AI 中文总结
本文通过XMM-Newton、NuSTAR及Chandra数据，分析IC5052 ULX的宽带X射线特性，提出含吸积柱或康普顿化冕的改进模型，识别出候选光学对应体，发现存在局域X射线吸收。
AI 中文摘要
我们利用2022年XMM-Newton与NuSTAR的同时观测数据，结合2013年存档的XMM-Newton数据，对IC5052中的超亮X射线源（ULX）开展了宽带X射线光谱与时序分析。双热成分模型通常被解释为来自超爱丁顿内吸积盘及其关联风的径向分离发射，该模型在统计上可接受，但会产生不合理的内盘温度$kT_\text{in} \neq 6.4$ keV，甚至与超爱丁顿盘模型不符。受其他ULX高信噪比观测结果的启发，加入来自吸积柱或康普顿化冕的额外连续谱成分，可在保持拟合优度相当的同时得到合理的内盘温度：吸积柱模型给出$kT_\text{in} \neq 1.2$ keV，且吸积柱贡献总流量的$F_\text{col} \neq 62\%$；康普顿化冕模型假设较热的盘提供种子光子，给出$kT_\text{in} \neq 3.0$ keV，散射占比约为1。时序分析最初对两种模型均提出挑战：吸积柱模型将IC5052 ULX置于先前结果表明可能探测到脉冲的区域（$F_\text{col} \neq 62\%$），但未探测到任何脉冲；而冕模型似乎与其缺乏观测到的短时标变异性不一致。然而，结合光谱信息可放宽这些约束，使两种模型对IC5052 ULX仍保持物理合理性。最后，利用改进的Chandra天体测量，我们识别出一个候选光学对应体，与演化的大质量供体星一致。光学消光与X射线拟合吸收之间的差异表明存在局域X射线吸收。
英文摘要
We present broadband X-ray spectral and timing analysis of the Ultra-luminous X-ray source (ULX) in IC5052 using simultaneous XMM-Newton and NuSTAR observations from 2022, supplemented by archival 2013 XMM-Newton data. A two-thermal component model, often interpreted as radially-segregated emission from a super-Eddington inner disc and its associated wind, provides a statistically acceptable fit but yields an implausibly high inner disc temperature of $k T_\mathrm{in} \approx 6.4$ keV, inconsistent with even super-Eddington disc models. Including an additional continuum component from either an accretion column or a Comptonizing corona, as motivated by high S/N observations from other ULXs, provides comparable goodness of fit while allowing plausible inner disc temperatures. The accretion column model yields $k T_\mathrm{in} \approx 1.2$ keV with the column contributing $F_\mathrm{col} \approx 62\%$ of total flux, while the Comptonizing corona model yields $k T_\mathrm{in} \approx 3.0$ keV with a scattered fraction $\sim 1$, assuming the hotter disc provides the seed photons. Timing analysis initially challenges both scenarios: the accretion column model places IC5052 ULX where prior results suggest pulsations may be detectable ($F_\mathrm{col} \sim 62\%$), yet none were detected, while the corona model appears inconsistent with its lack of observed short-timescale variability. However, incorporating spectral information relaxes these constraints, allowing both models to remain physically plausible for IC5052 ULX. Finally, using improved Chandra astrometry, we identified a candidate optical counterpart consistent with an evolved high mass donor. A discrepancy between the optical extinction and X-ray fitted absorption suggests localised X-ray absorption.
Comments17 pages, 8 figures, accepted for publication in MNRAS
