Photometry and spectroscopy of the Type Icn supernova 2021ckj
Photometry and spectroscopy of the Type Icn supernova 2021ckj
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Icn 型超新星 2021ckj 的光度测定和光谱学
DOI：
10.1051/0004-6361/202346084
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发表时间：
2023
影响因子：
6.5
通讯作者：
Regui
中科院分区：
文献类型：
--
作者：
Nagao T.;Kuncarayakti H.;Maeda K.;Moore T.;Pastorello A.;Mattila S.;Uno K.;Smartt S. J.;Sim S. A.;Ferrari L.;Tomasella L.;Anderson J. P.;Chen T.-W.;Galbany L.;Gao H.;Gromadzki M.;Guti?rrez C. P.;Inserra C.;Kankare E.;Magnier E. A.;M?ller-Bravo T. E.;Regui
我们给出了ICN超新星(SN)2021ckj型的光度和光谱观测结果。这种罕见的近地天体具有演化迅速、峰值光度高的特点，以及早期高度电离的碳线，这意味着它与贫氢和贫氦的星际物质(CSM)相互作用。SN2021CKJ在光学波段的峰值亮度为∼ − 20mag，在青色和黄色波段的上升时间和超过半峰值的时间分别为∼4和∼10天。这些特征让人联想到其他类型的ICN SNE(SNE 2019hgp、2021csp和2019jc)，SN 2021ockj的光度特性与SN 2021csp几乎相同。SN2021ockj的光谱模拟表明，它的组成以氧、碳、铁族元素为主，光球峰值速度为∼10 ，000 kM S−1。对SN2021ockj的光谱时间序列模拟表明，SN抛射是非球面的。通过对2021CKJ、2019hgp和2021csp型SNE的光曲线(LC)模拟，我们发现ICN型SNE的射出和CSM特性是不同的。SNE 2021CKJ和2021CSP可能有两个抛射分量(一个非球面高能分量和一个球面标准能分量)，其CSM大致为球形，而SN2019hgp可以仅用球形抛射-CSM相互作用来解释。SNE 2021CKJ和2021CSP的喷射物单位质量能量大于SN2019hgp的喷射物。CSM在这三个SNE中的密度分布相似，并与IBN SNE相当。这可能意味着质量损失机制在ICN型(以及IBN型)SNE中是常见的。SN2021CKJ和SN2021CSP的CSM质量比SN2019hgp的CSM质量大，尽管这些值都在IbN SNE的范围内。SN2021cj的早期光谱显示CⅡ和C III的发射线较窄，没有明显的吸收成分，这与SN2021csp的观测结果相反。这些谱线的发射成分的相似性意味着SNE 2021cj和2021csp的发射区具有相似的电离态，从而表明它们与ELECTA和CSM具有相似的性质，这也是从LC模型中推断出来的。考虑到吸收特征强度的差异，这种不均匀可能归因于在其他常见的非球面抛射中的视角效应。具体地，在该场景中，从极方向观察SN 2021CKJ，而从离轴方向观察SN 2021CSP。SNE 2021ckj和2021csp的后期时间谱显示出相似的特征，但线速度不同，这也支持了这一点。
We present photometric and spectroscopic observations of the Type Icn supernova (SN) 2021ckj. This rare type of SNe is characterized by a rapid evolution and high peak luminosity as well as narrow lines of highly ionized carbon at early phases, implying an interaction with hydrogen- and helium-poor circumstellar matter (CSM). SN 2021ckj reached a peak brightness of ∼ − 20 mag in the optical bands, with a rise time and a time above half maximum of ∼4 and ∼10 days, respectively, in thegand cyan bands. These features are reminiscent of those of other Type Icn SNe (SNe 2019hgp, 2021csp, and 2019jc), with the photometric properties of SN 2021ckj being almost identical to those of SN 2021csp. Spectral modeling of SN 2021ckj reveals that its composition is dominated by oxygen, carbon, and iron group elements, and the photospheric velocity at peak is ∼10 000 km s−1. Modeling the spectral time series of SN 2021ckj suggests aspherical SN ejecta. From the light curve (LC) modeling applied to SNe 2021ckj, 2019hgp, and 2021csp, we find that the ejecta and CSM properties of Type Icn SNe are diverse. SNe 2021ckj and 2021csp likely have two ejecta components (an aspherical high-energy component and a spherical standard-energy component) with a roughly spherical CSM, while SN 2019hgp can be explained by a spherical ejecta-CSM interaction alone. The ejecta of SNe 2021ckj and 2021csp have larger energy per ejecta mass than the ejecta of SN 2019hgp. The density distribution of the CSM is similar in these three SNe, and is comparable to those of Type Ibn SNe. This may imply that the mass-loss mechanism is common between Type Icn (and also Type Ibn) SNe. The CSM masses of SN 2021ckj and SN 2021csp are higher than that of SN 2019hgp, although all these values are within those seen in Type Ibn SNe. The early spectrum of SN 2021ckj shows narrow emission lines from C II and C III, without a clear absorption component, in contrast with that observed in SN 2021csp. The similarity of the emission components of these lines implies that the emitting regions of SNe 2021ckj and 2021csp have similar ionization states, and thus suggests that they have similar properties as the ejecta and CSM, which is also inferred from the LC modeling. Taking the difference in the strength of the absorption features into account, this heterogeneity may be attributed to viewing angle effects in otherwise common aspherical ejecta. In particular, in this scenario SN 2021ckj is observed from the polar direction, while SN 2021csp is seen from an off-axis direction. This is also supported by the fact that the late-time spectra of SNe 2021ckj and 2021csp show similar features but with different line velocities.