19 research outputs found
Using CMB, LSS and Galaxy Clusters as Cosmological Probes
In this thesis we have studied three independent tools to get information on cosmological parameters: the large scale structure (LSS) of matter in the Universe, galaxy clusters and the cosmic microwave background (CMB).
In the study of the LSS we have provided an analytical recipe for computing the conditional mass function (CMF), i.e. the mass distribution of the halo abundance in overdense and underdense regions. We have considered a formalism already discussed in the literature and introduced an additional parameter to ensure the CMF normalisation. We have compared the predicted halo abundance from this CMF recipe with the one obtained from numerical N-body simulations, for conditions with Eulerian radii from 5 to 30 Mpc/h, and for halo masses between 10^(11) and 10^(14) M_sun/h. We have found excellent agreement with simulated abundances in underdense regions at all scales, and in overdense regions at large scales; we have also confirmed that the CMF normalisation is satisfied at all scales. We have finally presented an analytical fit to the matter-to-halo bias function in underdense regions, which could be of special interest to speed-up the computation of the halo abundance when studying void statistics. This fit is capable of reproducing the computed halo bias with an error below 2% for the reference cosmology, and below 9% when considering different values of redshift and sigma_8.
With respect to the cosmology with galaxy clusters, we have considered the abundance of clusters as a function of redshift as a tool to estimate the cosmological parameters Omega_m and sigma_8. We have implemented the computation of the cluster redshift distribution according to a specified cosmology, and developed a statistical tool based on a Markov Chains Monte Carlo (MCMC) method to retrieve the cosmological parameters starting from the cluster abundance. We have applied our code to the cosmological subsample of the PSZ1 catalogue of clusters detected by the Planck satellite with signal-to-noise ratio above seven. We have obtained estimates of Omega_m and sigma_8 based on the cluster abundance in combination with BBN and BAO likelihoods, considering the bias 'b' in the determination of the cluster mass as a fixed or free parameter. With the bias parameter fixed to the value b=0.2 we found Omega_m=0.293±0.020 and sigma_8=0.760(+0.018,-0.017) (68% C.L.). With 'b' free to vary with a flat prior in the range [0.0,0.3] we found Omega_m=0.289(+0.022,-0.020) and sigma_8=0.750±0.028. These results are in very good agreement with the ones obtained by the Planck Collaboration using the same cluster catalogue. This proves the reliability of our method, that can therefore be applied in the future to broader catalogues, resulting in a significant reduction of the error bars in the estimation of these parameters. An example is the extended cosmological subsample of the PSZ1, that contains nearly three times the number of clusters employed for the analysis in this work and that will soon be made publicly available.
We have employed the Sunyaev-Zel'dovich effect as a cosmological probe. To this aim we computed the one dimensional probability distribution function (PDF) of the Compton parameter 'y' measured by the Planck satellite over the whole sky; this PDF is strongly dependent on the parameter sigma_8. We have modelled the galaxy cluster contribution to the PDF and tested our formalism with simulated Compton parameter maps. We have applied this formalism to fit for sigma_8 against the PDF extracted by Planck data. We have considered only values for
y>4.5*10^(-6) in order to leave out contamination from instrumental noise and other astrophysical foregrounds, and obtained the final estimate sigma_8=0.77±0.02 (68% C.L.). This result is compatible with other cluster-based estimates, and shows a tension with the value obtained from CMB analysis (~0.83). This tension may be due to systematics in the modelling or instrumental calibration or it can be the first hint for a necessary extension of the standard cosmological model.
The study related to the CMB presented in this thesis is based on the QUIJOTE experiment, and on the data obtained with the multi-frequency instrument (MFI). We have carried out the pointing calibration of the first QUIJOTE telescope, developing a set of coordinate transformations to correct for the telescope non-idealities: these transformations have been implemented in the MFI data reduction pipeline and are routinely employed to achieve a pointing correction with errors below 1 minute of arc. We have considered observations of the MFI in the galactic regions W49, W51 (molecular clouds) and IC443 (supernova remnant), and assessed the relative contribution of different emission mechanisms. In particular, we have found hints of detection of anomalous microwave emission (AME) in intensity in all regions, with a higher significance in W49. We have also detected synchrotron emission in the regions W49 and IC443. This information is relevant for modelling the synchrotron emission properties in our Galaxy, and this way making the separation of the cosmological B-modes signal easier in future data from this and other experiments
Cross-correlation between the thermal Sunyaev-Zeldovich effect and the Integrated Sachs-Wolfe effect
We present a joint cosmological analysis of the power spectra measurement of
the Planck Compton parameter and the integrated Sachs-Wolfe (ISW) maps. We
detect the statistical correlation between the Planck Thermal Sunyaev-Zeldovich
(tSZ) map and ISW data with a significance of a confidence
level~(CL), with the autocorrelation of the Planck tSZ data being measured at a
CL. The joint auto- and cross-power spectra constrain the matter
density to be , the Hubble constant
and the rms
matter density fluctuations to be at the
68% CL. The derived large-scale structure parameter is . If using only the
diagonal blocks of covariance matrices, the Hubble constant becomes
. In
addition, we obtain the constraint of the product of the gas bias, gas
temperature, and density as . We find that this constraint leads to an estimate on
the electron temperature today as , consistent with the expected temperature of the warm-hot
intergalactic medium. Our studies show that the ISW-tSZ cross-correlation is
capable of probing the properties of the large-scale diffuse gas.Comment: 25 pages, 15 figures, 2 table
Exploring the mass and redshift dependence of the cluster pressure profile with stacks on thermal SZ maps
We provide novel constraints on the parameters defining the universal
pressure profile (UPP) within clusters of galaxies, and explore their
dependence on the cluster mass and redshift, from measurements of
Sunyaev-Zel'dovich Compton- profiles. We employ both the
2015 MILCA and the ACT-DR4 maps over the common
footprint. We combine existing cluster catalogs based on KiDS, SDSS and DESI
observations, for a total of 23,820 clusters spanning the mass range
and the
redshift range . We split the clusters into three independent bins
in mass and redshift; for each combination we detect the stacked SZ cluster
signal and extract the mean angular profile. The latter is predicted
theoretically adopting a halo model framework, and MCMCs are employed to
estimate the UPP parameters, the hydrostatic mass bias and possible
cluster miscentering effects. We constrain to
with and to with ACT
using the full cluster sample, in agreement with previous findings. We do not
find any compelling evidence for a residual mass or redshift dependence, thus
expanding the validity of the cluster pressure profile over much larger
and ranges; this is the first time the model has been tested on
such a large (complete and representative) cluster sample. Finally, we obtain
loose constraints on the hydrostatic mass bias in the range 0.2-0.3, again in
broad agreement with previous works.Comment: 39 pages, 22 figures. Accepted for publication in Apj
Robustness of cosmic neutrino background detection in the cosmic microwave background
The existence of a cosmic neutrino background can be probed indirectly by CMB experiments, not only by measuring the background density of radiation in the universe, but also by searching for the typical signatures of the fluctuations of free-streaming species in the temperature and polarisation power spectrum. Previous studies have already proposed a rather generic parametrisation of these fluctuations, that could help to discriminate between the signature of ordinary free-streaming neutrinos, or of more exotic dark radiation models. Current data are compatible with standard values of these parameters, which seems to bring further evidence for the existence of a cosmic neutrino background. In this work, we investigate the robustness of this conclusion under various assumptions. We generalise the definition of an effective sound speed and viscosity speed to the case of massive neutrinos or other dark radiation components experiencing a non-relativistic transition. We show that current bounds on these effective parameters do not vary significantly when considering an arbitrary value of the particle mass, or extended cosmological models with a free effective neutrino number, dynamical dark energy or a running of the primordial spectrum tilt. We conclude that it is possible to make a robust statement about the detection of the cosmic neutrino background by CMB experiments
QUIJOTE scientific results -- XIII. Intensity and polarization study of supernova remnants in the QUIJOTE-MFI wide survey: CTB 80, Cygnus Loop, HB 21, CTA 1, Tycho and HB 9
We use the new QUIJOTE-MFI wide survey (11, 13, 17 and 19 GHz) to produce
spectral energy distributions (SEDs), on an angular scale of 1 deg, of the
supernova remnants (SNRs) CTB 80, Cygnus Loop, HB 21, CTA 1, Tycho and HB 9. We
provide new measurements of the polarized synchrotron radiation in the
microwave range. For each SNR, the intensity and polarization SEDs are obtained
and modelled by combining QUIJOTE-MFI maps with ancillary data. In intensity,
we confirm the curved power law spectra of CTB 80 and HB 21 with a break
frequency at 2.0 GHz and 5.0 GHz
respectively; and spectral indices respectively below and above the spectral
break of and for CTB 80, and and
for HB 21. In addition, we provide upper limits on the Anomalous
Microwave Emission (AME), suggesting that the AME contribution is negligible
towards these remnants. From a simultaneous intensity and polarization fit, we
recover synchrotron spectral indices as flat as , and the whole sample
has a mean and scatter of . The polarization fractions have a
mean and scatter of \%. When combining our results with the
measurements from other QUIJOTE studies of SNRs, we find that radio spectral
indices are flatter for mature SNRs, and particularly flatter for CTB 80
() and HB 21 (). In addition, the
evolution of the spectral indices against the SNRs age is modelled with a
power-law function, providing an exponent and amplitude
(normalised at 10 kyr), which are conservative with respect to
previous studies of our Galaxy and the Large Magellanic Cloud.Comment: 33 pages, 15 figure, 15 tables. Submitted to MNRAS. QUIJOTE data maps
available at https://research.iac.es/proyecto/quijot
QUIJOTE Scientific Results – XVII. Studying the anomalous microwave emission in the Andromeda Galaxy with QUIJOTE-MFI
The Andromeda Galaxy (M31) is the Local Group galaxy that is most similar to the Milky Way (MW). The similarities between the two galaxies make M31 useful for studying integrated properties common to spiral galaxies. We use the data from the recent QUIJOTE-MFI Wide Survey, together with new raster observations focused on M31, to study its integrated emission. The addition of raster data improves the sensitivity of QUIJOTE-MFI maps by almost a factor 3. Our main interest is to confirm if anomalous microwave emission (AME) is present in M31, as previous studies have suggested. To do so, we built the integrated spectral energy distribution of M31 between 0.408 and 3000 GHz. We then performed a component separation analysis taking into account synchrotron, free–free, AME, and thermal dust components. AME in M31 is modelled as a lognormal distribution with maximum amplitude, AAME, equal to 1.03 ± 0.32 Jy. It peaks at νAME = 17.2 ± 3.2 GHz with a width of WAME = 0.58 ± 0.16. Both the Akaike and Bayesian information criteria find the model without AME to be less than 1
per cent as probable as the one taking AME into consideration. We find that the AME emissivity per 100 μm intensity in M31 is 28.4 GHz AME = 9.6 ± 3.1 μK MJy−1 sr, similar to that of the MW. We also provide the first upper limits for the AME polarization fraction in an extragalactic object. M31 remains the only galaxy where an AME measurement has been made of its integrated spectrum.Partial financial support was provided by the Spanish Ministry of Science and Innovation under the projects AYA2007-68058-C03-01, AYA2007-68058-C03-02, AYA2010-21766-C03-01, AYA2010-21766-C03-02, AYA2014-60438-P, ESP2015-70646-C2-1-R, AYA2017-84185-P,ESP2017-83921-C2-1-R, PID2019-110610RB-C21, PID2020-120514GB-I00, IACA13-3E-2336, IACA15-BE-3707, EQC2018-004918-P, the Severo Ochoa Programs SEV-2015-0548 and CEX2019-000920-S, the Maria de Maeztu Program MDM-2017-0765, and by the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). We acknowledge support from the ACIISI, Consejeria de Economia, Conocimiento y Empleo del Gobierno de Canarias, and the European Regional Development Fund (ERDF) under grant with reference ProID2020010108. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement number 687312 (RADIOFOREGROUNDS). MFT acknowledges support from the Spanish Agencia Estatal de Investigación (AEI) of the Ministerio de Ciencia, Innovación y Universidades (MCIU) and the European Social Fund (ESF) under grant with reference PRE-C-2018-0067. CA-T acknowledges support from the Millennium Nucleus on Young Exoplanets and their Moons (YEMS). FP acknowledges support from the Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI) under the European FEDER (Fondo Europeo de Desarrollo Regional) de Canarias 2014–2020 grant No. PROID2021010078.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2019-000920-S).Peer reviewe
QUIJOTE scientific results - XIII. Intensity and polarization study of the microwave spectra of supernova remnants in the QUIJOTE-MFI wide survey: CTB 80, Cygnus Loop, HB 21, CTA 1, Tycho, and HB 9
We use the new QUIJOTE-MFI wide survey (11, 13, 17, and 19 GHz) to produce spectral energy distributions (SEDs), on an angular scale of 1◦, of the supernova remnants (SNRs) CTB 80, Cygnus Loop, HB 21, CTA 1, Tycho, and HB 9. We provide new
measurements of the polarized synchrotron radiation in the microwave range. The intensity and polarization SEDs are obtained and modelled by combining QUIJOTE-MFI maps with ancillary data. In intensity, we confirm the curved spectra of CTB 80
and HB 21 with a break frequency νb at 2.0+1.2−0.5 and 5.0+1.2 −1.0 GHz, respectively; and spectral indices above the break of −0.6+0.04−0.05 and −0.86+0.04−0.05. We provide constraints on the Anomalous Microwave Emission, suggesting that it is negligible towards these SNRs. From a simultaneous intensity and polarization fit, we recover synchrotron spectral indices as flat as −0.24, and the whole sample has a mean and scatter of −0.44 ± 0.12. The polarization fractions have a mean and scatter of 6.1 ± 1.9 per cent. When combining our results with the measurements from other QUIJOTE (Q-U-I JOint TEnerife CMB experiment) studies of SNRs, we find that radio spectral indices are flatter for mature SNRs, and particularly flatter for CTB 80 (−0.24+0.07 −0.06) and HB 21 (−0.34+0.04 −0.03). In addition, the evolution of the spectral indices against the SNRs age is modelled with a power-law function, providing an exponent −0.07 ± 0.03 and amplitude −0.49 ± 0.02 (at 10 kyr), which are conservative with respect to previous
studies of our Galaxy and the Large Magellanic Cloud.Partial financial support was provided by the Spanish Ministry of Science and Innovation under the projects AYA2007-68058-C03-01, AYA2007-68058-C03-02, AYA2010-21766-C03-01, AYA2010-21766-C03-02, AYA2014-60438-P, ESP2015-70646-C2-1-R, AYA2017-84185-P, ESP2017-83921-C2-1-R, PID2019-110610RB-C21, PID2020-120514GB-I00, PID2019-110614GB-C21, IACA13-3E-2336, IACA15-BE-3707, EQC2018-004918-P, the Severo Ochoa Programmes SEV-2015-0548 and CEX2019-000920-S, the Maria de Maeztu Programme MDM-2017-0765, and by the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). We acknowledge support from the ACIISI, Consejeria de Economia, Conocimiento y Empleo del Gobierno de Canarias, and the European Regional Development Fund (ERDF) under grant with reference ProID2020010108. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 687312 (RADIOFOREGROUNDS).With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2019-000920-S).Peer reviewe
Exploring Cosmic Origins with CORE: Cosmological Parameters
We forecast the main cosmological parameter constraints achievable with theCORE space mission which is dedicated to mapping the polarisation of the CosmicMicrowave Background (CMB). CORE was recently submitted in response to ESA'sfifth call for medium-sized mission proposals (M5). Here we report the resultsfrom our pre-submission study of the impact of various instrumental options, inparticular the telescope size and sensitivity level, and review the great,transformative potential of the mission as proposed. Specifically, we assessthe impact on a broad range of fundamental parameters of our Universe as afunction of the expected CMB characteristics, with other papers in the seriesfocusing on controlling astrophysical and instrumental residual systematics. Inthis paper, we assume that only a few central CORE frequency channels areusable for our purpose, all others being devoted to the cleaning ofastrophysical contaminants. On the theoretical side, we assume LCDM as ourgeneral framework and quantify the improvement provided by CORE over thecurrent constraints from the Planck 2015 release. We also study the jointsensitivity of CORE and of future Baryon Acoustic Oscillation and Large ScaleStructure experiments like DESI and Euclid. Specific constraints on the physicsof inflation are presented in another paper of the series. In addition to thesix parameters of the base LCDM, which describe the matter content of aspatially flat universe with adiabatic and scalar primordial fluctuations frominflation, we derive the precision achievable on parameters like thosedescribing curvature, neutrino physics, extra light relics, primordial heliumabundance, dark matter annihilation, recombination physics, variation offundamental constants, dark energy, modified gravity, reionization and cosmicbirefringence. (ABRIDGED
Cross correlation between the thermal Sunyaev-Zeldovich effect and the integrated Sachs-Wolfe effect
We present a joint cosmological analysis of the power spectra measurement of the Planck Compton parameter and the integrated Sachs–Wolfe (ISW) maps. We detect the statistical correlation between the Planck thermal Sunyaev–Zeldovich (tSZ) map and ISW data with a significance of a 3.6σ confidence level (CL), with the autocorrelation of
the Planck tSZ data being measured at a 25σ CL. The joint auto- and cross-power spectra constrain the matter density to be W = -+ m 0.317 0.0310.040, the Hubble constant to be = - H + - - 0 66.5 km s Mpc 1.92.0 1 1, and the rms matterdensity fluctuations to be s = -+8 0.730 0.0370.040 at the 68% CL. The derived large-scale structure S8 parameter is S8 8m ºW = s 0.3 0.755 0.060 0.5 ( ) . If using only the diagonal blocks of covariance matrices, the Hubble constant becomes = - H + - - 0 69.7 km s Mpc 1.52.0 1 1. In addition, we obtain the constraint of the product of the gas bias,
gas temperature, and density as - = -+ bgas e e T n 0.1 keV 1 m 3.09 30.3800.320 ( ( ))(¯ ) . We find that this constraint leads to an estimate on the electron temperature today as = ´ -+ Te 2.40 10 K 0.3000.250 6 ( ) , consistent with the expected temperature of the warm–hot intergalactic medium. Our studies show that the ISW–tSZ cross correlation is capable of probing the properties of the large-scale diffuse gas.A.I. acknowledges the support of the Alliance of International Science Organizations, grant No. ANSO-VF-2022-01. Y.Z.M. acknowledges the support of the National Research Foundation with grant No. 150580. P.V. thanks the Spanish Agencia Estatal de Investigación (AEI, MICIU) for the financial support provided under the projects with references PID2019-110610RB-C21, ESP2017-83921-C2-1-R, and AYA2017-90675-REDC, co-funded with EU FEDER funds, and acknowledges support from Universidad de Cantabria and Consejería de Universidades, Igualdad, Cultura y Deporte del Gobierno de Cantabria, via the "Instrumentación y ciencia de datos para sondear la naturaleza del universo" project, as well as from Unidad de Excelencia María de Maeztu (MDM-2017-0765). D.T. acknowledges financial support from the XJTLU Research Development Fund (RDF) grant with number RDF-22-02-068. W.M.D. acknowledges the support from the "Big Data for Science and Society" UKZN Research Flagship. X.L. acknowledges the support of the Ministry of Science and Technology (MoST) inter-government cooperation program China–South Africa Cooperation Flagship Project 2018YFE0120800.Peer reviewe