juliensimon/tgss-radio-catalog

---
license: cc-by-4.0
pretty_name: "TGSS Alternative Data Release 1 (150 MHz)"
language:
- en
description: "TGSS ADR1 catalog of 623,604 radio sources at 150 MHz from the Giant Metrewave Radio Telescope."
task_categories:
- tabular-classification
- tabular-regression
tags:
- space
- radio
- tgss
- gmrt
- 150mhz
- astronomy
- open-data
size_categories:
- 100K<n<1M
---

# TGSS Alternative Data Release 1 (150 MHz)

The TIFR GMRT Sky Survey Alternative Data Release 1 (TGSS ADR1), a 150 MHz radio continuum
survey covering 90% of the sky (declination > -53 deg) using the Giant Metrewave Radio Telescope.
Contains **623,604** discrete radio sources, filling the critical low-frequency gap in
all-sky radio catalogs.

## Dataset description

TGSS ADR1 is the largest 150 MHz radio survey, observed between 2010 and 2012 with the GMRT.
It provides 25 arcsecond resolution and a median rms noise of ~3.5 mJy/beam. The catalog is
essential for low-frequency radio spectral studies, identifying steep-spectrum sources such as
pulsars, high-redshift radio galaxies, and galaxy cluster relics.

## Schema

| Column | Type | Description |
|--------|------|-------------|
| `source_name` | string | TGSS source designation |
| `ra_deg` | float64 | Right ascension J2000 (degrees) |
| `dec_deg` | float64 | Declination J2000 (degrees) |
| `peak_flux_mjy` | float64 | Peak flux density (mJy/beam) |
| `integrated_flux_mjy` | float64 | Integrated flux density (mJy) |
| `e_peak_flux_mjy` | float64 | Error on peak flux (mJy/beam) |
| `e_integrated_flux_mjy` | float64 | Error on integrated flux (mJy) |
| `rms_mjy` | float64 | Local rms noise (mJy/beam) |
| `major_axis_arcsec` | float64 | Fitted major axis FWHM (arcsec) |
| `minor_axis_arcsec` | float64 | Fitted minor axis FWHM (arcsec) |
| `position_angle_deg` | float64 | Position angle (degrees) |

## Quick stats

- **623,604** radio sources at 150 MHz
- Median peak flux: 768.00 mJy/beam
- Median rms noise: 0.00 mJy/beam
- Sky coverage: RA 0.0--360.0 deg, Dec -53.1--89.6 deg

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/tgss-radio-catalog", split="train")
df = ds.to_pandas()

# Flux distribution
import matplotlib.pyplot as plt
df["peak_flux_mjy"].clip(upper=500).hist(bins=200, log=True)
plt.xlabel("Peak flux at 150 MHz (mJy/beam)")
plt.ylabel("Count")
plt.title("TGSS Source Flux Distribution")
plt.show()

# Sky coverage
plt.scatter(df["ra_deg"], df["dec_deg"], s=0.01, alpha=0.1)
plt.xlabel("RA (deg)")
plt.ylabel("Dec (deg)")
plt.title("TGSS ADR1 Sky Coverage (150 MHz)")
plt.show()

# Bright sources (> 1 Jy)
bright = df[df["integrated_flux_mjy"] > 1000]
print(f"{len(bright):,} sources brighter than 1 Jy at 150 MHz")
```

## Data source

Intema, H.T., Jagannathan, P., Mooley, K.P., and Frail, D.A. (2017),
*The GMRT 150 MHz all-sky radio survey -- First alternative data release TGSS ADR1.*
Astronomy & Astrophysics, 598, A78. Via [VizieR](https://vizier.cds.unistra.fr/) CDS Strasbourg.

## Pipeline

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

## Citation

```bibtex
@dataset{tgss_radio_catalog,
author = {Simon, Julien},
title = {TGSS Alternative Data Release 1 (150 MHz)},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/tgss-radio-catalog},
note = {Based on Intema et al. (2017) via VizieR CDS Strasbourg}
}
```

## License

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