SN 2022oqm: A Bright and Multi-peaked Calcium-rich Transient
arxiv(2023)
摘要
We present the photometric and spectroscopic evolution of SN 2022oqm, a
nearby multi-peaked hydrogen- and helium-weak calcium-rich transient (CaRT). SN
2022oqm was detected 13.1 kpc from its host galaxy, the face-on spiral galaxy
NGC 5875. Extensive spectroscopic coverage reveals an early hot (T >= 40,000 K)
continuum and carbon features observed ∼1 day after discovery, SN Ic-like
photospheric-phase spectra, and strong forbidden calcium emission starting 38
days after discovery. SN 2022oqm has a relatively high peak luminosity (MB =
-17 mag) for (CaRTs), making it an outlier in the population. We determine that
three power sources are necessary to explain the light curve (LC), with each
corresponding to a distinct peak. The first peak is powered by an expanding
blackbody with a power law luminosity, suggesting shock cooling by
circumstellar material (CSM). Subsequent LC evolution is powered by a double
radioactive decay model, consistent with two sources of photons diffusing
through optically thick ejecta. From the LC, we derive an ejecta mass and 56Ni
mass of 0.6 solar masses and 0.09 solar masses. Spectroscopic modeling
suggests 0.6 solar masses of ejecta, and with well-mixed Fe-peak elements
throughout. We discuss several physical origins for SN 2022oqm and find either
a surprisingly massive white dwarf progenitor or a peculiar stripped envelope
model could explain SN 2022oqm. A stripped envelope explosion inside a dense,
hydrogen- and helium-poor CSM, akin to SNe Icn, but with a large 56Ni mass and
small CSM mass could explain SN 2022oqm. Alternatively, helium detonation on an
unexpectedly massive white dwarf could also explain SN 2022oqm.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要