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arXiv · 2508.03656

The Nature of an Unidentified X-ray Source in the 7 Ms Chandra Deep Field-South Catalog

Quinn P. Sullivan·Zhibo Yu·William N. Brandt·Bin Luo·Fan Zou
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Abstract

In the 7 Ms Chandra Deep Field-South catalog, only one source, XID 912, was highly significantly detected in X-rays but had no formally reported counterparts in the UV, optical, infrared, or radio bands. We identified its potential JWST and VLT VIMOS counterparts and measured the corresponding aperture photometry to construct its spectral energy distribution (SED). We fitted this SED using CIGALE. The results indicate that the source is most likely an off-nuclear ultraluminous X-ray source, rather than a background active galactic nucleus.

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Quinn P. Sullivan, Zhibo Yu, William N. Brandt, Bin Luo, Fan Zou. 2025-08-05. The Nature of an Unidentified X-ray Source in the 7 Ms Chandra Deep Field-South Catalog. https://arxiv.org/abs/2508.03656

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