Missing catalog for cross-match

Question

I wish to cross-match a personalized catalogue (already uploaded) to a LS10 catalogue using the legacy tool (https://datalab.noirlab.edu/legacy/xmatch.php).

On this tool, I only find ls_dr10.psc_n, ls_dr10.psc_s, ls_dr10.tractor and ls_dr10.tractor_s. However, I would like the aperture fluxes that are stored in ls_dr10.apflux which is not available while appearing in the datalabs (https://datalab.noirlab.edu/data-explorer?showTable=ls_dr10.apflux).
How can I have access to it for cross-matching? Or should I download it and do the cross-match myself?

Thank you in advance for your help

Answer 1

Hi, thanks for your question. The ls_dr10.apflux table does not have RA/Dec columns, so it cannot be used directly with our crossmatch service. However, it does include a column named ls_id, which you can use to join with other LS DR10 tables.

A recommended workflow would be:

1. Crossmatch your input table with ls_dr10.tractor to get the corresponding ls_id values.

2. Save the results to your MyDB (for example, as "my_ls_dr10_xmatch").

3. In a Jupyter notebook on our notebook server, run a query that joins your saved table with ls_dr10.apflux using ls_id to retrieve the desired aperture flux columns. For example:

SELECT X.ra, X.dec, X.ls_id, A.apflux_g_1, A.apflux_r_1
FROM mydb://my_ls_dr10_xmatch AS X
JOIN ls_dr10.apflux AS A ON X.ls_id = A.ls_id

We also have a notebook with similar examples here: https://github.com/astro-datalab/notebooks-latest/blob/master/04_HowTos/CrossmatchTables/Examples_using_pre_crossmatched_tables.ipynb