataert(2023)]AntoniQuataert2023
—. 2023, , 525, 1229, 10.1093/mnras/stad2328

[Aschenbach et al.(1995)Aschenbach, Egger, & Trümper]Aschenbachetal1995
Aschenbach, B., Egger, R., & Trümper, J. 1995, , 373, 587, 10.1038/373587a0

[Bear et al.(2024)Bear, Shishkin, & Soker]BearShishkinSoker2024
Bear, E., Shishkin, D., & Soker, N. 2024, In preparation

[Bear & Soker(2023a)]BearSoker2023
Bear, E., & Soker, N. 2023a, Research Notes of the American Astronomical Society, 7, 266, 10.3847/2515-5172/ad1392

[Bear & Soker(2023b)]BearSoker2023RNAAS
—. 2023b, Research Notes of the American Astronomical Society, 7, 266, 10.3847/2515-5172/ad1392

[Bear & Soker(2024)]BearSoker2024
—. 2024, arXiv e-prints, arXiv:2403.07625, 10.48550/arXiv.2403.07625

[Burrows et al.(2024)Burrows, Wang, Vartanyan, & Coleman]Burrowsetal2024
Burrows, A., Wang, T., Vartanyan, D., & Coleman, M. S. B. 2024, , 963, 63, 10.3847/1538-4357/ad2353

[Chiotellis et al.(2021)Chiotellis, Boumis, & Spetsieri]Chiotellisetal2021
Chiotellis, A., Boumis, P., & Spetsieri, Z. T. 2021, , 502, 176, 10.1093/mnras/staa3573

[Chiotellis et al.(2024)Chiotellis, Zapartas, & Meyer]ChiotellisZapartasMeyer2024
Chiotellis, A., Zapartas, E., & Meyer, D. M. A. 2024, , 531, 5109, 10.1093/mnras/stae947

[DeLaney et al.(2010)DeLaney, Rudnick, Stage, Smith, Isensee, Rho, Allen, Gomez, Kozasa, Reach, Davis, & Houck]DeLaneyetal2010
DeLaney, T., Rudnick, L., Stage, M. D., et al. 2010, , 725, 2038, 10.1088/0004-637X/725/2/2038

[Dodson et al.(2003)Dodson, Legge, Reynolds, & McCulloch]Dodson_etal_2003
Dodson, R., Legge, D., Reynolds, J. E., & McCulloch, P. M. 2003, , 596, 1137, 10.1086/378089

[Fateeva et al.(2023)Fateeva, Levenfish, Ponomaryov, Petrov, & Fursov]Fateevaetal2023
Fateeva, S. S., Levenfish, K. P., Ponomaryov, G. A., Petrov, A. E., & Fursov, A. N. 2023, Astronomy Letters, 49, 56, 10.1134/S1063773723020020

[García et al.(2017)García, Suárez, Miceli, Bocchino, Combi, Orlando, & Sasaki]Garciaetal2017
García, F., Suárez, A. E., Miceli, M., et al. 2017, , 604, L5, 10.1051/0004-6361/201731418

[Gilkis & Soker(2014)]GilkisSoker2014
Gilkis, A., & Soker, N. 2014, , 439, 4011, 10.1093/mnras/stu257

[Gilkis & Soker(2016)]GilkisSoker2016
—. 2016, , 827, 40, 10.3847/0004-637X/827/1/40

[Gilkis et al.(2016)Gilkis, Soker, & Papish]Gilkisetal2016
Gilkis, A., Soker, N., & Papish, O. 2016, , 826, 178, 10.3847/0004-637X/826/2/178

[Grefenstette et al.(2017)Grefenstette, Fryer, Harrison, Boggs, DeLaney, Laming, Reynolds, Alexander, Barret, Christensen, Craig, Forster, Giommi, Hailey, Hornstrup, Kitaguchi, Koglin, Lopez, Mao, Madsen, Miyasaka, Mori, Perri, Pivovaroff, Puccetti, Rana, Stern, Westergaard, Wik, Zhang, & Zoglauer]Grefenstetteetal2017
Grefenstette, B. W., Fryer, C. L., Harrison, F. A., et al. 2017, , 834, 19, 10.3847/1538-4357/834/1/19

[Grichener & Soker(2017a)]GrichenerSoker2017ears
Grichener, A., & Soker, N. 2017a, , 468, 1226, 10.1093/mnras/stx534

[Grichener & Soker(2017b)]GrichenerSoker2017
—. 2017b, , 468, 1226, 10.1093/mnras/stx534

[Gvaramadze(2000)]Gvaramadze2000
Gvaramadze, V. 2000, , 274, 195, 10.1023/A:1026512410294

[Helfand et al.(2001)Helfand, Gotthelf, & Halpern]Helfandetal2001
Helfand, D. J., Gotthelf, E. V., & Halpern, J. P. 2001, , 556, 380, 10.1086/321533

[Hwang & Laming(2012)]HwangLaming2012
Hwang, U., & Laming, J. M. 2012, , 746, 130, 10.1088/0004-637X/746/2/130

[Janka & Kresse(2024)]JankaKresse2024
Janka, H. T., & Kresse, D. 2024, arXiv e-prints, arXiv:2401.13817, 10.48550/arXiv.2401.13817

[Janka et al.(2022)Janka, Wongwathanarat, & Kramer]Jankaetal2022spin
Janka, H.-T., Wongwathanarat, A., & Kramer, M. 2022, , 926, 9, 10.3847/1538-4357/ac403c

[Katsuda & Tsunemi(2005)]KatsudaTsunemi2005
Katsuda, S., & Tsunemi, H. 2005, , 57, 621, 10.1093/pasj/57.4.621

[Katsuda & Tsunemi(2006)]KatsudaTsunemi2006
—. 2006, , 642, 917, 10.1086/501434

[Kochanek(2022)]Kochanek2022
Kochanek, C. S. 2022, , 511, 3428, 10.1093/mnras/stac098

[Larsson et al.(2021)Larsson, Sollerman, Lyman, Spyromilio, Tenhu, Fransson, & Lundqvist]Larssonetal2021
Larsson, J., Sollerman, J., Lyman, J. D., et al. 2021, , 922, 265, 10.3847/1538-4357/ac2a41

[Lu et al.(2021)Lu, Yan, Wen, & Fang]LuYanetal2021
Lu, C.-Y., Yan, J.-W., Wen, L., & Fang, J. 2021, Research in Astronomy and Astrophysics, 21, 033, 10.1088/1674-4527/21/2/33

[Mayer et al.(2023)Mayer, Becker, Predehl, & Sasaki]Mayeretal2023
Mayer, M. G. F., Becker, W., Predehl, P., & Sasaki, M. 2023, , 676, A68, 10.1051/0004-6361/202346691

[Meyer et al.(2024a)Meyer, Meliani, Velázquez, Pohl, & Torres]MeyerMelianietal2024
Meyer, D. M. A., Meliani, Z., Velázquez, P. F., Pohl, M., & Torres, D. F. 2024a, , 527, 5514, 10.1093/mnras/stad3495

[Meyer et al.(2024b)Meyer, Velázquez, Pohl, Egberts, Petrov, Villagran, Torres, & Batzofin]MeyerDetal2024
Meyer, D. M. A., Velázquez, P. F., Pohl, M., et al. 2024b, , 687, A127, 10.1051/0004-6361/202449706

[Meyer et al.(2022)Meyer, Velázquez, Petruk, Chiotellis, Pohl, Camps-Fariña, Petrov, Reynoso, Toledo-Roy, Schneiter, Castellanos-Ramírez, & Esquivel]Meyeretal2022
Meyer, D. M. A., Velázquez, P. F., Petruk, O., et al. 2022, , 515, 594, 10.1093/mnras/stac1832

[Milisavljevic & Fesen(2013)]MilisavljevicFesen2013
Milisavljevic, D., & Fesen, R. A. 2013, , 772, 134, 10.1088/0004-637X/772/2/134

[Milisavljevic et al.(2024)Milisavljevic, Temim, De Looze, Dickinson, Laming, Fesen, Raymond, Arendt, Vink, Posselt, Pavlov, Fox, Pinarski, Subrayan, Schmidt, Blair, Rest, Patnaude, Koo, Rho, Orlando, Janka, Andrews, Barlow, Burrows, Chevalier, Clayton, Fransson, Fryer, Gomez, Kirchschlager, Lee, Matsuura, Niculescu-Duvaz, Pierel, Plucinsky, Priestley, Ravi, Sartorio, Schmidt, Shahbandeh, Slane, Smith, Sravan, Weil, Wesson, & Wheeler]Milisavljevicetal2024
Milisavljevic, D., Temim, T., De Looze, I., et al. 2024, , 965, L27, 10.3847/2041-8213/ad324b

[Morse et al.(2006)Morse, Smith, Blair, Kirshner, Winkler, & Hughes]Morseetal2006
Morse, J. A., Smith, N., Blair, W. P., et al. 2006, , 644, 188, 10.1086/503313

[Müller(2023)]Muller2023spin
Müller, B. 2023, , 526, 2880, 10.1093/mnras/stad2881

[Müller(2024)]Muler2024
—. 2024, arXiv e-prints, arXiv:2403.18952, 10.48550/arXiv.2403.18952

[Müller et al.(2024)Müller, Heger, & Powell]Mulleretal2024
Müller, B., Heger, A., & Powell, J. 2024, arXiv e-prints, arXiv:2407.08407, 10.48550/arXiv.2407.08407

[Nagakura et al.(2021)Nagakura, Burrows, Vartanyan, & Radice]Nagakuraetal2021
Nagakura, H., Burrows, A., Vartanyan, D., & Radice, D. 2021, , 500, 696, 10.1093/mnras/staa2691

[Nakamura et al.(2024)Nakamura, Takiwaki, Matsumoto, & Kotake]Nakamuraetal2024
Nakamura, K., Takiwaki, T., Matsumoto, J., & Kotake, K. 2024, arXiv e-prints, arXiv:2405.08367, 10.48550/arXiv.2405.08367

[Orlando et al.(2021)Orlando, Wongwathanarat, Janka, Miceli, Ono, Nagataki, Bocchino, & Peres]Orlandoetal2021
Orlando, S., Wongwathanarat, A., Janka, H. T., et al. 2021, , 645, A66, 10.1051/0004-6361/202039335

[Papish & Soker(2011)]PapishSoker2011
Papish, O., & Soker, N. 2011, , 416, 1697, 10.1111/j.1365-2966.2011.18671.x

[Papish & Soker(2014)]PapishSoker2014Planar
—. 2014, , 443, 664, 10.1093/mnras/stu1129

[Quataert et al.(2019)Quataert, Lecoanet, & Coughlin]Quataertetal2019
Quataert, E., Lecoanet, D., & Coughlin, E. R. 2019, , 485, L83, 10.1093/mnrasl/slz031

[Sankrit et al.(2003)Sankrit, Blair, & Raymond]Sankritetal2003
Sankrit, R., Blair, W. P., & Raymond, J. C. 2003, , 589, 242, 10.1086/374591

[Sapienza et al.(2021)Sapienza, Miceli, Peres, Bocchino, Orlando, Greco, Combi, García, & Sasaki]Sapienzaetal2021
Sapienza, V., Miceli, M., Peres, G., et al. 2021, , 649, A56, 10.1051/0004-6361/202140412

[Shibagaki et al.(2021)Shibagaki, Kuroda, Kotake, & Takiwaki]Shibagakietal2021
Shibagaki, S., Kuroda, T., Kotake, K., & Takiwaki, T. 2021, , 502, 3066, 10.1093/mnras/stab228

[Shibagaki et al.(2024)Shibagaki, Kuroda, Kotake, Takiwaki, & Fischer]Shibagakietal2024
Shibagaki, S., Kuroda, T., Kotake, K., Takiwaki, T., & Fischer, T. 2024, , 531, 3732, 10.1093/mnras/stae1361

[Shishkin et al.(2024)Shishkin, Kaye, & Soker]ShishkinKayeSoker2024
Shishkin, D., Kaye, R., & Soker, N. 2024, arXiv e-prints, arXiv:2408.11014.
2408.11014

[Shishkin & Soker(2021)]ShishkinSoker2021
Shishkin, D., & Soker, N. 2021, , 508, L43, 10.1093/mnrasl/slab105

[Shishkin & Soker(2023)]ShishkinSoker2023
—. 2023, , 522, 438, 10.1093/mnras/stad889

[Shishkin & Soker(2024)]ShishkinSoker2024
—. 2024, In preparation

[Sofue(2024)]Sofue2024
Sofue, Y. 2024, arXiv e-prints, arXiv:2408.00260, 10.48550/arXiv.2408.00260

[Soker(2010)]Soker2010
Soker, N. 2010, , 401, 2793, 10.1111/j.1365-2966.2009.15862.x

[Soker(2020)]Soker2020RAA
—. 2020, Research in Astronomy and Astrophysics, 20, 024, 10.1088/1674-4527/20/2/24

[Soker(2022a)]Soker2022nu
—. 2022a, Research in Astronomy and Astrophysics, 22, 095007, 10.1088/1674-4527/ac7cbc

[Soker(2022b)]Soker2022Rev
—. 2022b, Research in Astronomy and Astrophysics, 22, 122003, 10.1088/1674-4527/ac9782

[Soker(2022c)]Soker2022SNR0540
—. 2022c, Research in Astronomy and Astrophysics, 22, 035019, 10.1088/1674-4527/ac49e6

[Soker(2023a)]Soker2023gap
—. 2023a, Research in Astronomy and Astrophysics, 23, 095020, 10.1088/1674-4527/ace9b3

[Soker(2023b)]Soker2023SNRclass
—. 2023b, Research in Astronomy and Astrophysics, 23, 115017, 10.1088/1674-4527/acf446

[Soker(2024a)]Soker2024Rev
—. 2024a, The Open Journal of Astrophysics, 7, 31, 10.33232/001c.117147

[Soker(2024b)]Soker2024key
—. 2024b, Research in Astronomy and Astrophysics, 24, 075006, 10.1088/1674-4527/ad4fc2

[Soker(2024c)]Soker2024NA1987A
—. 2024c, , 107, 102154, 10.1016/j.newast.2023.102154

[Soker(2024d)]Soker2024CF
—. 2024d, The Open Journal of Astrophysics, 7, 49, 10.33232/001c.120279

[Soker(2024e)]Soker2024CounterJet
—. 2024e, The Open Journal of Astrophysics, 7, 12, 10.21105/astro.2311.03286

[Soker(2024f)]Soker2024PNSN
—. 2024f, Galaxies, 12, 29, 10.3390/galaxies12030029

[Tremblay et al.(2018)Tremblay, Combes, Oonk, Russell, McDonald, Gaspari, Husemann, Nulsen, McNamara, Hamer, O'Dea, Baum, Davis, Donahue, Voit, Edge, Blanton, Bremer, Bulbul, Clarke, David, Edwards, Eggerman, Fabian, Forman, Jones, Kerman, Kraft, Li, Powell, Randall, Salomé, Simionescu, Su, Sun, Urry, Vantyghem, Wilkes, & ZuHone]Tremblayetal2018
Tremblay, G. R., Combes, F., Oonk, J. B. R., et al. 2018, , 865, 13, 10.3847/1538-4357/aad6dd

[van Baal et al.(2024)van Baal, Jerkstrand, Wongwathanarat, & Janka]vanBaaletal2024
van Baal, B. F. A., Jerkstrand, A., Wongwathanarat, A., & Janka, H.-T. 2024, , 10.1093/mnras/stae1603

[Velázquez et al.(2023)Velázquez, Meyer, Chiotellis, Cruz-Álvarez, Schneiter, Toledo-Roy, Reynoso, & Esquivel]Velazquezetal2023
Velázquez, P. F., Meyer, D. M. A., Chiotellis, A., et al. 2023, , 519, 5358, 10.1093/mnras/stad039

[Walk et al.(2020)Walk, Tamborra, Janka, Summa, & Kresse]Walketal2020
Walk, L., Tamborra, I., Janka, H.-T., Summa, A., & Kresse, D. 2020, , 101, 123013, 10.1103/PhysRevD.101.123013

[Wang et al.(2024)Wang, Shishkin, & Soker]WangShishkinSoker2024
Wang, N. Y. N., Shishkin, D., & Soker, N. 2024, arXiv e-prints, arXiv:2401.06652, 10.48550/arXiv.2401.06652

[Wang & Burrows(2024)]WangBurrows2024
Wang, T., & Burrows, A. 2024, , 969, 74, 10.3847/1538-4357/ad5009

[Willingale et al.(2003)Willingale, Bleeker, van der Heyden, & Kaastra]Willingaleetal2003
Willingale, R., Bleeker, J. A. M., van der Heyden, K. J., & Kaastra, J. S. 2003, , 398, 1021, 10.1051/0004-6361:20021554

[Wongwathanarat et al.(2013)Wongwathanarat, Janka, & Müller]Wongwathanaratetal2013kick
Wongwathanarat, A., Janka, H. T., & Müller, E. 2013, , 552, A126, 10.1051/0004-6361/201220636

[Wongwathanarat et al.(2015)Wongwathanarat, Müller, & Janka]Wongwathanaratetal2015
Wongwathanarat, A., Müller, E., & Janka, H. T. 2015, , 577, A48, 10.1051/0004-6361/201425025

[Wu & Zhang(2019)]Wuetal2019
Wu, D., & Zhang, M.-F. 2019, Research in Astronomy and Astrophysics, 19, 124, 10.1088/1674-4527/19/9/124

[Yan et al.(2020)Yan, Lu, Wen, Yu, & Fang]YanLuetal2020
Yan, J.-W., Lu, C.-Y., Wen, L., Yu, H., & Fang, J. 2020, Research in Astronomy and Astrophysics, 20, 154, 10.1088/1674-4527/20/9/154

[Zha et al.(2024)Zha, Müller, & Powell]ZhaMullerPowell2024
Zha, S., Müller, B., & Powell, J. 2024, arXiv e-prints, arXiv:2403.02072, 10.48550/arXiv.2403.02072


