Showing papers by "Monique Arnaud published in 2022"

The maxPSZ catalogue of Planck clusters over the DES region

Abstract: We present the first systematic follow-up of Planck Sunyaev-Zeldovich effect (SZE) selected candidates down to signal-to-noise (S/N) of 3 over the 5000 deg$^2$ covered by the Dark Energy Survey. Using the MCMF cluster confirmation algorithm, we identify optical counterparts, determine photometric redshifts and richnesses and assign a parameter, $f_{\rm cont}$, that reflects the probability that each SZE-optical pairing represents a random superposition of physically unassociated systems rather than a real cluster. The new maxPSZ cluster catalogue consists of 853 MCMF confirmed clusters and has a purity of 90%. We present the properties of subsamples of the maxPSZ catalogue that have purities ranging from 90% to 97.5%, depending on the adopted $f_{\rm cont}$ threshold. Halo mass estimates $M_{500}$, redshifts, richnesses, and optical centers are presented for all maxPSZ clusters. The maxPSZ catalogue adds 589 previously unknown Planck identified clusters over the DES footprint and provides redshifts for an additional 50 previously published Planck selected clusters with S/N>4.5. Using the subsample with spectroscopic redshifts, we demonstrate excellent cluster photo-$z$ performance with an RMS scatter in $\Delta z/(1+z)$ of 0.47%. Our MCMF based analysis allows us to infer the contamination fraction of the initial S/N>3 Planck selected candidate list, which is ~50%. We present a method of estimating the completeness of the maxPSZ cluster sample. In comparison to the previously published Planck cluster catalogues. this new S/N>3 MCMF confirmed cluster catalogue populates the lower mass regime at all redshifts and includes clusters up to z$\sim$1.3.

Massive merging cluster PSZ2G091 as seen by the NIKA2 camera

Abstract: PSZ2 G091.83+26.11 is a galaxy cluster with M 500 = 7 . 43 × 10 14 M (cid:12) at z = 0 . 822 1 . This object exhibits a complex morphology with a clear bimodality observed in X-rays. However, it was detected and analysed in the Planck sample as a single, spherical cluster following a universal profile 2 . This model can lead to miscalculations of thermodynamical quantities, like the pressure profile. As future multiwavelength cluster experiments will detect more and more objects at high redshifts, it is crucial to quantify this systematic effect. In this work, we use high-resolution observations of the NIKA2 camera 3 , 4 , 5 , 6 to integrate the morphological characteristics of the cluster in our modelling. This is achieved by fitting a two-halo model to the SZ image and then by reconstruction of the resulting projected pressure profile. We then compare these results with the spherical assumption.

The MADPSZ catalogue of Planck clusters over the DES region: extending to lower mass and higher redshift

Abstract: We present the first systematic follow-up of Planck Sunyaev-Zeldovich effect (SZE) selected candidates down to signal-to-noise (S/N) of 3 over the 5000 deg 2 covered by the Dark Energy Survey. Using the MCMF cluster confirmation algorithm, we identify optical counterparts, determine photometric redshifts and richnesses and assign a parameter, 𝑓 cont , that reflects the probability that each SZE-optical pairing respresents a real cluster rather than a random superposition of physically unassociated systems. The new MADPSZ cluster catalogue con-sists of 1092 MCMF confirmed clusters and has a purity of 85%. We present the properties of subsamples of the MADPSZ catalogue that have purities ranging from 90% to 97.5%, depending on the adopted 𝑓 cont threshold. 𝑀 500 halo mass estimates, redshifts, richnesses, and optical centers are presented for all MADPSZ clusters. The MADPSZ catalogue adds 828 previously unknown Planck identified clusters over the DES footprint and provides redshifts for an additional 50 previously published Planck selected clusters with S/N>4.5. Using the subsample with spectroscopic redshifts, we demonstrate excellent cluster photo- 𝑧 performance with an RMS scatter in Δ 𝑧 /( 1 + 𝑧 ) of 0.47%. Our MCMF based analysis allows us to infer the contamination fraction of the initial S/N>3 Planck selected candidate list, which is 50%. We present a method of estimating the completeness of the MADPSZ cluster sample and 𝑓 cont selected subsamples. In comparison to the previously published Planck cluster catalogues. this new S/N > 3 MCMF confirmed cluster catalogue populates the lower mass regime at all redshifts and includes clusters up to z ∼ 1.3.

Linking a universal gas density profile to the core-excised X-ray luminosity in galaxy clusters up to z ~ 1.1

Abstract: We investigate the regularity of galaxy cluster gas density profiles and the link to the relation between core-excised luminosity, LXc, and mass from the Yx proxy, MYx, for 93 SZE-selected objects. The sample spans masses M500=[0.5 - 20] x 10e14 Msun, and lies at redshifts 0.05

Forecasting cosmological parameter constraints using multiple sparsity measurements as tracers of the mass profiles of dark matter haloes

Abstract: The dark matter halo sparsity, i.e. the ratio between spherical halo masses enclosing two different overdensities, provides a non-parametric proxy of the halo mass distribution which has been shown to be a sensitive probe of the cosmological imprint encoded in the mass profile of haloes hosting galaxy clusters. Mass estimations at several overdensities would allow for multiple sparsity measurements, that can potentially retrieve the entirety of the cosmological information imprinted on the halo profile. Here, we investigate the impact of multiple sparsity measurements on the cosmological model parameter inference. For this purpose, we analyse N-body halo catalogues from the Raygal and M2Csims simulations and evaluate the correlations among six different sparsities from Spherical Overdensity halo masses at Δ = 200, 500, 1000 and 2500 (in units of the critical density). Remarkably, sparsities associated to distinct halo mass shells are not highly correlated. This is not the case for sparsities obtained using halo masses estimated from the Navarro-Frenk-White (NFW) best-fit profile, that artificially correlates different sparsities to order one. This implies that there is additional information in the mass profile beyond the NFW parametrisation and that it can be exploited with multiple sparsities. In particular, from a likelihood analysis of synthetic average sparsity data, we show that cosmological parameter constraints significantly improve when increasing the number of sparsity combinations, though the constraints saturate beyond four sparsity estimates. We forecast constraints for the CHEX-MATE cluster sample and find that systematic mass bias errors mildly impact the parameter inference, though more studies are needed in this direction.