arXiv subjects

Mark Mirmelstein

Publications and source records attributed to Mark Mirmelstein.

4 recordsLinked to original sources

arXiv2022

CMB lensing from Planck PR4 maps

We reconstruct the Cosmic Microwave Background (CMB) lensing potential on the latest Planck CMB PR4 (NPIPE) maps, which include slightly more data than the 2018 PR3 release, and implement quadratic estimators using more optimal filtering. We increase the reconstruction signal to noise by almost $20\%$, constraining the amplitude of the CMB-marginalized lensing power spectrum in units of the Planck 2018 best-fit to $1.004 \pm 0.024$ ($68\%$ limits), which is the tightest constraint on the CMB lensing power spectrum to date. For a base $Λ$CDM cosmology we find $σ_8 Ω_m^{0.25} = 0.599\pm 0.016$ from CMB lensing alone in combination with weak priors and element abundance observations. Combination with baryon acoustic oscillation data gives tight $68\%$ constraints on individual $Λ$CDM parameters $σ_8 = 0.814\pm 0.016$, $H_0 = 68.1^{+1.0}_{-1.1}$km s$^{-1}$ Mpc$^{-1}$, $Ω_m = 0.313^{+0.014}_{-0.016}$. Planck polarized maps alone now constrain the lensing power to $7\%$.

astro-ph.CO↗

arXiv2021

Instrumental systematics biases in CMB lensing reconstruction: a simulation-based assessment

Weak gravitational lensing of the cosmic microwave background (CMB) is an important cosmological tool that allows us to learn about the structure, composition and evolution of the Universe. Upcoming CMB experiments, such as the Simons Observatory (SO), will provide high-resolution and low-noise CMB measurements. We consider the impact of instrumental systematics on the corresponding high-precision lensing reconstruction power spectrum measurements. We simulate CMB temperature and polarization maps for an SO-like instrument and potential scanning strategy, and explore systematics relating to beam asymmetries and offsets, boresight pointing, polarization angle, gain drifts, gain calibration and electric crosstalk. Our analysis shows that the majority of the biases induced by the systematics we modeled are below a detection level of $\sim 0.6σ$. We discuss potential mitigation techniques to further reduce the impact of the more significant systematics, and pave the way for future lensing-related systematics analyses.

astro-ph.CO↗

arXiv2020

Detection likelihood of cluster-induced CMB polarization

Nearby galaxy clusters can potentially induce sub-microkelvin polarization signals in the cosmic microwave background (CMB) at characteristic scales of a few arcminutes. We explore four such polarization signals induced in a rich nearby fiducial cluster and calculate the likelihood of their detection by a telescope project with capabilities such as those of the Simons Observatory (SO). In our feasibility analysis, we include instrumental noise, primordial CMB anisotropy, statistical thermal Sunyaev-Zeldovich (SZ) cluster signal, and point source confusion, assuming a few percent of the nominal telescope observation time of an SO-like project. Our analysis indicates that the thermal SZ intensity can be sensitively mapped in rich nearby clusters and that the kinematic SZ intensity can be measured with high statistical significance toward a fast moving nearby cluster. The detection of polarized SZ signals will be quite challenging but could still be feasible toward several very rich nearby clusters with very high SZ intensity. The polarized SZ signal from a sample of ~20 clusters can be statistically detected at S/N~3, if observed for several months.

astro-ph.CO↗

arXiv2019

Optimal filtering for CMB lensing reconstruction

Upcoming ground-based cosmic microwave background experiments will provide CMB maps with high sensitivity and resolution that can be used for high fidelity lensing reconstruction. However, the sky coverage will be incomplete and the noise highly anisotropic, so optimized estimators are required to extract the most information from the maps. We focus on quadratic-estimator based lensing reconstruction methods that are fast to implement, and compare new more-optimally filtered estimators with various estimators that have previously been used in the literature. Input CMB maps can be optimally inverse-signal-plus-noise filtered using conjugate gradient (or other) techniques to account for the noise anisotropy. However, lensing reconstructions from these filtered input maps have an anisotropic response to the lensing signal and are difficult to interpret directly. We describe a second-stage filtering of the lensing maps and analytic response model that can be used to construct lensing power spectrum estimates that account for the anisotropic response and noise inhomogeneity in an approximately optimal way while remaining fast to compute. We compare results for simulations of upcoming Simons Observatory and CMB Stage-4 experiments to show the robustness of the more optimal lensing reconstruction pipeline and quantify the improvement compared to less optimal estimators. We find a substantial improvement in reconstructed lensing power variance between optimal anisotropic and isotropic filtering of CMB maps, and up to 30% improvement in variance by using the additional filtering step on the reconstruction potential map. Our approximate analytic response model is unbiased to within a small percent-level additional Monte Carlo correction.

astro-ph.CO↗