J/A+A/695/A160 Morphological parameters of eROSITA clusters (Sanders+, 2025)
The SRG/eROSITA all-sky survey: The morphologies of clusters of galaxies.
I. A catalogue of morphological parameters.
Sanders J.S., Bahar Y.E., Bulbul E., Ghirardini V., Liu A., Clerc N.,
Ramos-Ceja M.E., Reiprich T.H., Balzer F., Comparat J., Kluge M., Pacaud F.,
Zhang X.
<Astron. Astrophys. 695, A160 (2025)>
=2025A&A...695A.160S 2025A&A...695A.160S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Morphology ; X-ray sources
Keywords: galaxies: clusters: intracluster medium - X-rays: galaxies: clusters
Abstract:
The first SRG/eROSITA all-sky X-ray survey, eRASS1, resulted in a
catalogue of over twelve thousand optically-confirmed galaxy groups
and clusters in the western Galactic hemisphere. Using the eROSITA
images of these objects, we measure and study their morphological
properties, including their concentration, central density and slope,
ellipticity, power ratios, photon asymmetry, centroid shift and Gini
coefficient. We also introduce new forward-modelled parameters which
take account of the instrument point spread function (PSF), which are
slosh, which measures how asymmetric the surface brightness
distribution is, and multipole magnitudes, which are analogues to
power ratios. Using simulations, we find some non forward-modelled
parameters are strongly biased due to PSF and data quality. For the
same clusters, we find similar values of concentration and central
density compared to results by ourselves using Chandra and previous
results from XMM-Newton. The population as a whole has log
concentrations which are typically around 0.3 dex larger than South
Pole Telescope or Planck-selected samples and the deeper eFEDS sample.
The exposure time, detection likelihood threshold, extension
likelihood threshold and number of counts affect the concentration
distribution, but generally not enough to reduce the concentration to
match the other samples. The concentration of clusters in the survey
strongly affects whether they are detected as a function of redshift
and luminosity. We introduce a combined disturbance score based on a
Gaussian mixture model fit to several of the parameters. For brighter
clusters, around 1/4 of objects are classified as disturbed using this
score, which may be due to our sensitivity to concentrated objects.
Description:
Morphological parameters for 12705 optically-confirmed galaxy clusters
detected in the eRASS1 eROSITA survey. For each cluster we measure the
central gas density, the cuspiness or inner density slope, the
concentration, the peak separation, power ratios, Gini coefficient,
photon asymmetry, centroid shift, ellipticity, slosh, multipole
magnitudes and disturbance parameter.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
morph.dat 1093 12705 Morphological parameters for 12705
optically-confirmed galaxy clusters detected
in the eRASS1 eROSITA survey (table A1)
--------------------------------------------------------------------------------
See also:
J/A+A/682/A34 : SRG/eROSITA all-sky survey catalogs (eRASS1) (Merloni+, 2024)
Byte-by-byte Description of file: morph.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Name (IAUNAME), 1eRASS JHHMMSS.s-FFMMSS
(NAME)
26- 57 A32 --- DetUId eROSITA detection ID (DETUID)
60- 70 F11.4 ct Cts800 Counts inside 800kpc (CTS_800)
73- 84 F12.4 ct E_Cts800 Counts inside 800kpc positive error
(CTS800POS)
87- 98 F12.4 ct e_Cts800 [] Counts inside 800kpc negative error
(CTS800NEG)
101- 108 F8.4 --- logNS0 Log gas density at a radius of 0.02R500
relative to a scaled critical density
(NS_0)
111- 116 F6.4 --- E_logNS0 Log gas density at a radius of 0.02R500
relative to a scaled critical density
positive error (NS0POS)
119- 125 F7.4 --- e_logNS0 [] Log gas density at a radius of
0.02R500 relative to a scaled critical
density negative error (NS0NEG)
128- 135 F8.4 --- logNS0P Log gas density at a radius of 0.02R500
relative to a scaled critical density,
peak (NS0P)
138- 143 F6.4 --- E_logNS0P Log gas density at a radius of 0.02R500
relative to a scaled critical density,
peak positive error (NS0P_POS)
146- 152 F7.4 --- e_logNS0P [] Log gas density at a radius of
0.02R500 relative to a scaled critical
density, peak negative error
(NS0P_NEG)
155- 162 F8.4 [cm-3] logNe50 Log gas electron density at a radius of
50kpc (NE_50)
165- 170 F6.4 [cm-3] E_logNe50 Log gas electron density at a radius of
50kpc positive error (NE50POS)
173- 179 F7.4 [cm-3] e_logNe50 [] Log gas electron density at a radius
of 50kpc negative error (NE50NEG)
182- 189 F8.4 [cm-3] logNe50P Log gas electron density at a radius of
50kpc, peak (NE50P)
192- 197 F6.4 [cm-3] E_logNe50P Log gas electron density at a radius of
50kpc, peak positive error (NE50P_POS)
200- 206 F7.4 [cm-3] e_logNe50P [] Log gas electron density at a radius
of 50kpc, peak negative error
(NE50P_NEG)
209- 215 F7.4 --- alpha Inner density slope at 0.04R500 radius
(ALPHA)
218- 223 F6.4 --- E_alpha Inner density slope at 0.04R500 radius
positive error (ALPHA_POS)
226- 232 F7.4 --- e_alpha [] Inner density slope at 0.04R500
radius negative error (ALPHA_NEG)
235- 241 F7.4 --- alphaP Inner density slope at 0.04R500 radius,
peak (ALPHA_P)
244- 249 F6.4 --- E_alphaP Inner density slope at 0.04R500 radius,
peak positive error (ALPHAPPOS)
252- 258 F7.4 --- e_alphaP [] Inner density slope at 0.04R500
radius, peak negative error
(ALPHAPNEG)
261- 267 F7.4 --- alpha50 Inner density slope at 50kpc radius
(ALPHA_50)
270- 275 F6.4 --- E_alpha50 Inner density slope at 50kpc radius
positive error (ALPHA50POS)
278- 284 F7.4 --- e_alpha50 [] Inner density slope at 50kpc radius
negative error (ALPHA50NEG)
287- 293 F7.4 --- alpha50P Inner density slope at 50kpc radius, peak
(ALPHA50P)
296- 301 F6.4 --- E_alpha50P Inner density slope at 50kpc radius, peak
positive error (ALPHA50P_POS)
304- 310 F7.4 --- e_alpha50P [] Inner density slope at 50kpc radius,
peak negative error (ALPHA50P_NEG)
313- 319 F7.4 --- logC80-800 Log ratio of integrated model surface
brightness in apertures of 80 and 800kpc
(C80800)
322- 327 F6.4 --- E_logC80-800 Log ratio of integrated model surface
brightness in apertures of 80 and 800kpc
positive error (C80800_POS)
330- 336 F7.4 --- e_logC80-800 [] Log ratio of integrated model surface
brightness in apertures of 80 and 800kpc
negative error (C80800_NEG)
339- 345 F7.4 --- logC80-800P Log ratio of integrated model surface
brightness in apertures of 80 and
800kpc, peak (C80800_P)
348- 353 F6.4 --- E_logC80-800P Log ratio of integrated model surface
brightness in apertures of 80 and
800kpc, peak positive error
(C80800PPOS)
356- 362 F7.4 --- e_logC80-800P [] Log ratio of integrated model surface
brightness in apertures of 80 and
800kpc, peak negative error
(C80800PNEG)
365- 371 F7.4 --- logCR500 Log ratio of integrated model surface
brightness in apertures of 0.1R500 and
R500 (C_R500)
374- 379 F6.4 --- E_logCR500 Log ratio of integrated model surface
brightness in apertures of 0.1R500 and
R500 positive error (CR500POS)
382- 388 F7.4 --- e_logCR500 [] Log ratio of integrated model surface
brightness in apertures of 0.1R500 and
R500 negative error (CR500NEG)
391- 397 F7.4 --- logCR500P Log ratio of integrated model surface
brightness in apertures of 0.1R500 and
R500, peak (CR500P)
400- 405 F6.4 --- E_logCR500P Log ratio of integrated model surface
brightness in apertures of 0.1R500 and
R500, peak positive error (CR500P_POS)
408- 414 F7.4 --- e_logCR500P [] Log ratio of integrated model surface
brightness in apertures of 0.1R500 and
R500, peak negative error (CR500P_NEG)
417- 423 F7.4 --- F Ratio of offset between best fitting
cluster centre and peak and R500 (F)
426- 431 F6.4 --- E_F Ratio of offset between best fitting
cluster centre and peak and R500
positive error (F_POS)
434- 440 F7.4 --- e_F [] Ratio of offset between best fitting
cluster centre and peak and R500
negative error (F_NEG)
443- 449 F7.4 --- logP10 ? Log power ratio P1/P0 (P10)
452- 457 F6.4 --- E_logP10 ? Log power ratio P1/P0
positive error (P10_POS)
460- 466 F7.4 --- e_logP10 []? Log power ratio P1/P0
negative error (P10_NEG)
469- 475 F7.4 --- logP10P ? Log power ratio P1/P0, peak (P10_P)
478- 483 F6.4 --- E_logP10P ? Log power ratio P1/P0, peak
positive error (P10PPOS)
486- 492 F7.4 --- e_logP10P []? Log power ratio P1/P0, peak
negative error (P10PNEG)
495- 501 F7.4 --- logP20 ? Log power ratio P2/P0 (P20)
504- 509 F6.4 --- E_logP20 ? Log power ratio P2/P0
positive error (P20_POS)
512- 518 F7.4 --- e_logP20 []? Log power ratio P2/P0
negative error (P20_NEG)
521- 527 F7.4 --- logP20P ? Log power ratio P2/P0, peak (P20_P)
530- 535 F6.4 --- E_logP20P ? Log power ratio P2/P0, peak
positive error (P20PPOS)
538- 544 F7.4 --- e_logP20P []? Log power ratio P2/P0, peak
negative error (P20PNEG)
547- 554 F8.4 --- logP30 ? Log power ratio P3/P0 (P30)
557- 562 F6.4 --- E_logP30 ? Log power ratio P3/P0
positive error (P30_POS)
565- 571 F7.4 --- e_logP30 []? Log power ratio P3/P0
negative error (P30_NEG)
574- 581 F8.4 --- logP40 ? Log power ratio P4/P0 (P40)
584- 589 F6.4 --- E_logP40 ? Log power ratio P4/P0
positive error (P40_POS)
592- 598 F7.4 --- e_logP40 []? Log power ratio P4/P0
negative error (P40_NEG)
601- 606 F6.4 --- Gini ? Gini coefficient (G) (GINI)
609- 614 F6.4 --- E_Gini ? Gini coefficient (G)
positive error (GINI_POS)
617- 623 F7.4 --- e_Gini []? Gini coefficient (G)
negative error (GINI_NEG)
626- 636 F11.4 --- Aphot ? Photon asymmetry (A_phot) (APHOT)
639- 648 F10.4 --- E_Aphot ? Photon asymmetry (A_phot)
positive error (APHOT_POS)
651- 661 F11.4 --- e_Aphot []? Photon asymmetry (A_phot)
negative error (APHOT_NEG)
664- 673 F10.4 --- AphotP ? Photon asymmetry (A_phot), peak
(APHOT_P)
676- 685 F10.4 --- E_AphotP ? Photon asymmetry (A_phot), peak
positive error (APHOTPPOS)
688- 698 F11.4 --- e_AphotP []? Photon asymmetry (A_phot), peak
negative error (APHOTPNEG)
701- 707 F7.4 --- Centroid ? Centroid shift (w) (CENTROID)
710- 715 F6.4 --- E_Centroid ? Centroid shift (w) positive error
(CENTROID_POS)
718- 724 F7.4 --- e_Centroid []? Centroid shift (w) negative error
(CENTROID_NEG)
727- 733 F7.4 --- Ell Ellipticity (epsilon) (ELLIPTICITY)
736- 741 F6.4 --- E_Ell Ellipticity (epsilon) positive error
(ELLIPTICITY_POS)
744- 750 F7.4 --- e_Ell [] Ellipticity (epsilon) negative error
(ELLIPTICITY_NEG)
753- 760 F8.4 deg EllTheta Ellipticity angle (ELLIPTICITY_THETA)
763- 771 F9.4 deg E_EllTheta [] Ellipticity angle positive error
(ELLIPTICITYTHETAPOS)
774- 782 F9.4 deg e_EllTheta [] Ellipticity angle negative error
(ELLIPTICITYTHETANEG)
785- 791 F7.4 --- SlosH Slosh (H), the degree of sloshing factor
(SLOSH)
794- 800 F7.4 --- E_SlosH [] Slosh (H), the degree of sloshing
factor, positive error (SLOSH_POS)
803- 809 F7.4 --- e_SlosH [] Slosh (H), the degree of sloshing
factor, negative error (SLOSH_NEG)
812- 820 F9.4 deg SlosHTheta Slosh, the degree of sloshing factor,
angle (SLOSH_THETA)
823- 831 F9.4 deg E_SlosHTheta [] Slosh (H), the degree of sloshing
factor, angle positive error
(SLOSHTHETAPOS)
834- 842 F9.4 deg e_SlosHTheta [] Slosh (H), the degree of sloshing
factor, angle negative error
(SLOSHTHETANEG)
845- 850 F6.4 --- M1 ? Multipole magnitude for order 1 (M1)
853- 858 F6.4 --- E_M1 ? Multipole magnitude for order 1
positive error (M1_POS)
861- 867 F7.4 --- e_M1 []? Multipole magnitude for order 1
negative error (M1_NEG)
870- 878 F9.4 deg M1Theta ? Multipole magnitude for order 1 angle
(M1_THETA)
881- 889 F9.4 deg E_M1Theta []? Multipole magnitude for order 1 angle
positive error (M1THETAPOS)
892- 900 F9.4 deg e_M1Theta []? Multipole magnitude for order 1 angle
negative error (M1THETANEG)
903- 909 F7.4 --- M2 Multipole magnitude for order 2 (M2)
912- 918 F7.4 --- E_M2 [] Multipole magnitude for order 2
positive error (M2_POS)
921- 927 F7.4 --- e_M2 [] Multipole magnitude for order 2
negative error (M2_NEG)
930- 938 F9.4 deg M2Theta Multipole magnitude for order 2 angle
(M2_THETA)
941- 949 F9.4 deg E_M2Theta [] Multipole magnitude for order 2 angle
positive error (M2THETAPOS)
952- 960 F9.4 deg e_M2Theta [] Multipole magnitude for order 2 angle
negative error (M2THETANEG)
963- 969 F7.4 --- M3 Multipole magnitude for order 3 (M3)
972- 977 F6.4 --- E_M3 Multipole magnitude for order 3
positive error (M3_POS)
980- 986 F7.4 --- e_M3 [] Multipole magnitude for order 3
negative error (M3_NEG)
989- 997 F9.4 deg M3Theta Multipole magnitude for order 3 angle
(M3_THETA)
1000-1008 F9.4 deg E_M3Theta [] Multipole magnitude for order 3 angle
positive error (M3THETAPOS)
1011-1019 F9.4 deg e_M3Theta [] Multipole magnitude for order 3 angle
negative error (M3THETANEG)
1022-1027 F6.4 --- M4 Multipole magnitude for order 4 (M4)
1030-1035 F6.4 --- E_M4 Multipole magnitude for order 4
positive error (M4_POS)
1038-1044 F7.4 --- e_M4 [] Multipole magnitude for order 4
negative error (M4_NEG)
1047-1055 F9.4 deg M4Theta ? Multipole magnitude for order 4 angle
(M4_THETA)
1058-1066 F9.4 deg E_M4Theta []? Multipole magnitude for order 4 angle
positive error (M4THETAPOS)
1069-1077 F9.4 deg e_M4Theta []? Multipole magnitude for order 4 angle
negative error (M4THETANEG)
1080-1085 F6.4 --- D-comb Combined disturbance score, based on Ell,
H, M1 to M4 and FD (D_COMB)
1088-1093 F6.4 --- D-shape Combined disturbance score, based on Ell,
H, M1 to M4, FD and C80-800 (D_SHAPE)
--------------------------------------------------------------------------------
Acknowledgements:
Jeremy Sanders, jsanders(at)mpe.mpg.de
(End) Jeremy Sanders [MPE, Germany]. Patricia Vannier [CDS] 05-Feb-2025