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J/A+A/311/384       ROSAT observations of BL Lacertae objects (Lamer+ 1996)

ROSAT observations of BL Lacertae objects. Lamer G., Brunner H., Staubert R. <Astron. Astrophys. 311, 384 (1996)> =1996A&A...311..384L (SIMBAD/NED BibCode)
ADC_Keywords: BL Lac objects ; X-ray sources Mission_Name: ROSAT Keywords: galaxies: active - BL Lacertae objects: general - radio continuum: galaxies - X-rays: galaxies Description: We present soft X-ray spectra of 74 BL Lacertae objects observed with the PSPC detector on board of the ROSAT satellite. The sample contains all BL Lac objects detected during the pointed observation phase as a target or serendipitously. We have investigated the soft X-ray and broad band spectral properties and discuss the consequences for the X-ray emission processes. For the first time a clear dependence of the X-ray spectral steepness on the radio to X-ray spectral energy distribution is found: αrx and αx are correlated in the X-ray selected (XBL) subsample and anticorrelated in the radio selected (RBL) subsample. The objects with intermediate αrx values thus do have the steepest soft X-ray spectra. Simulated PSPC spectra based on a set of simple two component multifrequency spectra are in good agreement with the measurements and suggest a broad range of synchrotron cutoff energies. We have calculated synchrotron self-Compton beaming factors for a subsample of radio bright objects and find a correlation of the beaming factors δIC with αrx and αx. The most extreme RBL objects are very similar to flat spectrum radio quasars in all their broad band and X-ray properties. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2 56 73 List of PSPC observations table3 63 74 X-ray and broad band spectra
Byte-by-byte Description of file: table2
Bytes Format Units Label Explanations
1- 11 A11 --- Name Object name 13- 18 I6 --- ROR ROSAT observation request (ROR) number 19 A1 --- n_ROR [-] '-' when two ROR numbers 20- 25 I6 --- ROR2 ? Second ROR number 27- 35 A9 --- Date Completed date 39- 43 I5 s Exp Exposition time 46- 53 E8.0 --- Counts Net counts 54- 56 I3 --- e_Counts ? rms uncertainty on Counts
Byte-by-byte Description of file: table3
Bytes Format Units Label Explanations
1- 12 A12 --- Name Object name 14- 18 F5.2 10+20cm-2 NH,gal Galactic hydrogen column density 19 A1 --- n_NH,gal Note on NH,gal (1) 22- 26 F5.2 10+20cm-2 NH,fit ? Fitted hydrogen column density 29- 33 F5.2 10+20cm-2 e_NH,fit ? rms uncertainty on NH,fit 35- 40 F6.2 uJy F1keV Flux at 1 keV 42- 45 F4.2 --- alpha Spectral index between .1kev and 2.4keV 49- 52 F4.2 --- e_alpha rms uncertainty on alpha 54- 57 F4.2 --- alpharx X-ray spectral index 59- 63 F5.2 --- deltaIC ? Inverse Compton beaming factor
Note (1): a: Elvis et al. 1989, other values: Stark et al. 1992
References: Elvis M. et al., 1989, AJ, 97, 777 =1989AJ.....97..777E Stark A.A. et al., 1992, ApJS, 79, 77 =1992ApJS...79...77S
(End) Patricia Bauer [CDS] 26-Mar-1996
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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