Filters

Contents

Filters#

Most of the filters available to speXtra are downloaded from the SVO database <http://svo2.cab.inta-csic.es/theory/fps/>. However, many other system are not included in that database so a few (at the moment) are included in the database.

To list the filter systems included in the database

    from spextra import spextra_database
    spextra_database["filter_systems"]
{'elt/micado': 'MICADO filters',
 'elt/metis': 'METIS filters',
 'etc': 'ESO ETC standard filters'}

The ::class::Pasband holds the information of an astronomical filter and can be called simply using:

from spextra import Passband
filt = Passband("elt/micado/Y")
filt.plot()
Downloading file 'filter_systems/elt/micado/index.yml' from 'https://scopesim.univie.ac.at/spextra/database/filter_systems/elt/micado/index.yml' to '/home/docs/.spextra_cache'.
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Downloading file 'filter_systems/elt/micado/Y.dat' from 'https://scopesim.univie.ac.at/spextra/database/filter_systems/elt/micado/Y.dat' to '/home/docs/.spextra_cache'.
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_images/35e015b5a5c44b5c85c92fb7cd3fa62d3c0b7dd63ea48b88c5360499395e555f.png

Many standard filters have been defined using shortcuts for quicker access. Here is a list.

from spextra import DEFAULT_DATA
DEFAULT_DATA.filters
{'U': 'etc/U',
 'B': 'etc/B',
 'V': 'etc/V',
 'R': 'etc/R',
 'I': 'etc/I',
 'Z': 'etc/Z',
 'Y': 'etc/Y',
 'J': 'etc/J',
 'H': 'etc/H',
 'K': 'etc/K',
 'Ks': '2MASS/2MASS.Ks',
 'L': 'etc/L',
 'M': 'etc/M',
 'N': 'etc/N',
 'Q': 'etc/Q',
 'u': 'SLOAN/SDSS.u',
 'g': 'SLOAN/SDSS.g',
 'r': 'SLOAN/SDSS.r',
 'i': 'SLOAN/SDSS.i',
 'z': 'SLOAN/SDSS.z',
 'HAlpha': 'Gemini/GMOS-N.Ha',
 'PaBeta': 'Gemini/NIRI.PaBeta-G0221',
 'BrGamma': 'Gemini/NIRI.BrG-G0218',
 'FUV': 'GALEX/GALEX.FUV',
 'NUV': 'GALEX/GALEX.NUV',
 'F435W': 'HST/ACS_WFC.F435W',
 'F475W': 'HST/ACS_WFC.F475W',
 'F606W': 'HST/ACS_WFC.F606W',
 'F775W': 'HST/ACS_WFC.F775W',
 'F814W': 'HST/ACS_WFC.F814W',
 'F850LP': 'HST/ACS_WFC.F850LP',
 'F105W': 'HST/WFC3_IR.F105W',
 'F110W': 'HST/WFC3_IR.F110W',
 'F125W': 'HST/WFC3_IR.F125W',
 'F140W': 'HST/WFC3_IR.F140W',
 'F160W': 'HST/WFC3_IR.F160W',
 'ch1': 'Spitzer/IRAC.I1',
 'ch2': 'Spitzer/IRAC.I2',
 'ch3': 'Spitzer/IRAC.I3',
 'ch4': 'Spitzer/IRAC.I4',
 'W1': 'WISE/WISE.W1',
 'W2': 'WISE/WISE.W2',
 'W3': 'WISE/WISE.W3',
 'W4': 'WISE/WISE.W4',
 'G': 'GAIA/GAIAO.G'}

These filters can be used simply using the shortcut

from spextra import Passband

filt = Passband("g")  # for sdss g-band filter
filt.plot()
Downloading data from 'http://svo2.cab.inta-csic.es/theory/fps3/fps.php?ID=SLOAN/SDSS.g' to file '/home/docs/.spextra_cache/svo_filters/SLOAN/SDSS.g'.
SHA256 hash of downloaded file: ea4dc3871f0c5dcd9ef276fcebe5e9bca6abd80cdb18abf055bba207a92fc119
Use this value as the 'known_hash' argument of 'pooch.retrieve' to ensure that the file hasn't changed if it is downloaded again in the future.
_images/88c7f73b3c9e0a633c2baa07e80122d9e91cc3677097148e0cc583c515bf4bfd.png

All methods in ::class::Spextrum that require to provide a filter name, can be used in either way, using the full name or just a shortcut.

For a full list of the filters available to spextra please visit the SVO

Additionally below you can find the filter systems for prospective ELT instruments and others not available at the SVO

MICADO#

# MICADO Design - pre PDR list of filters

filter_system : micado

instrument : micado

title : MICADO Design - pre PDR list of filterswa

author : Ric Davies

source : Ric Davies

spectral_coverage :
  - nir

data_type : ascii

file_extension : .dat

wave_unit : um

wave_column_name : wavelength

trans_column_name : transmission

filters: # filtername
  Br-gamma :            Br-gamma
  FeII :                FeII
  H2_1-0S1 :            H2_1-0S1
  H-cont :              H-cont
  H :                   H
  He-I :                He-I
  H-long :              H-long
  H-short :             H-short
  I-long :              I-long
  J :                   J
  J-long :              J-long
  J-short :             J-short
  K-cont :              K-cont
  K-long :              K-long
  K-mid :               K-mid
  Ks2 :                 Ks2
  Ks :                  Ks
  K-short :             K-short
  Pa-beta :             Pa-beta
  Spec_HK :             Spec_HK
  Spec_IJ :             Spec_IJ
  xH1 :                 xH1
  xH2 :                 xH2
  xI1 :                 xI1
  xI2 :                 xI2
  xJ1 :                 xJ1
  xJ2 :                 xJ2
  xK1 :                 xK1
  xK2 :                 xK2
  xY1 :                 xY1
  xY2 :                 xY2
  Y :                   Y

METIS#

# METIS Design - pre PDR list of filters

filter_system : metis

instrument : metis

title : METIS, pre PDR list of filterswa

author : NN

source : NN

spectral_coverage :
  - mir

data_type : ascii

file_extension : .dat

wave_unit : um

wave_column_name : wavelength

trans_column_name : transmission

filters : # filtername
  Br_alpha :          Br_alpha     
  Br_alpha_ref :      Br_alpha_ref    
  CO_1-0_ice :        CO_1-0_ice     
  CO_ref :            CO_ref            
  H2O-ice :           H2O-ice     
  HCI_L_long :        HCI_L_long     
  HCI_L_short :       HCI_L_short     
  HCI_M :             HCI_M            
  IB_4.05 :           IB_4.05     
  L :                 L         
  Lp :                Lp         
  Mp :                Mp         
  N1 :                N1         
  N2 :                N2         
  N3 :                N3         
  ND_OD1 :            ND_OD1            
  ND_OD2 :            ND_OD2            
  ND_OD3 :            ND_OD3            
  ND_OD4 :            ND_OD4            
  ND_OD5 :            ND_OD5            
  Ne_II :             Ne_II            
  Ne_II_ref :         Ne_II_ref     
  open :              open            
  PAH_11.25 :         PAH_11.25     
  PAH_11.25_ref :     PAH_11.25_ref   
  PAH_3.3 :           PAH_3.3     
  PAH_3.3_ref :       PAH_3.3_ref     
  PAH_8.6 :           PAH_8.6     
  PAH_8.6_ref :       PAH_8.6_ref     
  Q1 :                Q1         
  short-L :           short-L     
  S_IV :              S_IV            
  S_IV_ref :          S_IV_ref

ETC#

Also the standard filters used by the ESO Exposure Time Calculator

# ESO ETC standard filters

filter_system : etc

instrument : etc

title : Exposure Time Calculator filter set

author : ESO

source : https://www.eso.org/observing/etc/doc/skycalc/helpskycalc.html#mags

spectral_coverage :
  - vis
  - nir
  - mir

data_type : ascii

file_extension : .dat

wave_unit : um

wave_column_name : wavelength

trans_column_name : transmission

filters: # filtername
  U :   U-band
  B :   B-band
  V :   V-band
  R :   R-band
  I :   I-band
  Z :   Z-band
  Y :   Y-band
  J :   J-band
  H :   H-band
  K :   K-band
  L :   L-band
  M :   M-band
  N :   N-band
  Q :   Q-band