Indices#
Definitions#
pylick handles different indices definitions depending on the units value in the index table.
A (atomic Lick index)
mag (molecular Lick index)
break_nu (e.g., D4000-type),
break_lb (e.g., B4000-type),
bump (e.g., MgUV-type),
where \(F(\lambda)\) and \(F_c(\lambda)\) are the spectrum flux and the local pseudo-continuum, respectively. The latter is derived through linear interpolation: \(F_c(\lambda) = F_b \frac{\lambda_r -\lambda}{\lambda_r -\lambda_b} + F_r \frac{\lambda -\lambda_b}{\lambda_r -\lambda_b}\), where \(\lambda_{b,r}\) and \(F_{b,r}\) are the central wavelengths and mean fluxes of the lateral blue and red regions.
Measuring methods#
pylick handles different measuring methods. Basically, this is to account for the fact that the pixels of the observed spectrum may cover the full index region only partially.
int (Default): the spectrum is interpolated with a fine bin size of \(\text{Å}\);
exact: the spectrum is interpolated with scipy.interpolate.interp1d (0th order). The resulting function can be evaluated at each wavelenght, therefore the measurement is more precise at the edges of pass-bands windows;
wei: the flux of pixels is weighted by the fraction covered by the pass-bands definition.
performances (estimates for a 3 GHz processor, TBchecked)
int: 0.005 s/index/galaxy
wei: 0.010 s/index/galaxy
exact`: 0.125 s/index/galaxy
Index library#
Standard usage of pylick involves instantiating a pylick.analysis.IndexLibrary.
- class pylick.indices.IndexLibrary(index_keys=None, file_table=None)#
Loads the index library.
To show the full table of the available indices and assosiated keys use
>>> from pylick.indices import IndexLibrary >>> lib = IndexLibrary() >>> print(lib)
- Parameters:
index_keys (list, optional) – identifiers of the indices to be loaded. First column of file_table. Defaults to None (all the available indices).
file_table (str, optional) – path to the file containing the indices definitions. Must be formatted as the default one located at data/index_table.dat.
- Returns:
Itself, to allow chaining calls.
- Return type:
- add(center, blue, red, name, unit, tex_name, tex_unit)#
Note
TO BE IMPLEMENTED
Adds an index at the end of the file. Re-sorts(?) and saves(?) the library.
- find(name)#
Finds indices in the table.
- Parameters:
name (str) – the name (or part of it) of the index to search in the table.
- Returns:
list of the indices found.
- Return type:
list
- pop(key)#
Note
TO BE IMPLEMENTED
Removes an index from the library. Re-sorts(?) the library.
Available indices#
Last update 01 jun 2022
# Spectral Indices Definitions
#
#ID name units centr_b centr_r pcont_bb pcont_br pcont_rb pcont_rr latex_name latex_units ref.
000 BL1302 A 1292.000 1312.000 1270.000 1290.000 1345.000 1365.000 BL_{1302} \AA 3
001 SiIV A 1387.000 1407.000 1345.000 1365.000 1475.000 1495.000 SiIV \AA 3
002 BL1425 A 1415.000 1435.000 1345.000 1365.000 1475.000 1495.000 BL_{1425} \AA 3
003 Fe1453 A 1440.000 1466.000 1345.000 1365.000 1475.000 1495.000 Fe1453 \AA 3
004 CIV_A A 1530.000 1550.000 1500.000 1520.000 1577.000 1597.000 C_{IV}^{A} \AA 3
005 CIV A 1540.000 1560.000 1500.000 1520.000 1577.000 1597.000 CIV \AA 3
006 CIV_E A 1550.000 1570.000 1500.000 1520.000 1577.000 1597.000 C_{IV}^{E} \AA 3
007 BL1617 A 1604.000 1630.000 1577.000 1597.000 1685.000 1705.000 BL_{1617} \AA 3
008 BL1664 A 1651.000 1677.000 1577.000 1597.000 1685.000 1705.000 BL_{1664} \AA 3
009 BL1719 A 1709.000 1729.000 1685.000 1705.000 1803.000 1823.000 BL_{1719} \AA 3
010 BL1853 A 1838.000 1868.000 1803.000 1823.000 1885.000 1915.000 BL_{1853} \AA 3
011 FeII2402 A 2382.000 2422.000 2285.000 2325.000 2432.000 2458.000 FeII2402 \AA 3
012 BL2538 A 2520.000 2556.000 2432.000 2458.000 2562.000 2588.000 BL_{2538} \AA 3
013 FeII2609 A 2596.000 2622.000 2562.000 2588.000 2647.000 2673.000 FeII2609 \AA 3
014 B2640 break_lb 0.000 0.000 2600.000 2630.000 2645.000 2675.000 B(2640) dex 7
015 MgII A 2784.000 2814.000 2762.000 2782.000 2818.000 2838.000 MgII \AA 3
016 MgI A 2839.000 2865.000 2818.000 2838.000 2906.000 2936.000 MgI \AA 3
017 MgUV bump 2625.000 2725.000 2525.000 2625.000 2725.000 2825.000 Mg_{UV} dex 4
018 Mg_wide A 2670.000 2870.000 2470.000 2670.000 2930.000 3130.000 Mg_{wide} \AA 3
019 B2900 break_lb 0.000 0.000 2855.000 2885.000 2915.000 2945.000 B(2900) dex 7
020 FeI A 2965.000 3025.000 2906.000 2936.000 3031.000 3051.000 FeI \AA 3
021 BL3096 A 3086.000 3106.000 3031.000 3051.000 3115.000 3155.000 BL_{3096} \AA 3
022 CaII_K A 3925.650 3945.000 3845.000 3880.000 3950.000 3954.000 CaII~K \AA 9
023 CaII_H A 3959.400 3975.000 3950.000 3954.000 3983.000 3993.000 CaII~H \AA 9
024 D4000 break_nu 0.000 0.000 3750.000 3950.000 4050.000 4250.000 D4000 dex 5
025 Dn4000 break_nu 0.000 0.000 3850.000 3950.000 4000.000 4100.000 D_{n}4000 dex 6
026 Hdelta_A A 4083.500 4122.250 4041.600 4079.750 4128.500 4161.000 H\delta_A \AA 2
027 Hdelta_F A 4091.000 4112.250 4057.250 4088.500 4114.750 4137.250 H\delta_F \AA 2
028 CN1 mag 4142.125 4177.125 4080.125 4117.625 4244.125 4284.125 CN_1 mag 1
029 CN2 mag 4142.125 4177.125 4083.875 4096.375 4244.125 4284.125 CN_2 mag 1
030 Ca4227 A 4222.250 4234.750 4211.000 4219.750 4241.000 4251.000 Ca4227 \AA 1
031 G4300 A 4281.375 4316.375 4266.375 4282.625 4318.875 4335.125 G4300 \AA 1
032 Hgamma_A A 4319.750 4363.500 4283.500 4319.750 4367.250 4419.750 H\gamma_A \AA 2
033 Hgamma_F A 4331.250 4352.250 4283.500 4319.750 4354.750 4384.750 H\gamma_F \AA 2
034 Fe4383 A 4369.125 4420.375 4359.125 4370.375 4442.875 4455.375 Fe4383 \AA 1
035 Ca4455 A 4452.125 4474.625 4445.875 4454.625 4477.125 4492.125 Ca4455 \AA 1
036 Fe4531 A 4514.250 4559.250 4504.250 4514.250 4560.500 4579.250 Fe4531 \AA 1
037 C2_4668 A 4634.000 4720.250 4611.500 4630.250 4742.750 4756.500 C_{2}4668 \AA 1
038 Hbeta A 4847.875 4876.625 4827.875 4847.875 4876.625 4891.625 H_\beta \AA 1
039 Fe5015 A 4977.750 5054.000 4946.500 4977.750 5054.000 5065.250 Fe5015 \AA 1
040 Mg1 mag 5069.125 5134.125 4895.125 4957.625 5301.125 5366.125 Mg_1 mag 1
041 Mg2 mag 5154.125 5196.625 4895.125 4957.625 5301.125 5366.125 Mg_2 mag 1
042 Mgb A 5160.125 5192.625 5142.625 5161.375 5191.375 5206.375 Mg_b \AA 1
043 Fe5270 A 5245.650 5285.650 5233.150 5248.150 5285.650 5318.150 Fe5270 \AA 1
044 Fe5335 A 5312.125 5352.125 5304.625 5315.875 5353.375 5363.375 Fe5335 \AA 1
045 Fe5406 A 5387.500 5415.000 5376.250 5387.500 5415.000 5425.000 Fe5406 \AA 1
046 Fe5709 A 5696.625 5720.375 5672.875 5696.625 5722.875 5736.625 Fe5709 \AA 1
047 Fe5782 A 5776.625 5796.625 5765.375 5775.375 5797.875 5811.625 Fe5782 \AA 1
048 NaD A 5876.875 5909.375 5860.625 5875.625 5922.125 5948.125 NaD \AA 1
049 TiO1 mag 5936.625 5994.125 5816.625 5849.125 6038.625 6103.625 TiO_1 mag 1
050 TiO2 mag 6189.625 6272.125 6066.625 6141.625 6372.625 6415.125 TiO_2 mag 1
051 CaT_ast general 0.000 0.000 0.000 0.000 0.000 0.000 CaT^{\ast} \AA 8
052 CN0.93 A 9138.000 9465.000 9040.000 9070.000 9500.000 9530.000 CN0.93 \AA 10
053 FeH0.99 A 9880.000 9935.000 9830.000 9860.000 9955.000 9980.000 FeH0.99 \AA 10
054 CN1.10 A 10920.000 11012.000 10845.000 10860.000 11124.000 11170.000 CN1.10 \AA 10
055 NaI1.14 A 11362.000 11420.000 11305.000 11325.000 11453.000 11480.000 NaI1.14 \AA 10
056 FeI1.16 A 11593.000 11640.000 11540.000 11570.000 11705.000 11740.000 FeI1.16 \AA 10
057 MgI1.18 A 11810.000 11850.000 11705.000 11740.000 11905.000 11935.000 MgI1.18 \AA 10
058 Pab1.28 A 12790.000 12845.000 12760.000 12780.000 12855.000 12875.000 Pa$\beta$1.28 \AA 10
059 AlI1.31 A 13105.000 13160.000 13045.000 13075.000 13170.000 13195.000 AlI1.31 \AA 10
060 CN1.42 A 14070.000 14250.000 14015.000 14050.000 14315.000 14350.000 CN1.42 \AA 10
061 CN1.46 A 14500.000 14750.000 14460.000 14485.000 14800.000 14840.000 CN1.46 \AA 10
062 MgI1.50 A 15005.000 15044.000 14935.000 14985.000 15097.000 15120.000 MgI1.50 \AA 10
063 CO1.56 A 15545.000 15620.000 15445.000 15485.000 15640.000 15670.000 CO1.56 \AA 10
064 CO1.58 A 15750.000 15810.000 15705.000 15735.000 15835.000 15860.000 CO1.58 \AA 10
065 CO1.60 A 15970.000 16020.000 15920.000 15950.000 16045.000 16120.000 CO1.60 \AA 10
066 CO1.64 A 16370.000 16434.000 16330.000 16355.000 16480.000 16505.000 CO1.64 \AA 10
067 CO1.66 A 16600.000 16680.000 16565.000 16585.000 16780.000 16800.000 CO1.66 \AA 10
068 AlI1.67 A 16710.000 16770.000 16565.000 16585.000 16780.000 16800.000 AlI1.67 \AA 10
069 CO1.68 A 16815.000 16890.000 16780.000 16800.000 16905.000 16945.000 CO1.68 \AA 10
070 CaI1.95 A 19405.000 19530.000 19350.000 19385.000 19545.000 19580.000 CaI1.95 \AA 10
071 CaI1.99a A 19730.000 19800.000 19660.000 19695.000 20005.000 20090.000 CaI1.99a \AA 10
072 CaI1.99b A 19830.000 19885.000 19660.000 19695.000 20005.000 20090.000 CaI1.99b \AA 10
073 CaI1.99c A 19905.000 19980.000 19660.000 19695.000 20005.000 20090.000 CaI1.99c \AA 10
074 NaI2.21 A 22025.000 22114.000 21930.000 21975.000 22130.000 22185.000 NaI2.21 \AA 10
075 FeI2.24 A 22360.000 22480.000 22315.000 22350.000 22500.000 22545.000 FeI2.24 \AA 10
076 CaI2.26 A 22590.000 22680.000 22500.000 22545.000 22715.000 22765.000 CaI2.26 \AA 10
077 CO2.30 A 22915.000 23015.000 22850.000 22895.000 23090.000 23170.000 CO2.30 \AA 10
078 CO2.32 A 23190.000 23300.000 23090.000 23170.000 23340.000 23425.000 CO2.32 \AA 10
079 CO2.35 A 23440.000 23630.000 23340.000 23425.000 23660.000 23710.000 CO2.35 \AA 10
#
#
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