Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:0704.1729)
· On-line Data
· References in the article
· Citations to the Article (7) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (82)
· NED Objects (76)
· Associated Articles
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
The sedentary survey of extreme high-energy peaked BL Lacs. III. Results from optical spectroscopy
Authors:
Piranomonte, S.; Perri, M.; Giommi, P.; Landt, H.; Padovani, P.
Affiliation:
AA(INAF, Osservatorio Astronomico di Roma, via Frascati 33, 00040, Monte Porzio Catone (RM), Italy ), AB(ASI Science Data Center, c/o ESA-ESRIN, via Galileo Galilei, 00044 Frascati, Italy), AC(ASI Science Data Center, c/o ESA-ESRIN, via Galileo Galilei, 00044 Frascati, Italy), AD(Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-29 Cambridge, MA 02138, USA), AE(European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany)
Publication:
Astronomy and Astrophysics, Volume 470, Issue 2, August I 2007, pp.787-809 (A&A Homepage)
Publication Date:
08/2007
Origin:
EDP Sciences
Keywords:
galaxies: active, galaxies:, BL Lacertae objects: general, surveys
DOI:
10.1051/0004-6361:20077086
Bibliographic Code:
2007A&A...470..787P

Abstract

Aims:The multi-frequency sedentary survey is a flux-limited, statistically well-defined sample of highly X-ray dominated (i.e., with a very high X-ray to radio flux ratio) BL Lacertae objects, which includes 150 sources. In this paper, the third of the series, we report the results of a dedicated optical spectroscopy campaign that, together with results from other independent optical follow-up programs, led to the spectroscopic identification of all sources in the sample.
Methods: We carried out a systematic spectroscopic campaign for the observation of all unidentified objects of the sample using the ESO 3.6 m, the KPNO 4 m, and the TNG optical telescopes.
Results: We present new identifications and optical spectra for 76 sources, 50 of which are new BL Lac objects, 18 are sources previously referred as BL Lacs but for which no redshift information was available, and 8 are broad emission-line AGNs. We find that the multi-frequency selection technique used to build the survey is highly efficient (~90%) in selecting BL Lacs objects. We present positional and spectroscopic information for all confirmed BL Lac objects. Our data allowed us to determine 36 redshifts out of the 50 new BL Lacs and 5 new redshifts for the previously known objects. The redshift distribution of the complete sample is presented and compared with that of other BL Lacs samples. For 26 sources without recognizable absorption features, we calculated lower limits to the redshift using a method based on simulated optical spectra with different ratios between jet and galaxy emission. For a subsample of 38 object with high-quality spectra, we find a correlation between the optical spectral slope, the 1.4 GHz radio luminosity, and the Ca H&K break value, indicating that for powerful/beamed sources the optical light is dominated by the non-thermal emission from the jet.

Associated Articles

Part  2     Part 1     Part  3     Catalog Description    

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints