Multiwavelength Study of Chandra X-Ray Sources in the Antennae
  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 counterparts, almost doubling the number of IR
counterparts to X-ray sources first identified in Clark et al. (2007). In our
photometric analysis, we consider the 35 IR counterparts that are confirmed
star clusters. We show that the clusters with X-ray sources tend to be
brighter, K_s ~16 mag, with (J-K_s) = 1.1 mag. We then use archival HST images
of the Antennae to search for optical counterparts to the X-ray point sources.
We employ our previous IR-to-X-ray frame-tie as an intermediary to establish a
precise optical-to-X-ray frame-tie with <0.6 arcsec rms positional uncertainty.
Due to the high optical source density near the X-ray sources, we determine
that we cannot reliably identify counterparts. Comparing the HST positions to
the 35 identified IR star cluster counterparts, we find optical matches for 27
of these sources. Using Bruzual-Charlot spectral evolutionary models, we find
that most clusters associated with an X-ray source are massive, ~10^6 M_sun,
young, ~10^6 yr, with moderate metallicities, Z=0.05.
