SN 2006gy在可见光中辐射的能量比迄今为止任何其他超新星都要多,其能量需求的潜在解释对银河系化学演化和第一批恒星的死亡都有影响。它的亮度持续了200多天,比任何正常的超新星都要长,并且在可见光波段辐射出超过1e51尔格的光能。我认为,这种IIn型超新星可能是一个非常巨大的恒星,如船底座伊塔星爆炸时保留其氢包层,在其一生中遭受相对较小的质量损失。这发生在大约太阳的金属丰度挑战了目前的范式,质量损失的恒星演化。我探讨了SN2006gy的电源的一些潜在的解释,涉及要么拱星相互作用,或者相反,56Ni的衰变。如果SN 2006gy是由冲击能转化为光能提供动力的,那么条件必须是真正非凡的,传统的相互作用模型不起作用。如果SN 2006gy是由放射性衰变提供能量,那么令人不安的巨大56Ni质量要求这颗恒星爆炸为一颗对不稳定超新星。这种可能性使得SN 2006gy非常有趣,特别是在这次会议上,因为它是真正的对不稳定超新星的第一个很好的候选者。
英文摘要:
SN 2006gy radiated far more energy in visual light than any other supernova so far, and potential explanations for its energy demands have implications for galactic chemical evolution and the deaths of the first stars. It remained bright for over 200 days, longer than any normal supernova, and it radiated more than 1e51 ergs of luminous energy at visual wavelengths. I argue that this Type IIn supernova was probably the explosion of an extremely massive star like Eta Carinae that retained its hydrogen envelope when it exploded, having suffered relatively little mass loss during its lifetime. That this occurred at roughly Solar metallicity challenges current paradigms for mass loss in massive-star evolution. I explore a few potential explanations for SN2006gy's power source, involving either circumstellar interaction, or instead, the decay of 56Ni. If SN 2006gy was powered by the conversion of shock energy into light, then the conditions must be truly extraordinary and traditional interaction models don't work. If SN 2006gy was powered by radioactive decay, then the uncomfortably huge 56Ni mass requires that the star exploded as a pair instability supernova. The mere possibility of this makes SN 2006gy interesting, especially at this meeting, because it is the first good candidate for a genuine pair instability supernova.
Pair-Instability Supernovae, Gravity Waves, and Gamma-Ray Transients
越来越多的理论证据表明,第一代恒星的质量可能相当大(约100-300个太阳质量)。如果它们保持高质量直到死亡,这些恒星将在大约300万年后形成对不稳定的超新星。我们考虑两个零金属丰度恒星的250和300太阳质量的完整演化。爆炸性的氧和硅燃烧导致130太阳质量的氦核心爆炸,但爆炸性燃烧无法驱动300太阳质量的恒星爆炸,它坍缩成一个黑洞。对于这颗恒星,在前超新星模型中计算出的角动量足以延迟黑洞的形成,恒星最初形成了一个50个太阳质量,1000公里的核心,中微子被困在其中。虽然恒星不会变得动态不稳定,但计算出的长期旋转不稳定性的增长时间比黑洞形成时间短,并且这种不稳定性可能会发展。我们估计了在这次坍缩过程中发射的引力波的能量和振幅。黑洞形成后,吸积继续通过一个磁盘。虽然这个圆盘太大太冷,无法通过中微子湮灭有效地将能量传输到旋转轴,但它有足够的势能在磁场的驱动下产生1 e 54 erg的喷流。这种喷流与周围星周气体的相互作用可能会产生高能伽马射线瞬变,但考虑到红移和时间尺度,这可能不是典型伽马射线暴的模型。
On the spectrum of high-energy cosmic rays produced by supernova remnants in the presence of strong cosmic-ray streaming instability and wave dissipation