Astronomy Objects

Galaxies

class deepbench.astro_object.GalaxyObject(image_dimensions, amplitude=1, radius=25, n=1.0, noise_level=0.2, ellipse=0.45663448506266835, theta=0.09685431929984922, seed=None)

Produce a 2D galaxy using a Sersic2D distribution. View https://docs.astropy.org/en/stable/api/astropy.modeling.functional_models.Sersic2D.html for implimentation details.

Parameters:

  • image_dimensions (Union[tuple(int,int), tuple(float,float)]) – The dimension(s) of the object to be produced.

  • amplitude (Union[int, float]) – The amplitude of the object to be produced, surface brightness at radius.

  • noise_level (Union[float, list[float]]) – The Poisson noise level (lambda, the expected seperation) to be applied to the object.

  • radius (int, optional) – Effective half-light radius of the galaxy. Defaults to 25.

  • n (float, optional) – Sersic Index. Defaults to 1.0.

  • ellipse (float, optional) – Galaxy Ellipticity. Defaults to random.uniform(0.1, 0.9).

  • theta (float, optional) – The rotation of the galaxy in radians. Defaults to random.uniform(-1.5, 1.5). seed (Union[float, list[float]], optional): Seed to set the random state for noise in the object. Initialized at the init of the class. Default None.

  • seed (int | None)

Examples

>>> example_galaxy = GalaxyObject(image_dimensions=28)
create_Sersic_profile(center_x, center_y)

Wrapper for https://docs.astropy.org/en/stable/api/astropy.modeling.functional_models.Sersic2D.html

Parameters:

  • center_x (float) – x position of the center of the galaxy

  • center_y (float) – y position of the center of the galaxy

Returns:

created galaxy profile

Return type:

galaxy (numpy.array)

create_object(center_x=5.0, center_y=5.0)

Create the galaxy object from a Sersic distribution and Poisson or PSF noise.

Parameters:

  • center_x (float) – The x-axis placement of the galaxy object.

  • center_y (float) – The y-axis placement of the galaxy object.

Returns:

Two dimensional Galaxy object, composed of Sersic Distribution and noise appendings.

Return type:

ndarray

Examples

>>> example_prof = example_star.create_object(center_x = 1.0, center_y = 0.0)
displayObject()

Display the object created in a 2d plot

Raises:

NotImplementedError – Raised if not implimented in the child class

Spiral Galaxies

class deepbench.astro_object.SpiralGalaxyObject(image_dimensions, amplitude=1, radius=25, arm_thickness=1.0, noise_level=0.2, winding_number=2, spiral_pitch=0.2, seed=None, **kwargs)

Create a spiral galaxy object

Parameters:

  • image_dimensions (Union[Tuple(int,int), tuple(float,float)]) – The dimension(s) of the object to be produced.

  • amplitude (Union[int, float]) – The amplitude of the object to be produced, surface brightness at the sersic radius.

  • noise_level (Union[float, list[float]]) – The Poisson noise level to be applied to the object.

  • radius (int, optional) – Effective half-light radius of the galaxy. Defaults to 25.

  • arm_thickness (float, optional) – Width of each arm of the spiral. Defaults to 1.0.

  • winding_number (int, optional) – number of arms. Defaults to 2.

  • spiral_pitch (float, optional) – Severity of the spiral, the pitch angle. Defaults to 0.2. seed (Union[float, list[float]], optional): Seed to set the random state for noise in the object. Initialized at the init of the class. Default None.

  • seed (int | None)

Examples

>>> example_galaxy = SpiralGalaxyObject(image_dimensions=(28,28), winding_number=4)
create_object(center_x, center_y)

ref paper: https://doi.org/10.1111/j.1365-2966.2009.14950.x Create a spiral galaxy image

Parameters:

  • center_x (float) – x position of the center of the galaxy

  • center_y (float) – y position of the center of the galaxy

Returns:

Profile representing the spiral galaxy

Return type:

spiral profile (numpy array)

create_spiral_profile(center_x, center_y)

ref paper: https://doi.org/10.1111/j.1365-2966.2009.14950.x Impliment a spiral galaxy profile

Parameters:

  • center_x (float) – x position of the center of the galaxy

  • center_y (float) – y position of the center of the galaxy

Returns:

Profile representing the spiral galaxy

Return type:

spiral profile (numpy array)

displayObject()

Display the object created in a 2d plot

Raises:

NotImplementedError – Raised if not implimented in the child class

Stars

class deepbench.astro_object.StarObject(image_dimensions, noise_level=0.0, radius=1.0, amplitude=1.0, seed=None)

Create Stars

Args:

image_dimensions (Union[int, float, List[int], List[float]]): The dimension(s) of the object to be produced.

radius (Union[int, float]): The radius of the object to be produced. amplitude (Union[int, float]): The amplitude (brightness) of the object to be produced. noise_level (Union[float, list[float]]): The Poisson noise level (lambda, the expected seperation) to be applied to the object.

seed (Union[float, list[float]], optional): Seed to set the random state for noise in the object. Initialized at the init of the class. Default None.

Examples:

>>> example_star = StarObject(image_dimensions=28, noise=5.0, center=3, radius=0.7, amplitude=1.2)
>>> example_star = StarObject(image_dimensions=(28,28), noise=5.0)
Parameters:

  • image_dimensions (int | float | List[int] | List[float])

  • noise_level (float | List[float])

  • radius (int | float)

  • amplitude (int | float)

  • seed (int | None)

create_Moffat_profile(center_x, center_y, alpha=1.0)

Create the Moffat distribution used to simulate star objects.

Parameters:

  • center_x (float) – The x-axis placement of the star object.

  • center_y (float) – The y-axis placement of the star object.

  • alpha (float) – The luminosity of the Moffat distribution.

Returns:

Two dimensional Moffat distribution.

Return type:

ndarray

Examples

>>> example_prof = example_star.create_Moffat_profile(center_x = 1.0, center_y = 0.0, alpha=200.0)
>>> example_prof = example_star.create_Moffat_profile(center_x = 1.0, center_y = 0.0)
create_object(center_x, center_y, alpha=1.0)

Create the star object from a Moffat distribution and Poisson and PSF noise.

Parameters:

  • center_x (float) – The x-axis placement of the star object.

  • center_y (float) – The y-axis placement of the star object.

  • alpha (float) – The luminosity of the Moffat distribution.

Returns:

Two dimensional Star object, composed of Moffat Distribution and noise appendings.

Return type:

ndarray

Examples

>>> example_prof = example_star.create_object(center_x = 1.0, center_y = 0.0, alpha=200.0)
>>> example_prof = example_star.create_object(center_x = 1.0, center_y = 0.0)
displayObject()

Display the object created in a 2d plot

Raises:

NotImplementedError – Raised if not implimented in the child class