juliensimon/fermi-3pc-gamma-ray-pulsars

---
license: cc-by-4.0
pretty_name: "Fermi LAT Third Pulsar Catalog (3PC)"
language:
- en
description: "Gamma-ray pulsars detected by the Fermi Large Area Telescope, including spin parameters, fluxes, and spectral properties from the 3PC catalog"
task_categories:
- tabular-classification
tags:
- space
- open-data
- tabular-data
- parquet
- fermi
- nasa
- pulsar
- gamma-ray
- high-energy
- astronomy
size_categories:
- n<1K
configs:
- config_name: default
data_files:
- split: train
path: data/fermi-3pc.parquet
default: true
---

# Fermi LAT Third Pulsar Catalog (3PC)

<div align="center">
<img src="banner.jpg" alt="Cassiopeia A supernova remnant in X-ray, optical, and infrared light" width="400">
<p><em>Credit: NASA/JPL-Caltech/STScI/CXC/SAO</em></p>
</div>

*Part of the [Astronomy Datasets](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) and [Physics Datasets](https://huggingface.co/collections/juliensimon/physics-datasets-681b79c9a7e113e34e4467f4) collections on Hugging Face.*


Complete catalog of **7,197** gamma-ray pulsars detected by the
[Fermi Large Area Telescope (LAT)](https://fermi.gsfc.nasa.gov/ssc/),
sourced from NASA HEASARC.

## Dataset description

Pulsars are rapidly rotating, highly magnetized neutron stars that emit beams of electromagnetic radiation. When these beams sweep across Earth, they produce periodic pulses observed across the spectrum from radio to gamma rays. The **Fermi LAT Third Pulsar Catalog (3PC)** is the definitive census of pulsars detected at GeV gamma-ray energies by the Fermi Large Area Telescope, the most sensitive gamma-ray surveyor ever flown.

Gamma-ray pulsars fall into two broad populations:

- **Millisecond pulsars (MSPs)**: old neutron stars spun up to periods of 1-30 ms by accretion from a binary companion. They have weak surface magnetic fields (~10^8-10^9 G) but enormous spin-down luminosities. Many were first discovered through gamma-ray pulsation searches, having been missed by radio surveys.
- **Young pulsars**: recently formed neutron stars (characteristic ages < ~100 kyr) with strong magnetic fields (~10^12 G) and periods of 30 ms to several seconds. These include famous objects like the Crab and Vela pulsars.

The Fermi LAT is uniquely suited for pulsar studies because gamma rays probe the magnetospheric emission regions directly. Unlike radio emission (which originates from a narrow cone near the magnetic poles), gamma-ray emission arises from particle acceleration in the outer magnetosphere or current sheet, providing constraints on pulsar emission geometry and plasma physics that are inaccessible at other wavelengths.

The 3PC catalog includes spin parameters (period, period derivative), derived quantities (spin-down luminosity, characteristic age, surface magnetic field), spectral properties (spectral index, cutoff energy), and flux measurements for each detected pulsar.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `__row` | float | Row |
| `name` | string | Pulsar name (e.g. J0030+0451) |
| `data_release` | float | Data Release |
| `ra` | float | Right ascension (degrees, J2000) |
| `dec` | float | Declination (degrees, J2000) |
| `lii` | float | Galactic longitude (degrees) |
| `bii` | float | Galactic latitude (degrees) |
| `semi_major_axis_68` | float | Semi Major Axis 68 |
| `semi_minor_axis_68` | float | Semi Minor Axis 68 |
| `position_angle_68` | float | Position Angle 68 |
| `semi_major_axis_95` | float | Semi Major Axis 95 |
| `semi_minor_axis_95` | float | Semi Minor Axis 95 |
| `position_angle_95` | float | Position Angle 95 |
| `detection_significance` | float | Detection Significance |
| `pivot_energy` | float | Pivot Energy |
| `flux_1_100_gev` | float | Flux 1 100 Gev |
| `flux_1_100_gev_error` | float | Flux 1 100 Gev Error |
| `energy_flux` | float | Energy Flux |
| `energy_flux_error` | float | Energy Flux Error |
| `pl_flux_density` | float | Pl Flux Density |
| `pl_flux_density_error` | float | Pl Flux Density Error |
| `pl_index` | float | Pl Index |
| `pl_index_error` | float | Pl Index Error |
| `lp_flux_density` | float | Lp Flux Density |
| `lp_flux_density_error` | float | Lp Flux Density Error |
| `lp_index` | float | Lp Index |
| `lp_index_error` | float | Lp Index Error |
| `lp_beta` | float | Lp Beta |
| `lp_beta_error` | float | Lp Beta Error |
| `lp_curve_significance` | float | Lp Curve Significance |
| `lp_epeak` | float | Lp Epeak |
| `lp_epeak_error` | float | Lp Epeak Error |
| `plec_flux_density` | float | Plec Flux Density |
| `plec_flux_density_error` | float | Plec Flux Density Error |
| `plec_index_s` | float | Plec Index S |
| `plec_index_s_error` | float | Plec Index S Error |
| `plec_exp_factor_s` | float | Plec Exp Factor S |
| `plec_exp_factor_s_error` | float | Plec Exp Factor S Error |
| `plec_exp_index` | float | Plec Exp Index |
| `plec_curve_significance` | float | Plec Curve Significance |
| `plec_epeak` | float | Plec Epeak |
| `plec_epeak_error` | float | Plec Epeak Error |
| `npred` | float | Npred |
| `variability_index` | float | Variability Index |
| `frac_variability` | float | Frac Variability |
| `frac_variability_error` | float | Frac Variability Error |
| `significance_peak` | float | Significance Peak |
| `flux_peak` | float | Flux Peak |
| `flux_peak_error` | float | Flux Peak Error |
| `time_peak` | float | Time Peak |
| `time_peak_interval` | float | Time Peak Interval |
| `assoc_name` | string | Associated source name |
| `assoc_prob_bay` | float | Assoc Prob Bay |
| `assoc_prob_lr` | float | Assoc Prob Lr |
| `assoc_ra` | float | Assoc Ra |
| `assoc_dec` | float | Assoc Dec |
| `assoc_error_radius` | float | Assoc Error Radius |
| `analysis_flags` | float | Analysis Flags |
| `__x_ra_dec` | float | X Ra Dec |
| `__y_ra_dec` | float | Y Ra Dec |
| `__z_ra_dec` | float | Z Ra Dec |

## Quick stats

- **7,197** gamma-ray pulsars
- **61** columns retained after null filtering

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/fermi-3pc-gamma-ray-pulsars", split="train")
df = ds.to_pandas()

# Overview
print(f"{len(df):,} gamma-ray pulsars")
print(df.describe())
```

## Data source

All data comes from the [Fermi LAT Pulsar Catalog (fermilpsc)](https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermilpsc.html)
hosted by NASA's High Energy Astrophysics Science Archive Research Center (HEASARC),
accessed via the TAP protocol.

Based on: Smith, D.A. et al. (2023), "The Third Fermi Large Area Telescope Catalog of Gamma-Ray Pulsars",
*The Astrophysical Journal*, 958, 191. [arXiv:2307.11132](https://arxiv.org/abs/2307.11132)

## Update schedule

Static dataset. The 3PC catalog is a fixed publication; re-run only if HEASARC updates the table.

## Related datasets

- [pulsar-catalog](https://huggingface.co/datasets/juliensimon/pulsar-catalog) — ATNF Pulsar Catalog (radio + multiwavelength)
- [fermi-4fgl-dr4](https://huggingface.co/datasets/juliensimon/fermi-4fgl-dr4) — Fermi LAT 4FGL-DR4 source catalog
- [fermi-3fhl-hard-gamma-ray](https://huggingface.co/datasets/juliensimon/fermi-3fhl-hard-gamma-ray) — Fermi LAT 3FHL hard gamma-ray sources
- [fermi-4lac-agn-catalog](https://huggingface.co/datasets/juliensimon/fermi-4lac-agn-catalog) — Fermi LAT AGN catalog

## Pipeline

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

## Support

If you find this dataset useful, please give it a ❤️ on the [dataset page](https://huggingface.co/datasets/juliensimon/fermi-3pc-gamma-ray-pulsars) and share feedback in the Community tab! Also consider giving a ⭐️ to the [space-datasets](https://github.com/juliensimon/space-datasets) repo.

## Citation

```bibtex
@dataset{fermi_3pc_gamma_ray_pulsars,
author = {Simon, Julien},
title = {Fermi LAT Third Pulsar Catalog (3PC)},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/fermi-3pc-gamma-ray-pulsars},
note = {Based on Smith et al. (2023), NASA HEASARC fermilpsc table}
}
```

## License

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