converter (class) ∞
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class
converter
(log, settings=False)[source] ∞ Bases:
object
A converter to switch distance between various units of measurement
Key Arguments
log
– loggersettings
– the settings dictionary
Usage
To instantiate a
converter
object:from astrocalc.distances import converter c = converter(log=log)
Methods
distance_to_redshift
(mpc)Convert a distance from MPC to redshift
redshift_to_distance
(z[, WM, WV, H0])convert redshift to various distance measurements
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distance_to_redshift
(mpc)[source] ∞ Convert a distance from MPC to redshift
The code works by iteratively converting a redshift to a distance, correcting itself and honing in on the true answer (within a certain precision)
Key Arguments
mpc
– distance in MPC (assumes a luminousity distance).
Return
redshift
Todo
replace convert_mpc_to_redshift in all code
Usage
from astrocalc.distances import converter c = converter(log=log) z = c.distance_to_redshift( mpc=500 ) print(z) # OUTPUT: 0.108
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redshift_to_distance
(z, WM=0.3, WV=0.7, H0=70.0)[source] ∞ convert redshift to various distance measurements
Key Arguments
z
– redshift measurement.WM
– Omega_matter. Default 0.3WV
– Omega_vacuum. Default 0.7H0
– Hubble constant. (km s-1 Mpc-1) Default 70.0
Return
results
– result dictionary includingdcmr_mpc
– co-moving radius distanceda_mpc
– angular distanceda_scale
– angular distance scaledl_mpc
– luminosity distance (usually use this one)dmod
– distance modulus (determined from luminosity distance)
Todo
replace convert_redshift_to_distance in all other code
Usage
from astrocalc.distances import converter c = converter(log=log) dists = c.redshift_to_distance( z=0.343 ) print("Distance Modulus: " + str(dists["dmod"]) + " mag") print("Luminousity Distance: " + str(dists["dl_mpc"]) + " Mpc") print("Angular Size Scale: " + str(dists["da_scale"]) + " kpc/arcsec") print("Angular Size Distance: " + str(dists["da_mpc"]) + " Mpc") print("Comoving Radial Distance: " + str(dists["dcmr_mpc"]) + " Mpc") # OUTPUT : # Distance Modulus: 41.27 mag # Luminousity Distance: 1795.16 Mpc # Angular Size Scale: 4.85 kpc/arcsec # Angular Size Distance: 999.76 Mpc # Comoving Radial Distance: 1339.68 Mpc from astrocalc.distances import converter c = converter(log=log) dists = c.redshift_to_distance( z=0.343, WM=0.286, WV=0.714, H0=69.6 ) print("Distance Modulus: " + str(dists["dmod"]) + " mag") print("Luminousity Distance: " + str(dists["dl_mpc"]) + " Mpc") print("Angular Size Scale: " + str(dists["da_scale"]) + " kpc/arcsec") print("Angular Size Distance: " + str(dists["da_mpc"]) + " Mpc") print("Comoving Radial Distance: " + str(dists["dcmr_mpc"]) + " Mpc") # OUTPUT : # Distance Modulus: 41.29 mag # Luminousity Distance: 1811.71 Mpc # Angular Size Scale: 4.89 kpc/arcsec # Angular Size Distance: 1008.97 Mpc # Comoving Radial Distance: 1352.03 Mpc