ESO VERY LARGE TELESCOPE OPTICAL SPECTROSCOPY OF BL LACERTAE OBJECTS. IV. NEW SPECTRA AND PROPERTIES OF THE FULL SAMPLE
: Landoni M, Falomo R, Treves A, Sbarufatti B, Barattini M, Decarli R, Kotilainen J
Publisher: IOP PUBLISHING LTD
: 2013
: The Astronomical Journal
: ASTRONOMICAL JOURNAL
: ASTRON J
: ARTN 114
: 4
: 145
: 4
: 12
: 0004-6256
DOI: https://doi.org/10.1088/0004-6256/145/4/114
We present the last chapter of a spectroscopy program aimed at deriving the redshift or a lower limit to the redshift of BL Lac objects using medium-resolution spectroscopy. Here we report new spectra for 33 BL Lac object candidates obtained in 2008-2009, confirming the BL Lac nature of 25 sources and obtaining new redshifts for 5 objects. These new observations are combined with our previous data in order to construct a homogeneous sample of similar to 70 BL Lac objects with high-quality spectroscopy. All these spectra can be accessed at the Web site http://www.oapd.inaf.it/zbllac/. The average spectrum, beaming properties of the full sample, discussion of intervening systems, and future perspectives are addressed.