HII Regions Library

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Introduction

Star formation in galaxies is traced by the presence of emission lines, produced by the ionized gas surrounding young star clusters. In particular, hydrogen (H) recombination lines intensity is a direct measure of the number of massive stars still alive. Thus, emission lines are important tracers of the current star formation rate (SFR).
These regions are often embedded into dusty environments, and the effects of dust may be significant. Therefore, It is fundamental to model the nebular emission within a context that takes into account star-light reprocessing by dust.
For this reason I implemented the modelling of nebular emission by HII regions into GRASIL that was originally developed to simulate the spectral energy distribution (SED) of dusty galaxies. The implementation is based on a pre-computed library of HII region emission models.

HII Regions Library

The library of HII region emission models provides the emission line luminosities for a given ionizing stellar population. It can be used in other spectrophotometric codes. You can freely download the library and use it in your code. Please acknowledge if you use this library for a publication.

You can find a description of the model in this paper, (2003, A&A, 409, 99). A more detailed description of the HII region model will be aviable in the near future.

The library provides the emission line luminosities as a function of:

It is composed by plain ASCII files, one for each value of hydrogen density and filling factor. In the following table you can find the library's files.

densityfilling factorname densityfilling factorname
10 1.0 hii_d10f10.dat.gz 30 1.0 hii_d30f10.dat.gz
10 0.1 hii_d10f01.dat.gz 30 0.1 hii_d30f01.dat.gz
10 0.01 hii_d10f001.dat.gz 30 0.01 hii_d30f001.dat.gz
100 1.0 hii_d100f10.dat.gz 300 1.0 hii_d300f10.dat.gz
100 0.1 hii_d100f01.dat.gz 300 0.1 hii_d300f01.dat.gz
100 0.01 hii_d100f001.dat.gz 300 0.01 hii_d300f001.dat.gz
1000 1.0 hii_d1000f10.dat.gz 3000 0.1 hii_d3000f01.dat.gz
1000 0.1 hii_d1000f01.dat.gz 3000 0.01 hii_d3000f001.dat.gz
1000 0.01 hii_d1000f001.dat.gz 3000 0.001hii_d3000f0001.dat.gz
100000.1 hii_d10000f01.dat.gz
100000.01 hii_d10000f001.dat.gz
100000.001hii_d10000f0001.dat.gz
Last update of the library: Apr. 18th 2003

Parameter space

The HII region models are computed for different values of metallicity, namely:
Zgas=0.0008, 0.004, 0.008, 0.015, 0.02, 0.03, 0.04, 0.05, where 0.02 means solar metallicity.

The space of Q parameters is divided into two grids, identified by a grid index. In the first grid, with index number equal 1, QHe/QH is > 0.05; in the second (grid index = 2) QHe/QH is < 0.05.

In grid number 1, QHe/QH=0.05+0.05625*i with i=0,...,8; QO/QHe=0.13+0.1*j with j=0,...,5.

In grid 2, QHe/QH=0.05, 0.025, 0.01, 0.005, 0.0025, 0.0001, 0.; while QO/QHe=0.+0.1*j with j=0,...,4.

In both the grids, QH=1046+0.2*k with k=0,...,30.

Format

The first line is an header; each following line correspond to an HII region model.
This is an example of the first two lines of a library file (namely hii_d10f01.dat):

#density=  10.00 filling=  0.100 1)name  2)numgrid  3)zeta  4)lum  5)shi  6)sx  7)shei  8)so  9-135)intfluxline
bZ01H01E01O01 1 .0008 38.622  -2.0000  -2.4590  -3.3010  -4.1871 664505961859289591245900558898587045865964200631....

Description byte by byte

BytesFormat Description
1 - 13A13 Name of the model: bytes 1-13 are a string that identify the name of the input file for CLOUDY.
15 I1 Grid index
17 - 21 F5.4 Metallicity
23 - 28 F6.3Log of the luminosity of analytical spectrum in erg/s
30 - 37 F8.4Log(QH/1050 photons/second)
39 - 46 F8.4Log(QX/1050): QX is the number of photons per second with a wavelength shorter than 750 Å
48 - 55 F8.4Log(QHe/1050)
57 - 64 F8.4Log(QO/1050)
66 - 636 114I5Line luminosity
Bytes from 66 to 636 correspond to the flux of 114 emission lines, an integer of 5 digits for each emission line. The line luminosity can be obtained as Luminosity=exp(intLine/1000.-50.) where intLine is the integer read from the library. I wrote a FORTRAN90 module that provide a subroutine to read these libraries.

Computed lines

In the following table there is the list of the computed lines. The order is the same that you can find in the library files.
1: Ly alpha 1216 2: Ly beta 1025 3: Ly gamma 972 4: Ly delta 949 5: Ly 937 6: Ly 930 7: Ly 926 8: Ly 922
9: H alpha 6563 10: H beta 4861 11: H gamma 4340 12: H delta 4102 13: H 3970 14: H 3889 15: H 3835 16: H 3798
17: Pa alpha 18752 18: Pa beta 12819 19: Pa gamma 10939 20: Pa delta 10050 21: Pa 9546 22: Pa 9229 23: Pa 9015 24: Pa 8863
25: Br alpha 40515 26: Br beta 26254 27: Br gamma 21657 28: Br delta 19447 29: Br 18175 30: Br 17363 31: Br 16808 32: Br 16408
33: Pf alpha 74585 34: Pf beta 46529 35: Pf gamma 37398 36: Pf delta 32964 37: Pf 30386 38: Pf 28724 39: Pf 27577 40: Pf 26746
41: Hu alpha 12.4µm 42: Hu beta 75011 43: Hu gamma 59071 44: Hu delta 51277 45: Hu 46716 46: Hu 43756 47: Hu 41700 48: Hu 40201
49: HeI 4472 50: HeI 5877 51: HeI 6680 52: HeI 10833 53: HeI 3889 54: HeI 7065 55: [CI]9850 56: [CI]8727
57: [CI]4621 58: [CI]610µm 59: [CI]369µm 60: [CII]157.7µm 61: CII]2326 62: [NI]5200 63: [NI]3467 64: [NI]10405
65: [NII]6585 66: [NII]6549 67: [NII]5756 68: [NII]122µm 69: [NII]205µm 70: NII]2141 71: [NIII]57µm 72: [OI]6302
73: [OI]6365 74: [OI]5578 75: [OI]63µm 76: [OI]145µm 77: [OII]3727 78: [OII]7327 79: [OII]2471 80: OIII]1663
81: [OIII]5007 82: [OIII]4960 83: [OIII]4364 84: [OIII]2321 85: [OIII]88µm 86: [OIII]52µm 87: [NeII]12.8µm 88: [NeIII]15.5µm
89: [NeIII]36µm 90: [NeIII]3870 91: [NeIII]3968 92: [NeIII]3343 93: [NeIII]1815 94: MgII 2800 95: [SiII]35µm 96: [SII]10331
97: [SII]6732 98: [SII]6717 99: [SII]4070 100: [SII]4078 101: [SIII]18.7µm 102: [SIII]33.5µm 103: [SIII]9533 104: [SIII]9071
105: [SIII]6314 106: [SIII]3723 107: [SIV]10.5µm 108: [ArII]7µm 109: [ArIII]7138 110: [ArIII]7753 111: [ArIII]5193 112: [ArIII]3110
113: [ArIII]22µm 114: [ArIII]9µm

Problems?!?

Send me an email at pasquale dot panuzzo at cea dot fr!

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