The Spitzer Spectroscopic Data Fusion - Merged Spectroscopic Redshift Catalogs in Spitzer Fields

Merged Spec-Z ("specz-merged") catalogs merge miscellaneous spec-z information available<br> within a given field. Different spec-z catalogs available within a given field are merged<br> (using a search radius of 1.0 arcsec), and for sources with multiple spec-z measurements<br> the most reliable one is chosen following the (largely arbitrarily) assumed order of decreasing<br> reliability indicated below for each field. If CAT1,...,CATN spec-z catalogs are available<br> in a given field, Z_1 from CAT1 (i.e. NED) is adopted as "best" redshift (i.e. ZBEST),<br> if available, otherwise Z_2 from CAT_2 is adopted if available, and so on up to Z_N and CAT_N.<br> In using ZBEST it's thus important to bear in mind that this is not necessarily actually the<br> "best" redshift for science purposes, and in particular that the choice of NED as CAT1 is often<br> not ideal. However, Z_1,...,Z_N are included to allow users to define the "best" redshift based<br> on their science needs when multiple redshift estimates are available for a given source.<br> ZFLAG specifies which catalog is providing the ZBEST value according to the CATN number below.<br> ZCLASS is meant to provide further info about the class/quality of the spectroscopic redshift<br> measurement, but for the time being is not populated and is simply a copy of ZFLAG.<br> ZWHERE is an additional binary/bit flag indicating in which of the N catalogs each source<br> was given a spec-z estimate in. ZWHERE will e.g. be 2^0=1 if a redshift if available *only*<br> from CAT_1, whereas it will be 2^0+2^1=3 if a redshift is available *only* from CAT1 and CAT2,<br> so that a source with a redshift available from all catalogues will have ZWHERE=2^0+...+2^n. See AAAREADME.SPECZ-MERGED and https://adsabs.harvard.edu/abs/2015fers.confE..27V See also https://www.mattiavaccari.net/df and https://www.mattiavaccari.net/df/specz