The stream gap DF¶
- class galpy.df.streamgapdf(*args, **kwargs)[source]¶
The DF of a gap in a tidal stream
- __init__(*args, **kwargs)[source]¶
NAME:
__init__
PURPOSE:
Initialize the DF of a gap in a stellar stream
INPUT:
streamdf args and kwargs
Subhalo and impact parameters:
impactb= impact parameter (can be Quantity)
subhalovel= velocity of the subhalo shape=(3) (can be Quantity)
timpact time since impact (can be Quantity)
impact_angle= angle offset from progenitor at which the impact occurred (rad) (can be Quantity)
Subhalo: specify either 1( mass and size of Plummer sphere or 2( general spherical-potential object (kick is numerically computed)
1( GM= mass of the subhalo (can be Quantity)
rs= size parameter of the subhalo (can be Quantity)
2( subhalopot= galpy potential object or list thereof (should be spherical)
3( hernquist= (False) if True, use Hernquist kicks for GM/rs
deltaAngleTrackImpact= (None) angle to estimate the stream track over to determine the effect of the impact [similar to deltaAngleTrack] (rad)
nTrackChunksImpact= (floor(deltaAngleTrack/0.15)+1) number of chunks to divide the progenitor track in near the impact [similar to nTrackChunks]
nKickPoints= (30xnTrackChunksImpact) number of points along the stream to compute the kicks at (kicks are then interpolated); ‘30’ chosen such that higherorderTrack can be set to False and get calculations accurate to > 99%
nokicksetup= (False) if True, only run as far as setting up the coordinate transformation at the time of impact (useful when using this in streampepperdf)
spline_order= (3) order of the spline to interpolate the kicks with
higherorderTrack= (False) if True, calculate the track using higher-order terms
OUTPUT:
object
HISTORY:
2015-06-02 - Started - Bovy (IAS)