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arXiv · 0810.3563

ESO VLT optical spectroscopy of BL Lacertae objects. III. An extension of the sample

B. Sbarufatti·S. Ciprini·J. Kotilainen·R. Decarli·A. Treves·A. Veronesi·R. Falomo
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Abstract

We present results of an ongoing program at the ESO VLT for spectroscopy of BL Lac objects lacking a firm redshift estimate and here we report on 15 objects. For 11 sources we confirm the BL Lac classification, and we determine new redshifts for 3 objects, 1 with weak emission lines (PKS 1057-79, z=0.569) and 2 with absorptions from the host galaxy (RBS 1752, z=0.449; RBS 1915, z=0.243); moreover a sub Damped Lyman Alpha (sub-DLA) system is detected in the direction of the BL Lac PKS 0823-223 (z>=0.911). For the remaining 8 BL Lacs, from the very absence of absorption lines of the host galaxy, lower limits to the redshift are deduced with z_min in the interval 0.20-0.80. The remaining three sources are reclassified as a FSRQ (PKS 1145-676, z=0.210; TXS 2346+052, z=0.419) and a misclassified galactic star (PMNJ 1323-3652).

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B. Sbarufatti, S. Ciprini, J. Kotilainen, R. Decarli, A. Treves, A. Veronesi, R. Falomo. 2008-10-20. ESO VLT optical spectroscopy of BL Lacertae objects. III. An extension of the sample. https://arxiv.org/abs/0810.3563

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