Cosmological implications of baryon acoustic oscillation measurements

We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) data and a recent reanalysis of Type Ia supernova (SN) data. In particular, we take advantage of high-precision BAO measurements from galaxy clustering and the Lyman-α forest (LyaF) in the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). Treating the BAO scale as an uncalibrated standard ruler, BAO data alone yield a high confidence detection of dark energy; in combination with the CMB angular acoustic scale they further imply a nearly flat universe. Adding the CMB-calibrated physical scale of the sound horizon, the combination of BAO and SN data into an “inverse distance ladder” yields a measurement of H0 =67.3 ± 1.1 km s-1 Mpc-1, with 1.7% precision. This measurement assumes standard prerecombination physics but is insensitive to assumptions about dark energy or space curvature, so agreement with CMB-based estimates that assume a flat Λ CDM cosmology is an important corroboration of this minimal cosmological model. For constant dark energy (Λ), our BAO + SN + CMB combination yields matter density Ωm = 0.301 ± 0.008 and curvature Ωk = -0.003 ± 0.003. When we allow more general forms of evolving dark energy, the BAO + SN + CMB parameter constraints are always consistent with flat Λ CDM values at ≈1σ. While the overall χ2 of model fits is satisfactory, the LyaF BAO measurements are in moderate (2–2.5σ) tension with model predictions. Models with early dark energy that tracks the dominant energy component at high redshift remain consistent with our expansion history constraints, and they yield a higher H0 and lower matter clustering amplitude, improving agreement with some low redshift observations. Expansion history alone yields an upper limit on the summed mass of neutrino species, ∑mν (95% confidence), improving to ∑mν if we include the lensing signal in the Planck CMB power spectrum. In a flat Λ CDM model that allows extra relativistic species, our data combination yields Neff = 3.43 ± 0.26; while the LyaF BAO data prefer higher Neff when excluding galaxy BAO, the galaxy BAO alone favor Neff ≈ 3. When structure growth is extrapolated forward from the CMB to low redshift, standard dark energy models constrained by our data predict a level of matter clustering that is high compared to most, but not all, observational estimates

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 and [+1.2 -0.5] 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.CHLC appreciates the knowledge, professional training and affection received from Rodolfo Barbá, who has become the most important Supernova of my life. Now I can find you among the stars (RIP, 2021-12-07). We thank Terry Mahoney (Scientific Editorial Service of the IAC) for proofreading this manuscript. We thank the staff of the Teide Observatory for invaluable assistance in the commissioning and operation of QUIJOTE. The QUIJOTE experiment is being developed by the Instituto de Astrofisica de Canarias (IAC), the Instituto de Fisica de Cantabria (IFCA), and the Universities of Cantabria, Manchester and Cambridge. 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)

QUIJOTE scientific results - V. The microwave intensity and polarization spectra of the Galactic regions W49, W51 and IC443

We present new intensity and polarization maps obtained with the QUIJOTE experiment towards the Galactic regions W49, W51 and IC443, covering the frequency range from 10 to 20-GHz at ⁓1deg angular resolution, with a sensitivity in the range 35-79 µK Kbeam-1 for total intensity and 13-23 µK beam-1 for polarization. For each region, we combine QUIJOTE maps with ancillary data at frequencies ranging from 0.4 to 3000 GHz, reconstruct the spectral energy distribution and model it with a combination of known foregrounds. We detect anomalous microwave emission (AME) in total intensity towards W49 at 4.7σ and W51 at 4.0σ with peak frequencies vAME=(20.0±1.4)GHz and vAME=(17.7±3.6)GHz, respectively; this is the first detection of AME towards W51. The contamination from ultracompact HII regions to the residual AME flux density is estimated at 10 per cent in W49 and 5 per cent in W51, and does not rule out the AME detection. The polarized SEDs reveal a synchrotron contribution with spectral indices αs = -0.67 ± 0.10 in W49 and αs = -0.51 ± 0.07 in W51, ascribed to the diffuse Galactic emission and to the local supernova remnant, respectively. Towards IC443 in total intensity we measure a broken power-law synchrotron spectrum with cut-off frequency v0,s=(114±73)GHz, in agreement with previous studies; our analysis, however, rules out any AME contribution which had been previously claimed towards IC443. No evidence of polarized AME emission is detected in this study.We thank the staff of the Teide Observatory for invaluable assistance in the commissioning and operation of QUIJOTE. The QUIJOTE experiment is being developed by the Instituto de Astrofisica de Canarias (IAC), the Instituto de Fisica de Cantabria (IFCA), and the Universities of Cantabria, Manchester and Cambridge. 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,AYA2017-90675-REDC (co-funded with EU FEDER funds), PGC2018-101814-B-I00, 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). DT acknowledges the support from the Chinese Academy of Sciences (CAS) President’s International Fellowship Initiative (PIFI) with Grant N. 2020PM0042; DT also acknowledges the support from the South African Claude Leon Foundation, that partially funded this work. EdlH acknowledges partial financial support from the Concepción Arenal Programme of the Universidad de Cantabria. FG acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 101001897). FP acknowledges the European Commission under the Marie Sklodowska-Curie Actions within the European Union’s Horizon 2020 research and innovation programme under Grant Agreement number 658499 (PolAME). FP acknowledges support from the Spanish State Research Agency (AEI) under grant numbers PID2019-105552RB-C43. BR-G acknowledges ASI-INFN Agreement 2014-037-R.0