dustmaps3d 2.2.1

An all-sky 3D dust map based on Gaia and LAMOST.

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dustmaps3d

🌌 An all-sky 3D dust extinction map based on Gaia and LAMOST

📄 Wang et al. (2025), An all-sky 3D dust map based on Gaia and LAMOST
📌 DOI: 10.12149/101620

📦 A Python package for easy access to the 3D dust map
📌 DOI: 10.12149/101619

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📦 Installation

Install via pip:

pip install dustmaps3d

📦 Data File Notice

⚠️ The package does not include the data file. Upon first use, a ~400MB model file will be automatically downloaded from GitHub or the NADC mirror.

🚀 Automatic Download Mechanism

• When dustmaps3d() is called, the package will attempt to download the file data_v3.fits.gz;
• After the download, the file will be automatically decompressed into data_v3.fits and cached locally;
• Subsequent calls will directly load from the cache without re-downloading.

🌐 What If the Download Fails?

If you're outside China, the default download source is GitHub. However, network issues (like connect timeout) may still occur. The package supports fallback to an alternative mirror:

• ✅ Primary source (international users): GitHub Releases
• 🌀 Backup source (Chinese mirror): NADC (currently under review, coming soon)

If both sources fail, you can manually download the data file.

📥 Manual Download (Recommended for Chinese Users)

1. Visit the mirror link (coming soon)
2. Download the file: data_v3.fits.gz
3. Decompress it into data_v3.fits
4. Place the file in the local cache directory (the location will be printed the first time you run the package)

Example path on Windows:
C:\Users\<username>\AppData\Local\dustmaps3d\data_v3.fits

Example path on Linux/macOS:
/home/<username>/.local/share/dustmaps3d/data_v3.fits

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🚀 Usage

from dustmaps3d import dustmaps3d

l = [120.0]
b = [30.0]
d = [1.5]

EBV, dust, sigma, max_d = dustmaps3d(l, b, d)
print(f"EBV: {EBV.values[0]:.4f} [mag]")
print(f"Dust: {dust.values[0]:.4f} [mag/kpc]")
print(f"Sigma: {sigma.values[0]:.4f} [mag]")
print(f"Max distance: {max_d.values[0]:.4f} kpc")

Batch example with FITS:

import numpy as np
from astropy.table import Table
from dustmaps3d import dustmaps3d

data = Table.read('input.fits')   
l = data['l'].astype(float)
b = data['b'].astype(float)
d = data['d'].astype(float)

EBV, dust, sigma, max_d = dustmaps3d(l, b, d)

data['EBV_3d'] = EBV
data['dust'] = dust
data['sigma'] = sigma
data['max_distance'] = max_d
data.write('output.fits', overwrite=True)

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🧠 Function Description

dustmaps3d(l, b, d, n_process=None)

Estimates 3D dust extinction and related quantities for given galactic coordinates and distances.

Input	Type	Description	Unit
l	np.ndarray	Galactic longitude	degrees
b	np.ndarray	Galactic latitude	degrees
d	np.ndarray	Distance	kpc

Returns:

Output	Type	Description	Unit
EBV	np.ndarray	E(B–V) extinction	mag
dust	np.ndarray	Dust density (d(EBV)/dx)	mag/kpc
sigma	np.ndarray	Estimated uncertainty in E(B–V)	mag
max_d	np.ndarray	Maximum reliable distance	kpc

If d contains NaN, it will be automatically replaced by the maximum reliable distance along that line of sight (max_d).

If the input d exceeds max_d, it indicates the point lies beyond the model's reliable range. The returned values in this case are extrapolated and not guaranteed to be accurate.

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⚡ Performance

• Fully vectorized and optimized with NumPy
• On a modern personal computer, evaluating 100 million stars takes only ~100 seconds

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📜 Citation

If you use this model or the Python package, please cite both:

• Wang, T. (2025), An all-sky 3D dust map based on Gaia and LAMOST. DOI: 10.12149/101620
• dustmaps3d: A Python package for easy access to the 3D dust map. DOI: 10.12149/101619

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🛠️ License

This project is open-source and distributed under the MIT License.

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📫 Contact

If you have any questions, suggestions, or encounter issues using this package,
please feel free to contact the authors via GitHub issues or email.

• Prof. Yuan Haibo: [e-mail]
• Wang Tao: [e-mail]

🔗 GitHub Repository