Component-separated, CIB-cleaned thermal Sunyaev-Zel'dovich maps from Planck PR4 data with a flexible public needlet ILC pipeline
Abstract
We use the full-mission Planck PR4 data to construct maps of the thermal Sunyaev-Zel'dovich effect (Compton-y parameter) in our Universe. To do so, we implement a custom needlet internal linear combination (NILC) pipeline in a Python package, PYILC, which we make publicly available. We publicly release our Compton-y maps, which we construct using various constrained ILC ("deprojection") options in order to minimize contamination from the cosmic infrared background (CIB) in the reconstructed signal. In particular, we use a moment-based deprojection that minimizes sensitivity to the assumed frequency dependence of the CIB. Our code PYILC performs needlet or harmonic ILC on mm-wave sky maps in a flexible manner, with options to deproject various components on all or some scales. We validate our maps and compare them to the official Planck 2015 y map, finding that we obtain consistent results on large scales and 10-20% lower noise on small scales. We expect that these maps will be useful for many auto- and cross-correlation analyses; in a companion paper, we use them to measure the tSZ—CMB lensing cross-correlation. We anticipate that PYILC will be useful both for data analysis and for pipeline validation on simulations to understand the propagation of foreground components through a full NILC pipeline.
- Publication:
-
Physical Review D
- Pub Date:
- January 2024
- DOI:
- 10.1103/PhysRevD.109.023528
- arXiv:
- arXiv:2307.01043
- Bibcode:
- 2024PhRvD.109b3528M
- Keywords:
-
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 28 pages, 15 figures. Public maps and other data products are available at https://users.flatironinstitute.org/~fmccarthy/ymaps_PR4_McCH23/