J/A+A/661/A10 eFEDS galaxy clusters and groups in disguise (Bulbul+, 2022)
The eROSITA Final Equatorial-Depth Survey (eFEDS).
Galaxy clusters and groups in disguise.
Bulbul E., Liu A., Pasini T., Comparat J., Hoang D.N., Klein M.,
Ghirardini V., Salvato M., Merloni A., Seppi R., Wolf J., Anderson S.F.,
Bahar E.Y., Brusa M., Brueggen M., Buchner J., Dwelly T.,
Ibarra-Medel H., Ider Chitham J., Liu T., Nandra K., Ramos-Ceja M.E.,
Sanders J.S., Shen Y.
<Astron. Astrophys. 661, A10 (2022)>
=2022A&A...661A..10B 2022A&A...661A..10B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Surveys ; X-ray sources
Keywords: galaxies: clusters: general - X-rays: galaxies: clusters -
galaxies: groups: general
Abstract:
The eROSITA Final Equatorial-Depth Survey (eFEDS), executed during the
performance verification phase of the Spectrum-Roentgen-Gamma
(SRG)/eROSITA telescope, was completed in November 2019. One of the
science goals of this survey is to demonstrate the ability of eROSITA
to detect samples of clusters and groups at the final depth of the
eROSITA all-sky survey. Because of the sizeable (∼26" HEW FOV average)
point-spread function of eROSITA, high-redshift clusters of galaxies
or compact nearby groups hosting bright active galactic nuclei (AGN)
can be misclassified as point sources by the source detection
algorithms. A total of 346 galaxy clusters and groups in the redshift
range of 0.1<z<1.3 were identified based on their red sequence in the
eFEDS point source catalog. We examine the multiwavelength properties
of these clusters and groups to understand the potential biases in our
selection process and the completeness of the extent-selected sample.
We find that the majority of the clusters and groups in the point
source sample are indeed underluminous and compact compared to the
extent-selected sample. Their faint X-ray emission, well below the
flux limit of the extent-selected eFEDS clusters, and their compact
X-ray emission are likely to be the main reason for this
misclassification. In the sample, we confirm that 10% of the sources
host AGN in their brightest cluster galaxies (BCGs) through optical
spectroscopy and visual inspection. By studying their X-ray, optical,
infrared, and radio properties, we establish a method for identifying
clusters and groups that host AGN in their BCGs. We successfully test
this method on the current point source catalog through the Sloan
Digital Sky Survey optical spectroscopy and find eight low-mass
clusters and groups with active radio-loud AGN that are particularly
bright in the infrared. They include eFEDS J091437.8+024558, eFEDS
J083520.1+012516, and eFEDS J092227.1+043339 at redshifts 0.3-0.4.
This study helps us to characterize and understand our selection
process and assess the completeness of the eROSITA extent-selected
samples. The method we developed will be used to identify
high-redshift clusters, AGN-dominated groups, and low-mass clusters
that are misclassified in the future eROSITA all-sky survey point
source catalogs.
Description:
This catalog presents the X-ray and radio properties of the 346 galaxy
clusters and groups detected as point sources in the eROSITA Final
Equatorial-Depth Survey (eFEDS).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
clusters.dat 413 346 eFEDS PS cluster catalog
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See also:
J/A+A/661/A1 : The eFEDS X-ray catalogs (V7.4) (Brunner+, 2022)
J/A+A/661/A2 : Galaxy clusters and groups in eFEDS (Liu+, 2022)
J/A+A/661/A3 : eFEDS counterparts to point-like sources (Salvato+, 2022)
J/A+A/661/A4 : eFEDS optical cluster and group catalog (Klein+, 2022)
J/A+A/661/A5 : The eFEDS AGN catalog (Liu+, 2022)
J/A+A/661/A7 : X-ray properties of eFEDS clusters and groups (Bahar+, 2022)
J/A+A/661/A8 : eFEDS catalogue of variable X-ray sources (Boller+, 2022)
J/A+A/661/A23 : Exoplanet X-ray irradiation & evaporation rates (Foster+, 2022)
J/A+A/661/A24 : Corona-chromosphere connection (Fuhrmeister+, 2022)
J/A+A/661/A29 : First eROSITA study of nearby M dwarfs (Magaudda+, 2022)
J/A+A/661/A34 : eta Cha cluster eROSITA X-ray scan (Robrade+, 2022)
J/A+A/661/A35 : eROSITA study of 47 Tuc globular cluster (Saeedi+, 2022)
J/A+A/661/A38 : SRG/ART-XC 1st year all-sky X-ray survey (Pavlinsky+, 2022)
J/A+A/661/A40 : eRASS1 X-ray sources Sco-Cen members (Schmitt+, 2022)
J/A+A/661/A44 : A first eROSITA view of ultracool dwarfs (Stelzer+, 2022
Byte-by-byte Description of file: clusters.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name eROSITA official source Name,
eFEDS JHHMMSS.s+DDMMSS (ERO_Name)
24- 28 I5 --- ID-SRC Source ID in the Main Sample (EROIDSRC)
30- 39 F10.6 deg RAdeg Cluster right ascension (J2000)
(ERORACORR)
41- 50 F10.6 deg DEdeg Cluster declination (J2000) (ERODECCORR)
52 I1 --- Class Cluster class (CLUSTER_CLASS)
54- 61 F8.6 --- z Redshift (Z_LFC)
63- 70 F8.4 --- lambda Richness (LAMBDA_LFC)
72- 75 I4 kpc R500 R500 from X-ray scaling relation (R500)
77- 79 I3 kpc e_R500 1sigma lower limit of R500 (R500_L)
81- 84 I4 kpc E_R500 1sigma upper limit of R500 (R500_H)
86- 97 E12.6 Msun M500 M500 from X-ray scaling relation (M500)
99-110 E12.6 Msun e_M500 1sigma lower limit of M500 (M500_L)
112-123 E12.6 Msun E_M500 1sigma upper limit of M500 (M500_H)
125-136 E12.6 10-7W L500 L500 from X-ray scaling relation (L500)
138-149 E12.6 10-7W e_L500 1sigma lower limit of L500 (L500_L)
151-162 E12.6 10-7W E_L500 1sigma upper limit of M500 (L500_H)
164-172 F9.6 Jy TotalFlux ?=-1 Flux of the BCG in 144 MHz (Total_flux)
174-182 F9.6 Jy e_TotalFlux ?=-1 1sigma uncertainty of Total_flux
(ETotalflux)
184 I1 --- withIRbrAGN [0/1] With IR bright AGN or not
(withIRbright_AGN)
186 I1 --- inCDA [0/1] Chandra archival observation (inCDA)
188 I1 --- inXSA [0/1] XMM-Newton archival observation
(inXSA)
190-413 A224 --- Notes Notes (notes)
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Acknowledgements:
Esra Bulbul, ebulbu(at)mpe.mpg.de
References:
The Early Data Release of eROSITA and Mikhail Pavlinsky ART-XC on the
SRG mission, 2022, A&A, 661, A1-A46
(End) Esra Bulbul [MPE, Germany], Patricia Vannier [CDS] 16-Mar-2022