How do I know if MaNGA has observed my galaxy?

dpf=mrdfits('drpall-v2_4_3.fits',1,hdr)

Now dpf is an IDL structure of the drpall file.

By RA, Dec

Assuming for the moment that your galaxy has RA = 229.52558 deg and declination DEC = 42.745842 deg, you can see if there is a galaxy near this position.

ii=where(abs(dpf.objra-229.52558) lt 0.001 and abs(dpf.objdec-42.745842) lt 0.001)
print,dpf[ii].mangaid  ;should print 12-193481

By MaNGA-ID or plate-IFU

If you know the MaNGA id or the plate and ifu design of your galaxy, similar procedure can be followed:

ii=where(dpf.mangaid eq '12-193481')
jj=where(dpf.plateifu eq '7443-12703')

Here ii and jj would be the indices for your given galaxy. A value of -1 means no galaxy was found.

# Imports
import numpy as np
from astropy.io import fits

# Read in the DRPall table data
drpall = fits.open('drpall-v2_4_3.fits')[1].data

By RA, Dec

# Find galaxy at (RA,DEC) = (229.52558, 42.745842)
i = (np.abs(drpall['OBJRA']-229.52558) < 0.001) & (np.abs(drpall['OBJDEC']-42.745842) < 0.001)
print(drpall['MANGAID'][i])

By MaNGA-ID or plate-IFU

# Find a specific galaxy using the MaNGA ID
j = drpall['MANGAID'] == '12-193481'

# Find a specific observation
k = drpall['PLATEIFU'] == '7443-12703'

# i, j, k are boolean arrays

By RA, Dec

# given an RA, or DEC
(RA,DEC) = (229.525575871, 42.7458424664)

# create and run a Query
from marvin.tools.query import Query
q = Query(search_filter='cube.ra == {0} and cube.dec == {1}'.format(RA,DEC))
r = q.run()

# see the results
r.results

[ResultRow(mangaid=u'12-193481', plate=7443, plateifu=u'7443-12703', ifu_name=u'12703', ra=229.525575871, dec=42.7458424664)]

# convert to a Marvin Cube
r.convertToTool('cube')
cube = r.objects[0]

By MaNGA-ID

# check if your target has been observed
from marvin.utils.general import target_status, target_is_observed

# return a boolean
target_is_observed('12-193481’)
True

# or get a string status indicator
target_status('12-193481’)
‘observed'

# or just grab a Cube
from marvin.tools.cube import Cube
cube = Cube('12-193481’)

By plate-IFU

# by plate-IFU
from marvin.utils.general import get_drpall_row
row = get_drpall_row('7443-12703')

# or just grab a Cube
from marvin.tools.cube import Cube
cube = Cube('7443-12703')