The mean transmission of the neutral inter galactic medium in the LYα-line from a sample of high-resolution quasar spectra

1Torbaniuk, O, 2Ivashchenko, G
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2017, 33(4):57-67
Start Page: Extragalactic Astronomy
Language: Russian

We present our measurements of the mean transmission F(z) of the neutral intergalactic medium in the line Lα. For this purpose we used the sample of 33 high-resolution (R = 5300...45000) spectra selected from the public available archive of the European Southern Observatory with the help of the Virtual Observatory tools. For continuum determination in each spectra the points with maximum flux in Lα-forest region were selected and fitted by spline. The obtained values of the mean transmission F(z) was fitted by power-law τeff =α(1+z)β, where α =4.4+0.4-0.2*10-3 , β=3.278+0.083-0.054 for averaging of the F(z) over the redshift bins Δz= 0.1 and α =10.6+1.1-1.0 *10-3,β = 2.685+0.081-0.071 for averaging over each quasar. The results were compared with those ones from previous studies of high- and low-resolution quasar spectra.

Keywords: neutral intergalactic medium, quasar, spectra

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