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On the nature of Extremely Red Objects: the 2 Ms Chandra Deep Field-North Survey results

C. Vignali·D. M. Alexander·F. E. Bauer·W. N. Brandt·A. E. Hornschemeier·G. P. Garmire·D. P. Schneider
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Abstract

Understanding the nature of Extremely Red Objects [EROs; (I-K)>=4] is one of the most challenging issues in observational cosmology. Here we report on the X-ray constraints provided by the 2 Ms Chandra Deep Field-North Survey (CDF-N). X-ray emission has been detected from 11 out of 36 EROs (approx 30%). Five of these have hard X-ray emission and appear to be obscured AGNs, while non-AGN emission (star formation or normal elliptical galaxy emission) is likely to be the dominant source of X-rays from the soft X-ray sources detected at the faintest X-ray flux levels.

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C. Vignali, D. M. Alexander, F. E. Bauer, W. N. Brandt, A. E. Hornschemeier, G. P. Garmire, D. P. Schneider. 2002-09-19. On the nature of Extremely Red Objects: the 2 Ms Chandra Deep Field-North Survey results. https://arxiv.org/abs/astro-ph/0209415

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