Assessing Galactic RM from the Oppermann+14 map



In [1]:

    
%matplotlib inline



In [12]:

    
# imports
from pkg_resources import resource_filename
import numpy as np

from astropy.io import fits
from astropy.coordinates import SkyCoord

import healpy as hp

from frb import rm

Load map



In [3]:

    
fg_file = resource_filename('frb', 'data/RM/opp14_foreground.fits')



In [4]:

    
hdu = fits.open(fg_file)
hdu.info()









    



Filename: /data/Projects/FRB/frb/data/RM/opp14_foreground.fits
No.    Name      Ver    Type      Cards   Dimensions   Format
  0  PRIMARY       1 PrimaryHDU       6   ()      
  1  angspec       1 BinTableHDU     12   384R x 1C   [D]   
  2  profile       1 BinTableHDU     17   196608R x 1C   [E]   
  3  maps/s        1 BinTableHDU     17   196608R x 1C   [E]   
  4  maps/phi      1 BinTableHDU     17   196608R x 1C   [E]   
  5  uncertainty/s    1 BinTableHDU     17   196608R x 1C   [E]   
  6  uncertainty/phi    1 BinTableHDU     17   196608R x 1C   [E]



In [5]:

    
rm_sky = hp.read_map(fg_file, hdu=4)









    



NSIDE = 128
ORDERING = RING in fits file
INDXSCHM = IMPLICIT



In [6]:

    
sig_sky = hp.read_map(fg_file, hdu=6)









    



NSIDE = 128
ORDERING = RING in fits file
INDXSCHM = IMPLICIT

HealPix time

View



In [7]:

    
hp.mollview(rm_sky, title="Mollview image RING")
hp.graticule()









    



0.0 180.0 -180.0 180.0
The interval between parallels is 30 deg -0.00'.
The interval between meridians is 30 deg -0.00'.

Galactic RM

Query a Coordinate



In [8]:

    
repeater_coord = SkyCoord('05h31m58.698s +33d8m52.59s', frame='icrs')



In [14]:

    
RM, RM_err = rm.galactic_rm(repeater_coord)
RM, RM_err









    



NSIDE = 128
ORDERING = RING in fits file
INDXSCHM = IMPLICIT
NSIDE = 128
ORDERING = RING in fits file
INDXSCHM = IMPLICIT






    Out[14]:





(<Quantity -17.72799492 rad / m2>, <Quantity 76.43039703 rad / m2>)