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The proximity Effect on the Lyman alpha Forest due to a Foreground QSO

A. Fernandez-Soto·X. Barcons·R. Carballo·J. K. Webb
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Abstract

We present the results of our study on three close pairs of QSOs. Our results are consistent with the existence of a proximity effect due to the foreground QSO, but due to its weakness we can only reject the absence of such effect at approx. 1 sigma level. By modelling this proximity effect in terms of a simple photoionisation model, we find the best value for the UV ionizing background to be approx. 10**(-20.5) erg cm**(-2) s**(-1) Hz**(-1) srad**(-1) at the Lyman limit, and an absolute lower limit (95\% confidence) of 10**(-21.8) in the same units. This lower limit rejects a number of models for the UV background where it is mostly contributed by QSOs and absorption by Lyman limit systems is taken into account.

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A. Fernandez-Soto, X. Barcons, R. Carballo, J. K. Webb. 1995-04-06. The proximity Effect on the Lyman alpha Forest due to a Foreground QSO. https://arxiv.org/abs/astro-ph/9504017

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