For refcode 2010A&A...517A..92A: Retrieve 34 NED objects in this reference. Please click here for ADS abstract
NED Abstract
Copyright by European Southern Observatory (ESO).
Reproduced by permission
2010A&A...517A..92A
The universal galaxy cluster pressure profile from a representative sample
of nearby systems (REXCESS) and the Y_SZ_  M_500_ relation
Arnaud, M.; Pratt, G. W.; Piffaretti, R.; Bohringer, H.; Croston, J. H.;
Pointecouteau, E.
Abstract. We investigate the regularity of cluster pressure profiles with
REXCESS, a representative sample of 33 local (z < 0.2) clusters drawn from
the REFLEX catalogue and observed with XMMNewton. The sample spans a mass
range of 10^14^ M_o_ < M_500_ < 10^15^ M_o_, where M_500_ is the mass
corresponding to a density contrast of 500. We derive an average profile
from observations scaled by mass and redshift according to the standard
selfsimilar model, and find that the dispersion about the mean is
remarkably low, at less than 30 per cent beyond 0.2 R_500_, but increases
towards the center. Deviations about the mean are related to both the mass
and the thermodynamical state of the cluster. Morphologically disturbed
systems have systematically shallower profiles while cooling core systems
are more concentrated. The scaled profiles exhibit a residual mass
dependence with a slope of ~0.12, consistent with that expected from the
empiricallyderived slope of the M_500_  Y_X_ relation; however, the
departure from standard scaling decreases with radius and is consistent
with zero at R_500_. The scatter in the core and departure from
selfsimilar mass scaling is smaller compared to that of the entropy
profiles, showing that the pressure is the quantity least affected by
dynamical history and nongravitational physics. Comparison with scaled
data from several state of the art numerical simulations shows good
agreement outside the core. Combining the observational data in the radial
range [0.031] R_500_ with simulation data in the radial range [14]
R_500_, we derive a robust measure of the universal pressure profile,
that, in an analytical form, defines the physical pressure profile of
clusters as a function of mass and redshift up to the cluster "boundary".
Using this profile and direct spherical integration of the observed
pressure profiles, we estimate the integrated Compton parameter Y and
investigate its scaling with M_500_ and L_X_, the soft band Xray
luminosity. We consider both the spherically integrated quantity,
Y_sph_(R), proportional to the gas thermal energy, and the cylindrically
integrated quantity, Y_cyl_(R)=Y_SZ_ D_A_^2^, which is directly related to
the SunyaevZel'dovich (SZ) effect signal. From the low scatter of the
observed Y_sph_(R_500_)  Y_X_ relation we show that variations in
pressure profile shape do not introduce extra scatter into the
Y_sph_(R_500_)  M_500_ relation as compared to that from the Y_X_ 
M_500_ relation. The Y_sph_(R_500_)  M_500_ and Y_sph_(R_500_)  L_X_
relations derived from the data are in excellent agreement with those
expected from the universal profile. This profile is used to derive the
expected Y_SZ_  M_500_ and Y_SZ_  L_X_ relations for any aperture.
Key words: cosmology: observations, dark matter, galaxies: clusters:
general, intergalactic, medium, Xrays: galaxies: clusters
Retrieve 34 NED objects in this reference. Please click here for ADS abstract
