Kd. Borne et al., Hubble Space Telescope observations of the serendipitous X-ray companion to Markarian 273: Cluster at z=0.46?, ASTROPHYS J, 527(2), 1999, pp. 554-560
We have used Hubble Space Telescope (HST) I-band images to identify Mrk 273
X, the very unusual high-redshift X-ray-luminous Seyfert 2 galaxy found by
ROSAT in the same held of view as Mrk 273. We have measured the photometric
properties of Mrk 273X and have also analyzed the luminosity distribution
of the faint galaxy population seen in the HST image. The luminosity of the
galaxy and the properties of the surrounding environment suggest that Mrk
273X is the brightest galaxy in a relatively poor cluster at z approximate
to 0.46. Its off-center location in the cluster and the presence of other g
alaxy groupings in the HST image may indicate that this is a dynamically yo
ung cluster on the verge of merging with its neighboring clusters. We find
that Mrk 273X is a bright, featureless elliptical galaxy, with no evidence
for a disk. It follows the de Vaucouleurs (r(1/4)) surface brightness law v
ery well over a range of 8 mag. Although the surface brightness profile doe
s not appear to be dominated by the active galactic nucleus (AGN), the gala
xy has very blue colors that do appear to be produced by the AGN. Mrk 273X
is most similar to the IC 5063 class of active galaxies-a hybrid Seyfert 2/
powerful radio galaxy.