Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: ESO VLT optical spectroscopy of BL Lacertae objects. III. An extension
  of the sample   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).

27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th