<figure><img src="image_24.png" /></figure>

**Fig. A.8.** MCXC J0056.0-3732, a case in which the RXGCC position has an offset with respect to the X-ray peak due to a nearby point source. We have associated the MCXC and RXGCC clusters because both detections come from the same X-ray emission, although the RXGCC catalogue has chosen an incorrect redshift (from the nearby cluster Abell S 102) and its flux may be contaminated. The left and right panels show the RASS and *XMM-Newton* images, respectively. The positions of MCXC J0056.0-3732 ($z = 0.163$) and RXGCC 42 ($z = 0.056$) are marked with a light blue cross and a small red circle, respectively. The corresponding solid and dashed circles represent the size $\theta_{500}$ of the clusters and their aperture radius. The magenta plus represents the position of Abell cluster Abell S 102 ($z = 0.056$).

**MCXC J2350.5+2929:** MCXC J2350.5+2929 ($z = 0.1498$, NORAS) and MCXC J2350.5+2931 ($z = 0.095$, BCS), are both associated with ZwCl 2348.4+2908 ($z = 0.15$) in NED. The RASS image shows a regular extended emission, with a peak at the NORAS position, while the BCS position is slightly offset. However, there is a significant difference between the published MCXC redshifts. The NORAS value is confirmed by the cross-match with WHL J235035.1+292944 at 0.35' with $z_{spec} = 0.1526$ from 15 galaxies or the recent study of Rines et al. (2016, $z = 0.1542$). The cluster is also identified with MS 2348+2913 and the BCS redshift is based on the EMSS reference. As discussed by Bottini (2001) this is the redshift of a foreground galaxy.

### A.3. Cross-match between RXGCC and MCXC-II

**MCXC J0056.0-3732:** This cluster at $z = 0.163$ is close to another object at $z = 0.056$, Abell S 102 (see Fig. A.8). There is an RXGCC detection very close to MCXC J0056.0-373, slightly off-centred due to the presence of a nearby point source, and with an aperture radius that is large enough to also cover Abell S 102. Of the two redshift peaks found by RXGCC, the one assigned to the cluster ($z = 0.056$) corresponds to the galaxies situated around Abell S 102, not to those around MCXC J0056.0-3732. Due to the difference in redshifts, the RXGCC catalogue does not include the match with MCXC J0056.0-3732. However, taking into account that the X-ray emission producing the RXGCC detection is from MCXC J0056.0-3732, we have associated them. We note that the RXGCC redshift is not correct and that its mass estimation, even with the correct redshift, may

still be inaccurate due to the large aperture radius that includes Abell S 102.

**MCXC J0909.1+1059:** There are two likely pre-merging clusters visible in the *XMM-Newton* image at very close redshifts: $z \sim 0.175$ (main contribution) and $z \sim 0.165$ (f fainter). Two ACT clusters are approximately centred at the two X-ray peaks: ACT-CL J0909.2+1058 ($z_{spec} = 0.1764$) and ACT-CL J0908.8+1102 ($z_{spec} = 0.1636$). NORAS, BSC, EMSS, and RXGCC all detect the system as a single object covering both clusters, so we have decided to associate all of these detections. However, RXGCC provides a redshift of $z = 0.165$, while the other catalogues give $z = 0.175$. We have taken NORAS as the primary detection, as its redshift corresponds to the main X-ray contribution. The RXGCC redshift is likely different due to its being photometric, and it may have contamination from the secondary cluster.

**MCXC J0956.4-1004:** this is the supercluster Abell 0901-Abell 0902, which has three components at $z = 0.163$: Abell 0901a (N-E), Abell 0901b (N-W) and Abell 0902 (S). It is detected by REFLEX and RXGCC. The REFLEX position is in between the three components, with an aperture radius that covers all the emission. The RXGCC position is centred on component Abell 0901a with a smaller aperture radius that does not cover all the emission. Since the morphology is different from an AB model, the derived $L_{500}$ is not accurate. According to Gilmour et al. (2007), the main diffuse emission is around Abell 0901b, and there is also a fainter diffuse emission around Abell 0902. However, the emission in the region of Abell 0901a is a very bright point source rather than an extended emission. Therefore, the RXGCC detection seems to be driven by a
<figure><img src="image_25.png" /></figure>

**Fig. A.9.** MCXC J1032.2+4015, a system with two components at different redshifts. We have associated the MCXC and RXGCC detections since both cover the whole system. The left and right panels show the RASS and XMM-Newton images, respectively. The positions of MCXC J1032.2+4015 ($z = 0.079$) and RXGCC 363 ($z = 0.068$) are marked with a light blue cross and a small red circle, respectively. The corresponding solid and dashed circles represent the size $\theta_{500}$ of the clusters and their aperture radius. The orange and green pluses represent the position of two optical clusters: WHL J103214.0+401616, in the North with a spectroscopic redshift of $z = 0.0745$ (Wen & Han 2015), and WHL J103215.3+401012, in the South with a spectroscopic redshift of $z = 0.0671$ (Wen et al. 2009, 2010). The magenta plus shows the position of Abell cluster Abell 1035.

point source and, for this reason, we have taken the REFLEX measurements as prime.

**MCXC J1032.2+4015:** There are two nearby clusters visible in the XMM image (see Fig. A.9): a brighter cluster to the North, where SDSS shows many galaxies with $z_{spec} \sim 0.079$, and a fainter cluster to the South, where SDSS shows many galaxies with $z_{spec} \sim 0.067$. Both are detected as a single object by NORAS, eBCS, and RXGCC, so we have decided to associate all these detections. However, RXGCC provides a redshift of $z = 0.068$, while the other catalogues give $z = 0.079$. Since the main X-ray contribution is the cluster in the North, we have taken NORAS as the primary detection in this case.

**MCXC J1601.3+5354:** This is a line-of-sight superposition of two clusters at $z = 0.065$ and $z = 0.107$. They were detected as a single system by NORAS/eBCS and RXGCC, with different assigned redshifts ($z = 0.1068$ for NORAS, $z = 0.065$ for RXGCC). The GalWeight cluster catalog (Abdullah et al. 2020) finds both clusters and provides an estimation of their mass. Taking into account these masses and the luminosity distances, it seems that the most distant cluster would contribute more to the X-ray flux. Therefore, we have kept $z = 0.1068$ as the preferred redshift in MCXC-II.

**MCXC J1659.6+6826:** This detection is a collection of point sources dominated by two AGNs, which were classified as a cluster by NORAS and RXGCC with different assigned redshifts ($z = 0.05$ for NORAS and $z = 0.037$ for RXGCC). The two brightest point sources are a blazar at $z = 0.05$ at the NORAS/RXGCC position and NGC 6289 at $z = 0.036$ at the

position where RXGCC measured the redshifts of the galaxies. There may be a very poor group (three members) around NGC 6289 which is a potentially extended faint source (with a very small extension of 80"). The sum of the three brightest faint sources (from the ROSAT FSC) in the aperture radius agrees with the count rate of the NORAS cluster.

**MCXC J1700.7+6412:** This system at $z = 0.225$ is very close to another MCXC cluster, MCXC J1701.3+6414, at $z = 0.45$ (see Fig. A.10). The RXGCC detection is centred in between the two clusters and in extent it covers both of them plus a nearby point source. We have associated the RXGCC cluster (which has an assigned redshift of $z = 0.239$) to MCXC J1700.7+6412, because it is the stronger contributor to the X-ray emission. Since the RXGCC detection includes multiple sources, its flux and mass estimation may be inaccurate.

### A.4. Revised redshift

We discuss below the rationale for the redshift revision of certain clusters, focussing on cases where the revision is particularly large (Sect. 3 and Table 6).

**MCXC J0016.3-3121:** This is a SGP cluster identified with Abell 2571, located at 2.2' from the X-ray centre ($0.3R_{500}$). The catalogue redshift is based on the long-slit spectroscopic measurement of one galaxy close to the X-ray centre (1.9') by Dalton et al. (1994). The study by De Propris et al. (2002) of known clusters within the 2dF Galaxy Redshift Survey gives a
<figure><img src="image_26.png" /></figure>

**Fig. A.10.** MCXC J1700.7+6412, a system with two components at different redshifts. MCXC detects the two components separately, while RXGCC detects the system as a whole. We have associated RXGCC to the MCXC with a stronger contribution to the X-ray emission. The left and right panels show the RASS and *XMM-Newton* images, respectively. The positions of MCXC J1700.7+6412 ($z = 0.225$) and MCXC J1701.3+6414 ($z = 0.453$) are marked with a light and dark blue cross, respectively. The position of RXGCC 687 ($z = 0.239$) is marked with a small red circle. The corresponding solid and dashed circles represent the size $\theta_{500}$ of the clusters and their aperture radius. The green and orange pluses represent the position of two optical clusters: WHL J170041.8+641259, with an spectroscopic redshift of $z = 0.2350$ (Wen & Han 2015), and WHL J170123.5+641411, with an spectroscopic redshift of $z = 0.4521$ (Wen et al. 2009, 2010). The magenta plus shows the position of Abell cluster Abell 1035.

higher value, $z = 0.106$, based on 36 redshifts. We also cross-identified MCXC J0016.3-3121 with WHY J001617.2-311938 (at $2.3'$ offset) and RXGCC 16, both at consistent redshift, $z_{spec} = 0.1060$ and $z = 0.1065$, respectively. In view of the redshift difference the original measurement is likely that of a foreground galaxy.

**MCXC J0019.6+2517:** The catalogue redshift $z = 0.1353$ is based on the dedicated NORAS follow-up (Böhringer et al. 2000). There are two WHL clusters very close to the X-ray centre: WHL J001941.3+251807 ($z = 0.3657$ from five galaxies) at $0.85'$ ($0.22\theta_{500}$) and WHL J001939.4+251647 ($z = 0.1336$ from two galaxies) at $0.66'$ ($0.22\theta_{500}$). Their respective richnesses are $R_{L,500} = 130$ and $R_{L,500} = 23$. The *XMM-Newton* archive image shows a regular single cluster, with more than 21 DR17 galaxies at $z \sim 0.36$ within the X-ray contours, and two galaxies at $z \sim 0.14$. MCXC J0019.6+2517 is clearly a superposition along the line of sight of a rich cluster at $z = 0.365$, and a more nearby group at $z = 0.1353$. MCXC J0019.6+2517 is also detected at high S/N by Planck and is coincident at $0.85'$ distance with RM J001941.3+251807.3 at $z_{phot} = 0.3709$. We thus revised the redshift to $z = 0.365$, that of the likely main component.

**MCXC J0210.4-3929:** MCXC J0210.4-3929 is a 160SD/WARPS cluster. It is a case of redshift mismatch listed by Piffaretti et al. (2011), who cross-identified WARP J0210.4-3929 at $z = 0.273$ in the WARPS catalogue (Perlman et al. 2002) with RXJ0210.4-3929 (VMF 25) at $z = 0.165$ in the 160SD catalogue (Mullis et al. 2003). The close-by system MCXC J0210.2-3932, located $4.1'$ distance to the South-West, is also a case of redshift mismatch between WARP J0210.2-3932 (uncertain $z = 0.19$) and [VMF98] 024 ($z = 0.168$).

Piffaretti et al. (2011) adopted the 160SD values: $z = 0.168$ (MCXC J0210.4-3929) and $z = 0.165$ (MCXC J0210.2-3932), while NED assigns MCXC J0210.4-3929 a redshift of $z = 0.306$ from cross-identification with the Ridl et al. (2017, X-CLASS catalogue).

The field was observed with *XMM-Newton* and both objects are in the X-CLASS catalogue: X-CLASS 2078 (MCXC J0210.4-3929) at $z = 0.306$ from eight galaxies and X-CLASS 2079 (MCXC J0210.2-3932) at $z = 0.166$ from three galaxies. Most of the redshifts are from the [MLF2006] catalogue (Mulchaey et al. 2006). An overlay of the position of the spectroscopic galaxies from the X-CLASS database onto the *XMM-Newton* image clearly confirms the respective redshifts of the two MCXC clusters. However, one of the [MLF2006] galaxies at $z = 0.1655$ (i.e. a MCXC J0210.2-3932 member) is very close to the centre of MCXC J0210.4-3929. Therefore it is likely that the 160SD redshift was based on measurement of this foreground galaxy.

**MCXC J0507.7-0915:** This is a REFLEX cluster cross-identified with Abell 0536, at $1'$ distance. The catalogue redshift, $z = 0.0398$, taken from Struble & Rood (1999), is based on one galaxy measurement (Valentijn & Casertano 1988). We cross-identified the cluster with WHY J050744.5-091526 ($z = 0.14830$) at $1'$ distance and RXGCC 196 at a similarly consistent redshift ($z = 0.1455$). The redshift histogram in the RXGCC database shows a prominent peak at that redshift, with galaxies concentrated inside the X-ray contours. There is no galaxy peak around the REFLEX redshift value, which is likely that of a foreground galaxy.
**MCXC J1011.4+5450:** This is a 400SD cluster, matching the 160SD cluster, [VMF98] 086, at $z = 0.294$ from the dedicated 160SD follow-up (Mullis et al. 2003). It is also a WARPS cluster, WARP J1011.5+5450, given at the same redshift (Horner et al. 2008).

This is one of the cases of mismatch between the MCXC redshift and redMaPPer photometric redshift ($z_{phot} = 0.3841$ from Rozo et al. 2015) identified by Rozo & Rykoff (2014). The RM cluster, RM J101135.7+545005.3, corresponds to WHL J101135.7+545005 with $z_{spec} = 0.3798$ from one galaxy, confirming the photometric redshift. The ROSAT/PSPC image shows a bimodal structure, with a secondary, much fainter, peak at ~ 2.4' to the West. The WARPS iso-contours (Horner et al. 2008, their Figure 2) and position correspond to that of the main peak, while the published 400SD position lies between the two peaks. The spectroscopic galaxy SDSS J101135.73+545005.0 ($z = 0.3797 \pm 0.0001$ from the SDSS-DR17 release), the central galaxy of both the WHL and RM clusters in view of its position, is very close (0.21') to the X-ray maximum, further supporting the MCXC-SDSS cross-identification. The second closest SDSS spectroscopic galaxy is a brighter object at $z = 0.2956$, located at the western border of the secondary peak. This is likely the galaxy upon which the 400SD redshift is based, explaining the mismatch.

**MCXC J1016.6+2448:** MCXC J1016.6+2448 is a NORAS cluster cross-identified with Abell 0964, located at 0.5' distance. The catalogue redshift, $z = 0.0811$ is from dedicated follow-up but the number of galaxies is not specified. The cross-match with SDSS cluster catalogues gives WHL J101636.5+244803, a rich cluster ($R_{L,500} = 83.1$) at 0.45' distance with $z = 0.1732$ (from 21 galaxies), and RM J101633.5+244843.9 at 0.63' distance with $z_{spec} = 0.1788$ from BCG, obviously the SDSS detection of Abell 0964. The NORAS value is likely that of foreground galaxies.

**MCXC J1017.5+5934:** This is a NORAS cluster cross-identified with Abell 0959, located at 1.3' from the X-ray detection. The catalogue redshift, $z = 0.353$ is based on two galaxy redshifts from Huchra et al. (1990b). This is one of the cases of mismatch between the MCXC redshift and redMaPPer photometric redshift, identified by Rozo & Rykoff (2014) ($z_{phot} = 0.2891$ from Rozo et al. (2015)). This lower value is confirmed by the dynamical analysis of Boschin et al. (2009) and the cross-identification with WHL J101734.3+593340 at 0.37', which lies at $z = 0.2880$ based on 14 galaxies (Wen & Han 2015).

**MCXC J1159.2+4947:** MCXC J1159.2+4947 is a NORAS cluster identified with Abell 1430 (located at a distance a 1.85' from the X-ray centre). Its redshift is $z_{spec} = 0.211$, taken from Struble & Rood (1999), which refers to Kopylov et al. (1984). It is based on two galaxies. MCXC J1159.2+4947 is located 0.45' away from RM J115914.9+494748.4 ($z_{spec} = 0.3501$ from BCG) and 0.45' away from WHL J115914.9+494748 ($z_{spec} = 0.3486$ based on 13 galaxies, richness $R_{L,500} = 138$). An SDSS search within the X-ray contours yielded 29 spectroscopic redshifts including the BCG. RXGCC 437 is located at 0.94' distance and shows a clear redshift peak on the line-of-sight at $z = 0.3435$, with a second peak at $z = 0.08$. Three galaxies at $z \sim 0.2$, the NORAS catalogue value, are also visible. The original NORAS redshift is likely that of the two foreground galaxies. We adopted the redshift $z_{spec} = 0.3486$ from Wen & Han (2015, WHL15).

**MCXC J1340.9+3958:** This 160SD/400SD cluster was cross-identified by Mullis et al. (2003) with Abell 1774, with a redshift $z = 0.1690$ from Kopylov et al. (1984). This publication is not available on ADS but Struble & Rood (1991), quoting this reference for Abell 1774, specifies that the redshift is based on two galaxies. However, Abell 1774 is located 3.5' away from the X-ray peak, while WHL J134053.6+395755 is closer, at 0.56', with $z = 0.2772$ from two galaxies. WHL J134053.6+395755 is also in the redMaPPer catalogue as RM 134053.6+395754.8 at the same redshift. The ROSAT/PSPC and SWIFT images show a small cluster extent, with X-ray contours overlaid on the SDSS image supporting the cross-match with the RM and WHL cluster. There are more than ten galaxies with SDSS redshift $z \sim 0.169$ around the Abell 1774 position, confirming its redshift. Abell 1774 is a foreground object, but it remains unclear whether it can contaminate the 160SD cluster emission.

**MCXC J1343.4+4053:** This is a 160SD cluster with redshift $z_{spec} = 0.14$ from Mullis et al. (2003) based on an unknown number of galaxies. MCXC J1343.4+4053 is located 0.13' from WHL J134325.6+405318 ($z_{spec} = 0.2546$ based on two galaxies, richness $R_{L,500} = 18.6$) and 0.13' from RM J134325.6+405317.7 ($z_{spec} = 0.2560$ based on the central galaxy), on which the NED and Simbad preferred redshifts are based. We adopted the redshift $z_{spec} = 0.2560$ from Rykoff et al. (2016, redMaPPer).

**MCXC J1359.2+2758:** This MCXC cluster corresponds to Abell 1831, in which Smith et al. (2004) identified two components (Abell 1831A and B) superposed along the line of sight. Abell 1831B seems to be richer with a higher velocity dispersion, and thus a priori Abell 1831B is more massive and likely to be the main contributor to the X-ray signal. We have updated its redshift to $z = 0.07507$ from Abdullah et al. (2020), the most recent reference, based on 75 galaxies.

**MCXC J1415.1+3612:** The original redshift $z = 0.7$ is from Perlman et al. (2002) but mentioned by the authors as from noisy data, and the X-ray morphology indicates possible point-source contamination. The Simbad redshift is $z_{spec} = 1.027$ from Koulouridis et al. (2021, X-CLASS) based on nine galaxies. We changed the redshift to $z_{spec} = 1.026$ from Huang et al. (2009) based on its determination from a larger number of galaxies, $Nz = 25$.

**MCXC J1447.4+0827:** This is a NORAS cluster with original redshift $z = 0.1954$ from dedicated follow-up (Böhringer et al. 2000). This object is now associated with a MACS DR3 cluster located 0.3' away, lying at $z = 0.38$ based on optical data from SDSS (Mann & Ebeling 2012). MCXC J1447.4+0827 can be matched to Planck, ACT, ComPRASS, Wen, and redMaPPer clusters. From Wen & Han (2015), the closest match is WHL 144726.0+082825 at 0.6' (0.92' from the MACS DR3 cluster) with $z_{spec} = 0.376$ based on four spectra. The cluster is rich with $R_{L,500} = 83.5700$ and a number of galaxies $N = 45$. The ACT cluster has a redshift $z_{spec} = 0.375$ based on redMaPPer, which is consistent with the redshift from the Wen et al. cluster. We changed the MCXC J1447.4+0827 redshift to $z_{spec} = 0.376$ from Wen & Han (2015, WHL15).

**MCXC J1501.1+0141:** The original redshift of this REFLEX cluster is $z = 0.0050$ (Böhringer et al. 2004), which is an average of two sources: Smith et al. (2000) at $z_{spec} \sim 0.00659$ from spectroscopic data and NED information prior to 1992, without reference. The current NED redshift is $z = 0.0065$
from RXGCC 585 (Xu et al. 2022). Simbad associated the cluster with X-CLASS 2301, with $z = 0.005$ (Koulouridis et al. 2021). This redshift is based on ~ 30 galaxies over a large region, ~ $\theta_{500}$ in radius with a biweight re-estimate of $z_{spec} = 0.00553 \pm 0.00016$. However, the XMM-Newton image shows that the emission is dominated by the NGC 5813 galaxy (located at 25'' from the X-ray peak) and its associated halo. All redshift references in NED and Simbad of NGC 5813 confirm $z \sim 0.0065$, with the latest being $z = 0.00677$ from Hamer et al. (2016). Since the X-ray emission is dominated by the NGC 5813 halo, we adopted the latter value.

**MCXC J1520.9+4840:** This is a NORAS cluster with an original redshift $z = 0.1076$. The catalogue redshift references are Struble & Rood (1987) (based on two galaxies) and J.P. Huchra (2000, private communication). The NED redshift is $z = 0.0736$ from RXGCC 602 Xu et al. (2022) consistent with the Simbad spectroscopic redshift $z = 0.0738$ from Rines & Diaferio (2006). We adopted the more recent and well-matched spectroscopic measurement $z_{spec} = 0.074$ from von der Linden et al. (2007, based on $Nz = 38$ galaxies) The cluster also matches the GalWCat cluster #103 at $z = 0.0735$ from 24 galaxies.

**MCXC J1544.0+5346:** This is a 160SD cluster with an original redshift $z_{spec} = 0.112$ from Mullis et al. (2003). Takey et al. (2011) associated this object with an extended source (35 arcsec extent) from the 2XMM catalogue and with WHL J154407.3+534657 at $z_{spec} = 0.4970$. In Simbad, MCXC J1544.0+5346 is also associated with X-CLASS 638 at $z_{spec} = 0.50$ from SPIDERS spectroscopy (Koulouridis et al. 2021, four galaxies). There is an AGN (SDSS J154407.18+534559.6, 2XMM J154407.2+534600) at $z = 0.10911$ (Nisbet & Best 2016) very close to the 160SD cluster centre, and a few galaxies around that redshift in the image. Presumably, the 160SD follow-up identified this galaxy as the cluster BCG, hence the incorrect redshift. One can also note that the original $z_{phot}$ from Vikhlinin et al. (1998) was $z_{phot} = 0.33$. We adopted the redshift $z_{spec} = 0.50$ from Koulouridis et al. (2021).

**MCXC J1730.4+7422:** The redshift of $z_{spec} = 0.110$ (Böhringer et al. 2000) is from a dedicated follow-up and is thus a priori better than the previous redshift $z = 0.041$ from Appenzeller et al. (1998). However the cluster can be associated with RXGCC 724 (Xu et al. 2022) at 1.12' distance, with $z = 0.0470$. The histogram of redshifts from RXGCC shows only one galaxy at $z = 0.1$ and ~ 5 galaxies around $z = 0.0470$ located near the centre of the X-ray contours. The NGC 6414 galaxy at $z = 0.054$ is located 0.5' from the MCXC object and is an optical AGN (Zaw et al. 2019). The cluster was also imaged by XMM-Newton. The emission is dominated by this 'BCG' galaxy and it may be possible that the NORAS follow-up includes background objects. We changed to redshift to $z = 0.047$ based on Xu et al. (2022).

**MCXC J2032.1-5627:** This is a REFLEX cluster with original redshift $z_{spec} = 0.138$ in Piffaretti et al. (2011). From the dedicated spectroscopic follow-up programme for the REFLEX clusters, there are in fact three different cluster redshifts for the given cluster position (Guzzo et al. 2009): (i) $z_{spec} = 0.08025$, the redshift obtained from a low-S/N spectrum; (ii) $z_{spec} = 0.138$ is an average of five galaxy redshifts; (iii) $z_{spec} = 0.285$ is an average of six galaxy redshifts. The cluster is matched to SPT-CL J2032-5627 at the robust redshift $z_{spec} = 0.284$

obtained from 32 cluster member spectra, as reported by Song et al. (2012). The authors describe it as a superposition of structures along the same line of sight. More details can be found in the paper's appendix. Given the above, we have adopted $z_{spec} = 0.284$ from Song et al. (2012).

**MCXC J2135.2+0125:** This is a REFLEX cluster cross-identified with Abell 2355, located at 2.7' separation. The original redshift $z = 0.1244$, with reference Struble & Rood (1999), is based on two galaxies. This is one of the cases of mismatch identified by Rozo & Rykoff (2014), between the MCXC redshift and redMaPPer photometric redshift ($z_{phot} = 0.234$). The RM cluster, RM J213518.8+012527.0, corresponds to WHL J101135.7+545005, both located at 0.6' from the X-ray position, at $z_{spec} = 0.2301$. This value is consistent with the redshift of the BCG of the RM cluster ($z_{spec} = 0.2306$). MCXC J2135.2+0125 is also in the Planck and ACT catalogues and matches RXGCC 853 ($z = 0.2324$). The redshift histogram of RXGCC 853 shows two clear peaks, one at $z = 0.1187$ (the galaxies are mostly in the south, but one galaxy is very close to the Abell position) and the other at $z = 0.2324$ with galaxies centred on the X-ray cluster.

The REFLEX redshift is likely that of foreground galaxies. The WHL redshift is based on two galaxies. More redshifts are now available from SDSS-DR17, and we, therefore, re-estimated the cluster redshift to be $z = 0.229 \pm 0.004$ from ten spectroscopic galaxies.

**MCXC J2306.5-1319:** This is a REFLEX cluster with an original redshift $z = 0.0659$ based on two galaxies, estimated from the dedicated ESO Key Project follow-up. MCXC J2306.5-1319 also matches RXGCC 913 at a consistent $z = 0.0683$. We identified a potential counterpart, WHY J230621.3-131552, at 4.9' but at a discrepant redshift of $z = 0.1095$. WHY J230621.3-131552 matches Abell 2529, at $z = 0.11$ from Struble & Rood (1999). MCXC J2306.5-1319 is also close to the SGP cluster, MCXC J2306.8-1324, south-east of MCXC J2306.5-1319, at $z = 0.0659$. This redshift is based on two galaxies with a reference given as H. Boehringer & L. Guzzo, 1999, ESO Key Project, private communication, i.e. likely the same data as that used for MCXC J2306.5-1319.

The XMM-Newton observation, together with the information in the RXGCC database allows us to disentangle this case. There are two clusters, clearly separated in the XMM-Newton image, WHY J230621.3-131552 (A2529) in the north at $z = 0.1095$, and the SGP cluster in the south-east. The XMM-Newton emission of the latter is much fainter than that of the former. The position of the REFLEX cluster is in between, closer to WHY J230621.3-131552, with an extraction aperture encompassing both clusters. The RXGCC 913 ROSAT image does not resolve the two clusters either, but the maximum is at the WHY cluster location. The redshift histogram shows two peaks. A main peak is at $z \sim 0.0683$ with galaxies located in the south, consistent with the SGP redshift. There is a second peak at $z = 0.1077$, with galaxies concentrated in the north, around the WHY cluster position. In conclusion, this confirms the position and redshift of the SGP cluster, MCXC J2306.8-1324, which may be however contaminated by the more massive cluster in the North. The REFLEX (and RXGCC) detection is a confusion between the two objects at different redshifts but is dominated by the brighter component in the north. We thus changed the redshift to $z = 0.1095$.
**MCXC J2334.0+0704:** This is a NORAS cluster initially associated with Abell 2620. The redshift is $z = 0.099$ from Struble & Rood (1999) with reference Fetisova et al. (1993). We note that the Abell position is about 9.7' away from the NORAS position, so the initial association is probably not correct. We found 20 galaxy redshifts from SDSS at $z \sim 0.29$ matching with the X-ray contours within 6' and more than half of these within 3' of the X-ray peak. The average $z = 0.295$ ($0.2952 \pm 0.0022$) based on these 20 galaxy redshifts was adopted for MCXC J2334.0+0704.

**MCXC J2341.1+0018:** This is a NORAS cluster with $z = 0.11$ from dedicated follow-up, with reference Katgert et al. (1998). The number of galaxies is not specified. We cross-identified the cluster with WHL J234106.9+001833 at 0.36'separation, lying at $z = 0.2768$ from four galaxies ($R_L = 41$). This object also corresponds to a rich cluster in the RM catalogue, RM J234105.4+001815.2 at consistent $z_{phot} = 0.2928$. From the latest SDSS data, there are 18 spectroscopic redshifts including the BCG within the X-ray contours, with an average $z = 0.2757 \pm 0.0031$, in agreement with the WHL value. The NORAS $z$ estimate was likely based on foreground objects.

## Appendix B: K, $K_L$ and aperture corrections

### B.1. K-correction factors

Table B.1 Details the K-correction as a function of redshift and temperature for the [0.1–2.4] and [0.5–2] keV energy bands. Table B.2 gives the $K_L$-correction factor, the ratio of the luminosity in [0.1–2.4] keV energy band to that in the [0.5–2.] keV band, as a function of the temperature.

<table><caption>**Table B.1.** K-correction as a function of redshift for four different temperatures (1, 2, 4 and 10 keV) and for two energy bands of the ROSAT input flux, [0.5–2.] keV and [0.1–2.4] keV.</caption><thead><tr><th rowspan="2">z</th><th colspan="4">[0.1–2.4] keV</th><th colspan="4">[0.5–2.0] keV</th></tr><tr><th>1.0</th><th>2.0</th><th>4.0</th><th>10.0</th><th>1.0</th><th>2.0</th><th>4.0</th><th>10.0</th></tr></thead><tbody><tr><td>0.00</td><td>1.000</td><td>1.000</td><td>1.000</td><td>1.000</td><td>1.000</td><td>1.000</td><td>1.000</td><td>1.000</td></tr><tr><td>0.01</td><td>1.000</td><td>0.997</td><td>0.995</td><td>0.994</td><td>1.000</td><td>0.995</td><td>0.995</td><td>0.993</td></tr><tr><td>0.02</td><td>1.005</td><td>0.994</td><td>0.991</td><td>0.987</td><td>0.998</td><td>0.990</td><td>0.989</td><td>0.987</td></tr><tr><td>0.05</td><td>1.007</td><td>0.984</td><td>0.978</td><td>0.970</td><td>1.000</td><td>0.983</td><td>0.977</td><td>0.969</td></tr><tr><td>0.10</td><td>1.025</td><td>0.973</td><td>0.955</td><td>0.941</td><td>1.004</td><td>0.978</td><td>0.959</td><td>0.942</td></tr><tr><td>0.15</td><td>1.036</td><td>0.963</td><td>0.936</td><td>0.915</td><td>1.011</td><td>0.976</td><td>0.943</td><td>0.917</td></tr><tr><td>0.20</td><td>1.039</td><td>0.956</td><td>0.920</td><td>0.890</td><td>1.019</td><td>0.973</td><td>0.929</td><td>0.894</td></tr><tr><td>0.30</td><td>1.051</td><td>0.940</td><td>0.890</td><td>0.849</td><td>1.028</td><td>0.968</td><td>0.905</td><td>0.853</td></tr><tr><td>0.40</td><td>1.061</td><td>0.929</td><td>0.864</td><td>0.812</td><td>1.062</td><td>0.970</td><td>0.884</td><td>0.818</td></tr><tr><td>0.50</td><td>1.067</td><td>0.921</td><td>0.842</td><td>0.779</td><td>1.096</td><td>0.972</td><td>0.867</td><td>0.787</td></tr><tr><td>0.60</td><td>1.072</td><td>0.914</td><td>0.823</td><td>0.751</td><td>1.156</td><td>0.978</td><td>0.853</td><td>0.760</td></tr><tr><td>0.70</td><td>1.078</td><td>0.909</td><td>0.806</td><td>0.726</td><td>1.236</td><td>0.978</td><td>0.838</td><td>0.735</td></tr><tr><td>0.80</td><td>1.084</td><td>0.905</td><td>0.792</td><td>0.703</td><td>1.386</td><td>0.992</td><td>0.830</td><td>0.715</td></tr><tr><td>0.90</td><td>1.091</td><td>0.904</td><td>0.780</td><td>0.684</td><td>1.607</td><td>1.002</td><td>0.820</td><td>0.696</td></tr><tr><td>1.10</td><td>1.106</td><td>0.903</td><td>0.760</td><td>0.649</td><td>2.338</td><td>1.051</td><td>0.810</td><td>0.663</td></tr><tr><td>1.27</td><td>1.119</td><td>0.902</td><td>0.743</td><td>0.621</td><td>3.830</td><td>1.098</td><td>0.802</td><td>0.637</td></tr></tbody></table>

<table><caption>**Table B.2.** $K_L$-correction factor, the ratio of the luminosity in [0.1–2.4] keV energy band to that in the [0.5–2.] keV band, as a function of the temperature, $T$, in keV.</caption><thead><tr><th>log(T)</th><th>K<sub>L</sub></th></tr></thead><tbody><tr><td>-1.00</td><td>5.4916</td></tr><tr><td>-0.95</td><td>4.6962</td></tr><tr><td>-0.90</td><td>4.0376</td></tr><tr><td>-0.85</td><td>3.4923</td></tr><tr><td>-0.80</td><td>3.0408</td></tr><tr><td>-0.75</td><td>2.6670</td></tr><tr><td>-0.70</td><td>2.3576</td></tr><tr><td>-0.65</td><td>2.1018</td></tr><tr><td>-0.60</td><td>1.8904</td></tr><tr><td>-0.55</td><td>1.7159</td></tr><tr><td>-0.50</td><td>1.5720</td></tr><tr><td>-0.45</td><td>1.4534</td></tr><tr><td>-0.40</td><td>1.3559</td></tr><tr><td>-0.35</td><td>1.2757</td></tr><tr><td>-0.30</td><td>1.2098</td></tr><tr><td>-0.40</td><td>1.3559</td></tr><tr><td>-0.30</td><td>1.2098</td></tr><tr><td>-0.20</td><td>1.1113</td></tr><tr><td>-0.10</td><td>1.0449</td></tr><tr><td>-0.00</td><td>1.0000</td></tr><tr><td>0.10</td><td>0.9696</td></tr><tr><td>0.20</td><td>0.9491</td></tr><tr><td>0.30</td><td>0.9351</td></tr><tr><td>0.40</td><td>0.9257</td></tr><tr><td>0.50</td><td>0.9195</td></tr><tr><td>0.60</td><td>0.9156</td></tr><tr><td>0.70</td><td>0.9138</td></tr><tr><td>0.80</td><td>0.9138</td></tr><tr><td>0.90</td><td>0.9138</td></tr><tr><td>1.00</td><td>0.9138</td></tr></tbody></table>

### B.2. Aperture correction

The luminosity within a given radius $R$ scales as

$$L(<R) \equiv \int_{0}^{R} 2\pi r dr \int_{r}^{R_{\max}} \frac{2 \rho_{\text{gas}}^{2}(r') r' dr'}{\sqrt{r'^{2} - r^{2}}} \quad (\text{B.1})$$

$$= \int_{0}^{R_{\max}} 4\pi \rho_{\text{gas}}^{2} r^{2} dr - \int_{R}^{R_{\max}} 4\pi \rho_{\text{gas}}^{2} \sqrt{r^{2} - R^{2}} r dr \quad (\text{B.2})$$

where $\rho_{gas}$ is the gas density profile and $R_{max}$ is the cluster radial extent. We adopted $R_{max} = 5R_{500}$. For a universal gas profile:

$$\rho_{\text{gas}}^{2}(r) = A F_{g}(x) \quad \text{with} \quad x = r/R_{500} \quad (\text{B.3})$$

and defining:

$$I(x) = \int_{0}^{x} F_{g}(u) u^{2} du \quad (\text{B.4})$$

$$J(x) = \int_{x}^{5} F_{g}(u) \sqrt{u^{2} - x^{2}} u \, du \quad (\text{B.5})$$

The aperture correction is:

$$\frac{L_{500}}{L_{\text{ap}}} = f_{\text{ap}}(x_{\text{ap}} = R_{\text{ap}}/R_{500}) \quad (\text{B.6})$$
$$f_{\text{ap}}(x) = \frac{I(5) - J(1)}{I(5) - J(x)} \qquad (\text{B.7})$$

The numerical values for the REXCESS profile:

$$\rho_{\text{gas}} \propto \left(\frac{x}{x_c}\right)^{-\alpha} \times \left[1 + \left(\frac{x}{x_c}\right)^2\right]^{-3\beta/2+\alpha/2} \qquad (\text{B.8})$$

with $x_c = 0.303$, $\alpha = 0.525$, and $\beta = 0.768$ are given in the Table B.3.

<table><caption>**Table B.3.** Aperture correction factor, the ratio of the luminosity within the aperture radius, $R_{\text{ap}}$, to that within $R_{500}$, as a function of the ratio $R_{\text{ap}}/R_{500}$.</caption><thead><tr><th>log(R<sub>ap</sub>/R<sub>500</sub>)</th><th>L<sub>500</sub>/L<sub>ap</sub></th></tr></thead><tbody><tr><td>-1.00</td><td>5.4916</td></tr><tr><td>-0.95</td><td>4.6962</td></tr><tr><td>-0.90</td><td>4.0376</td></tr><tr><td>-0.85</td><td>3.4923</td></tr><tr><td>-0.80</td><td>3.0408</td></tr><tr><td>-0.75</td><td>2.6670</td></tr><tr><td>-0.70</td><td>2.3576</td></tr><tr><td>-0.65</td><td>2.1018</td></tr><tr><td>-0.60</td><td>1.8904</td></tr><tr><td>-0.55</td><td>1.7159</td></tr><tr><td>-0.50</td><td>1.5720</td></tr><tr><td>-0.45</td><td>1.4534</td></tr><tr><td>-0.40</td><td>1.3559</td></tr><tr><td>-0.35</td><td>1.2757</td></tr><tr><td>-0.30</td><td>1.2098</td></tr><tr><td>-0.40</td><td>1.3559</td></tr><tr><td>-0.30</td><td>1.2098</td></tr><tr><td>-0.20</td><td>1.1113</td></tr><tr><td>-0.10</td><td>1.0449</td></tr><tr><td>-0.00</td><td>1.0000</td></tr><tr><td>0.10</td><td>0.9696</td></tr><tr><td>0.20</td><td>0.9491</td></tr><tr><td>0.30</td><td>0.9351</td></tr><tr><td>0.40</td><td>0.9257</td></tr><tr><td>0.50</td><td>0.9195</td></tr><tr><td>0.60</td><td>0.9156</td></tr><tr><td>0.70</td><td>0.9138</td></tr><tr><td>0.80</td><td>0.9138</td></tr><tr><td>0.90</td><td>0.9138</td></tr><tr><td>1.00</td><td>0.9138</td></tr></tbody></table>

### B.3. Iteration convergence

We discuss here the convergence of the iterative process described in Sect. 4.1, which is used to determine the temperature, mass and luminosity. The convergence stems from the properties of the implicit equation that must verify the temperature. Combining the Eqs. 2, 3, 4, which provide the estimated luminosity from the input flux, and the $L_{500}-T$ relation (Eq. 5), the implicit equation on the temperature is of the form $f_1(T) = f_2(T)$ with:

$$f_1(T) = A \left( \frac{T}{5 \text{ keV}} \right)^{\alpha_T} \qquad (\text{B.9})$$

$$f_2(T) = K_{L,[E_1-E_2]}(T) K_{[E_1-E_2]}(T, z) f_{\text{ap}}(R_{\text{ap}}/R_{500}) \qquad (\text{B.10})$$

<figure><img src="image_27.png" /><figcaption>**Fig. B.1.** Illustration of the determination of the temperature for three 400SD clusters. The dashed line is the $f_1(T)$ function, the luminosity corresponding to the temperature, $T$, given the $L_{500}-T$ relation, divided by the luminosity $(4\pi D_1^2(z) F_{\text{ap}})$ estimated from the input aperture flux without correction (Eq. B.9). The solid line is the correction function $f_2(T)$ defined in Eq. B.10, the product of the K-correction, the $K_L$ correction factor used to convert the luminosity from the [0.5–2.] keV input band to [0.1–2.4] keV band and $F_{\text{ap}}$ is the aperture correction (fixed in that case). Both functions depend on cluster redshift. The curves are color-coded in blue, green and red for the MCXC J1116.9+1803 ($z = 0.0032$), MCXC J1823.7+5658 ($z = 0.1050$), and MCXC J1226.9+3332 ($z = 0.888$), respectively. The temperature is the intersection of the two curves (points). Starting from $T = 3$ keV, the iterative trajectory is shown in a thin blue line with arrows for the cluster MCXC J1116.9+1803 ($z = 0.0032$). We note the rapid convergence.</figcaption></figure>

where $K_{L,[E_1-E_2]}(T)$ can be omitted if the input flux is given in the [0.1–2.4] keV energy band. The normalisation factor $A$ of $f_1(T)$ is a constant for a given cluster, determined by its flux and redshift: $A = A_T E(z)^{-\beta_T} / (4\pi D_1^2(z) F_{\text{ap},[E_1-E_2]})$.

The left-hand side of the equation, $f_1(T)$, is simply a power law with a slope of $\alpha_T = 3$, which is a very steeply increasing function of the temperature. The right hand function is slightly more complex:

- For a fixed aperture correction, $f_2(T)$ is essentially a decreasing function of $T$, except via the $K_L$ factor in the ~ [0.5–2] keV band. Here $K_L$ increases mildly with $T$ but much less steeply than the $f_1(T)$ function (see Fig. B.1). In the typical cluster temperature range, 0.1–15 keV, there is only one intersection between the steeply increasing $f_1(T)$ and the mostly decreasing $f_2(T)$ function, spanning a smaller range of variation. In other words, the $T$ solution is unique. Furthermore, the convergence is rapid and the starting $T_0$ point is not critical. After the first iteration, the temperature, $T_1$ is where $f_1(T) \propto T^3$ is equal to $f_2(T_0)$, already close to the final value. The next iterations simply refine the $T$ value, due to the milder variations of $f_2(T)$ as compared to $f_1(T)$. This is illustrated in Fig. B.1, where we plot the $f_1(T)$ and $f_2(T)$ functions for three 400SD clusters, at very low redshift, median redshift and high redshift. For this catalogue,
the aperture correction is fixed but we have to apply a $K_L$ correction.

- For cases of available aperture flux, the aperture correction, $f_{ap}(R_{ap}/R_{500}) = L_{500}/L_{ap}$ in $f_2(T)$ is itself determined iteratively and depends on the temperature of the iteration step in question. This dependence is via the computation of the current $L_{ap}$, which appears in the corresponding implicit equation that has to be solved for $R_{500}$. Combining Eq. 2 and Eq. 3, which determines $L_{ap}$ from the input flux, and the scaling relation in Eqs. 6 and 7, we must solve:

$$f_{ap}(R_{ap}/R_{500}) = B R_{500}^{3*1.675}/(K_L(T) K(T, z)) \quad (B.11)$$

where B is a constant for a given cluster. The solution always exists due to the restricted range of the aperture variation (see Table B.3) as compared to that of the right-hand power law. It is unique as the left hand and right hand functions in the equation increase monotonically with increasing $R_{500}$. Generally, their intersection moves to the right in the log-log plane (that is, to higher $R_{500}$ and aperture correction) for a higher iteration step temperature, as the normalisation of the power law increases (lower K corrections). The convergence is again rapid and is only weakly dependent on the starting point due to the steepness of the right hand power law. Note that this is the second iteration on $R_{500}$ which in practice fixes the next iteration step temperature via the $L_{500}-M_{500}$ and $L_{500}-T$ scaling relations with the corresponding $M_{500}$.

# Appendix C: OBSID of XMM-Newton observations

Table C.1 gives the XMM-Newton OBSIDs that were used in catalogue validation.

# Appendix D: Catalogue content

Table D.1 gives an overview of the 46 fields contained in the MCXC-II catalogue.

We added an individual formatted note for 59 clusters that are displayed in the column NOTES. Each note comprises three components: 1) a simplified category code; 2) if the object is discussed in the paper, the corresponding Section location; and 3) a text note providing information concerning the cluster category code.

The category code covers eight different cases: (PLc) – Point-Like contamination: cluster emission contaminated by AGN (no AGN redshift available); (PLc_intra) – Point-Like contamination intra: cluster emission contaminated by AGN inside the cluster; (PLc_extra) – Point-Like contamination extra: cluster emission contaminated by foreground/background AGN; (complexStr) – Complex X-ray structure: cluster with sub-structures and/or close-by clusters on the plane of the sky; (Dupl) – Duplicate: two different objects in MCXC-I identified as one single object in MCXC-II; (losStr) – line-of-sight structure: structure on the line of sight; (X0off) – Offset between the X-ray and Optical-counterparts as discussed in the paper; and (Other) – Any other useful information identified during the construction of MCXC-II.
<table><caption>**Table C.1.** List of XMM-Newton observations used in this work. Col. 1: MCXC-II cluster; Col. 2: Name of the target of the observations; Col. 3: OBSID.</caption><thead><tr><td>MCXC-II name</td><td>Target name</td><td>OBSID</td></tr></thead><tbody><tr><td>J0019.6+2517</td><td>PSZ2G113.91-37.01</td><td>0827021001</td></tr><tr><td>J0034.2-0204</td><td>RXCJ0034.6-0208</td><td>0720250401</td></tr><tr><td>J0040.0+0649</td><td>Abell 76</td><td>0405550101</td></tr><tr><td>J0056.0-3732</td><td>NGC 300</td><td>0305860301</td></tr><tr><td>J0125.4+0145</td><td>A 189</td><td>0109860101</td></tr><tr><td>J0152.9-1345</td><td>NGC 720</td><td>0602010101</td></tr><tr><td>J0159.0-3412</td><td>PSZ2G243.15-73.84</td><td>0827011301</td></tr><tr><td>J0210.4-3929</td><td>RXJ0210.4-3929</td><td>0401130101</td></tr><tr><td>J0236.0-5225</td><td>WW Hor</td><td>0098810101</td></tr><tr><td>J0338.4-3526</td><td>NGC 1399</td><td>0400620101</td></tr><tr><td>J0345.7-4112</td><td>RXCJ0345.7-4112</td><td>0201900801</td></tr><tr><td>J0416.7-5525</td><td>NGC1549</td><td>0205090201</td></tr><tr><td>J0553.4-3342</td><td>PSZ2G239.27-26.01</td><td>0827010401</td></tr><tr><td>J0748.1+1832</td><td>RXCJ0748.1+1832</td><td>0651780201</td></tr><tr><td>J0823.1+0421</td><td>ZwCl1665</td><td>0741580501</td></tr><tr><td>J0857.7+2747</td><td>3C 210</td><td>0210280101</td></tr><tr><td>J0900.6+2054</td><td>Z2089</td><td>0402250701</td></tr><tr><td>J0909.1+1059</td><td>PSZ2G218.81+35.51</td><td>0827351301</td></tr><tr><td>J0926.7+1234</td><td>PG 0923+129</td><td>0783270401</td></tr><tr><td>J0956.4-1004</td><td>Abell 901</td><td>0148170101</td></tr><tr><td>J1022.0+3830</td><td>RXCJ1022.0+3830</td><td>0503601301</td></tr><tr><td>J1032.2+4015</td><td>A1035</td><td>0653810501</td></tr><tr><td>J1058.1+0135</td><td>cl1058+0137</td><td>0601930101</td></tr><tr><td>J1253.2-1522</td><td>NGC 4756</td><td>0551600101</td></tr><tr><td>J1310.4+2151</td><td>RXCJ1310.9+2157</td><td>0841900201</td></tr><tr><td>J1311.7+2201</td><td>Z5768</td><td>0402250301</td></tr><tr><td>J1314.4-2515</td><td>RXCJ 1314.4-2515</td><td>0501730101</td></tr><tr><td>J1329.4+1143</td><td>NGC 5171 Group</td><td>0041180801</td></tr><tr><td>J1330.8-0152</td><td>A1750</td><td>0112240301</td></tr><tr><td>J1359.2+2758</td><td>PSZ2G040.03+74.95</td><td>0827031901</td></tr><tr><td>J1411.4+5212</td><td>XMM-RM19</td><td>0804271501</td></tr><tr><td>J1414.2+7115</td><td>PLCKESZG113.82+44.35</td><td>0692933601</td></tr><tr><td>J1415.2-0030</td><td>MCXC J1415.2-0030</td><td>0762870501</td></tr><tr><td>J1419.3+0638</td><td>RXJ1419.3/RXJ1419.9</td><td>0303670101</td></tr><tr><td>J1419.8+0634</td><td>RXJ1419.3/RXJ1419.9</td><td>0303670101</td></tr><tr><td>J1501.1+0141</td><td>NGC 5813</td><td>0554680301</td></tr><tr><td>J1506.4+0136</td><td>NGC 5846</td><td>0723800201</td></tr><tr><td>J1544.0+5346</td><td>SBS 1542+541</td><td>0060370901</td></tr><tr><td>J1700.7+6412</td><td>HS 1700+6416</td><td>0723700201</td></tr><tr><td>J1705.1-8210</td><td>S0792</td><td>0761111801</td></tr><tr><td>J1730.4+7422</td><td>RXJ 1730</td><td>0014150401</td></tr><tr><td>J1736.3+6803</td><td>RXCJ1736.3+6803</td><td>0203610401</td></tr><tr><td>J1755.7+6752</td><td>PLCKESZ G098.12+30.3</td><td>0841950201</td></tr><tr><td>J1847.3-6320</td><td>2XMMi J184725-63172</td><td>0694610101</td></tr><tr><td>J1925.4-4256</td><td>A3638</td><td>0765020101</td></tr><tr><td>J2004.8-5603</td><td>CL 2003-5556</td><td>0673180401</td></tr><tr><td>J2032.1-5627</td><td>SPT-CLJ2032-5627</td><td>0674490401</td></tr><tr><td>J2034.3-3429</td><td>Abell 3693</td><td>0404520201</td></tr><tr><td>J2127.1-1209</td><td>Abell 2345</td><td>0604740101</td></tr><tr><td>J2218.2-0350</td><td>1E2216/1E2215</td><td>0800380101</td></tr><tr><td>J2256.9+0532</td><td>MCXC J2256.9+0532</td><td>0762871101</td></tr><tr><td>J2306.5-1319</td><td>RXCJ2306.6-1319</td><td>0765030201</td></tr><tr><td>J2306.8-1324</td><td>RXCJ2306.6-1319</td><td>0765030201</td></tr><tr><td>J2311.5+0338</td><td>A2552</td><td>0693010201</td></tr><tr><td>J2318.5+1842</td><td>ABELL 2572b</td><td>0741580601</td></tr><tr><td>J2325.6-5443</td><td>XBCSM2-19b</td><td>0677820144</td></tr><tr><td>J2359.3-6042</td><td>RXCJ2359.3-6042</td><td>0677180601</td></tr></tbody></table>
<table><caption>Table D.1. Summary overview of catalogue fields.</caption><thead><tr><th>Field Name</th><th>FORMAT</th><th>UNIT</th><th>DESCRIPTION</th></tr></thead><tbody><tr><td>INDEX</td><td>SHORT</td><td></td><td>Cluster index</td></tr><tr><td>NAME MCXC</td><td>STRING</td><td></td><td>Name in MCXC</td></tr><tr><td>NAME</td><td>STRING</td><td></td><td>Name in the input catalogue</td></tr><tr><td>NAME ALT</td><td>STRING</td><td></td><td>Other names</td></tr><tr><td>_RAJ2000</td><td>STRING</td><td>h:m:s</td><td>Right Ascension (J2000)</td></tr><tr><td>_DEJ2000</td><td>STRING</td><td>d:m:s</td><td>Declination (J2000)</td></tr><tr><td>RAJ2000</td><td>FLOAT</td><td>deg</td><td>Right Ascension (J2000)</td></tr><tr><td>DEJ2000</td><td>FLOAT</td><td>deg</td><td>Declination (J2000)</td></tr><tr><td>GLON</td><td>FLOAT</td><td>deg</td><td>Galactic longitude</td></tr><tr><td>GLAT</td><td>FLOAT</td><td>deg</td><td>Galactic latitude</td></tr><tr><td>CATALOGUE</td><td>STRING</td><td></td><td>Catalogue name</td></tr><tr><td>SUB_CATALOGUE</td><td>STRING</td><td></td><td>Sub-catalogue name</td></tr><tr><td>Z</td><td>FLOAT</td><td></td><td>Redshift</td></tr><tr><td>Z_TYPE</td><td>STRING</td><td></td><td>Redshift type (1)</td></tr><tr><td>Z_REF</td><td>STRING</td><td></td><td>Redshift Reference (BIBCODE and/or present work (PW))</td></tr><tr><td>Z_FLAG</td><td>STRING</td><td></td><td>Redshift Flag (2)</td></tr><tr><td>SCALE</td><td>FLOAT</td><td>kpc arcsec<sup>-1</sup></td><td>Scale factor</td></tr><tr><td>ERANGE</td><td>FLOAT(2)</td><td>keV</td><td>Energy range of the flux</td></tr><tr><td>R_AP_ARCMIN</td><td>DOUBLE</td><td>arcmin</td><td>Radius of aperture of flux extraction (-1. for input total flux)</td></tr><tr><td>FX</td><td>DOUBLE</td><td>10<sup>-12</sup> erg s<sup>-1</sup> cm<sup>-2</sup></td><td>Flux</td></tr><tr><td>ERRFX</td><td>DOUBLE</td><td>10<sup>-12</sup> erg s<sup>-1</sup> cm<sup>-2</sup></td><td>Error on the flux</td></tr><tr><td>LX2L500</td><td>STRING</td><td></td><td>Method to convert L_AP to L500 (3)</td></tr><tr><td>L_AP</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Luminosity within aperture (-1. for input total flux)</td></tr><tr><td>L500</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Luminosity within R500</td></tr><tr><td>ERRML500</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Lower error on L500</td></tr><tr><td>ERRPL500</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Upper error on L500</td></tr><tr><td>R500</td><td>DOUBLE</td><td>Mpc</td><td>Radius corresponding to a density contrast of 500</td></tr><tr><td>M500</td><td>DOUBLE</td><td>10<sup>14</sup> solar mass</td><td>Mass corresponding to a density contrast of 500</td></tr><tr><td>ERRMM500</td><td>DOUBLE</td><td>10<sup>14</sup> solar mass</td><td>Lower error on M500</td></tr><tr><td>ERRPM500</td><td>DOUBLE</td><td>10<sup>14</sup> solar mass</td><td>Upper error on M500</td></tr><tr><td>OVLP</td><td>STRING</td><td></td><td>Overlap in different catalogues</td></tr><tr><td>CAT1</td><td>STRING</td><td></td><td>First overlapped catalogue</td></tr><tr><td>CAT2</td><td>STRING</td><td></td><td>Second overlapped catalogue</td></tr><tr><td>CAT3</td><td>STRING</td><td></td><td>Third overlapped catalogue</td></tr><tr><td>CAT4</td><td>STRING</td><td></td><td>Fourth overlapped catalogue</td></tr><tr><td>L5001</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Luminosity within R500 for first catalogue overlapped</td></tr><tr><td>ERRML5001</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Lower error on L5001</td></tr><tr><td>ERRPL5001</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Upper error on L5001</td></tr><tr><td>L5002</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Luminosity within R500 for second catalogue overlapped</td></tr><tr><td>ERRML5002</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Lower error on L5002</td></tr><tr><td>ERRPL5002</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Upper error on L5002</td></tr><tr><td>L5003</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Luminosity within R500 for third catalogue overlapped</td></tr><tr><td>ERRML5003</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Lower error on L5003</td></tr><tr><td>ERRPL5003</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Upper error on L5003</td></tr><tr><td>L5004</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Luminosity within R500 for fourth catalogue overlapped</td></tr><tr><td>ERRML5004</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Lower error on L5004</td></tr><tr><td>ERRPL5004</td><td>DOUBLE</td><td>10<sup>44</sup> erg s<sup>-1</sup></td><td>Upper error on L5004</td></tr><tr><td>NOTES_ORIG</td><td>STRING</td><td></td><td>Note (expanded) on the cluster as given in the source catalogue (4)</td></tr><tr><td>NOTES</td><td>STRING</td><td></td><td>Note on the cluster (5)</td></tr><tr><td>INDEX MCXC_P2011</td><td>SHORT</td><td></td><td>Index in MCXC published by Piffaretti et al. 2011</td></tr></tbody></table>

### Notes.

(1) redshift type: spectroscopic (S), photometric (P), a combination of photometric and spectroscopic values (SP), estimated (E) or unknown (U)

(2) Redshift flag:

- 'Catalogue': original value from catalogue.

- 'New': No redshift was available in the source catalogue; the new redshift origin is given in Z_REF

- 'Revised': redshift in the catalog has been updated

- 'Consolidated': the source of the redshift in the catalogue and/or its type was unclear. We propose another reference (given in Z_ref), with the corresponding redshift for consistency. The difference with the catalogue value is negligible.

(3) Method to convert aperture luminosity to L500: by iteration ('ITER') or using a fixed size correction ('SC')

(4) Collated notes from original input source catalogues. In some cases, these have been expanded from the original abbreviated form, or combined from different tables in the input catalogue paper.

(5) Individual formatted notes on the cluster (Code | Section | Description). More details are in the text, see Appendix D.