A1 Refereed original research article in a scientific journal
Spectral energy distributions of a large sample of BL Lacertae objects
Authors: Nieppola E, Tornikoski M, Valtaoja E
Publisher: EDP SCIENCES S A
Publication year: 2006
Journal name in source: ASTRONOMY & ASTROPHYSICS
Journal acronym: ASTRON ASTROPHYS
Volume: 445
Issue: 2
First page : 441
Last page: U72
Number of pages: 37
ISSN: 0004-6361
DOI: https://doi.org/10.1051/0004-6361:20053316
Abstract
The range of v(peak) in our study was considerably extended compared to previous studies. There were 22 objects for which log v(peak) > 19. The data shows that at 5 GHz, 37 GHz, and 5500 angstrom, there is negative correlation between luminosity and v(peak), whereas in X-rays the correlation turns slightly positive. There is no significant correlation between source luminosity at synchrotron peak and v(peak). Several low radio luminosity-low energy peaked BL Lacs were found. The negative correlation between broad band spectral indices and v(peak) is also significant, although there is substantial scatter. Therefore we find that neither alpha(rx) nor alpha(ro) can be used to determine the synchrotron peak of BL Lacs. On the grounds of our results, we conclude that the blazar sequence scenario is not valid. In all our results, the BL Lac population is continuous with no hint of the bimodality of the first BL Lac samples.
The range of v(peak) in our study was considerably extended compared to previous studies. There were 22 objects for which log v(peak) > 19. The data shows that at 5 GHz, 37 GHz, and 5500 angstrom, there is negative correlation between luminosity and v(peak), whereas in X-rays the correlation turns slightly positive. There is no significant correlation between source luminosity at synchrotron peak and v(peak). Several low radio luminosity-low energy peaked BL Lacs were found. The negative correlation between broad band spectral indices and v(peak) is also significant, although there is substantial scatter. Therefore we find that neither alpha(rx) nor alpha(ro) can be used to determine the synchrotron peak of BL Lacs. On the grounds of our results, we conclude that the blazar sequence scenario is not valid. In all our results, the BL Lac population is continuous with no hint of the bimodality of the first BL Lac samples.
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