2005A&A...441....9A

Query : 2005A&A...441....9A

2005A&A...441....9A - Astronomy and Astrophysics, volume 441, 9 (2005/10-1)

Spectral energy distribution of the metagalactic ionizing radiation field from QSO absorption spectra.

AGAFONOVA I.I., CENTURION M., LEVSHAKOV S.A. and MOLARO P.

Abstract (from CDS):

A computational procedure is presented to estimate the spectral shape of the ionizing background between 1 and 10Ryd by analyzing optically thin absorption systems in the spectra of high redshift quasars. The procedure is based on the response surface methodology from the theory of experimental design. The shape of the recovered UV background at z∼3 shows a significant intensity decrease between 3 and 4Ryd compared to the metagalactic spectrum of Haardt & Madau (1996ApJ...461...20H). This decrease is interpreted as produced by HeII Gunn-Peterson effect. There are no features indicating a contribution from galaxies to the UV background which is therefore dominated by QSOs at z∼3.

Abstract Copyright: ∼

Journal keyword(s): cosmology: observations - line: formation - line: profiles - Galaxy: abundances - galaxies: quasars: absorption lines

Nomenclature: paragr.3.3: [ACL2005] QSO J0942-1104 abs N.NNNN N=1.

Simbad objects: 4

Full paper

View the references in ADS

Number of rows : 4

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag U	Mag B	Mag V	Mag R	Mag I	Sp type	#ref 1850 - 2023
1	QSO B0347-383	QSO	03 49 43.6603590912	-38 10 30.825444900			17.3			~	189
2	QSO B0940-1050	QSO	09 42 53.5078384704	-11 04 25.931336376		16.96	16.6	16.6		~	96
3	QSO J2233-606	QSO	22 33 37.5812706336	-60 33 29.149992936	16.90	17.39	17.16	16.93	16.51	~	89
4	QSO B2347-4342	QSO	23 50 34.2593744544	-43 25 59.683985652		16.3	16.3			~	169

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