J/A+A/665/A78 First eROSITA all sky survey (eRASS1) simulation (Seppi+, 2022)
Detecting clusters of galaxies and active galactic nuclei in an eROSITA
all-sky survey digital twin.
Seppi R., Comparat J., Bulbul E., Nandra K., Merloni A., Clerc N., Liu T.,
Ghirardini V., Liu A., Salvato M., Sanders J.S., Wilms J., Dwelly T.,
Dauser T., Koenig O., Ramos-Ceja M.E., Garrel C., Reiprich T.H.
<Astron. Astrophys. 665, A78 (2022)>
=2022A&A...665A..78S 2022A&A...665A..78S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Surveys ; X-ray sources; Active gal. nuclei
Keywords: surveys - catalogs - X-rays: galaxies: clusters - galaxies: active -
methods: data analysis - large-scale structure of Universe
Abstract:
The extended ROentgen Survey with an Imaging Telescope Array (eROSITA)
onboard the Spectrum-Roentgen-Gamma (SRG) observatory is
revolutionizing X-ray astronomy. The mission provides unprecedented
samples of active galactic nuclei (AGN) and clusters of galaxies, with
the potential of studying astrophysical properties of X-ray sources
and measuring cosmological parameters using X-ray-selected samples
with higher precision than ever before. Aims. We aim to study the
detection, and the selection of AGN and clusters of galaxies in the
first eROSITA all-sky survey, and to characterize the properties of
the source catalog.
We produced a half-sky simulation at the depth of the first eROSITA
survey (eRASS1), by combining models that truthfully represent the
population of clusters and AGN. In total, we simulated 1116758
clusters and 225583320 AGN. We ran the standard eROSITA detection
algorithm, optimized for extragalactic sources. We matched the input
and the source catalogs with a photon-based matching algorithm.
Results. We perfectly recovered the bright AGN and clusters. We
detected half of the simulated AGN with flux larger than
2x10-14erg/s/cm2 as point sources and half of the simulated
clusters with flux larger than 3x1013erg/s/cm2 as extended sources
in the 0.5-2.0keV band. We quantified the detection performance in
terms of completeness, false detection rate, and contamination. We
studied the population in the source catalog according to multiple
cuts of source detection and extension likelihood. We find that the
latter is suitable for removing contamination, and the former is very
efficient in minimizing the false detection rate. We find that the
detection of clusters of galaxies is mainly driven by flux and
exposure time. It additionally depends on secondary effects, such as
the size of the clusters on the sky plane and their dynamical state.
The cool core bias mostly affects faint clusters classified as point
sources, while its impact on the extent-selected sample is small. We
measured the fraction of the area covered by our simulation as a
function of limiting flux. We measured the X-ray luminosity of the
detected clusters and find that it is compatible with the simulated
values. Conclusions. We discuss how to best build samples of galaxy
clusters for cosmological purposes, accounting for the nonuniform
depth of eROSITA. This simulation provides a digital twin of the real
eRASS1.
Description:
These catalog presents the simulated clusters, agn, and stars, the
events generated by these sources, and the output eSASS detections.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
clustin.dat 1416 1116758 Simulated clusters
(eRASS1mockinputCLUSTERSv1.fits)
agnin.dat 852 41116070 Simulated AGN (eRASS1mockinputAGN2ct_v1.fits)
starsin.dat 196 373316 Simulated stars (eRASS1mockinputSTARv1.fits)
agnev.dat 46 23729930 Events generated by simulated AGN
(eRASS1mockevents_AGN.fits)
bkgev.dat 46 164841071 Events generated by the simulated background
(eRASS1mockevents_BKG.fits)
starsev.dat 46 1918322 Events generated by simulated stars
(eRASS1mockevents_STAR.fits)
clustev.dat 46 3526788 Events generated by simulated clusters
(eRASS1mockevents_CLUSTER.fits)
esass1b.dat 199 1133807 Catalog from the eSASS single band detection
(eRASS1mockeSASSsinglebandv1.fits)
esass3b.dat 256 486005 Catalog from the eSASS three band detection
(eRASS1mockeSASSthreebandv1.fits)
fits/* . 9 Catalogs in fits format
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Byte-by-byte Description of file: clustin.dat
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Bytes Format Units Label Explanations
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1- 10 I10 --- SRCID Source ID, CLUSTER: ≥4x108 and <109
12- 21 F10.6 deg RAdeg Right Ascension (J2000)
23- 32 F10.6 deg DEdeg Declination (J2000)
34- 45 E12.6 mW/m2 Flux Input Flux in the 0.5-2.0keV band
47 I1 --- Flag [0/1] flaghasevents
49- 58 F10.6 deg GLAT Galactic latitude
60- 69 F10.6 deg GLON Galactic longitude
71- 78 F8.6 --- zR Redshift in real space
80- 87 F8.6 --- zS Redshift in redshift space
89- 100 E12.6 cm dL Luminosity distance in the cosmology
adopted by Comparat et al. (2020)
102- 113 E12.6 cm-2 nH Column density
115- 116 I2 --- HALOpid Halo flag in the dark matter light cone
(-1 for distinct halos, >0 for subhalos)
118- 129 E12.6 Msun HALOMvir Halo mass within the virial radius
131- 141 F11.6 kpc HALORvir Halo virial radius
143- 153 F11.6 kpc HALOrs Halo scale radius
155- 166 E12.6 Msun HALOM200c Halo mass within the R200c
168- 179 E12.6 Msun HALO500c Halo mass within the R500c
181- 190 F10.6 kpc HALOXoff Halo offset parameter
192- 199 F8.6 --- HALOb/a500c Halo ellipticity
201- 207 F7.4 10-7W LXsoft Rest-frame X-ray luminosity in the
0.5-2.0 keV band
209- 215 F7.4 10-7W LXsoftObs Observer-frame X-ray luminosity in the
0.5-2.0 keV band
217- 225 F9.6 keV kT Temperature of the cluster [keV]
227- 238 E12.6 mW/m2 FXsoftAtt Observed flux in the 0.5-2.0keV band,
corrected by galactic absorption
240- 250 F11.6 kpc R500ckpc Halo R500c [kpc]
252- 260 F9.6 arcmin R500carcmin R500c [arcmin]
262- 269 F8.6 --- EM0 Central Emissivity
270- 341 12I6 --- ct02-23CC Counts by clusters (12 values) (1)
342- 413 12I6 --- ct02-23CA Counts by AGN (12 values) (1)
414- 497 12I7 --- ct02-23CB Counts by the background (12 values) (1)
498- 569 12I6 --- ct02-23CS Counts by stars (12 values) (1)
570- 749 20F9.6 ct/pix Bg3Model Average Value of the eSASS background
maps in the nearest 20 pixels
(20 values)
750-1009 20F13.6 s TexpModel Average Value of the eSASS exposure maps
in the nearest 20 pixels
(20 values)
1010-1269 20E13.6 mW/m2 ErsenModel ?=- Average Value of the eSASS
sensitivity maps for extended sources
in the nearest 20 pixels (20 values)
1271-1276 A6 --- Tile Number of the eROSITA tile
1278-1280 I3 --- healpix Number of the HEALPix field
1283-1292 F10.6 deg RAedeg ?=-99 Right Ascension of the
corresponding eSASS detection (J2000)
1294-1303 F10.6 deg DEedeg ?=-99 Declination of the corresponding
eSASS detection (J2000)
1305-1315 F11.6 arcsec Sep ?=-99 Separation between the source and
the corresponding eSASS detection
1317-1328 F12.6 --- DetLike0 ?=-99 Detection likelihood of the
corresponding eSASS detection
1330-1341 F12.6 --- ExtLike ?=-99 Extension likelihood of the
corresponding eSASS detection
1343-1354 F12.6 arcsec Ext ?=-99 Extent of the corresponding eSASS
detection
1356-1367 F12.6 ct MLcts0 ?=-99 Maximum likelihood number of counts
from eSASS
1369-1378 F10.6 s-1 MLRate0 ?=-99 Maximum likelihood count rate
from eSASS
1380-1391 E12.6 mW/m2 MLFlux0 ?=-99 Maximum likelihood flux estimate
from eSASS
1393-1402 F10.3 arcsec ePos ?=-99 Positional error from eSASS
1404-1414 I11 --- IDcontam ID of the contaminating source
1416 I1 --- detected [0/1] Flag to identify simulated source
that are detected by eSASS
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Note (1): Counts in
[0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0]xR500carcmin
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Byte-by-byte Description of file: agnin.dat
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Bytes Format Units Label Explanations
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1- 10 I10 --- SRCID Source ID, AGN: ≥ 109
12- 21 F10.6 deg RAdeg Right Ascension (J2000)
23- 32 F10.6 deg DEdeg Declination (J2000)
34- 45 E12.6 mW/m2 Flux Input Flux in the 0.5-2.0keV band
47- 58 E12.6 cm dL Luminosity distance in the cosmology
adopted by Comparat et al. (2020)
60- 71 E12.6 cm-2 nH Column density
73- 80 F8.6 --- zR Redshift in real space
82- 89 F8.6 --- zS Redshift in redshift space
91- 97 F7.4 10-7W LXhard Rest-frame X-ray luminosity in the
2.0-10.0keV band
99-105 F7.4 10-7W LXsoft Rest-frame X-ray luminosity in the
0.5-2.0keV band
107-118 E12.6 mW/m2 FXsoftAtt Observed flux in the 0.5-2.0keV band,
corrected by galactic absorption
120-127 F8.5 Msun galSMHMRmass Host galaxy stellar mass
128-157 6I5 ct ct02-23AA Counts by AGN (6 values) (1)
158-193 6I6 ct ct02-23AC Counts by clusters (6 values) (1)
194-223 6I5 ct ct02-23AB Counts by the background (6 values) (1)
224-259 6I6 ct ct02-23AS Counts by stars (6 values) (1)
260-439 20F9.6 ct/pix Bg3Model Average Value of the eSASS background maps
in the nearest 20 pixels (20 values)
440-699 20F13.6 s TexpModel Average Value of the eSASS exposure maps in
the nearest 20 pixels (20 values)
701-711 I11 --- IDcontam ID of the contaminating source
713-718 A6 --- Tile Number of the eROSITA tile
720-722 I3 --- healpix Number of the HEALPix field
725-734 F10.6 deg RAedeg ?=-99 Right Ascension of the corresponding
eSASS detection (J2000)
736-745 F10.6 deg DEedeg ?=-99 Declination of the corresponding
eSASS detection (J2000)
747-758 F12.6 arcsec Sep ?=-99 Separation between the source and the
corresponding eSASS detection
760-771 F12.6 --- DetLike0 ?=-99 Detection likelihood of
the corresponding eSASS detection
773-782 F10.6 --- ExtLike ?=-99 Extension likelihood of the
corresponding eSASS detection
784-793 F10.6 arcsec Ext ?=-99 Extent of the corresponding eSASS
detection
795-805 F11.6 ct MLCts0 ?=-99 Maximum likelihood number of counts
from eSASS
807-816 F10.6 s-1 MLRate0 ?=-99 Maximum likelihood count rate
from eSASS
818-829 E12.6 mW/m2 MLFlux0 ?=-99 Maximum likelihood flux estimate
from eSASS
831-840 F10.3 arcsec ePos ?=-99 Positional error from eSASS
842-850 F9.5 arcsec srcRad ?=-99 Source radius
852 I1 --- detected [0/1] Flag to identify simulated source
that are detected by eSASS
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Note (1): Counts in [10, 20, 30, 40, 50, 60] arcsec
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Byte-by-byte Description of file: starsin.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- SRCID Source ID, STAR: ≥107 <4x108
10- 19 F10.6 deg RAdeg Right Ascension (J2000)
21- 30 F10.6 deg DEdeg Declination (J2000)
32- 43 E12.6 mW/m2 Flux Input Flux in the 0.5-2.0keV band
45- 50 A6 --- Tile Number of the eROSITA tile
52- 54 I3 --- healpix Number of the HEALPix field
56- 66 I11 --- IDcontam ID of the contaminating source
69- 78 F10.6 deg RAedeg ?=-99 Right Ascension of the corresponding
eSASS detection (J2000)
80- 89 F10.6 deg DEedeg ?=-99 Declination of the corresponding
eSASS detection (J2000)
91-100 F10.6 arcsec Sep ?=-99 Separation between the source and the
corresponding eSASS detection [arcsec]
102-114 F13.6 --- DetLike0 ?=-99 Detection likelihood of the
corresponding eSASS detection
116-125 F10.6 --- ExtLike ?=-99 Extension likelihood of the
corresponding eSASS detection
127-136 F10.6 arcsec Ext ?=-99 Extent of the corresponding eSASS
detection
138-149 F12.6 ct MLCts0 ?=-99 Maximum likelihood number of counts
from eSASS
151-160 F10.6 s-1 MLRate0 ?=-99 Maximum likelihood count rate from eSASS
162-173 E12.6 mW/m2 MLFlux0 ?=-99 Maximum likelihood flux estimate
from eSASS
175-184 F10.3 arcsec ePos ?=-99 Positional error from eSASS
186-194 F9.5 arcsec srcRad ?=-99 Source radius
196 I1 --- detected [0/1] Flag to identify simulated source that
are detected by eSASS
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Byte-by-byte Description of file: agnev.dat bkgev.dat clustev.dat starsev.dat
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Bytes Format Units Label Explanations
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1- 18 F18.14 deg RAdeg Right Ascension (J2000)
20- 37 F18.14 deg DEdeg Declination (J2000)
39- 46 F8.6 keV Signal Photon energy
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Byte-by-byte Description of file: esass1b.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- IDcat ID of the eSASS detection
6- 14 F9.5 deg RAdeg Right Ascension (J2000)
16- 24 F9.5 deg DEdeg Declination (J2000)
26- 35 F10.3 arcsec epos [] Position error
37- 49 F13.6 --- DetLike0 Detection likelihood of the corresponding
eSASS detection
51- 59 F9.6 arcsec Ext Extent of the corresponding eSASS detection
61- 71 F11.6 --- ExtLike Extension likelihood of the corresponding
eSASS detection
73- 84 F12.6 ct MLCts0 Maximum likelihood number of counts
from eSASS
86- 94 F9.6 ct/s MLRate0 Maximum likelihood count rate from eSASS
96-107 E12.6 mW/m2 MLFlux0 Maximum likelihood flux estimate from eSASS
109-118 I10 --- IDUniq ?=-99 ID of the unique input simulated
counterpart
120-128 F9.5 arcsec srcRad Source radius
130-141 E12.6 --- Ersenmap Sensitivity map
143-148 A6 --- Tile Number of the eROSITA tile
150-152 I3 --- healpix Number of the HEALPix field
154 I1 --- Flag [0/1] flag "ingoodregion"
156-165 I10 --- IDAny ?=-99 ID of the brightest input simulated
counterpart, allowing for duplicates
167-176 I10 --- IDAny2 ?=-99 ID of the secondary input simulated
counterpart
178-188 I11 --- IDcontam ID of the simulated source that
contaminates the unique simulated
counterpart
190-199 F10.6 ct/arcmin2 MLBkg0 Background at the source position
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Byte-by-byte Description of file: esass3b.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- IDcat ID of the eSASS detection
6- 14 F9.5 deg RAdeg Right Ascension (J2000)
16- 24 F9.5 deg DEdeg Declination (J2000)
26- 38 F13.6 --- DetLike0 Detection likelihood of the corresponding
eSASS detection, band 0
40- 50 F11.6 --- DetLike1 Detection likelihood of the corresponding
eSASS detection, band 1
52- 63 F12.6 --- DetLike2 Detection likelihood of the corresponding
eSASS detection, band 2
65- 75 F11.6 --- DetLike3 Detection likelihood of the corresponding
eSASS detection, band 3
77- 85 F9.6 arcsec Ext Extent of the corresponding eSASS detection
87- 97 F11.6 --- ExtLike Extension likelihood of the corresponding
eSASS detection
99-110 F12.6 ct MLCts0 Maximum likelihood number of counts from
eSASS, band 0
112-123 F12.6 ct MLCts1 Maximum likelihood number of counts from
eSASS, band 1
125-136 F12.6 ct MLCts2 Maximum likelihood number of counts from
eSASS, band 2
138-147 F10.6 ct MLCts3 Maximum likelihood number of counts from
eSASS, band 3
149-157 F9.6 ct/s MLRate0 Maximum likelihood count rate from eSASS,
band 0
159-166 F8.6 ct/s MLRate1 Maximum likelihood count rate from eSASS,
band 1
168-176 F9.6 ct/s MLRate2 Maximum likelihood count rate from eSASS,
band 2
178-185 F8.6 ct/s MLRate3 Maximum likelihood count rate from eSASS,
band 3
187-198 E12.6 mW/m2 MLFlux0 Maximum likelihood flux estimate from eSASS
200-209 I10 --- IDUniq ?=-99 ID of the unique input simulated
counterpart
211-216 A6 --- Tile Number of the eROSITA tile
218-220 I3 --- healpix Number of the HEALPix field
222 I1 --- Flag [0/1] Flag "ingoodregion"
224-233 I10 --- IDAny ?=-99 ID of the brightest input simulated
counterpart, allowing for duplicates
235-244 I10 --- IDAny2 ?=-99 ID of the secondary input simulated
counterpart
246-256 I11 --- IDcontam ID of the simulated source that contaminates
the unique simulated counterpart
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Acknowledgements:
Riccardo Seppi, rseppi(at)mpe.mpg.de
(End) Patricia Vannier [CDS] 19-Jul-2022