ACS Zeropoints Calculator
This module contains a class, Query, that was implemented to provide
users with means to programmatically query the
ACS Zeropoints Calculator API.
This class works by submitting requests directly to the AWS API, which also
handles the requests from the above web address. It is only valid for ACS
specific instruments (HRC, SBC, or WFC).
The API can be used in two ways by specifying either a
(date, detector, filter) combination or just a (date, detector)
combination. In the first case, the query
will return the zeropoint information for the specific filter and detector at
specified date. In the second case, the query will return the zeropoint
information for all the filters for the desired detector at the specified date.
In either case, the result will be an astropy.table.QTable where each column
is an astropy.units.quantity.Quantity object with the appropriate units attached.
Examples
Retrieve the zeropoint information for all the filters on 2016-04-01 for WFC:
>>> from acstools import acszpt
>>> q = acszpt.Query(date="2016-04-01", detector="WFC")
>>> zpt_table = q.fetch()
>>> print(zpt_table)
Filter PHOTLAM PHOTFLAM STmag VEGAmag ABmag
Angstrom erg / (Angstrom cm2 electron) mag(ST) mag mag(AB)
------ -------- ----------------------------- ------- ------- -------
F435W 4329.9 3.1858e-19 25.142 25.767 25.652
F475W 4747.0 1.845e-19 25.735 26.151 26.045
F502N 5023.0 5.2934e-18 22.091 22.367 22.278
F550M 5581.5 4.0186e-19 24.89 24.825 24.848
F555W 5361.0 1.9798e-19 25.658 25.714 25.704
F606W 5921.9 7.8774e-20 26.659 26.402 26.489
F625W 6311.8 1.198e-19 26.204 25.728 25.895
F658N 6584.0 1.9976e-18 23.149 22.378 22.748
F660N 6599.4 5.2219e-18 22.105 21.414 21.7
F775W 7693.5 1.0033e-19 26.396 25.26 25.658
F814W 8045.5 7.092e-20 26.773 25.506 25.937
F850LP 9031.5 1.5313e-19 25.937 24.323 24.851
F892N 8914.8 1.5105e-18 23.452 21.892 22.394
Retrieve the zeropoint information for the F435W filter on 2016-04-01 for WFC:
>>> from acstools import acszpt
>>> q = acszpt.Query(date="2016-04-01", detector="WFC", filt="F435W")
>>> zpt_table = q.fetch()
>>> print(zpt_table)
Filter PHOTLAM PHOTFLAM STmag VEGAmag ABmag
Angstrom erg / (Angstrom cm2 electron) mag(ST) mag mag(AB)
------ -------- ----------------------------- ------- ------- -------
F435W 4329.9 3.1858e-19 25.142 25.767 25.652
Retrieve the zeropoint information for the F435W filter for WFC at multiple dates:
>>> from acstools import acszpt
>>> dates = ['2004-10-13', '2011-04-01', '2014-01-17', '2018-05-23']
>>> queries = []
>>> for date in dates:
... q = acszpt.Query(date=date, detector='WFC', filt='F435W')
... zpt_table = q.fetch()
... # Each object has a zpt_table attribute, so we save the instance
... queries.append(q)
>>> for q in queries:
... print(q.date, q.zpt_table['PHOTFLAM'][0], q.zpt_table['STmag'][0])
2004-10-13 3.1111e-19 erg / (Angstrom cm2 electron) 25.168 mag(ST)
2011-04-01 3.1766e-19 erg / (Angstrom cm2 electron) 25.145 mag(ST)
2014-01-17 3.1817e-19 erg / (Angstrom cm2 electron) 25.143 mag(ST)
2018-05-23 3.1897e-19 erg / (Angstrom cm2 electron) 25.141 mag(ST)
>>> type(queries[0].zpt_table['PHOTFLAM'])
astropy.units.quantity.Quantity
Classes
Class used for raising exceptions with API Gateway post requests. |
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Class used to interface with the ACS Zeropoints Calculator API. |