MAST Queries¶
The Mast class provides more direct access to the MAST interface. It requires more knowledge of the inner workings of the MAST API, and should be rarely needed. However in the case of new functionality not yet implemented in astroquery, this class does allow access. See the MAST api documentation for more information.
The basic MAST query function allows users to query through the following
MAST Services using
their corresponding parameters and returns query results as an
Table.
Filtered Mast Queries¶
MAST’s Filtered services use the parameters ‘columns’ and ‘filters’. The ‘columns’
parameter is a required string that specifies the columns to be returned as a
comma-separated list. The ‘filters’ parameter is a required list of filters to be
applied. The mast_query method accepts that list of
filters as keyword arguments paired with a list of values, similar to
query_criteria.
The following example uses a JWST service with column names and filters specific to JWST services. For the full list of valid parameters view the JWST Field Documentation.
>>> from astroquery.mast import Mast
...
>>> observations = Mast.mast_query('Mast.Jwst.Filtered.Nirspec',
... columns='title, instrume, targname',
... targoopp=['T'])
>>> print(observations)
title instrume targname
------------------------------- -------- ----------------
ToO Comet NIRSPEC ZTF (C/2022 E3)
ToO Comet NIRSPEC ZTF (C/2022 E3)
ToO Comet NIRSPEC ZTF (C/2022 E3)
ToO Comet NIRSPEC ZTF (C/2022 E3)
De-Mystifying SPRITEs with JWST NIRSPEC SPIRITS18nu
ToO Comet NIRSPEC ZTF (C/2022 E3)
... ... ...
ToO Comet NIRSPEC ZTF (C/2022 E3)
ToO Comet NIRSPEC ZTF (C/2022 E3)
ToO Comet NIRSPEC ZTF (C/2022 E3)
Length = 319 rows
TESS Queries¶
TESS queries have 2 types of filtered services. To output a table and specify columns for a TESS query, use TIC or CTL services with ‘.Rows’ on the end (e.g. Mast.Catalogs.Filtered.Tic.Rows). Valid parameters for TIC and CTL services are detailed in the TIC Field Documentation.
>>> from astroquery.mast import Mast
...
>>> observations = Mast.mast_query('Mast.Catalogs.Filtered.Tic.Rows',
... columns='id',
... dec=[{'min': -90, 'max': -30}],
... Teff=[{'min': 4250, 'max': 4500}],
... logg=[{'min': 4.5, 'max': 5.0}],
... Tmag=[{'min': 8, 'max': 10}])
>>> print(observations)
ID
---------
320274328
408290683
186485314
395586623
82007673
299550797
...
333372236
394008846
261525246
240766734
240849919
219338557
92131304
Length = 814 rows
TESS services without ‘.Rows’ in the title are used for count queries and will not mask the output tables using the columns parameter. Additionally, using a ‘.Rows’ service for a count query will result in an error.
>>> from astroquery.mast import Mast
...
>>> observations = Mast.mast_query('Mast.Catalogs.Filtered.Tic.Rows',
... columns = 'COUNT_BIG(*)',
... dec=[{'min': -90, 'max': -30}],
... Teff=[{'min': 4250, 'max': 4500}],
... logg=[{'min': 4.5, 'max': 5.0}],
... Tmag=[{'min': 8, 'max': 10}])
Traceback (most recent call last):
...
astroquery.exceptions.RemoteServiceError: Incorrect syntax near '*'.
Cone Searches¶
MAST’s cone search services use the parameters ‘ra’, ‘dec’, and ‘radius’ and return a table of observations with all columns present.
>>> from astroquery.mast import Mast
...
>>> observations = Mast.mast_query('Mast.Caom.Cone',
... ra=184.3,
... dec=54.5,
... radius=0.2)
>>> print(observations)
intentType obs_collection provenance_name ... obsid distance
---------- -------------- --------------- ... ----------- ------------------
science TESS SPOC ... 17001016097 0.0
science TESS SPOC ... 17000855562 0.0
science TESS SPOC ... 17000815577 203.70471189751947
science TESS SPOC ... 17000981417 325.4085155315165
science TESS SPOC ... 17000821493 325.4085155315165
science PS1 3PI ... 16000864847 0.0
science PS1 3PI ... 16000864848 0.0
science PS1 3PI ... 16000864849 0.0
science PS1 3PI ... 16000864850 0.0
science PS1 3PI ... 16000864851 0.0
... ... ... ... ... ...
science HLSP QLP ... 18013987996 637.806560287869
science HLSP QLP ... 18007518640 637.806560287869
science HLSP TESS-SPOC ... 18013510950 637.806560287869
science HLSP TESS-SPOC ... 18007364076 637.806560287869
science GALEX MIS ... 1000007123 0.0
science GALEX AIS ... 1000016562 0.0
science GALEX AIS ... 1000016562 0.0
science GALEX AIS ... 1000016563 0.0
science GALEX AIS ... 1000016563 0.0
science GALEX AIS ... 1000016556 302.4058357983673
science GALEX AIS ... 1000016556 302.4058357983673
Length = 77 rows
Cone search services only require positional parameters. Using the wrong service parameters will result in an error. Read the MAST API services documentation for more information on valid service parameters.
>>> from astroquery.mast import Mast
...
>>> observations = Mast.mast_query('Mast.Caom.Cone',
... columns='ra',
... Teff=[{'min': 4250, 'max': 4500}],
... logg=[{'min': 4.5, 'max': 5.0}])
Traceback (most recent call last):
...
astroquery.exceptions.RemoteServiceError: Request Object is Missing Required Parameter : RA
Using the ‘columns’ parameter in addition to the required cone search parameters will result in a warning.
>>> from astroquery.mast import Mast
...
>>> observations = Mast.mast_query('Mast.Catalogs.GaiaDR1.Cone',
... columns="ra",
... ra=254.287,
... dec=-4.09933,
... radius=0.02)
InputWarning: 'columns' parameter will not mask non-filtered services
Advanced Service Request¶
Certain MAST Services, such as Mast.Name.Lookup will not work with
astroquery.mast.MastClass.mast_query due to it’s return type. If the output of a query
is not the MAST json result type it cannot be properly parsed into a Table.
In this case, the service_request_async method should be used
to get the raw http response, which can then be manually parsed.
>>> from astroquery.mast import Mast
...
>>> service = 'Mast.Name.Lookup'
>>> params ={'input':"M8",
... 'format':'json'}
...
>>> response = Mast.service_request_async(service, params)
>>> result = response[0].json()
>>> print(result)
{'resolvedCoordinate': [{'cacheDate': 'Apr 12, 2017 9:28:24 PM',
'cached': True,
'canonicalName': 'MESSIER 008',
'decl': -24.38017,
'objectType': 'Neb',
'ra': 270.92194,
'resolver': 'NED',
'resolverTime': 113,
'searchRadius': -1.0,
'searchString': 'm8'}],
'status': ''}