SN 2014av is a type Ibn supernova(SN)characterized by the interaction between the SN ejecta and a helium-rich circumstellar medium(CSM).We use the^(56)Ni model,the ejecta-CSM interaction(CSI)model,and the CSI plus^(56...SN 2014av is a type Ibn supernova(SN)characterized by the interaction between the SN ejecta and a helium-rich circumstellar medium(CSM).We use the^(56)Ni model,the ejecta-CSM interaction(CSI)model,and the CSI plus^(56)Ni model to fit the multiband light curves(LCs)of SN 2014av.For the CSI and CSI plus^(56)Ni models,we assume that the CSM is a constant density shell(“shell”)or a steady-state stellar wind(“wind”)with density∝r-2.We find that both the^(56)Ni and CSI models fail to fit the multiband LCs of SN 2014av,while the CSI plus^(56)Ni model can account for the LCs.In the last scenario,the LCs around the peaks were mainly powered by the CSI,while the flattening of the LCs was mainly powered by the radioactive decay of^(56)Ni.For the wind case,the derived mass-loss rate of the progenitor is≈20.5-205.5 M_(⊙)yr^(-1),whose lower limit is significantly larger than the upper limit of normal stellar winds,and comparable the upper limit of hyper-winds.Hence,we suggest that the wind case is disfavored.For the shell case,the best-fitting values of the ejecta,^(56)Ni,and the CSM are2.29 M_(⊙),0.09 M_(⊙),and 5.00 M_(⊙),respectively.Provided the velocity of the CSM shell is 100-1000 km s^(-1),we infer that the shell might be expelled≈0.49-5.20 yr before the SN exploded.展开更多
I suggest the double-degenerate(DD)scenario with a merger-to-explosion delay(MED)time(the DD-MED scenario)of about 1-2 yr to explain the rare properties of the recently analyzed typeⅠa supernova(SN Ia)SN2020aeuh.The ...I suggest the double-degenerate(DD)scenario with a merger-to-explosion delay(MED)time(the DD-MED scenario)of about 1-2 yr to explain the rare properties of the recently analyzed typeⅠa supernova(SN Ia)SN2020aeuh.The rare properties are the SNⅠa ejecta interacting with a carbon-oxygen(CO)-rich circumstellar material(CSM)at approximately 50 days post-explosion.In this DD-MED scenario,two massive CO white dwarfs(WDs),with masses of M_(1)■1.1M_(☉)and M_(2)■M_(☉),merge to leave a rapidly rotating lonely WD of about the Chandrasekhar mass.The merger process ejects M_(CSM)■0.7M_(☉)to form a nonspherical CO-rich CSM.At the explosion,there is a lonely WD and a detached hydrogen-and helium-deficient CSM.Studies proposed the other lonely WD scenario,the core-degenerate(CD)scenario,to explain several specific SNe Ia and SN Ia remnants.SN 2020aeuh is the first particular SN Ia that is attributed to the DD-MED scenario.Besides being slightly brighter than typical SNe Ia and the CSM interaction,SN 2020aeuh is a normal SN Ia.Therefore,this study strengthens the claim of earlier studies,which are based on other arguments,like the properties of SN Ia remnants,that the lonely WD scenarios,i.e.,the DD-MED and CD scenarios,might account for most,if not all,normal SNe Ia.These earlier studies also argue that all SN Ia scenarios,whether lonely WD or not,might contribute to peculiar SNe Ia.展开更多
I examine the morphology of the core-collapse supernova(CCSN)remnant(SNR)G0.9+0.1 and reveal a pointsymmetrical morphology that implies shaping by three or more pairs of jets,as expected in the jittering jets explosio...I examine the morphology of the core-collapse supernova(CCSN)remnant(SNR)G0.9+0.1 and reveal a pointsymmetrical morphology that implies shaping by three or more pairs of jets,as expected in the jittering jets explosion mechanism(JJEM).The large northwest protrusion,the ear(or lobe),has two bright rims.I compare this ear with its rims to an ear with three rims of a jet-shaped planetary nebula and jets from an active galactic nucleus that shaped several rims on one side.Based on this similarity,I argue that two jets or more shaped the northwest ear of SNR G0.9+0.1 and its two rims.I identified the bright region south of the main shell of SNR G0.9+0.1 as a jet-shaped blowout formed by a jet that broke out from the main SNR shell.I base this on the similarity of the blowout of SNR G0.9+0.1 with that of SNR G309.2-00.6,argued in the past to be shaped by jets.I identify four symmetry axes along different directions that compose the point-symmetric morphology of SNR G0.9+0.1.I show that the morphological features of holes,granular texture,and random filaments exist in CCSNe and planetary nebulae and are unlikely to result from some unique processes in CCSNe.These structures result from similar instabilities in the JJEM and the neutrino-driven explosion mechanism and,unlike a point-symmetric morphology,cannot determine the explosion mechanism.Identifying SNR G0.9+0.1 as a new point-symmetric CCSN strengthens the JJEM as the primary explosion mechanism of CCSNe.展开更多
基金supported by the National Key R&D Program(2024YFA1611700)the National Natural Science Foundation of China(grant Nos.12133003,12494571 and 11963001)supported by the Guangxi Talent Program(“Highland of Innovation Talents”)and Program of Bagui Scholars(LHJ)。
文摘SN 2014av is a type Ibn supernova(SN)characterized by the interaction between the SN ejecta and a helium-rich circumstellar medium(CSM).We use the^(56)Ni model,the ejecta-CSM interaction(CSI)model,and the CSI plus^(56)Ni model to fit the multiband light curves(LCs)of SN 2014av.For the CSI and CSI plus^(56)Ni models,we assume that the CSM is a constant density shell(“shell”)or a steady-state stellar wind(“wind”)with density∝r-2.We find that both the^(56)Ni and CSI models fail to fit the multiband LCs of SN 2014av,while the CSI plus^(56)Ni model can account for the LCs.In the last scenario,the LCs around the peaks were mainly powered by the CSI,while the flattening of the LCs was mainly powered by the radioactive decay of^(56)Ni.For the wind case,the derived mass-loss rate of the progenitor is≈20.5-205.5 M_(⊙)yr^(-1),whose lower limit is significantly larger than the upper limit of normal stellar winds,and comparable the upper limit of hyper-winds.Hence,we suggest that the wind case is disfavored.For the shell case,the best-fitting values of the ejecta,^(56)Ni,and the CSM are2.29 M_(⊙),0.09 M_(⊙),and 5.00 M_(⊙),respectively.Provided the velocity of the CSM shell is 100-1000 km s^(-1),we infer that the shell might be expelled≈0.49-5.20 yr before the SN exploded.
文摘I suggest the double-degenerate(DD)scenario with a merger-to-explosion delay(MED)time(the DD-MED scenario)of about 1-2 yr to explain the rare properties of the recently analyzed typeⅠa supernova(SN Ia)SN2020aeuh.The rare properties are the SNⅠa ejecta interacting with a carbon-oxygen(CO)-rich circumstellar material(CSM)at approximately 50 days post-explosion.In this DD-MED scenario,two massive CO white dwarfs(WDs),with masses of M_(1)■1.1M_(☉)and M_(2)■M_(☉),merge to leave a rapidly rotating lonely WD of about the Chandrasekhar mass.The merger process ejects M_(CSM)■0.7M_(☉)to form a nonspherical CO-rich CSM.At the explosion,there is a lonely WD and a detached hydrogen-and helium-deficient CSM.Studies proposed the other lonely WD scenario,the core-degenerate(CD)scenario,to explain several specific SNe Ia and SN Ia remnants.SN 2020aeuh is the first particular SN Ia that is attributed to the DD-MED scenario.Besides being slightly brighter than typical SNe Ia and the CSM interaction,SN 2020aeuh is a normal SN Ia.Therefore,this study strengthens the claim of earlier studies,which are based on other arguments,like the properties of SN Ia remnants,that the lonely WD scenarios,i.e.,the DD-MED and CD scenarios,might account for most,if not all,normal SNe Ia.These earlier studies also argue that all SN Ia scenarios,whether lonely WD or not,might contribute to peculiar SNe Ia.
文摘I examine the morphology of the core-collapse supernova(CCSN)remnant(SNR)G0.9+0.1 and reveal a pointsymmetrical morphology that implies shaping by three or more pairs of jets,as expected in the jittering jets explosion mechanism(JJEM).The large northwest protrusion,the ear(or lobe),has two bright rims.I compare this ear with its rims to an ear with three rims of a jet-shaped planetary nebula and jets from an active galactic nucleus that shaped several rims on one side.Based on this similarity,I argue that two jets or more shaped the northwest ear of SNR G0.9+0.1 and its two rims.I identified the bright region south of the main shell of SNR G0.9+0.1 as a jet-shaped blowout formed by a jet that broke out from the main SNR shell.I base this on the similarity of the blowout of SNR G0.9+0.1 with that of SNR G309.2-00.6,argued in the past to be shaped by jets.I identify four symmetry axes along different directions that compose the point-symmetric morphology of SNR G0.9+0.1.I show that the morphological features of holes,granular texture,and random filaments exist in CCSNe and planetary nebulae and are unlikely to result from some unique processes in CCSNe.These structures result from similar instabilities in the JJEM and the neutrino-driven explosion mechanism and,unlike a point-symmetric morphology,cannot determine the explosion mechanism.Identifying SNR G0.9+0.1 as a new point-symmetric CCSN strengthens the JJEM as the primary explosion mechanism of CCSNe.
