astro-legacy-archive/spider1-cmb-results

SPIDER 1 CMB results

This dataset contains all 93 files in the SPIDER 1 CMB results release served by LAMBDA: bandpowers, covariance matrices, bandpower windows, beam profiles, transfer functions, the input simulation spectrum, the marginalized r likelihood, an analysis mask, 40 sample signal/noise simulation maps, and two map-weight tables.

No observed SPIDER survey map is released here. The 40 files beginning 'map_signal_' or 'map_noise_scaled_' are simulations, the two 'weight_' files are weights, and 'mask_latlon_pointsource_removed' is an analysis mask. Those identities are stated explicitly rather than allowing the presence of map-shaped products to imply observed sky measurements.

Structure

The release becomes 93 one-source configurations:

• 44 ASCII tables use statistical-product 1.2.0: 18 bandpower tables, 18 window tables, two beam profiles, four transfer functions, one input simulation spectrum, and one likelihood table.
• Six 27-by-27 covariance arrays use dense-matrix 1.0.0. Their published unit is uK_CMB^4.
• The implicit full-sky analysis mask uses healpix-map 2.1.0. Its sole source field remains named 'T', with source 'TFORM1=1024L' and dtype '|b1'; each source row is a fixed-size list of 1024 Boolean values. LAMBDA documents the frame as equatorial and says that True pixels are included in the analysis; no additional mask classes or meanings are derived.
• Forty simulation maps and two weight tables use explicit-pixel 1.0.0. Their source identifiers remain verbatim. Most simulation files use 'TEMPERATURE', 'Q_POLARISATION', and 'U_POLARISATION'; the 150 GHz signal files instead use 'I_STOKES', 'Q_STOKES', and 'U_STOKES'. LAMBDA documents all simulation maps as equatorial with units uKcmb. Each Stokes column in each of the ten 150 GHz signal maps contains 4,016 measured NaNs, recorded separately as structured special values.

How to use

from datasets import load_dataset
mask = load_dataset("astro-legacy-archive/spider1-cmb-results", "mask_latlon_pointsource_removed", split="train", columns=["T"], streaming=True)
print(next(iter(mask))["T"][:8])

[False, False, False, False, False, False, False, False]

import json
from huggingface_hub import hf_hub_download
import pyarrow.parquet as pq
path = hf_hub_download("astro-legacy-archive/spider1-cmb-results", "mask_latlon_pointsource_removed.parquet", repo_type="dataset")
print(json.loads(pq.read_metadata(path).metadata[b"healpix_map"])["healpix"]["coordsys"])

equatorial coordinates

Provenance

The source manifest, sources.tsv, records the exact originating URL, byte size, and SHA-256 digest for every released file. The preview is rendered from the Parquet products.

LAMBDA's product table says 94 files overall, while its current generated download manifests expose 93: 49 general products, 43 map products, and one likelihood file. This dataset contains those 93 served and pinned files.

Scientific context

These products accompany the first-flight SPIDER analysis at 95 and 150 GHz. Bandpower products cover EE, BB, and EB in both Cl and Dl forms for the individual frequencies and their combination. The map products are sample end-to-end signal and noise simulations used to characterize the analysis, not observations of the survey field.

For scientific interpretation, cite SPIDER Collaboration, P. A. R. Ade et al. (2022), “A Constraint on Primordial B-Modes from the First Flight of the SPIDER Balloon-Borne Telescope,” The Astrophysical Journal 927, 174, arXiv:2103.13334.

Licensing and credit

HEASARC states: “HEASARC materials are all available freely for your use.” No separate named data licence was found on the checked SPIDER pages.

LAMBDA requests:

We acknowledge the use of the Legacy Archive for Microwave Background Data Analysis (LAMBDA), part of the High Energy Astrophysics Science Archive Center (HEASARC). HEASARC/LAMBDA is a service of the Astrophysics Science Division at the NASA Goddard Space Flight Center.

Errata and requests

To report an erratum, propose a correction, or ask a question about this dataset, open a Discussion or Pull Request in its Community tab; posting requires a free Hugging Face account. Dataset requests and archive-wide questions may be posted in the README space's Community tab or the Community tab of any dataset. Confirmed corrections are made in the source conversion tools and published by rebuilding the dataset.