Gaia-2MASS Local Sharded SQLite Catalogue

This repository contains sharded SQLite databases of the Gaia-2MASS crossmatch catalogue, enabling fast local queries, up to different J magnitudes.

The locally created database is currently optimised for offline astrometric plate solving for visible and near-infrared observations.

The catalogue was generated by cross-matching Gaia DR2 and 2MASS catalogues using the astroquery Python package.

Usage

To use a local catalogue, download one of the already created Gaia-2MASS SQLite database files.

You can find an example of how to use the database in [example.py](example.py) from gaia-tmass-sqlite-generating-code.zip:

```python
if __name__ == '__main__':
    min_dec = -50.2
    max_dec = -49.2
    min_ra = 23.3
    max_ra = 24.4

    t0 = datetime.now()
    df = db_query('./db/gaia_tmass_16_jm_cut.db', min_dec, max_dec, min_ra, max_ra)
    print("Executed query", datetime.now() - t0)
    print(df)

```

```
Executed query 0:00:00.236333

            ra        dec       pmra      pmdec  phot_g_mean_mag     j_m
0    23.693215 -49.805034   17.91935 -36.989641         7.487380   5.177
1    23.573126 -49.448267  91.111847  10.057243         9.748498   8.751
2    24.121133 -49.926295  91.715677  47.979666         9.838325   8.860
3    23.817866 -49.549265  14.543387   8.118343        10.602289   9.109
4    24.226083 -49.414841  -2.335897 -87.573116        10.764868   9.329
..         ...        ...        ...        ...              ...     ...
615  23.629336 -50.186380  11.270629  -0.525701        17.416536  15.977
616  24.218084 -50.074234  12.997597  -0.806246        17.658678  15.986
617  24.326128 -49.769186  11.724527  -6.793672        18.224480  15.989
618  23.476797 -49.334399   0.578949  -1.991031        17.085663  15.993
619  23.386318 -49.613298  22.275294  -0.469569        17.023968  15.998

```