The +cats package contains astronomical catalogs, maps, spectra, and auxiliary files. Its main function is to allow easy access, search and cross-match of astronomical catalogs. This package is optimized for catalogs whose size (number of rows) is smaller than about 10^5-10^6. For larger catalogs see catsHTM.

The package contains subpacakes of catalogs. The catalosg are saved in either mat files, hdf5 files, or FITS files. When a new catalof is added, it is important to execute the VO.search.prep_data_dir command (see also VO documentation). Most catalogs are stored as AstCat object (a catalog container). However, other formats are supported too. The interface function to the catalogs is called VO.search.catalog_interface. Content and subpacakges To view the contents of the cats directory, type from the matlab command prompt "cats." followed by . Content

If you are using this code or products in your scientific publication please give a reference to Ofek (2014; ascl.soft 07005).

Unless specified otherwise this code and products are released under the GNU general public license version 3.

The installation of the +cats package requires running the command: VO.search_prep_data_dir. You have to run this command once after you install the MATLAB Astronomy & Astrophysics Toolbox.

Before using the cats package, you need to generate the interface functions. This is done using the VO.search.prep_data_dir command. This command will generate an interface function for each catalog. VO.search.prep_data_dir % or if you want to install in a different location: VO.search.prep_data_dir('Dir','/home/myname/matlab/data/+cats');

Currently, the following sub-packages are available:

• binaries - Binary stars catalogs.
• bright - Bright stars and object catalogs.
• compact - Compact objects - White Dwarfs, Neutron Stars, and Black Holes.
• galaxies - Galaxy and galaxy cluster catalogs.
• gamma - gamma-rays catalogs.
• maps - Maps (e.g., FIRST coverage map, SFD Galactic extinction).
• radio - Radio catalogs.
• SDSS - SDSS-related catalogs.
• SN - Supernovae-related catalogs.
• sources - UV/Visible/IR catalogs.
• spec - Spectroscopy-related catalogs (e.g., Astronomical filters - see AstFilter; spectral lines).
• stars - Stellar evolutionary tracks.
• X - X-Ray catalogs.
• GALEX - GALEX-related catalogs
• DECaLS - DECaLS-related catalogs
• SolarSys -
• XMM
• PTF
• ZTF

% load the FIRST catalog
F = cats.radio.FIRST

Important: when you load a catalog, it is uploaded to your output variable (F in the example) and also is uploaded to the MATLAB session under the catalog name (FIRST in the example). The next time you run this command, the function will identify the file in the matlab session and will not re-upload the file (saves times). If for some reason you need to delete the file or upload it again you have to clear the variable name (e.g., "clear FIRST"). You can search the catalogs directly using the upload command. For example, search the FIRST catalog around RA=180 deg, Dec=10 deg with a search radius of 1800 arcsec:

F=cats.radio.FIRST(180,10,1800)

Note this command returns an AstCat object with the objects found in the search radius. However, in addition, the full catalog is uploaded into a session variable named in this example FIRST. In order to view the help for additional options:

cats.radio.FIRST('h')

To see the catalog available columns and units:

cats.radio.FIRST('c');

You can also execute a query on the catalog columns

cats.radio.FIRST('q','RA>pi & Dec<1 & Fpeak>Fint & Fpeak>100')