A1 Refereed original research article in a scientific journal
Optical spectroscopy of BL Lac objects: New redshifts and mis-identified sources
Authors: Carangelo N, Falomo R, Kotilainen J, Treves A, Ulrich MH
Publisher: E D P SCIENCES
Publication year: 2003
Journal name in sourceASTRONOMY & ASTROPHYSICS
Journal acronym: ASTRON ASTROPHYS
Volume: 412
Issue: 3
First page : 651
Last page: 655
Number of pages: 5
ISSN: 0004-6361
DOI: https://doi.org/10.1051/0004-6361:20031519
Abstract
We are carrying out a multi- purpose program of high signal to noise optical spectroscopy at medium resolution of 30 BL Lac objects. Here we report the detection of three new redshifts, and the discovery of three misclassified sources. The new redshifts refer to PKS 0754+ 100 ( z = 0.266), H- 1914- 194 ( z = 0.137) and 1ES0715- 259, for which we derive a redshift of z = 0.465 and also a " new" classification a Steep Spectrum Radio Quasar. In two cases ( UM493 and 1620+ 103) stellar spectra indicate a wrong classification. The three sources with new redshift measurement show strong [ OIII] emission in their spectra and their host galaxy properties are known. The central black hole masses derived using the M-BH - L-bulge and the M-BH- sigma([OIII]) relations are compared.
We are carrying out a multi- purpose program of high signal to noise optical spectroscopy at medium resolution of 30 BL Lac objects. Here we report the detection of three new redshifts, and the discovery of three misclassified sources. The new redshifts refer to PKS 0754+ 100 ( z = 0.266), H- 1914- 194 ( z = 0.137) and 1ES0715- 259, for which we derive a redshift of z = 0.465 and also a " new" classification a Steep Spectrum Radio Quasar. In two cases ( UM493 and 1620+ 103) stellar spectra indicate a wrong classification. The three sources with new redshift measurement show strong [ OIII] emission in their spectra and their host galaxy properties are known. The central black hole masses derived using the M-BH - L-bulge and the M-BH- sigma([OIII]) relations are compared.
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