Gaia@AIP updated!

Dear Gaia Community,

We have the pleasure to announce that our services have seen considerable improvement.
Some are fixes and are improvements:

  • General performances tuning for all tables.
  • Specific gaiaedr3.gaia_source performances tuning.
  • The releases gdr2, gdr2_contrib and gdr1 were renamed to gaiadr2, gaiadr2_contrib and gaiadr1 respectively.
  • FITs export is back.
  • Cone-search web interface now works on gaia_source of Gaia EDR3
  • Cone-serach API can now access various tables: gaiaedr3.gaia_source, gaiaedr3.gaia_source_simulation, gaiadr2.gaia_source, gaiadr1.gaia_source
  • A few other improvements in queue management.

We hope you’ll enjoy these and we wish you all a nice weekend.

Your Gaia@AIP team

Scheduled maintenance – Dec 22, 2020

Postgres server update on 22.12.2020 from 2pm to 6pm. The Query webinterface and the TAP queries services will be affected.

Non-available features

Dear Gaia community,

After identifying some issues with our services, we would like to announce that two features are currently not available:

  1. export to FIT files
  2. Cone search from the web interface

We are working hard to re-establish these services as soon as possible. In the mean time here are the possible work around:

Exporting to FITs file, work around

You can download your results as VOTable and export them to the FIT format using astropy:

from astropy.io.votable import parse_single_table
table = parse_single_table("votable.xml").to_table()
table.write('table.fits', format='fits')

Cone search, work around

The Cone Search can be simulated within the web interface as follow:

SELECT * FROM gaiaedr3.gaia_source
WHERE pos @ scircle(spoint(RADIANS(<ra>), RADIANS(<dec>)), RADIANS(<radius>))

Where <ra>, <dec>, <radius> are the right-ascension, declination and radius of your search, respectively. To make it work remember to choose the ADQL language and a queue of 2h.

We hope it helps,

Your Gaia team @ AIP

Website updated

Dear Gaia community,

We used the opportunity of the Gaia Early Data Release 3 to restructured our website, hopefully to make it easier for you to find what you need. Here is a short overview:

  • Services: there you will find the list of the services offered at Gaia@AIP from hosted data, to scriptable data access down to credits and licenses.
  • Database tables: For the new user, here you will find all the metadata about the data hosted at AIP: catalogues, tables columns, units, descriptions – everything you need to use the data.
  • Query: That is the so-called Query Interface, there you will find a user-friendly web interface to access the data, either with SQL queries, or via Cone search.
  • News: That is the main information channel we use at Gaia@AIP.
  • FAQ: You have a question? You may not be the first one, so please check it out, you may found what you need! In case you don’t feel free to contact us, we will be glad to support.

You are looking for the documentation? We moved it to the right-hand side. In case something is missing, let us know.

We hope you will appreciate the new organization and the new content we have added. More coming, stay tuned…

Your Gaia team @ AIP

Gaia Early Data Release 3 – Now available !

The Gaia early data release is now available for the public. The AIP hosts the Gaia data as one of the external data centers along with the main Gaia archive maintained by ESAC.

Gaia early data release - The Gaia Sky in colour.

Gaia early data release – The Gaia Sky in colour – Image credit: ESA/Gaia/DPAC – Image license: CC-BY-SA 3.0 IGO – Acknowledgement: created by A. Moitinho, University of Lisbon, Portugal

Plenty of events are organized today, so please join to celebrate this new release!

Gaia@AIP hosts the data from all Gaia data releases complemented with additional catalogues and cross-matches. The data can be queried directly using the Structured Query Language (SQL), so you can retrieve only the data subset you interested in. After registration, you can use the Query Form to perform your query. We also prepared a set of examples and tutorials for you to get started.

For more information please refer to the Documentation.

TAP interface documentation updated

The documentation for the TAP interface was updated for Python 3 and pyvo version>=1.0. The TAP interface allows you to run Queries via scripted access.

VOTable upload available

With the latest update of Daiquiri, VOTable upload is finally available. You can find the upload tab on the Query interface. The upload interface expects the table to be in the VOTable format.

Re-normalised Unit Weight Error (RUWE)

We added a table containing the recently released re-normalised unit weight error estimates for many of the sources from the Gaia DR2 list. The error estimates are available through gdr2_contrib.ruwe table which can be easily joined with the gaia_source table or other tables containing the source_id identifier. Full documentation on how the error values were derived and their suggested usage can be found in this document.

Distance estimations from parallaxes

Distances estimated from parallaxes of Gaia’s second data release as described in the paper by Bailer-Jones et al. (2018) are now available on gaia.aip.de! The data can be found in the gdr2_contrib schema and it’s easily linked to the gaia_source table through the source_id unique identifier.

ADQL and PostgreSQL queries in the new framework

One of the new features in the new Daiquiri framework is the support of the Astronomical Data Query Language v2.0 (ADQL). This version of the SQL was designed specifically to be used in astronomy and comes with statements that facilitate cone-search queries and other positional selections. All ADQL queries that are submitted for the execution are translated to PostgreSQL dialect before they are passed to the database server. Users can also choose to write their queries in the PostgreSQL directly. In some cases this is more desirable since the ADQL does not support all features that are available in PostgreSQL, namely working with array structures.

As an example let us write an ADQL query that selects stars around the M4 globular cluster from the Gaia DR1 main table:

SELECT ra, dec
FROM gdr1.gaia_source
WHERE 1 = CONTAINS(POINT('ICRS', ra, dec),
                   CIRCLE('ICRS',4.2917,-0.4629, 0.008))

The cone selection is done using the CONTAINS statement. Alternatively, we can rewrite the same query using the PostgreSQL dialect in the following way:

SELECT ra, dec
FROM gdr1.gaia_source
WHERE pos @ scircle(spoint(RADIANS(4.2917),RADIANS(-0.4629)), RADIANS(0.008))

Here we use the PgSphere functions ‘scircle’ and ‘spoint’ to define the region. We connect the column containing the positional information (right ascension and declination) ‘pos’ to the cone selection with the @ operator. But you need to apply RADIANS() to the (RA,DEC) values. To learn more about the available PgSphere functions and capabilities please refer to the documentation here.