\section{Information on individual objects }

RXCJ0014.3-6604, A2746 (also included in XBACS) is a typical example of a
point-like X-ray source which was inspected in more detail. The X-ray spectral
hardness ratio is not outside the acceptable limit for cluster emission. The
source appears very compact with a core radius 2{sigma} upper limit of about 120
h_50_^-1^ kpc at a redshift of z=0.156. This does not rule out that the X-ray
emission comes from a cluster. We have five concordant redshifts including the
cD galaxy, with no spectrum indicating an AGN and the optical image is clearly
showing a galaxy cluster. Therefore, even though we cannot establish the extent
of the X-ray source, we conclude that the source is most likely a cluster.

RXCJ0015.4-2350, A14, has an X-ray emission which is very faint and diffuse:
about 48 source photons spread in a clumpy distribution over a region with a
radius of about 12 arcmin. The cluster position was not taken as the center of
the large-scale distribution but at a local maximum. The cD galaxy, ESO 473-G005
at the position 00 15 10.6, -23 52 57.0 is located at this highest local
maximum. This is surely a good example of a dynamically young cluster with a
size slightly smaller than the Virgo cluster. Even though there is a small
probability that the X-ray emission originates from a collection of point
sources, by far the most likely interpretation is that of a poor galaxy cluster.
This is supported by the finding of four coincident galaxy redshift in the
optical follow-up.

RXCJ0117.8-5455 is another source with X-ray emission consistent with a point
source origin. The source is also detected as a bright radio source in the SUMSS
survey (Mauch et al. 2003MNRAS.342.1117M). Since the cluster is found to be at a
redshift of z=0.2510 as determined from 6 galaxy velocities (where none of the
spectra indicate an AGN), an upper limit on the X-ray core radius of about 270
h_50_^-1^ kpc is consistent with a cluster source and also the spectral hardness
ratio is within the limits expected for cluster emission. Therefore this
point-like X-ray source is kept in the catalogue until we have better data for a
more secure identification.

RXCJ0132.6-0804 is classified as Seyfert 1.5 in the cross correlation work of
the ROSAT All-Sky Survey and the NVSS sources by Bauer et al.
(2000ApJS..129..547B). We find narrow emission lines in the central galaxy, PKS
0130-083, of this cluster at z=0.1485. The [OIII] lines are more prominent than
the H{beta} lines which makes the AGN identification more likely than that of
the typical emission lines often found in central cluster galaxies in cooling
core clusters (e.g., Crawford et al. 1999MNRAS.306..857C). The X-ray luminosity
of the object is about 3.6x10^44^ erg.s^-1^ which is quite high for a Seyfert
galaxy. The Digital Sky Survey image shows clearly a central dominant galaxy
surrounded by a collection of galaxies and we recorded three coincident galaxy
redshifts. The spectral hardness ratio is within the limits expected for thermal
emission from a cluster. Therefore the identification of this X-ray source is
uncertain at this stage. The X-ray emission could come from the cluster or the
AGN. A high resolution X-ray observation is required for a definitive decision.

RXCJ0250.2-2129 has been classified as a BL Lac ( z=0.4980, off-set 0.4 arcmin)
in the ROSAT Bright Source Catalogue by Schwope et al. (2000AN....321....1S) and
is listed as a radio source in Bauer et al. (2000ApJS..129..547B). The BL Lac is
not at the same redshift as the cluster. The X-ray source shows a marginal
extent and is too soft by about 1.3{sigma} compared to the expectation. Our
deeper CCD image clearly shows an optical cluster and we found two coincident
galaxy redshifts. We therefore take the cluster identification as more likely,
but cannot rule out a contribution to the X-ray emission by the AGN. The cluster
is also coverd by a ROSAT PSPC archive observation. But the offset from the
pointing center is so large that the possibility to better resolve a point
source is not improved over the survey data.

RXCJ0301.6+0155: This source, which has previously been identified as a cluster
in the NORAS Survey (Boehringer et al. 2000ApJS..129..435B) and which is
coinciding with a Zwicky cluster (ZwCl0258.9+01), appears point-like. A ROSAT
HRI observation in the archive showed that the source is very compact but
definitely not a point source. Therefore the cluster identification is well
justified. The comparison between the surface brightness profile and the point
spread function of the ROSAT HRI is shown in Fig. A.1 of the paper.

RXCJ0331.1-2100 is coincident within 0.5 arcmin with a Seyfert 1.9 galaxy
identified by Bauer et al. (2000ApJS..129..547B). The source is listed in
Schwope et al. (2000AN....321....1S) as RBS 0436. The X-ray emission is only
marginally extended, but the spectral hardness ratio is consistent with thermal
intracluster medium emission. We have nine coincident galaxy redshifts for this
cluster. Therefore it is possible that the AGN is contaminating the X-ray
radiation, but there is also definitely a cluster at this position.

RXCJ0336.3-0347: This is a compact X-ray source with a peaked center and a weak
extent. The central galaxy is listed as an AGN, as 2MASS and radio source,
probably a BL Lac at z=0.1595 (Bauer et al. 2000ApJS..129..547B; Veron-Cetty &
Veron 2001, Cat. VII/224). It appears to have a bright central spot in sky
images, but our spectra also easily show the underlying galaxy continuum with
the Balmer break. The optical image also shows an optical cluster for which we
have three concordant redshifts at the same redshift as the AGN. The most likely
interpretation of this source is that it is indeed a galaxy cluster with some
(less than half) contamination of the X-ray emission by the AGN. The hardness
ratio of the X-ray emission is consistent with a cluster, also.

RXCJ0425.8-0833 is coincident within 1.3 arcmin with a Seyfert 2 galaxy
identified by Hewitt & Burbidge (1991, Cat. VII/178). The source is listed in
Schwope et al. (2000AN....321....1S) as RBS 0540. The central dominant galaxy
has the spectrum of a passive elliptical galaxy without emission lines as found
in our follow-up observations. The X-ray emission is very extended and the
dominant part of the X-ray emission must come from the cluster, for which we
have two concordant redshifts.

RXCJ0437.1-2027, A499, is detected with only 26 photons and the result for the
extent is not completely convincing. A ROSAT HRI observation from the archive
shows that the source is quite compact but clearly extended. Two coincident
galaxy redshifts are available for this cluster.

RXCJ0528.9-3927 also identified as RBS0653 (Schwope et al. 2000ApJS..129..547B)
is listed in NED as a QSO. The X-ray emission is slightly extended but the
spectral hardness ratio deviates by 5.2{sigma} from the value expected for
thermal cluster emission. A deeper X-ray observation with XMM-Newton shows this
object to be an X-ray luminous cluster with a less than 20% contamination (in
the ROSAT hard band) by a bright, soft AGN point source.

RXCJ0918.1-1205, A780 or Hydra A, is a well known X-ray cluster. Thus even
though one finds a coincidence within 0.2 arcmin with a Seyfert galaxy listed by
de Vaucouleurs et al. (1991, Cat. VII/155), there is no doubt about the clear
dominance of the thermal cluster emission.

RXCJ1027.9-0647, A1023, is coincident within 0.2 arcmin with an AGN at z=0.1165
identified by Grazian et al. (2002AJ....124.2955G). The X-ray emission is
marginally extended and the spectral hardness ratio is consistent with thermal
cluster emission. There is a residual possibility that the X-ray emission of
this source is contaminated by an AGN. Six coincident galaxy redshifts support
the existence of a galaxy cluster at this position.

RXCJ1050.5-0236, A1111, is coincident within 0.6 arcmin with a Seyfert 2 galaxy
identified by Machalski & Condon (1999ApJS..123...41M). The X-ray emission is
found to be extended and the dominant part of the X-ray emission comes from the
cluster. There is an X-ray emitting star in the south of the cluster whose X-ray
emission was deblended. Nine coincident galaxy redshifts leave no doubt about
the existence of a cluster at this position (see also the ASCA study of
Matsumoto et al. 2001A&A...374...28M).

RXCJ1050.6-2405 features a point source and an extended fainter halo in the
RASS. About one third of the flux seems to come from the central compact
emission. The hardness ratio gives no indication for two source components,
however, and is perfectly consistent with thermal emission from a cluster. At
the cluster redshift of z=0.2037 the compact center could still be a bright
compact cluster cooling core as well as a contaminating central AGN. Near the
center (0.4 arcmin offset) is a radio source, PKS B1048-238 (MRC1048-238), at a
redshift of z=0.2060 (McCarthy et al. 1996ApJS..107...19M) and identified with a
broad line radio galaxy Kapahi et al. (1998ApJS..118..275K). We expect that most
of the X-ray emission is due to the cluster. But so far we have made no effort
to subtract the possible AGN contribution.

RXCJ1141.4-1216, A1348, is coincident within 0.2 arcmin with a Seyfert 1.8
galaxy listed by Machalski & Condon (1999ApJS..123...41M). The X-ray emission
shows a small extent and the X-ray emission is slightly softer (~2.9{sigma})
than expected. From the extended X-ray emission we still conclude that most of
the emission comes from the cluster. The X-ray luminosity of the object is
3.3x10^44^ erg.s^-1^ which would be towards the upper end of the luminosity
distribution of Seyfert galaxies. Six coincident galaxy redshifts confirm the
existence of a cluster at this position.

RXCJ1149.7-1219, A1391, is coincident within 0.9 arcmin with an AGN listed by
Machalski & Condon (1999ApJS..123...41M). The X-ray emission is found to be
clearly extended and the dominant part of the X-ray emission must come from the
cluster. Six coincident galaxy redshifts confirm the existence of a cluster at
this position.

RXCJ1212.3-1816 was detected with only 12.5 source photons with a significance
of just about 3{sigma}. This signal is detected in an aperture significantly
larger than the point spread function and the significance decreases for a
smaller detection cell. Therefore, if the detection is accepted, the source has
to be extended. We have two coincident cluster galaxy redshifts.

RXCJ1234.2-3856 appears as a point source in RASS with a spectral hardness ratio
consistent with thermal cluster emission. It is also listed as a radio source
without classification by Bauer et al. (2000ApJS..129..547B). Two coincident
galaxy redshifts give some further support for the cluster identification.

RXCJ1253.6-3931 appears as point-like source in the RASS with a cluster like
hardness ratio and coincides within 0.5 arcmin with the unclassified radio
source PMN J1253-3932 (see also Bauer et al. 2000ApJS..129..547B). We have a
spectrum as well as a redshift from the central galaxy which does not show an
AGN or BL Lac signature. A CCD image shows a galaxy cluster. Therefore we keep
this source in our list as a likely cluster candidate.

RXCJ1326.2+0013 is coincident within 0.2 arcmin with a BL Lac found in the 2dF
survey. The X-ray emission is clearly extended and the emission from the
intracluster medium certainly dominates. The spectral hardness ratio is as
expected and there are 16 coincident galaxy redshift. Therefore there is no
doubt about the cluster identification of this source.

RXCJ1332.9-2519 is detected in the RASS with very low surface brightness, but
with 50 counts and an about 4{sigma} detection. An archival PSPC observation,
with an exposure of only 982 s shows a similar very low surface brightness
structure providing a good confirmation of this very diffuse structure. We have
three coincident galaxy redshifts from the follow-up observations confirming the
existence of a cluster at this position.

RXCJ1347.2-3025 and 
RXCJ1349.3-3018, A 3574 or Klemola 27 at a redshifts of 0.0145 and 0.0160,
respectively, is a cluster with two components. It presents a particular problem
to its detection and identification. The central galaxy is the X-ray luminous
Seyfert 1 galaxy, IC 4329, and two further AGNs contribute to the X-ray emission
from the cluster region. While the central detection could easily have been
dismissed because of its almost point-like appearance in the RASS and its
identification with a known X-ray AGN, the additional detection of fragments of
the diffuse outer emission in the RASS analysis triggered a further inspection
of this cluster. A pointed observation shows clearly the diffuse X-ray halo of
the cluster in addition to the three cluster AGN point sources. We have used
this pointed observation to subtract the contribution of the three AGN from the
total emission. The central AGN IC4329A carries about 75% of the flux, the two
other AGNs contribute about 4 to 5% each and the cluster emission amounts to
15-20%. Therefore, with a net flux of ~1.35x10^-11^ erg.s^-1^.cm^-2^ in the
ROSAT band, the cluster is well above the flux limit of the REFLEX and the XBACS
survey. Figure A.2 shows the surface brightness distribution of this cluster. In
the catalogue we have listed the central cluster region and the western
concentration (about 25 arcmin, ~0.6Mpc distance) as separate sources identified
with A3574E and A3574W, respectively, recognizing that they are two separate
virializing clumps. Also the diffuse Western component is, with a nominal flux,
F_n_ ~ 3.5x10^-12^ erg.s^-1^.cm ^-2^, above the REFLEX flux limit.
\par 
The cluster properties were determined also with the help of the pointed
observation, which allows a better contamination subtraction. The cluster was
dismissed in XBACS as an AGN. At a larger distance it would probably have
escaped its identification as a cluster in REFLEX. This shows that there is
probably not only a small fraction of clusters which are erroneously included in
the sample because of an AGN contribution to the X-ray flux, but also a small
fraction of clusters which are erroneously discarded because the cluster X-ray
emission is not easily visible if it is blended by a bright AGN.

RXCJ1415.2-0030, tentatively identified with A1882 (offset 13.3 arcmin), is
coincident within 1.6 arcmin with a QSO identified in the Sloan Digital Sky
Survey. The X-ray emission is very extended and diffuse, however, and we do not
detect a contribution by a point source. 20 concordant redshifts confirm the
existence of a cluster.

RXCJ1416.8-1158 appears as a point source in RASS and has a spectrum that is
1.7{sigma} too soft. 10 coincident galaxy redshift give good support for the
existence of a cluster at this position.

RXCJ1504.1-0248 is a very peculiar object. We have obtained a spectrum of the
central galaxy (with an offset of 0.3 arcmin from our reference position of the
cluster) which shows Liner like emission lines. It was identified as an AGN by
Shectman et al. (1996ApJ...470..172S, Cat. VII/203). The X-ray source is very
compact but significantly extented (the probability that the emission comes from
a point source is estimated to be 0.0016). The X-ray luminosity is extremely
high with L_x_ ~ 4.3x10^45^ erg.s^-1^ in the 0.1-2.4 keV band and not typical
for a narrow line AGN. A short CHANDRA observation that was finally performed
early 2004 shows a perfect galaxy cluster image without any significant AGN
contamination. This is in our sample the most spectacular example of an object
which was for long time marked as very suspicious for its unusual compactness
for given brightness and distance but was finally revealed to be a prominent
X-ray cluster. The Liner-like spectrum observed for the central galaxy is also
typical for cooling flow clusters (e.g., Crawford et al. 1999MNRAS.306..857C,
and references therein).

RXCJ1958.2-3011 is an X-ray source that appears point-like in RASS with a
hardness ratio consistent with cluster emission. It is listed as an unclassified
radio source in Bauer et al. (2000ApJS..129..547B). The optical image shows a
galaxy with a bright nucleus and our ESO spectrum indicates an enhanced blue
continuum. There is clearly a cluster visible with a likely Bright Cluster
Galaxy (BCG) that is about 1 arcmin offset to the NEE from the radio source and
the center of the cluster emission. The cluster detection is further supported
by four concordant redshifts. Therefore, we classify this object as a
cluster-AGN combination whose fluxes must be determined by a higher angular
resolution X-ray image. Since low X-ray luminosity AGN appear very frequently in
clusters, with an X-ray luminosity well below that of the cluster emission, we
keep this object in the REFLEX catalogue at present.

RXCJ2035.7-2513 shows diffuse X-ray emission around a large early type galaxy
with a luminosity of about 4x10^42^ erg.s^-1^. An archival PSPC image also shows
the diffuse emission but also some contamination of 10-20% by point sources,
which is within the error of the flux determination in the catalogue and no
correction has been made. The object is probably associated with A3698 whose
center has an offset of 4.6 arcmin assumed to coincide with NGC 6936. Seven
coincident galaxy redshifts confirm the existence of a cluster at the X-ray
source position.

RXCJ2147.0-1019 contains a BL Lac identified by Bauer et al.
(2000ApJS..129..547B) within 0.2 arcmin of our reference position. The X-ray
source is marginally extended (probability 97%) and has a hardness ratio well
consistent with thermal cluster emission. We cannot rule out that the BL Lac
could substantially contribute to the cluster emission, however.

RXCJ2216.9-1725 contains a Seyfert galaxy identified by Schwope et al.
(2000AN....321....1S) within 0.2 arcmin of our reference position. The X-ray
source is marginally extended (probability 90%) and the X-ray hardness ration
shows that the source is about 2{sigma} too soft. Therefore, it is not
impossible that the Seyfert galaxy contributes to the X-ray emission. The
cluster is with an X-ray luminosity of L_x_ ~ 4x10^44^ erg.s^-1^ so luminous
that the Seyfert galaxy has to be relatively bright to affect the total flux.

RXCJ2220.5-3509, A3866, has an AGN found in our spectroscopic follow-up 40
arcsec from the X-ray center at z=0.0754. The X-ray emission shows a small but
significant extent, but the core of the emission looks like a point source. The
cluster redshift is measured as z=0.1544 and the optical image shows a nice
cluster with a dominant giant galaxy close to the X-ray maximum. We expect that
the X-ray emission from the cluster is partly contaminated by the AGN.

RXCJ2234.5-3744, A3888, is a cluster in which we also detected a Seyfert 1
galaxy within 2 arcmin from the center (Romer 1994Natur.372...75R, Ph.D.
Thesis). Therefore, there was some concern about the X-ray contamination from
the AGN in this source. An XMM-Newton observation (P.I. A.C. Edge) allows us to
distinguish the cluster and AGN X-ray emission. We find that the AGN
contribution is about 10% of the total emission in the 0.5-2.0 keV band. 70
coincident galaxy redshifts confirm the existence of a cluster at this position.

RXCJ2251.7-3206 is an X-ray source that appears point-like in RASS with a
hardness ratio which is too soft by about 2.9{sigma} compared to the expectation
for cluster emission. It has been found to be a radio source (Bauer et al.
2000ApJS..129..547B) classified as a BL Lac (Schwope et al.
2000AN....321....1S). We have one galaxy redshift for this cluster. The question
if it is an X-ray BL Lac or an X-ray cluster is undecided. This is to be
clarified by further observations.

RXCJ2351.6-2605 contains an AGN within 0.2 arcmin of our reference position
identified by Caccianiga et al. (2000A&AS..144..247C). The X-ray source is,
however, extended with high significance, and the X-ray hardness ratio is
perfectly consistent with thermal emission from a cluster. We do not detect a
signature of point source contribution. Therefore, the identification of this
X-ray source as a cluster is safe inspite of the coincidence with the AGN. For
some of the objects in this list, where the central cluster galaxy is identified
with an AGN because of the observation of emission lines, the emission lines
could also be associated to the cluster cooling core. Emission lines with
preferentially low excitation energies are frequently observed in cooling core
clusters (e.g., Crawford et al. 1999MNRAS.306..857C, and references therein). In
these cases the dominant X-ray emission comes from the cluster and its cooling
core. Therefore the observation of emission lines in the central cluster
galaxies does not cast doubts on the cluster identification in general.

\section{Objects removed from the present catalogue at final inspection}

In the final two observing runs a number of
cluster candidates were observed which had been flagged to be weak cluster
candidates. A large fraction of them turned out to be clusters at the telescope
and were therefore included in the catalogue. Now, during this final inspection
a few of them turn out to be most probably optical clusters with a dominant
X-ray AGN. In the following we list these 7 objects which were excluded from our
catalogue.

RXCJ0730.8-6602 looks like a point source. The central galaxy with a redshift of
z=0.1063 could be an AGN; it has a bright core in the optical image. While the
DSS image shows a trace of a promising galaxy grouping at the center of the
X-ray position, a deeper R-band CCD did not confirm the presence of a rich
enough cluster. The Parks 4.85 GHz survey lists a 84 mJy radio source,
PMN0730-6602, (Griffith & Wright 1993AJ....105.1666G, Cat. VIII/38) and the
SUMSS survey (Mauch et al. 2003MNRAS.342.1117M) as a 81.7 mJy source at 485 MHz.
Therefore we have removed this object from the final catalogue and classify it
tentatively as an X-ray AGN, possibly a BL Lac, within a galaxy group, where the
X-ray emission comes preferentially from the AGN.

RXCJ0934.4-1721 is a source with a marginal X-ray extent, but a hardness ratio
consistent with thermal cluster emission within 1{sigma}. There is no striking
galaxy overdensity in deeper optical images and no clear central BCG. A galaxy
close to the center with a redshift of z=0.2499 was identified as a BL Lac
candidate by Bauer et al. (2000ApJS..129..547B) in the ROSAT-NVSS correlation
sample. Therefore, this object is most probably not a cluster and was removed
from our cluster catalogue.

RXCJ1046.8-2535 looks like a point source in the RASS and is confirmed to be a
point source in a ROSAT HRI observation. Therefore, a cluster identification is
ruled out for the dominant fraction of the X-ray emission. Nevertheless we find
an optical cluster at redshift z=0.2426 with 8 coincident galaxy velocities. The
source is also listed as a radio source in Condon et al. (1998AJ....115.1693C,
Cat. VIII/65) and Bauer et al. (2000ApJS..129..547B). There is an indication in
the HRI observation that there is a faint halo underneath the point source with
a flux of at most 5% of that of the central source, which could be the emission
from the cluster. The flux is, however, more than an order of magnitude below
the REFLEX limit and therefore the cluster was removed from the REFLEX sample.
This object falls most probably into the category of X-ray AGN in a galaxy group
or cluster.

RXCJ1213.3-2617 is coincident within 0.5 arcmin with a BL Lac identified by
Fischer et al. (1998AN....319..347F, Cat. IX/32). Our spetrum of the central
galaxy does not show an AGN or BL Lac signature, however, and a CCD image
provides some indication of a cluster. The X-ray emission is not significantly
extended and the spectral hardness ratio is consistent with thermal cluster
emission. A short ROSAT HRI exposure (2.7 ks) shows only a point source, whose
flux corresponds only to about 0.13 PSPC counts s^-1^ compared to 0.244 observed
in the survey. There is no signature of further extended emission in the HRI
image. Therefore the most likely interpretation of this X-ray source is an AGN
which has shown a dimming by a factor of 1.8 between the two ROSAT observations.

RXCJ1545.7-2339 appears as point-like in RASS, but has a reasonable hardness
ratio for cluster emission. The archival HRI data show that more than 90% of the
flux comes from a point source. Since the total flux of the source is only about
twice above the REFLEX flux limit and since the cluster emission for this object
at a redshift of z=0.1205 should well be extended at the HRI resolution, we
remove this source from the REFLEX sample. Bauer et al. (2000ApJS..129..547B)
list this as a radio source without further classification, making an AGN
counterpart likely, but our ESO spectroscopic observations provided no evidence
for an AGN. Two coincident galaxy redshifts found make it likely that the AGN
resides in a group or cluster.

RXCJ2040.0-7114, tentatively identified with the cluster A3701 at redshift
z=0.1607, is an X-ray source that appears point-like in the RASS with a hardness
ratio consistent with cluster emission. An archival ROSAT HRI observation shows
a surface brightness distribution with a bright point source and a faint, small
halo with an upper limit on the flux contribution of only a few percent. This
brings this X-ray source well below the REFLEX flux limit and we removed this
source from the REFLEX catalogue. An R-band CCD image shows a nice galaxy
cluster with two bright central galaxies, which is no surprise as it was already
classified as a cluster by Abell et al. (1989ApJS...70....1A, Cat. VII/110). Our
spectroscopic follow-up provides 12 coincident galaxy redshifts confirming the
cluster detection. Therefore, this object falls most probably into the category
of X-ray luminous AGN in a galaxy cluster.

RXCJ2041.8-3733, tentatively identified with the cluster S892 at redshift
z=0.0997 (offset ~5 arcmin), is an X-ray source that appears point-like in the
RASS with a hardness ratio which is too soft by about 1.8{sigma} compared to the
expectation for cluster emission. An archival ROSAT HRI observation shows only a
point source. Our spectroscopic follow-up observations show a Seyfert 1 spectrum
for the central galaxy and provide 8 further coincident galaxy refdshifts. A
deep R-band image shows a cluster with an appearance consistent with the
determined redshift around z=0.1and the central galaxy appears to have a bright
core. At the measured redshift this cluster should appear clearly as an extended
X-ray source in the RASS and definitely in the HRI image. Therefore we identify
the main X-ray emission with the AGN and removed this object from the REFLEX
catalogue. The source is also listed in the bright RASS-NVSS correlation by
Bauer et al. (2000ApJS..129..547B) as an unclassified radio source and as a
cluster in the ROSAT Bright Survey (Schwope et al. 2000AN....321....1S).