Forbidden hugs in pandemic times: IV. Panchromatic evolution of three luminous red novae
Forbidden hugs in pandemic times: IV. Panchromatic evolution of three luminous red novae
复制标题
大流行时期禁止的拥抱：IV。
DOI：
10.1051/0004-6361/202244684
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发表时间：
2023
影响因子：
6.5
通讯作者：
Valenti, S.
中科院分区：
文献类型：
--
作者：
Pastorello, A.;Valerin, G.;Fraser, M.;Reguitti, A.;Elias-Rosa, N.;Filippenko, A. V.;Rojas-Bravo, C.;Tartaglia, L.;Reynolds, T. M.;Valenti, S.
我们提供了三颗河外发光红新星 (LRNe) 的光度和光谱数据：AT 2018bwo、AT 2021afy 和 AT 2021blu。 AT 2018bwo 在爆发几周后在 NGC 45 中被发现（约 6.8 Mpc）。在监测期间，瞬态光度峰值达到1040erg s−1。由 UGC 10043 (∼49.2 Mpc) 主办的 AT 2021afy 显示出双峰光曲线，两个峰达到相似的光度 2.1(±0.6)×1041erg s−1。最后，对于 UGC 5829 中的 AT 2021blu (∼8.6 Mpc)，爆发前阶段通过几次光度测量得到了很好的监测，并且该物体在爆发前表现出缓慢的光度上升。 AT 2021blu 的光变曲线以前所未有的节奏进行采样，直到该物体消失在太阳后面，然后在后期被恢复。 LRN AT 2021blu的光变曲线呈现双峰，早期极大值突出，光度达到6.5 × 1040erg s−1，是AT 2021afy的一半。 AT 2021afy 和 AT 2021blu 的光谱显示了 LRNe 的预期演变：在第一个峰值期间，蓝色连续谱以突出的巴尔默线为主，而在第二个宽峰值期间，红色连续谱与具有窄吸收金属谱线的 K 型恒星一致。 AT 2018bwo 的光谱明显不同，具有由广泛的分子吸收特征主导的非常红色的连续谱。由于这些光谱与第二个峰值后的 LRNe 光谱非常相似，因此 AT 2018bwo 可能是在进化的非常晚期阶段发现的。这可以解释它的快速演化以及与 M 型恒星兼容的光谱特性。根据对爆发前数年LRN站点深部框架的分析以及光变曲线的考虑，三个LRNe的静止前体系统可能非常庞大，初级范围从AT 2018bwo的约13M⊙，到AT 2021blu的M⊙，以及AT 2021afy的超过40M⊙。
We present photometric and spectroscopic data on three extragalactic luminous red novae (LRNe): AT 2018bwo, AT 2021afy, and AT 2021blu. AT 2018bwo was discovered in NGC 45 (at about 6.8 Mpc) a few weeks after the outburst onset. During the monitoring period, the transient reached a peak luminosity of 1040erg s−1. AT 2021afy, hosted by UGC 10043 (∼49.2 Mpc), showed a double-peaked light curve, with the two peaks reaching a similar luminosity of 2.1(±0.6)×1041erg s−1. Finally, for AT 2021blu in UGC 5829 (∼8.6 Mpc), the pre-outburst phase was well-monitored by several photometric surveys, and the object showed a slow luminosity rise before the outburst. The light curve of AT 2021blu was sampled with an unprecedented cadence until the object disappeared behind the Sun, and it was then recovered at late phases. The light curve of LRN AT 2021blu shows a double peak, with a prominent early maximum reaching a luminosity of 6.5 × 1040erg s−1, which is half of that of AT 2021afy. The spectra of AT 2021afy and AT 2021blu display the expected evolution for LRNe: a blue continuum dominated by prominent Balmer lines in emission during the first peak, and a redder continuum consistent with that of a K-type star with narrow absorption metal lines during the second, broad maximum. The spectra of AT 2018bwo are markedly different, with a very red continuum dominated by broad molecular features in absorption. As these spectra closely resemble those of LRNe after the second peak, AT 2018bwo was probably discovered at the very late evolutionary stages. This would explain its fast evolution and the spectral properties compatible with that of an M-type star. From the analysis of deep frames of the LRN sites years before the outburst, and considerations of the light curves, the quiescent progenitor systems of the three LRNe were likely massive, with primaries ranging from about 13M⊙for AT 2018bwo, toM⊙for AT 2021blu, and over 40M⊙for AT 2021afy.