Introduction

Distribution on the sky of galaxies included in GSWLC. Each panel shows SDSS target galaxies as shaded areas, covering ~9000 sq. deg.

Data Products

There are four different catalogs, in both ASCII and FITS format. They are summarized in the table below, and are available for download. You can also query the catalogs (without downloading all of them) using STScI's CasJobs. See the Data Access section below for instructions. The column names are defined in Table 1 of Salim et al. 2016, and are also included below and in the table notes section in CasJobs.

Data Access

In addition to downloading the data files above, you may also conduct SQL queries using STScI's CasJobs and download the results as csv or FITS tables. First, sign-up for an STScI CasJobs account. Note that this is NOT the same as any general STScI account you may have registered: CasJobs accounts are self-contained within STScI. Some example screenshots and simple queries are provided below.

Example Screenshots (click for larger versions)
You'll see this screen when you visit the CasJobs page, if not signed in. The login button is at the top.	The "Query" tab is where you execute your SQL queries. You select a Context with the drop-down at the top left. In the case of GSWLC, you select "HLSP_GSWLC" to query the four tables.	The "MyDB" tab is where you can examine output tables you create, or output tables stored by STScI. Be sure to change the Context to the appropriate area (your output tables are always under "MyDB").

Example SQL Scripts

Example 1: Select star-forming galaxies in the Coma Cluster.

This example selects sources from the GSWLC-M catalog that satisfiy RA, DEC, redshift, and star formation rate cuts. The "select *" component selects all rows from the GSWLC-M table.

Example 2: Select galaxies including data from SDSS tables in MAST CasJobs.

This example selects galaxies based on columns from both GSWLC and SDSS. It uses a SQL join to cross-identify objects in the GSWLC with SDSS DR12. You can use SQL joins to match objects in one table within MAST CasJobs with another table, as long as they share at least one column of unique values in common, referred to as a "primary key". In this case, the SDSS identifier is in both tables and can be used to do matching between objects.

[1 ]  select h.*, mc.NUV_A_WORLD, mc.NUV_B_WORLD from gswlc_galex_sdss_wise_multi_a1 as h
[2 ]  into mydb.GSWLC_galaxies
[3 ]  inner join GALEX_GR6Plus7.photoobjall as mc on glxid = mc.objid
[4 ]  where
[5 ]  logsfrsed - logmstar > -10.9 and logsfrsed - logmstar < -10.3
[6 ]  and logmstar > 10.5 and logmstar < 11.1
[7 ]  and mc.NUV_B_WORLD / mc.NUV_A_WORLD > 0.8
[8 ]  and NUV_A_WORLD > 0.002
[9 ]  and NUV_A_WORLD > 0.
[10]  and NUV_B_WORLD > 0.
  

Explanation of SQL:

Line 1: Selects all columns in GSWLC A1 table, and the NUV_A_WORLD and NUV_B_WORLD columns from the GALEX PhotoObjAll table. Note that "h" and "mc" are aliases for these tables defined later in the script.

Line 2: The output table of results in put into a new table called "GSWLC_galaxies" inside the MyDB Context. Note that the name of your output table must not exist, since result tables will not be overwritten. You must either drop a table in the MyDB tab or choose a new output table name if a table already exists with your output name.

Line 3: This uses SQL "inner join" to match the "glxid" column in GSWLC A1 table with the "objid" column in the GALEX PhotoObjAll table. So this uses the GALEX ID in both tables to allow cross-identification between the two tables.

Lines 4-10: These are the constraints on which rows to keep, applying cuts on star formation rate and object shape/size.