Observation
ocelot.model.observation.GaiaDR3ObservationModel
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Bases: BaseObservation
name
property
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Type of observation modelled by this class.
Should return a lowercase string, like 'gaia_dr3'.
photometric_band_names
property
¤
Names of photometric bands modelled by this system.
apply_astrometric_errors(cluster)
¤
Apply astrometric errors to the cluster and save observed astrometry to the cluster.
calculate_astrometric_errors should be called before this method.
By default, this is just a simple UNCORRELATED Gaussian; it may be overwritten if desired. In addition, this method only works on proper motions and parallaxes; if you're writing an observation class that also needs to simulate positional errors, then you should overwrite this function.
__init__(representative_stars=None, subsample_selection_functions=tuple(), overestimate_bp_rp_fluxes=True)
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A model for an observation made with Gaia DR3.
calculate_photometric_errors(cluster)
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Calculate photometric errors for a simulated cluster.
apply_photometric_errors(cluster)
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Custom method to apply photometric errors to a simulated cluster.
Method incorporates the underestimated BP and RP flux measurement issue in DR3.
Follows things discussed in Riello+21, section 8.1.
calculate_astrometric_errors(cluster)
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Calculate astrometric errors for a simulated cluster.
get_selection_functions(cluster)
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Get an initialized GaiaDR3SelectionFunction in addition to any subsample selection functions defined by the user.
calculate_extinction(cluster)
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Applies extinction in a given photometric band observed in this dataset.
calculate_resolving_power(primary, secondary, separation)
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Calculates the probability that a given pair of stars would be separately resolved.
mag_to_flux(magnitude, band)
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Convert a magnitude in some band into a flux in some band.
flux_to_mag(flux, band)
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Convert a flux in some band into a magnitude in some band.
ocelot.model.observation.GaiaDR3SelectionFunction
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Bases: BaseSelectionFunction
query(cluster, observation)
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Query a selection function. Assigns a column called 'selection_probability_NAME' to the dataframe, along with the column name.
__init__(coordinate, resolution=500, g_range=(2, 22))
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Gaia DR3 selection function. Based on
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
coordinate
|
SkyCoord
|
Coordinate to query the selection function at. Must have length one! |
required |
resolution
|
int
|
Resolution of the selection function interpolator. Default: 500 |
500
|
g_range
|
tuple or list
|
Range of values in G magnitude to sample, from min to max. Default: (2, 22). |
(2, 22)
|
ocelot.model.observation.GenericSubsampleSelectionFunction
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Bases: BaseSelectionFunction
query(cluster, observation)
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Query a selection function. Assigns a column called 'selection_probability_NAME' to the dataframe, along with the column name.
__init__(data_all, data_cut, column, minimum_bin_width=0.2, minimum_bin_size=10, bounds_value=0.0, range=None, column_in_data=None)
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A generic subsample selection function, following the prescription from [1, 2] and using binomial statistics.
By default, it uses a variable bin width histogram - set minimum_bin_size to zero to prevent this.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
data_all
|
DataFrame
|
A dataset in the region of interest. |
required |
data_cut
|
DataFrame
|
A dataset in the region of interest that |
required |
column
|
str
|
Column to create the selection function on. |
required |
minimum_bin_width
|
float
|
Minimum width of each bin. Set higher to reduce the granularity of the selection function. Default: 0.2 |
0.2
|
minimum_bin_size
|
int
|
Minimum number of stars in each bin. Default: 10 |
10
|
bounds_value
|
float
|
Value of the selection function outside of the range of observed data. Default: 0.0 |
0.0
|
range
|
tuple | None
|
Length-2 array of the minimum and maximum values of 'column' in data_all. Default: None, meaning that the range of data values is inferred from the data itself. This may be inappropriate with small datasets. |
None
|
column_in_data
|
str | None
|
Alternative column name to use for the datasets. If not specified, 'column' is used. Default: None |
None
|
References
[1] https://ui.adsabs.harvard.edu/abs/2021AJ....162..142R/abstract [2] https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..37C/abstract
ocelot.model.observation.BaseObservation
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Bases: ABC
Class defining a model to simulate an observation by some telescope.
name
abstractmethod
property
¤
Type of observation modelled by this class.
Should return a lowercase string, like 'gaia_dr3'.
photometric_band_names
abstractmethod
property
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Names of photometric bands modelled by this system.
Should return a list of strings, like ['gaia_dr3_g', 'gaia_dr3_bp'].
has_proper_motions
abstractmethod
property
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Boolean flag indicating whether or not a given dataset includes proper motions.
has_parallaxes
abstractmethod
property
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Boolean flag indicating whether or not a given dataset includes parallaxes.
calculate_photometric_errors(cluster)
abstractmethod
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Calculate photometric errors and save them to the observation.
calculate_astrometric_errors(cluster)
abstractmethod
¤
Calculate astrometric errors and save them to the observation.
apply_photometric_errors(cluster)
¤
Apply photometric errors to the cluster and save observed photometry to the cluster.
calculate_photometric_errors should be called before this method.
By default, this is just a simple Gaussian; it may be overwritten if desired.
apply_astrometric_errors(cluster)
¤
Apply astrometric errors to the cluster and save observed astrometry to the cluster.
calculate_astrometric_errors should be called before this method.
By default, this is just a simple UNCORRELATED Gaussian; it may be overwritten if desired. In addition, this method only works on proper motions and parallaxes; if you're writing an observation class that also needs to simulate positional errors, then you should overwrite this function.
get_selection_functions(cluster)
abstractmethod
¤
Fetch all selection functions associated with this observation.
calculate_resolving_power(primary, secondary, separation)
abstractmethod
¤
Calculates the probability that a given pair of stars would be separately resolved. Overwrite me please!
calculate_extinction(cluster)
abstractmethod
¤
Calculate extinction in all photometric bands and saves them to the observation.
mag_to_flux(magnitude, band)
abstractmethod
¤
Convert a magnitude in some band into a flux in some band.
flux_to_mag(flux, band)
abstractmethod
¤
Convert a flux in some band into a magnitude in some band.