Astron. Astrophys. 336, L21-L24 (1998)

2. Observations and data reduction

We took deep ROSAT observations of Mrk 266 with the HRI over the time period June 28th to July 6th, 1996, with a total integration time of 39,740 seconds. During our long-term observing run the background X-ray flux was very low: 2.9 . Further archival X-ray data will not be taken into account; these images differ in a not reproducible way for individual satellite orbits causing a spurious extent in the co-added image. Additionally, we obtained multicolour optical images as well as spectra at various opportunities. Optical B,V,R-images of Mrk 266 were taken under photometric conditions with the 2.2m telescope at Calar Alto observatory. The observations were made under seeing conditions of 1.0 - 1.2 arcsec. Our exposure times amounted to 3,600 s (Johnson B), 1,800 s (Johnson V) and 480 s (Johnson R), respectively. The pixel scale of the RCA-chip corresponds to 0.351 x 0.351 arcsec. The original images were aligned better than 0.1 pixel for the generation of B-V,B-R and V-R difference images. In Fig. 1 the V-band image and in Fig. 2 the V-R image of Mrk 266 are shown with the HRI X-ray contour levels overlaid. We present an optical spectrum obtained with the Calar Alto 3.5 m telescope. A RCA-chip (1024x640) was attached at the Boller and Chivens spectrograph. The spectrograph slit had a projected width of 2 arcsec and length of about 2 arcmin. We covered the wavelength range from 3700-7100 Å with a spectral resolution of 3.4 Å per pixel. An archival HST image taken with WFPC 2 is shown in Fig. 3. The observing time amounted to 500 sec. The image was taken with the broad band filter F606W integrating the flux from 4700 - 7200 Å. We obtained high-resolution radio observations at 6 cm and 20 cm with the VLA in the snapshot mode in the extended A configuration. The beam-width (HPBW) was 035 035 at 6 cm and 12 12 at 20 cm. Our radio maps are similar to those obtained by Hutchings et al.(1988) and Mazzarella et al.(1988).

Fig. 1. ROSAT HRI X-ray contour levels overlaid on an optical V-band image of Mrk 266. The X-ray data (exp.time: 39,740 s) have been smoothed with a Gaussian filter of 5 arcsec FWHM. The contour levels are at 5,7.5,10,13,20,30,40,45,50 . North is to the top; east is to the left.

Fig. 2. V-R colour image of Mrk 266. Overlay of X-ray contour levels as in Fig. 1.

Fig. 3. WFPC2 HST observations of Mrk 266 with overlay of radio contours (VLA 20cm). North is up; east is to the left.

© European Southern Observatory (ESO) 1998

Online publication: July 20, 1998
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