J/A+A/674/A102 Cool-core condens. rad in massive galaxy clusters (Wang+, 2023)
Physical cool-core condensation radius in massive galaxy clusters.
Wang L., Tozzi P., Yu H., Gaspari M., Ettori S.
<Astron. Astrophys. 674, A102 (2023)>
=2023A&A...674A.102W 2023A&A...674A.102W (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; X-ray sources ; Velocity dispersion
Keywords: galaxies: clusters: intracluster medium -
X-rays: galaxies: clusters - hydrodynamics
Abstract:
We investigate the properties of cool cores in an optimally-selected
sample of 37 massive and X-ray-bright galaxy clusters, with regular
morphology, observed with Chandra, by measuring the density,
temperature, and abundance radial profiles of their intracluster
medium (ICM). From these independent quantities we compute the cooling
(tcool), free-fall (tff), and turbulence (teddy) timescales as a
function of radius.
By requiring the profile-crossing condition tcool/teddy=1, we
measure the cool-core condensation radius Rccc within which the
balancing feeding and feedback processes generate the turbulent
condensation rain and related chaotic cold accretion (CCA). We also
constrain the complementary (quenched) cooling flow radius Rqcf,
obtained via the condition tcool=25xtff, that encompasses the
region of thermally unstable cooling.
We find that in our our massive cluster sample and in the limited
redshift range considered (1.3x1014<M500<16.6x1014M☉,
0.03<z<0.29) the distribution of Rccc is peaked at ∼0.01r500 and
entirely included below ∼0.07r500, with a very weak increase with
redshift and no dependence on the cluster mass.We find that Rqcf is
typically 3x larger than Rccc, has a wider distribution, and grows
slowly with R_ccc according to an average relation
Rqcf≈Rccc0.46, with a large intrinsic scatter.
We suggest that this sub-linear relation can be understood as an
effect of the micro rain of pockets of cooled gas flickering in the
turbulent ICM, whose dynamical and thermodynamical properties are
referred to as "macro weather". Substituting the classical ad-hoc
cool-core radius R7.7Gyr, we propose that Rqcf is an indicator of the
size of global cool cores tied to the long-term macro weather, with
the inner R_ccc closely tracing the effective condensation rain and
chaotic cold accretion (CCA) zone that feeds the central supermassive
black hole (SMBH).
Description:
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 113 37 Sample of clusters observed with Chandra and
satisfying the criteria defined in Section 3
table2.dat 134 37 Results of our analysis for all the clusters
in our sample
profile.dat 62 753 Data for cooling (t_cool) and free-fall (t_ff)
timescales profiles in the appendix
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Cluster Cluster name
17- 22 F6.4 --- z Redshift
24- 25 I2 h RAh Cluster center right ascension (J2000)
27- 28 I2 min RAm Cluster center right ascension (J2000)
30- 34 F5.2 s RAs Cluster right ascension (J2000)
36 A1 --- DE- Cluster center declination sign (J2000)
37- 38 I2 deg DEd Cluster center declination (J2000)
40- 41 I2 arcmin DEm Cluster center declination (J2000)
43- 46 F4.1 arcsec DEs Cluster center declination (J2000)
48- 53 F6.2 ks Texp Exposure time after data reduction
55- 62 F8.1 ct Counts Net photon counts within 40kpc in
the 0.5-7.0 keV band
64-113 A50 --- ObsID Obsid used in the analysis (ACIS-S and ACIS-I
observations are marked with (S) and (I),
separated by coma
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Cluster Cluster name
17- 20 I4 kpc r500 Radius at which the average density of a
cluster is 500 times the critical density
of the Universe
22- 26 F5.2 keV T Core-excised temperature
(for r>40kpc and r<r500)
29- 32 F4.2 keV e_T Temperature lower limit of error
34- 37 F4.2 keV E_T Temperature upper limit of error
39- 42 F4.1 10+14Msun M500 Total mass within R500
45- 47 F3.1 10+14Msun e_M500 Mass lower limit of error
49- 51 F3.1 10+14Msun E_M500 Mass upper limit of error
53- 57 F5.1 km/s sigmav Velocity dispersion sigma_v calculated from
equation 9
60- 64 F5.1 km/s e_sigmav Velocity dispersion lower limit of error
66- 70 F5.1 km/s E_sigmav Velocity dispersion upper limit of error
72 A1 --- l_Rccc Limit flag on Rccc
73- 76 F4.1 kpc Rccc Cool-core condensation radius defined by the
condition tcool(Rccc)/teddy(Rccc)=1
79- 81 F3.1 kpc e_Rccc ?=- Cool-core condensation radius
lower limit of error
83- 86 F4.1 kpc E_Rccc ?=- Cool-core condensation radius
upper limit of error
88 A1 --- l_Rqcf Limit flag on Rqcf
89- 93 F5.1 kpc Rqcf Quenched cooling flow radius defined by the
condition
tcool(Rqcf)/[25*tff(Rqcf)]=1
96- 98 F3.1 kpc e_Rqcf ?=- Quenched cooling flow radius
lower limit of error
100-103 F4.1 kpc E_Rqcf ?=- Quenched cooling flow radius
upper limit of error
105 A1 --- l_Rccc500 Limit flag on Rccc500
106-108 F3.1 --- Rccc500 Cool-core condensation radius in units of
10-2*r500
111-113 F3.1 --- e_Rccc500 ?=- Cool-core condensation radius in units
of 10-2*r500
lower limit of error
115-117 F3.1 --- E_Rccc500 ?=- Cool-core condensation radius in units
of 10-2*r500 upper limit of error
119 A1 --- l_Rqcfr500 Limit flag on Rqcfr500
120-123 F4.1 --- Rqcfr500 Quenched cooling flow radius in units
of 10-2*r500
126-128 F3.1 --- e_Rqcfr500 ?=- Quenched cooling flow radius in units
of 10-2*r500 lower limit of error
130-132 F3.1 --- E_Rqcfr500 ?=- Quenched cooling flow radius in units
of 10-2*r500 upper limit of error
134 A1 --- Ref [abc] A reference of sigma_v measurements
to each cluster (1)
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Note (1): Referecnes as follows:
a = Gaspari et al. (2018ApJ...854..167G 2018ApJ...854..167G)
b = Olivares et al. (2019A&A...631A..22O 2019A&A...631A..22O)
c = this work using equation 9
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Byte-by-byte Description of file: profile.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Cluster Cluster name
18- 22 F5.1 kpc Radius Radius
26- 32 F7.4 Gyr tcool Cooling timescale
36- 43 F8.5 Gyr e_tcool Cooling timescale error
47- 52 F6.4 Gyr tff Free-fall timescale
56- 62 F7.5 Gyr e_tff Free-fall timescale error
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Acknowledgements:
Paolo Tozzi, paolo.tozzi(at)inaf.it
(End) Patricia Vannier [CDS] 31-Mar-2023