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Extracting reduced data of M dwarfs

Anonymous 2 months ago updated by Archive Science Group 2 months ago 1

Hi,

I'm working on the X-Shooter library and M dwarfs. I'm trying to extract the reduced data of M dwarfs resolved by X-Shooter using a list of M dwarfs obtained from SIMBAD. The stars range from M0V-M9.5V. Is there an easy way of doing this programmatically? The list contains many stars that are not resolved by X-Shooter too so it will have to only extract the ones that are present in the ESO archive. I have been downloading the files manually from the website but it has an upper limit of 1000 items per list which has prevented me from using lists containing more than 1000 stars. I would also like to know if there is a way to go around this limit programmatically as well as on the website.

Many thanks!

Questions

Answer

Answer
Completed

Dear user,

   many thanks for using the ESO archive system!

To access to XSHOOTER data programmatically you can use a query similar to this one:


SELECT
    target_name, dp_id, s_ra, s_dec, t_exptime, em_min, em_max, 
    dataproduct_type, instrument_name, obstech, abmaglim,
    proposal_id, obs_collection
FROM
    ivoa.ObsCore
WHERE
    (INTERSECTS(CIRCLE('ICRS',109.66824871,-24.55869773,5./3600), s_region)=1 OR
     INTERSECTS(CIRCLE('ICRS',279.729582,6.27016,5./3600), s_region)=1
    )
AND
    instrument_name LIKE 'XSHOO%'

where you can include a list of INTERSECTS conditions connected with the OR logic (see these HOWTOs for further details). With this, however, you will still hit a limit in the number of objects to be queried. This is due to the maximum length of the url that could be sent to the TAP service.

It is not possible to overcome the 1000 object limit in the Archive Science Portal. If splitting your list in groups containing <1000 items each is not an option for you, an alternative can be found in this forum page. Here with provide a walk-through on how to get data given a list of star names with python. This requires the installation of the unofficial ESOAsg python package.

Enjoy your data!

Answer
Completed

Dear user,

   many thanks for using the ESO archive system!

To access to XSHOOTER data programmatically you can use a query similar to this one:


SELECT
    target_name, dp_id, s_ra, s_dec, t_exptime, em_min, em_max, 
    dataproduct_type, instrument_name, obstech, abmaglim,
    proposal_id, obs_collection
FROM
    ivoa.ObsCore
WHERE
    (INTERSECTS(CIRCLE('ICRS',109.66824871,-24.55869773,5./3600), s_region)=1 OR
     INTERSECTS(CIRCLE('ICRS',279.729582,6.27016,5./3600), s_region)=1
    )
AND
    instrument_name LIKE 'XSHOO%'

where you can include a list of INTERSECTS conditions connected with the OR logic (see these HOWTOs for further details). With this, however, you will still hit a limit in the number of objects to be queried. This is due to the maximum length of the url that could be sent to the TAP service.

It is not possible to overcome the 1000 object limit in the Archive Science Portal. If splitting your list in groups containing <1000 items each is not an option for you, an alternative can be found in this forum page. Here with provide a walk-through on how to get data given a list of star names with python. This requires the installation of the unofficial ESOAsg python package.

Enjoy your data!