spiral_profile¶

simcado.source.spiral_profile(r_eff, ellipticity=0.5, angle=45, n_arms=2, tightness=4.0, arms_width=0.1, central_brightness=10, normalization='total', width=1024, height=1024, oversample=1, **kwargs)[source]¶

Creates a spiral profile with arbitary parameters

Parameters

r_efffloat: [pixel] Effective (half-light) radius
ellipticityfloat: Ellipticity is defined as (a - b)/a. Default = 0.5
anglefloat: [deg] Default = 45. Rotation anti-clockwise from the x-axis
n_armsint: Number of spiral arms
tightnessfloat: How many times an arm crosses the major axis. Default = 4.
arms_widthfloat: An arbitary scaling factor for how think the arms should be. Seems to scale with central_brightness. Default = 0.1
central_brightnessfloat: An arbitary scaling factor for the strength of the central region. Has some connection to ars_width. Default = 10
normalizationstr, optional: [“half-light”, “centre”, “total”] Where the profile equals unity If normalization equals: - “centre” : the maximum values are set to 1 - “total” : the image sums to 1
width, heightint, int: [pixel] Dimensions of the image
x_offset, y_offsetfloat: [pixel] The distance between the centre of the profile and the centre of the image
oversampleint: Factor of oversampling, default factor = 1. If > 1, the model is discretized by taking the average of an oversampled grid.

Returns

imgnp.ndarray: A 2D image of a spiral disk