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تسجيل مستخدم جديدInfrared Counterparts to Chandra X-Ray Sources in the Antennae
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We use deep J and Ks images of the Antennae (NGC 4038/9) obtained with WIRC on the Palomar 200-inch telescope, together with the Chandra X-ray source list of Zezas et al. (2002a), to search for IR counterparts to X-ray point sources. We establish an X-ray/IR astrometric frame tie with 0.5 rms residuals over a ~4.3 field. We find 13 ``strong IR counterparts brighter than Ks = 17.8 mag and < 1.0 from X-ray sources, and an additional 6 ``possible IR counterparts between 1.0 and 1.5 from X-ray sources. The surface density of IR sources near the X-ray sources suggests only ~2 of the ``strong counterparts and ~3 of the ``possible counterparts are chance superpositions of unrelated objects. Comparing both strong and possible IR counterparts to our photometric study of ~220 Antennae, IR clusters, we find the IR counterparts to X-ray sources are ~1.2 mag more luminous in Ks than average non-X-ray clusters. We also note that the X-ray/IR matches are concentrated in the spiral arms and ``overlap regions of the Antennae. This implies that these X-ray sources lie in the most ``super of the Antennaes Super Star Clusters, and thus trace the recent massive star formation history here. Based on the N_H inferred from the X-ray sources without IR counterparts, we determine that the absence of most of the ``missing IR counterparts is because they are intrinsically less luminous in the IR, implying that they trace a different (possibly older) stellar population.
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We use WIRC, IR images of the Antennae (NGC 4038/4039) together with the extensive catalogue of 120 X-ray point sources (Zezas et al. 2006) to search for counterpart candidates. Using our proven frame-tie technique, we find 38 X-ray sources with IR c
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