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Register a new userCross-Correlation of Far-Infrared Background Anisotropies and CMB Lensing from Herschel and Planck satellites
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The cosmic infrared background (CIB) anisotropies and cosmic microwave background (CMB) lensing are powerful measurements for exploring the cosmological and astrophysical problems. In this work, we measure the auto-correlation power spectrum of the CIB anisotropies in the Herschel-SPIRE HerMES Large Mode Survey (HeLMS) field, and the cross power spectrum with the CMB lensing measurements from the Planck satellite. The HeLMS field covers more than 270 deg^2, which is much larger than the previous analysis. We use the Herschel Level 1 time stream data to merge the CIB maps at 250, 350, and 500 um bands, and mask the areas where the flux is greater than 3-sigma (~50 mJy/beam) or no measured data. We obtain the final CIB power spectra at 100<ell<20000 by considering several effects, such as beam function, mode coupling, transfer function, and so on. We also calculate the theoretical CIB auto- and cross-power spectra of CIB and CMB lensing by assuming that the CIB emissivity follows Gaussian distribution in redshift. We find that, for the CIB auto power spectra, we obtain the signal to noise ratio (SNR) of 15.9, 15.7, and 15.3 at 250, 350, and 500 um, and for the CIBxCMB lensing power spectra, SNR of 7.5, 7.0, and 6.2 at 250, 350, and 500 um, respectively. Comparing to previous works, the constraints on the relevant CIB parameters are improved by factors of 2~5 in this study.
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We present the cross-correlation between the far-infrared background fluctuations as measured with the Herschel Space Observatory at 250, 350, and 500 {mu}m and the near-infrared background fluctuations with Spitzer Space Telescope at 3.6 {mu}m. The cross-correlation between far and near-IR background anisotropies are detected such that the correlation coefficient at a few to ten arcminute angular scales decreases from 0.3 to 0.1 when the far-IR wavelength increases from 250 {mu}m to 500 {mu}m. We model the cross-correlation using a halo model with three components: (a) far-IR bright or dusty star-forming galaxies below the masking depth in Herschel maps, (b) near-IR faint galaxies below the masking depth at 3.6 {mu}m, and (c) intra-halo light, or diffuse stars in dark matter halos, that likely dominates fluctuations at 3.6 {mu}m. The model is able to reasonably reproduce the auto correlations at each of the far-IR wavelengths and at 3.6 {mu}m and their corresponding cross-correlations. While the far and near-IR auto-correlations are dominated by faint dusty, star-forming galaxies and intra-halo light, respectively, we find that roughly half of the cross-correlation between near and far-IR backgrounds is due to the same galaxies that remain unmasked at 3.6 {mu}m. The remaining signal in the cross-correlation is due to intra-halo light present in the same dark matter halos as those hosting the same faint and unmasked galaxies. In this model, the decrease in the cross-correlation signal from 250 {mu}m to 500 {mu}m comes from the fact that the galaxies that are primarily contributing to 500 {mu}m fluctuations peak at a higher redshift than those at 250 {mu}m.
We present the first study of cross-correlation between Cosmic Microwave Background (CMB) gravitational lensing potential map measured by the $Planck$ satellite and $zgeq 0.8$ galaxies from the photometric redshift catalogues from Herschel Extragalactic Legacy Project (HELP), divided into four sky patches: NGP, Herschel Stripe-82 and two halves of SGP field, covering in total $sim 660$ deg$^{2}$ of the sky. Contrary to previous studies exploiting only the common area between galaxy surveys and CMB lensing data, we improve the cross-correlation measurements using the full available area of the CMB lensing map. We estimate galaxy linear bias parameter, $b$, from joint analysis of cross-power spectrum and galaxy auto-power spectrum using Maximum Likelihood Estimation technique to obtain the value averaged over four fields as $b=2.06_{-0.02}^{+0.02}$, ranging from $1.94_{-0.03}^{+0.04}$ for SGP Part-2 to $3.03_{-0.09}^{+0.10}$ for NGP. We also estimate the amplitude of cross-correlation and find the averaged value to be $A=0.52_{-0.08}^{+0.08}$ spanning from $0.34_{-0.19}^{+0.19}$ for NGP to $0.67_{-0.20}^{+0.21}$ for SGP Part-1 respectively, significantly lower than expected value for the standard cosmological model. We perform several tests on systematic errors that can account for this discrepancy. We find that lower amplitude could be to some extent explained by the lower value of median redshift of the catalogue, however, we do not have any evidence that redshifts are systematically overestimated.
We present a measurement of the gravitational lensing of the Cosmic Microwave Background (CMB) temperature and polarization fields obtained by cross-correlating the reconstructed convergence signal from the first season of ACTPol data at 146 GHz with Cosmic Infrared Background (CIB) fluctuations measured using the Planck satellite. Using an overlap area of 206 square degrees, we detect gravitational lensing of the CMB polarization by large-scale structure at a statistical significance of 4.5 sigma. Combining both CMB temperature and polarization data gives a lensing detection at 9.1 sigma significance. A B-mode polarization lensing signal is present with a significance of 3.2 sigma. We also present the first measurement of CMB lensing--CIB correlation at small scales corresponding to l > 2000. Null tests and systematic checks show that our results are not significantly biased by astrophysical or instrumental systematic effects, including Galactic dust. Fitting our measurements to the best-fit lensing-CIB cross power spectrum measured in Planck data, scaled by an amplitude A, gives A=1.02 +0.12/-0.18 (stat.) +/-0.06(syst.), consistent with the Planck results.
We measure the cross-correlation between galaxy groups constructed from DESI Legacy Imaging Survey DR8 and Planck CMB lensing, over overlapping sky area of 16876 $rm deg^2$. The detections are significant and consistent with the expected signal of the large scale structure of the universe, over group samples of various redshift, mass and richness $N_{rm g}$ and over various scale cuts. The overall S/N is 39 for a conservative sample with $N_{rm g}geq 5$, and increases to $48$ for the sample with $N_{rm g}geq 2$. Adopting the Planck 2018 cosmology, we constrain the density bias of groups with $N_{rm g}geq 5$ as $b_{rm g}=1.31pm 0.10$, $2.22pm 0.10$, $3.52pm 0.20$ at $0.1<zleq 0.33$, $0.33<zleq 0.67$, $0.67<zleq1$ respectively. The value-added group catalog allows us to detect the dependence of bias on group mass with high significance. It also allows us to compare the measured bias with the theoretically predicted one using the estimated group mass. We find excellent agreement for the two high redshift bins. However, it is lower than the theory by $sim 3sigma$ for the lowest redshift bin. Another interesting finding is the significant impact of the thermal Sunyaev Zeldovich (tSZ). It contaminates the galaxy group-CMB lensing cross-correlation at $sim 30%$ level, and must be deprojected first in CMB lensing reconstruction.
Cross-correlations between the lensing of the cosmic microwave background (CMB) and other tracers of large-scale structure provide a unique way to reconstruct the growth of dark matter, break degeneracies between cosmology and galaxy physics, and test theories of modified gravity. We detect a cross-correlation between DESI-like luminous red galaxies (LRGs) selected from DECaLS imaging and CMB lensing maps reconstructed with the Planck satellite at a significance of $S/N = 27.2$ over scales $ell_{rm min} = 30$, $ell_{rm max} = 1000$. To correct for magnification bias, we determine the slope of the LRG cumulative magnitude function at the faint limit as $s = 0.999 pm 0.015$, and find corresponding corrections on the order of a few percent for $C^{kappa g}_{ell}, C^{gg}_{ell}$ across the scales of interest. We fit the large-scale galaxy bias at the effective redshift of the cross-correlation $z_{rm eff} approx 0.68$ using two different bias evolution agnostic models: a HaloFit times linear bias model where the bias evolution is folded into the clustering-based estimation of the redshift kernel, and a Lagrangian perturbation theory model of the clustering evaluated at $z_{rm eff}$. We also determine the error on the bias from uncertainty in the redshift distribution; within this error, the two methods show excellent agreement with each other and with DESI survey expectations.
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