Accessing metadata¶

NSA¶

Data from the NASA Sloan Atlas can be accessed for each Cube, Maps, and modelcube.ModelCube object via the nsa attribute. The feature is implemented via the NSAMixIn class. For example:

>>> my_cube = Cube('8485-1901', mode='remote')
>>> my_cube.nsa
{'iauname': 'J153010.73+484124.8',
'subdir': '15h/p48/J153010.73+484124.8',
'ra': 232.544703894,
'dec': 48.6902009334,
'isdss': 225926,
'ined': 167868,
'isixdf': -1,
'ialfalfa': -1,
'izcat': 373580,
'itwodf': -1,
'mag': 17.3247,
'z': 0.0407447,
'zsrc': 'sdss   ',
'size': 0.07,
...

How much NSA information is available depends on the mode in which the object was created. If you opened a Cube or Maps from a file, Marvin will try to use the local DRPall file, which contains only a subset of the NSA data. If loaded remotely, Marvin will make an API call to retrieve the full NSA information from the server. You can change this behaviour in runtime by setting the nsa_source attribute from 'drpall' to 'nsa'.

DAPall¶

The DAPall file contains galaxy-summed, derived information from the Data Analysis Pipeline, such as total fluxes, SFR, etc. Similarly to the NSA data, it can be accessed from Maps and ModelCube objects via the dapall attribute.

VACs¶

Value Added Catalogues (VAC) provide analysis of MaNGA data created by collaborators and that are distributed as part of SDSS data releases. VAC owners can integrate their catalogues in Marvin following this procedure. VACs can be accessed via the .vacs attribute. The first time you access a VAC (or, depending on the VAC, the first you access a VAC for a certain object) a download will be triggered and the catalogue will be downloaded to you local SAS. From that moment on the VAC will be accessible offline. Available VACs are listed below.

Reference¶