J-PLUS DR2 Data Release (July, 2020) provides access to the combined scientific images in 12 filters covering a total area of ~ 2000 square degrees. J-PLUS-DR2 is based on images collected from November 2015 to February 2020 by the JAST80 telescope. It includes two types of data: images and single and dual catalogue data (parameters measured from images, such as photometry or morphology data). Single catalogues are the ones where the detection and photometry had been done on each image independently. While, dual catalogues are the catalogues where the detection and photometry had been done using as reference image the r-SDSS image.
J-PLUS web site offers dual catalogues data through several different online data access tools, each suited to a particular need. The table below gives a short description of each of tool indicating when you might use each one, based on what information you know already and what information you want to find out. Click on the name of a tool to access to it. Single catalogue data is also available but, currently, only through V.O. services.
| Tool | What it Does | Use it when... |
|---|---|---|
| Sky Navigator | Lets you navigate through the sky by panning and zooming. When you click on an object, you get a summary of it and you have options to see its photospectrum, explore it or search it in other catalogues. | You are looking through the sky for objects to study. |
| Object List Search | Lets you upload a list of sky positions, object names or objects identifiers, then returns a list of objects near those positions. Displays a summary, photospectra and thumbnail images for the list of objects. | You want to quickly scan through a list of objects or you have a list of sky objects from another astronomical database and you want to find all objects near each of your objects. You want to create a report of a list of objects. |
| Image Search | Lets you search and download coadded images by position or name. Lets you see a preview for each image. This service is only available if you have logged in. | You want to look at or download a coadded image. |
| Reduced Individual Image Search | Lets you search and download reduced individual images by position, astronomical night or name. Lets you see a preview for each image. This service is only available if you have logged in. | You want to look at or download a reduced individual image. |
| Cone Search | Lets you search the database for objects near a certain sky position and with certain brightnesses. | You want to find objects in one part of the sky. |
| Coverage Map | Lets you display the sky area covered by the data release. | You want to know the fields covered by the data release. These fields are linked to see them quickly in the sky navigator tool. |
| Multi-Order Coverage Map (MOC) | Lets you download the Multi-Order Coverage map (MOC) which describes the area covered by the data release (fits file). | You want to download the MOC file to compute very fast data set operations (unions, intersections,...) or query data (sources, images,...) of other data releases only inside this data release area using external tools like VizieR, Aladin or Topcat. |
| Custom Statistical Maps | Lets you generate statistical maps based on different parameters for the area covered by the data release. This service is only available if you have logged in. | You want to generate a custom statistical map based on a parameter, like FWHM, of the fields covered by the data release. |
| V.O. Services | Lets you access to images and objects data through Virtual Observatory (V.O.) protocols using V.O. compatible applications. V.O. services offered are Simple Cone Search (SCS), Table Access Protocol (TAP), Simple Image Access Protocol (SIAP) and Simple Spectral Access Protocol (SSAP). | You want to use a V.O. compatible application to access catalogue data or images and you want to know the URL of the service. |
| V.O. Asynchronous Queries (ADQL) | Lets you search the database for all objects that meet any criteria you can think of, then returns whatever object data you request. Database queries are in Astronomical Data Query Language (ADQL), which is basically a standardised version of SQL (ADQL help and examples). This service is only available if you have logged in. | You want to answer a specific astronomical research question. |
| Direct Download Services | Lets you build the URL for different services for images or objects data download. This service is only available if you have logged in. | You want to download images or objects data from the command line or from your own scripts and you want to know how to build the URL of the service. |