Mission Overview

GALEX UV Unique Source Catalogs ("GUVcat")  and Cross-Matches With Gaia and SDSS  ("GUVmatch")

 

Primary Investigator: Luciana Bianchi

HLSP Authors: Luciana Bianchi, Bernie Shiao, David Thilker

Released: 2020-05-18

Updated: 2020-05-18

Primary Reference(s): Bianchi et al. (2017)Bianchi & Shiao 2020

DOI: 10.17909/t9-pyxy-kg53

Citations: See ADS Statistics

Read Me

 
GUVCat Coverage
GUVcat coverage (all observations with both the FUV and NUV detectors on).

Overview

The GALEX database contains almost 600 million source measurements in far-UV and near-UV. Some sources have repeated measurements (useful to search for variability, for example), due to repeated observations of the same field or overlap between fields.  Bianchi, Shiao, and Thilker 2017 constructed catalogs of clean, unique (i.e. only one entry for each object) UV sources, useful to estimate density of sources across the sky or the number of sources with given magnitude or color ranges, or to match UV sources with other catalogs (revised version 2020).  Flags are included to check for artifacts, as well as for existing multiple observations, and flags indicating whether a source is within the footprint of a large galaxy or stellar cluster (see Figure 5 in Bianchi et al. 2017) where source identification and photometry may be unreliable or inconsistent across the bands.  GUVcat is composed using tiles from the AIS (All-Sky Imaging Survey), with a depth of about 19.9/20.8 in FUV/NUV ABmag.  Additional tables and images of UV sources over extended objects (galaxies and stellar clusters) can be found at the author's website: http://dolomiti.pha.jhu.edu/uvsky

Bianchi & Shiao 2020 matched the GUVcat_AIS with SDSS DR14 and Gaia DR2 databases (GUVmatch).  Tags are included to identify and track multiple optical matches to UV sources.  For details about the matching parameters, and catalogs content in terms of astrophysical classes of objects, see Bianchi & Shiao 2020.   For sky coverage of GUVcat and GUVmatched catalogs, see Bianchi et al. 2019, ApJS 241, 14  and the AREAcat tool at: http://dolomiti.pha.jhu.edu/uvsky/area/AREAcat.php

There are four total tables available at MAST:

  1. AIS ("GUVcat_AISfov055") = catalog of sources with duplicate entries removed
  2. AISPlus ("GUVcat_AISfov055plus") = catalog of sources where duplicate entries are tagged but not removed
  3. AISxGaiaDR2 ("GUVmatch_AISxGaiaDR2") = AIS GUVcat cross-matched with Gaia DR2
  4. AISxSDSSDR14 ("GUVmatch_AISxSDSSdr14") = AIS GUVcat cross-matched with SDSS DR14

For additional information, see the team's page (outside MAST) at http://dolomiti.pha.jhu.edu/uvsky/, for additional information and ways to access the catalogs.

Relationship To Other GALEX Unique Source Catalogs

This catalog supersedes the previously released BCSCat entirely, by patching some fields that had been incorrectly merged by the pipeline (a bug that had introduced some flawed sources and artifacts in the database and in previous catalogs), and by adding useful tags for science analysis.  Compared to GCAT, GUVcat includes tiles released as part of the final GALEX data release (GR7) and thus uses the most amount of available AIS tiles between the other unique source catalogs.  In addition, GUVcat patches the incorrect co-adds and adds tags useful for science analysis and sample cleaning.

Data Products

Data file naming convention:

hlsp_guvcat_galex_imaging_<catalog_name>-glat-<lat1>-<lat2>_fuv-nuv_v1_cat.csv

where:

  • <catalog_name> = Name of the catalog, one of "ais", "aisplus", "aisxgaiadr2", "aisxsdssdr14"
  • <lat1> = Lower Galactic boundary, in degrees, for this slice. Example: "15s" corresponds to -15 degrees or "45n" corresponds to +45 degrees
  • <lat2> = Upper Galactic boundary, in degrees, for this slice. Example: "15s" corresponds to -15 degrees or "45n" corresponds to +45 degrees

Data file types:

_cat.csv Full catalog exported as a .csv file.

Data Access

The catalogs are availalbe in CasJobs for searching and cross-matching with SQL access, and as CSV files for bulk downloads.  Each of the four GUVcat catalogs and cross-match catalogs are stored in separate tables under the "GALEX_Catalogs" Context.  The four table names are "GUVcat_AIS_FOV055" ("AIS"), "GUVcat_AIS_FOV055Plus" ("AISPlus"), "GUVmatch_AISxGaiaDR2" ("AISxGaiaDR2"), and "GUVmatch_AISxSDSSdr14" ("AISxSDSSDR14").

Link to MAST CasJobs.

MAST CasJobs

A web-based SQL interface to query and cross-match between catalogs. Export tables, saved queries, long query submissions.

The catalogs are available for direct download from the table below.  Each .csv file is typically between 1 and 10 GB in size.  You can also download the catalogs in various formats from the author's webpage: ttp://dolomiti.pha.jhu.edu/uvsky

Column descriptions are for available for the GUVcat AIS, Gaia DR2, and SDSS DR14 columns.  Note that the cross-matched tables include both the GUVcat columns and the Gaia or SDSS columns.

GLAT Lower GLAT Upper AIS AISPlus AISxGaiaDR2 AISxSDSSDR14
-90 -75

ais-glat-90s-75s

aisplus-glat-90s-75s

aisxgaiadr2-glat-90s-75s

aisxsdssdr14-glat-90s-75s

-75 -60

ais-glat-75s-60s

aisplus-glat-75s-60s

aisxgaiadr2-glat-75s-60s

aisxsdssdr14-glat-75s-60s

-60 -45

ais-glat-60s-45s

aisplus-glat-60s-45s

aisxgaiadr2-glat-60s-45s

aisxsdssdr14-glat-60s-45s

-45 -30

ais-glat-45s-30s

aisplus-glat-45s-30s

aisxgaiadr2-glat-45s-30s

aisxsdssdr14-glat-45s-30s

-30 -15

ais-glat-30s-15s

aisplus-glat-30s-15s

aisxgaiadr2-glat-30s-15s

aisxsdssdr14-glat-30s-15s

-15 00

ais-glat-15s-00n

aisplus-glat-15s-00n

aisxgaiadr2-glat-15s-00n

aisxsdssdr14-glat-15s-00n

00 15

ais-glat-00n-15n

aisplus-glat-00n-15n

aisxgaiadr2-glat-00n-15n

aisxsdssdr14-glat-00n-15n

15 30

ais-glat-15n-30n

aisplus-glat-15n-30n

aisxgaiadr2-glat-15n-30n

aisxsdssdr14-glat-15n-30n

30 45

ais-glat-30n-45n

aisplus-glat-30n-45n

aisxgaiadr2-glat-30n-45n

aisxsdssdr14-glat-30n-45n

45 60

ais-glat-45n-60n

aisplus-glat-45n-60n

aisxgaiadr2-glat-45n-60n

aisxsdssdr14-glat-45n-60n

60 75

ais-glat-60n-75n

aisplus-glat-60n-75n

aisxgaiadr2-glat-60n-75n

aisxsdssdr14-glat-60n-75n

75 90

ais-glat-75n-90n

aisplus-glat-75n-90n

aisxgaiadr2-glat-75n-90n

aisxsdssdr14-glat-75n-90n

Citations

Please remember to cite the appropriate paper(s) below and the DOI if you use these data in a published work. 

Note: These HLSP data products are licensed for use under CC BY 4.0.

References