scopesim_templates.stellar.stellar.star

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scopesim_templates.stellar.stellar.star#

scopesim_templates.stellar.stellar.star(filter_name, amplitude, spec_type='A0V', x=0, y=0, library='pyckles')#

Create a scopesim.Source object for a list of stars with given amplitudes.

Note

If amplitudes have no units, vega magnitudes are assumed

Parameters:

  • filter_name (str) – For scaling the stars. Use either common names or Spanish-VO identifiers.

  • amplitudes (list of Quanitity, float) – [mag, Jy] amplitudes for the list of stars. Acceptable astropy.units: [u.mag, u.ABmag, u.Janksy]. If no units are given, Vega magnitudes are assumed

  • spec_types (list of strings) – the spectral type(s) of the stars, e.g. “A0V”, “G5III”

  • x (arrays of float) – [arcsec] x and y coordinates of the stars on the focal plane

  • y (arrays of float) – [arcsec] x and y coordinates of the stars on the focal plane

  • ra (float) – coordinates of the center of the field

  • dec (float) – coordinates of the center of the field

  • library (str) – Library where the spectroscopic types are taken. By default are taken from the pickles library using the pyckles package. Other libraries available are kurucz, bosz/lr, bosz/mr, bosz/hr, etc for MIR coverage and different spectral resolutions. Please see the spextra package for more information

Returns:

src

Return type:

scopesim.Source

Examples

Create a Source object for a random group of stars:

>>> import numpy as np
>>> import astropy.units as u
>>> from scopesim_templates.stellar import stars
>>>
>>> n = 100
>>> spec_types = ["A0V", "G2V", "K0III", "M5III", "O8I"] * (n // 5)
>>> ids = np.random.randint(0, 5, size=n)
>>> star_list = [spec_types[i] for i in ids]
>>> mags = np.random.normal(loc=20, scale=3, size=n) * u.mag
>>> x, y = np.random.random(size=(2, n))
>>>
>>> src = stars("Ks", mags, spec_types, x, y)

The final positions table is kept in the <Source>.fields attribute:

>>> my_pos_table = src.fields[0]

Each star in this table has an associated spectrum kept in the <Source>.spectra attribute. These stars are connected to the spectra in the list by the “ref” column in the .fields table:

>>> list(src.spectra.values())
[SpextrumNone, SpextrumNone, SpextrumNone, SpextrumNone, SpextrumNone]

The stars can be scaled in units of u.mag, u.ABmag or u.Jansky. Any filter listed on the spanish VO filter profile service can be used for the scaling (http://svo2.cab.inta-csic.es/theory/fps/). SVO filter names need to be in the following format observatory/instrument.filter:

>>> amplitudes = np.linspace(1, 3631, n) * u.Jansky
>>> filter_name = "Paranal/HAWKI.Ks"
>>> my_source = stars(filter_name, amplitudes, spec_types, x=x, y=y)
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