Ultrahigh-Resolution Microwave Sky Simulations
Overview

Here, we provide ultrahigh-resolution (0.04 arcminute pixel) microwave sky simulations on an 11 deg x 11 deg square patch of the sky. The simulation products include:

• Simulated maps on an 11 degree by 11 degree patch of sky, centered at right ascension = 6 degrees and declination = 6 degrees, of:
• Lensed and unlensed CMB temperature and polarization maps (T, Q, and U)
• CMB lensing convergence map
• Kinetic SZ (kSZ) map
• Thermal SZ (tSZ) maps at 30, 90, 148, 219, 277, and 350 GHz
• Cosmic infrared background (CIB) maps at 30, 90, 148, 219, 277, and 350 GHz
• Radio galaxies maps at 30, 90, 148, 219, 277, and 350 GHz
• Catalogs of the SZ clusters, CIB galaxies, and radio galaxies within the simulated maps
• Power spectra of the simulated maps

These simulations are described in MacInnis, Ange, Sehgal, Kable, Fite (2026) (arxiv.org/abs/XXXX.XXXXX). They are based on the full-sky maps and catalogs (available at lambda.gsfc.nasa.gov/simulation/full_sky_sims_ov.html) presented in Sehgal et al., 2010 (arxiv.org/abs/0908.0540) and modified for Simons Observatory forecasting (https://arxiv.org/abs/1808.07445) , which we will refer to as "S10". We provide the python code used to generate these simulations on github at github.com/CMB-HD/hdsims, along with examples of how to generate new simulations (e.g. on a different patch of the sky), combine maps of different components, convolve them with an instrumental beam, add white noise, and calculate their power spectra. The hdsims package can also be easily modified to use a different set of lower-resolution input simulations.

To better match more recent kSZ observations, the S10 kSZ map has been multiplied by a factor of 1/sqrt(2). The S10 CIB catalogs are further modified by summing the fluxes of all S10 sources that fall into the same 0.25 arcminute pixel to produce a single source (see MacInnis et al., 2026 for details). The cosmology used to generate the simulations is based on the cosmology of the S10 simulations, but it has been updated to include three massive neutrinos with the sum of their masses equal to 0.06 eV, and calculations are done with higher-accuracy CAMB (camb.readthedocs.io) settings. See MacInnis et al. 2026 for more details.

Maps

The maps use the CAR projection and are saved as .fits files (see, e.g., the pixell python package for functions to handle CAR maps: pixell.readthedocs.io). The files containing the CMB maps are about 6 GB in size; the T, Q, and U maps are contained in a single file. The other map files are about 2 GB in size. Refer to the readme.txt file for the file name and a brief description of each map provided below.

Aside from the dimensionless lensing convergence map, all other maps are in units of uK and have been convolved with the CAR pixel window function (using pixell.enmap.apply_window). We provide one CMB, lensing convergence, and kSZ map since they are frequency-independent; we provide the tSZ, CIB, and radio maps at 30, 90, 148, 219, 277, and 350 GHz.

Please note that these links point directly at binary files; you should right click on the links and select the "Save link as" option.

Each green dot is a link to a single map for the corresponding data type/frequency pair. The blue squares point to compressed tarballs containing all the maps in the corresponding column or row.

Thermal SZ, CIB, Radio, and Combined Temperature Maps
Map Type	Frequency [GHz]
	30	90	148	219	277	350	All
Thermal SZ
CIB
Radio
Total Temp Map = Lensed CMB + kSZ + tSZ + CIB + radio
All

Catalogs

The catalogs of the SZ clusters, CIB galaxies, and radio galaxies within the simulated maps are provided as .csv files. The read_csv function of the pandas python package (https://pandas.pydata.org/) can be used to load the catalogs, e.g. catalog = pandas.read_csv(catalog_filename). Refer to the readme.txt file for the file name and a brief description of each catalog provided below.

Power Spectra

Here, we provide the power spectra of the inner 100 square degree region of the lensed CMB (temperature and polarization), lensing convergence, kSZ, tSZ, CIB, and radio maps out to a maximum multipole of 21,000. The lensing convergence power spectrum is dimensionless; all other power spectra have units of uK². For the lensed CMB, we provide TT, EE, BB, and TE power spectra.

Before taking their power spectra, all 11 deg x 11 deg maps are apodized along their edges over a 0.5 degree region, and the CAR pixel window function is deconvolved from the CMB, kSZ, tSZ, CIB, and radio maps. The binned power spectra are then computed (using a uniform bin width of 200) and corrected for the mode-coupling induced by the apodization mask (this is done using the pspy python package: pspy.readthedocs.io).

The power spectra are provided as two sets of .txt files. The readme.txt file contains the name of each file along with a brief description of its contents.

• hdsims_spectra_cls.tar : The binned power spectra as C_ℓ’s, i.e., not multiplied by any multipole, etc. factors.
• hdsims_spectra_dls.tar : The power spectra as D_ℓ's, i.e., the C_ell's multiplied by ell * (ℓ + 1) / 2 * pi at each multipole ell before binning (except for lensing convergence). (The lensing convergence power spectrum is the same file as in hdsims_spectra_cls.tar).

For the lensed CMB power spectra, the columns in the file are the bin centers of the binned multipoles and the binned TT, EE, BB, and TE power spectra. All other files contain two columns: the bin centers of binned multipoles, and the binned power spectrum.