clustertools.tidaltail.tails module

Functions and Operations for analysing a cluster’s tidal tails

clustertools.tidaltail.tails.tail_path(cluster, tfinal=0.1, no=1000, nt=100, ntail=100, pot=None, dmax=None, bintype='fix', from_centre=False, skypath=False, to_path=False, do_full=False, ro=None, vo=None, zo=None, solarmotion=None, plot=False, projected=False, **kwargs)[source]

Calculate tail path +/- tfinal Gyr around the cluster

Parameters:
clusterclass

StarCluster

tfinalfloat

final time (in cluster.units) to integrate orbit to (default: 0.1 Gyr)

noint

number of timesteps for orbit integration (default:1000)

ntint

number of points along the tail to set the tail spacing (default: 100)

ntailint

number of points along the tail with roaming average (default: 1000)

potclass

galpy Potential that orbit is to be integrate in (default: None)

dmaxfloat

maximum distance (assumed to be same units as cluster) from orbital path to be included in generating tail path (default: None)

bintypestr

type of binning for tail stars (default : ‘fix’)

from_centrebool

genrate orbit from cluster’s exact centre instead of its assigned galactocentric coordinates (default: False)

skypathbool

return sky coordinates instead of cartesian coordinates (default: False)

to_pathbool

measure distance to the path itself instead of distance to central point along the path (default: False)

do_fullbool

calculate dpath all at once in a single numpy array (can be memory intensive) (default:False)

rofloat

distance to the Galactic centre (Default: None)

vofloat

circular velocity at ro (Default: None)

zofloat

Sun’s distance above the Galactic plane (default: None)

solarmotionfloat

array representing U,V,W of Sun (default: None)

plotbool

plot a snapshot of the cluster in galactocentric coordinates with the orbital path (defualt: False)

projectedbool

match to projected orbital path, which means matching just x and y coordinates or Ra and Dec coordinates (not z, or dist) (default:False)

Returns:
tfloat

times for which path is provided

x,y,zfloat

tail path positions

vx,vy,vzfloat

tail path velocities

History
2018 - Written - Webb (UofT)
2019 - Implemented numpy array preallocation to minimize runtime - Nathaniel Starkman (UofT)
clustertools.tidaltail.tails.tail_path_match(cluster, tfinal=0.1, no=1000, nt=100, ntail=100, pot=None, path=None, from_centre=False, skypath=False, to_path=False, do_full=False, ro=None, vo=None, zo=None, solarmotion=None, plot=False, projected=False, **kwargs)[source]

Match stars to a position along the tail path of the cluster

Parameters:
clusterclass

StarCluster

tfinalfloat

final time (in cluster.units) to integrate orbit to (default: 0.1 Gyr)

noint

number of timesteps for orbit integration (default:1000)

ntint

number of points along the tail to set the tail spacing (default: 100)

ntailint

number of points along the tail with roaming average (default: 1000)

potclass

galpy Potential that orbit is to be integrate in (default: None)

patharray

array of (t,x,y,x,vx,vy,vz) corresponding to the tail path. If none path is calculated (default: None)

from_centrebool

genrate orbit from cluster’s exact centre instead of its assigned galactocentric coordinates (default: False)

skypathbool

return sky coordinates instead of cartesian coordinates (default: False) if True, projected is set to True

to_pathbool

measure distance to the path itself instead of distance to central point along the path (default: False)

do_fullbool

calculate dpath all at once in a single numpy array (can be memory intensive) (default:False)

rofloat

distance to the Galactic centre (Default: None)

vofloat

circular velocity at ro (Default: None)

zofloat

Sun’s distance above the Galactic plane (default: None)

solarmotionfloat

array representing U,V,W of Sun (default: None)

plotbool

plot a snapshot of the cluster in galactocentric coordinates with the orbital path (defualt: False)

projectedbool

match to projected orbital path, which means matching just x and y coordinates or Ra and Dec coordinates (not z, or dist) (default:False)

Returns:
tstarfloat

orbital time associated with star

dprogfloat

distance along the path to the progenitor

dpath

distance to centre of the tail path bin (default) or the tail path (to_path = True)

clustertools.tidaltail.tails.to_tail(cluster)[source]
Calculate positions and velocities of stars when rotated such that clusters velocity vector

points along x-axis

  • no change to coordinates in StarCluster

Parameters:
clusterclass

StarCluster

Returns:
x_tail,y_tail,z_tail,vx_tail,vy_tail,vz_tailfloat

rotated coordinates with cluster’s velocity vector point along x-axis

History:
2018 - Written - Webb (UofT)