juliensimon/swift-bat-hard-xray-survey

---
license: cc-by-4.0
pretty_name: "Swift-BAT 157-Month Hard X-Ray Survey"
language:
- en
description: "Hard X-ray source catalog (14-195 keV) from 157 months of Swift BAT all-sky observations, including fluxes, spectral parameters, and counterpart identifications."
task_categories:
- tabular-classification
tags:
- space
- x-ray
- swift
- nasa
- hard-x-ray
- astronomy
- open-data
- tabular-data
size_categories:
- 1K<n<10K
configs:
- config_name: default
data_files:
- split: train
path: data/swift-bat.parquet
default: true
---

# Swift-BAT 157-Month Hard X-Ray Survey

*Part of the [Astronomy Datasets](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) collection on Hugging Face.*

Catalog of **1,893** hard X-ray sources detected in the 14-195 keV band by the
[Swift Burst Alert Telescope (BAT)](https://swift.gsfc.nasa.gov/about_swift/bat_desc.html)
over 157 months of all-sky survey observations, sourced from NASA HEASARC.

## Dataset description

The Swift-BAT hard X-ray survey is the most sensitive and uniform survey of the sky
in the 14-195 keV energy band. The Burst Alert Telescope (BAT) is a coded-aperture
instrument aboard the Neil Gehrels Swift Observatory that continuously monitors the
hard X-ray sky. This 157-month catalog represents over 13 years of observations,
providing positions, fluxes, and spectral parameters for detected sources including
active galactic nuclei (AGN), X-ray binaries, galaxy clusters, and other high-energy
objects.

Hard X-rays penetrate gas and dust that absorb softer X-rays, making BAT uniquely
suited for finding obscured AGN and mapping the local hard X-ray universe.

## Quick stats

- **1,893** hard X-ray sources (14-195 keV)
- **1,098** sources with measured redshifts
- Median detection SNR: **7.2**

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/swift-bat-hard-xray-survey", split="train")
df = ds.to_pandas()

# Brightest sources by SNR
top = df.nlargest(10, "snr")
print(top[["name", "snr", "ra", "dec"]].to_string())

# Sources with redshifts
with_z = df.dropna(subset=["redshift"])
print(f"{len(with_z):,} sources with redshifts")

# Sky map
import matplotlib.pyplot as plt
fig, ax = plt.subplots(subplot_kw={"projection": "mollweide"})
import numpy as np
ra = np.deg2rad(df["ra"] - 180)
dec = np.deg2rad(df["dec"])
ax.scatter(ra, dec, s=1, alpha=0.5)
ax.set_title("Swift-BAT Hard X-Ray Sources")
```

## Data source

All data comes from the [Swift-BAT 157-Month Hard X-Ray Survey](https://swift.gsfc.nasa.gov/results/bs157mon/)
(Oh et al. 2018, ApJS, 235, 4), accessed via the
[NASA HEASARC TAP service](https://heasarc.gsfc.nasa.gov/xamin/vo/tap/).

## Pipeline

Source code: [juliensimon/space-datasets](https://github.com/juliensimon/space-datasets)

## Related datasets

- [gamma-ray-bursts](https://huggingface.co/datasets/juliensimon/gamma-ray-bursts) — Fermi GBM Gamma-Ray Burst Catalog
- [pulsar-catalog](https://huggingface.co/datasets/juliensimon/pulsar-catalog) — ATNF Pulsar Catalogue
- [rosat-all-sky](https://huggingface.co/datasets/juliensimon/rosat-all-sky) — ROSAT All-Sky Survey

## Citation

```bibtex
@dataset{swift_bat_hard_xray,
author = {Simon, Julien},
title = {Swift-BAT 157-Month Hard X-Ray Survey},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/swift-bat-hard-xray-survey},
note = {Based on Oh et al. 2018 via NASA HEASARC}
}
```

## License

[CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/)