A stellar library of synthetic spectra of H Balmer and HeI absorption lines

Rosa M. González Delgado & Claus Leitherer 1999, ApJS, 125, 479.

A grid is presented of synthetic profiles of stellar H Balmer and HeI lines at optical wavelengths with a sampling of 0.3 Å. The grid spans a range of effective temperature (Teff) between 50000 K and 4000 K, and gravity  (log g) between 0.0 and 5.0 at solar metallicity. For  Teff>25000 K, NLTE stellar atmosphere models are computed using the code TLUSTY (Hubeny 1988). For cooler stars, Kurucz (1993) LTE models are used to compute the synthetic spectra. The grid includes the profiles of the high-order hydrogen Balmer series and HeI lines for effective temperatures and gravities that have not been previously synthesized. The behavior of H8 to H13 and HeI 3819 with effective temperature and gravity is very similar to that of the lower terms of the series (e.g. Hb) and the other HeI lines at longer wavelengths; therefore, they are suited for the determination of the atmospheric parameters of stars. These lines are potentially important to make predictions for these stellar absorption features in galaxies with active star formation. Evolutionary synthesis models of these lines for starburst and post-starburst galaxies have also been computed. The full set of the synthetic stellar spectra is available for retrieval here below and at our Spanish website http://www.iaa.es/ae/page.html.

The main spectral lines synthesized are:
spectral range  main lines
3720-3920 H13, H12, H11, H10, HeI 3819, H9, H8
3990-4150 HeI 4009, HeI 4026, Hd, HeI 4121, HeI 4144
4300-4400 Hg, HeI 4388
4420-4550 HeI 4471
4820-4900 Hb
4900-4950 HeI 4922
The full set of the stellar library spectra is available in a gziped tar file library.tar.gz. that contains the six files (L1.dat, L2.dat, L3.dat, L4.dat, L5.dat, L6.dat) corresponding to each of the above six wavelength ranges synthesized. Each file contains 13 columns with the following values:

Column 1:    Effective Temperature (from 4000 K to 50000 K).
Column 2:    Wavelength (in Angstroms).
Cols. 3-13:   normalized spectrum for the 11 values of
                     log(g) = 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5 and 0.0.

The equivalent widths of the lines have been measured in the following spectral windows:
line ew  window continuum
H8 3874-3904 1
Hd 4070-4130, 4086-4116 2
Hg 4311-4371, 4830-4890 3
Hb 4830-4890, 4846-4876 4
HeI 3819 3816-3823 1
HeI 4009 4006-4012 2
HeI 4026 4020-4031 2
HeI 4121 4118-4124 2
HeI 4143 4139-4148 2
HeI 4388 4381-4395 3
HeI 4471 4464-4478 5
HeI 4922 4915-4929 6
The measurements are carried out from a pseudo-continuum determined by fitting a first order polynomial (except for the spectral range 3700-3900 A, for which a third order polynomial was used) to the following continuum windows:
1 3726-3729, 3740-3743, 3760-3762, 3782-3785, 3811-3812, 3869-3870, 3909-3911
2 4019-4020, 4037-4038, 4060-4061, 4138-4140, 4148-4150
3 4301-4305, 4310-4312, 4316-4318, 4377-4381, 4392-4394, 4397-4398
4 4820-4830, 4890-4900
5 4439-4440, 4445-4446, 4478-4479, 4503-4506
6 4900-4902, 4905-4906, 4915-4916, 4928-4929, 4948-4950
The full set of equivalent widths measurements is available in a gziped tar file Ew-stars.tar.gz. that contains the following eight files with the values for the Balmer lines (Hb, Hd and H8) and HeI lines (3819, 4026, 4388, 4471 and 4922):

Ew-Hb.tab, Ew-Hd.tab, Ew-H8.tab,
Ew-He3819.tab, Ew-He4026.tab, Ew-He4388.tab, Ew-He4471.tab, Ew-He4922.tab,

The format of each of these files is:

Column 1:   Effective Temperature
Cols. 2-9:    Equivalent width of stars with gravity
                    log(g) = 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5.

y