2 The data

 

The data were obtained during two runs with the ESO 2.2 m telescope with IRAC2B in 1996. The detector was a NICMOS-3 array with pixels of size $40\,\mu$m, a Read Out Noise of 46 e^- and a Gain of 6.6 e^-/ADU. We used lenses B (0.278''/pix) and C (0.507''/pix), that give field sizes of $71''\times 71''$ and $129'' \times 129''$ respectively. The observing strategy for each object was the following: we first obtained a J image with lense C and if it showed any hint of an extension we changed to lense B and obtained the K' image. Details on the observations are given in Table 1. For every target, we obtained a number of images (less than 1 minute exposure each) shifting the quasar position by about 15''-20'' until the total exposure time was attained. For the flux calibration we measured the following standard stars: HD 29250, HD 56189, HD 84503, HD 105116 (first run), HD 84090, HD 1148951, DM 597287, HD 177619 and SJ 9149 (second run). The data reduction and calibration was performed, following the standard procedures with the IRAF software and SQIID package. We used dome flat-fields by subtracting the images taken with the lamps off from those taken with the lamps on. We compute the median of object images to obtain the corresponding sky frame. Sky-subtracted images were used to obtain the final mosaics. We reach a photometric accuracy of about 10%. In Col. 9 of Table 1 we give the isophotal magnitude/arcsec² corresponding to 2$\sigma$ of the background for the regions close to the quasar (where the S/N is the highest). Total magnitudes given in Table 2 were measured in circular apertures.

Deconvolution from the point spread function was performed using the Lucy algorithm in the stsdas.analysis.restore package. We estimated the shape of the PSF by using starlike objects in the field. Average isophotal profiles were determined using the IRAF task ellipse in the stsdas.analysis.isophote package. We have computed the host galaxy contribution by subtracting the PSF profile (for the images with suitable stars to compute the PSF) from that of the quasar, forcing that the resulting profile has no central hole (Aretxaga et al. 1995; Rönnback et al. 1996); the magnitudes of the host galaxies are given in Table 3. Since the deconvolution procedure does not conserve calibrated fluxes, we have deconvolved sky-subtracted non-calibrated images. This explains why the deconvolved images are given with fluxes in arbitrary units (Figs. 2, 12, 14 and 15).

Table 2 lists for every object detected in our images: (1) our order number (mentioned in the text with a # symbol); (2) and (3) abridged $\alpha$ and $\delta$ coordinates; (4) and (5) $\alpha$ and $\delta$ positions relative to the quasar (the quasar coordinates were taken from the Simbad database, in order to have more accurate values than those written in the image headers); (6) and (7) our J and K' magnitude measurements (note that the spatial coverage is smaller for the higher resolution scale of the K' images); (8) R magnitudes from published optical photometry; (9) references; (10) numbering in the corresponding reference; (11) type of the object (1 = galaxy, 2 = probable galaxy, 3 = star) given by the reference or, when no reference was given, type assigned by us. When available, we also give the redshift in Col. 11 in parentheses, with the corresponding reference; (12) Yes for radio-loud, No for radio-quiet objects.

  

Table 2: Magnitudes and positions for quasars and nearby detected objets

 

Table 2: continued

 

Table 2: continued

 

Table 2: continued

 

Table 2: continued

 

Table 2: continued

  

Table 3: Magnitudes of the host galaxies

To calculate absolute magnitudes we have used $H_0= 50\,{\rm km\,s}^{-1}$ Mpc^-1 and q₀=0.

A few of the objects closest to the quasar are indicated in the various plots (Figs. 1 to 16) with their corresponding numbers as given in Table 2, Col. 1. Whenever they are mentioned in the text we use the #number; when we mention the numbering given by other authors we just use the number.

We compare the infra-red images with optical HST images (Figs. 17 to 23) from the public archive when available to verifiy in particular that the extensions that we detect are not a consequence of the presence of close companions.

  

Figure 1: Image of A 0401-350A in the J band. As in all following figures, the quasar is at the (0,0) position; North is to the top and East to the left. Numbers on the figures refer to the object numbers in Table 2. Contour levels are 2.2 10-10, 1.8 10-9, 5.7 10-9 and 2.9 10-8 erg s-1 arcsec-2

  

Figure 2: Image of PKS 0812+020 in the J band after deconvolution for seeing effects. Contour levels are 0.075, 0.1, 0.2, 1 and 10 (in arbitrary units)

  

Figure 3: Image of PKS 0837-120 in the J band. Contour levels are 1.0 10-9, 2.2 10-9, 4.1 10-9, 8.0 10-9, 2.0 10-8 and 1.2 10-7 erg s-1 arcsec-2

  

Figure 4: Image of 3C 215 in the J band. Contour levels are 2.4 10-9, 3.4 10-9, 5.3 10-9, 2.1 10-8 and 7.9 10-8 erg s-1 arcsec-2

  

Figure 5: Image of IRAS 09149-6206 in the J band. Contour levels are 1.7 10-8, 1.9 10-8, 2.3 10-8, 3.5 10-8, 5.4 10-8 and 2.1 10-7 erg s-1 arcsec-2

  

Figure 6: Image of PKS 1011-282 in the J band. Contour levels are 9.6 10-10, 1.7 10-9, 3.7 10-9, 1.9 10-8 and 1.9 10-7 erg s-1 arcsec-2

  

Figure 7: Image of 3C 275.1 in the J band. Contour levels are 1.0 10-9, 1.7 10-9, 8.0 10-9 and 2.0 10-8 erg s-1 arcsec-2

  

Figure 8: Image of PKS 1302-102 in the J band. Contour levels are 3.0 10-10, 8.9 10-10, 2.8 10-9, 6.7 10-9, 3.8 10-8 and 1.9 10-7 erg s-1 arcsec-2

  

Figure 9: Image of 3C 281 in the J band. Contour levels are 9.9 10-10, 1.4 10-9, 2.2 10-9, 3.7 10-9, 2.9 10-9 and 2.2 10-8 erg s-1 arcsec-2

  

Figure 10: Image of 4C 20.33 in the J band. Contour levels are 6.6 10-10, 1.2 10-9, 3.2 10-9, 1.9 10-8 and 1.9 10-7 erg s-1 arcsec-2

  

Figure 11: Image of 4C 11.50 in the J band. Contour levels are 8.9 10-10, 2.1 10-9 and 9.8 10-9 erg s-1 arcsec-2

  

Figure 12: Image of 4C 11.50 in the K' band corrected for seeing effects. Contour levels are 1, 1.5, 2, 5, 10 and 20 (in arbitrary units)

  

Figure 13: Image of MRK 877 in the J band. Contour levels are 2.8 10-9, 3.6 10-9, 5.1 10-9, 1.0 10-8, 3.0 10-8 and 2.0 10-7 erg s-1 arcsec-2

  

Figure 14: Image of 3C 334 in the J band after deconvolution for seeing effects. Contour levels are 0.8, 1.0, 1.2, 2.0, 10 and 100 (in arbitrary units)

  

Figure 15: Image of MC 1745+163 in the J band. Contour levels are 3, 5, 7.5, 50 and 200 (in arbitrary units)

  

Figure 16: Image of 4C 11.72 in the J band. Contour levels are 7.4 10-10, 1.3 10-9, 2.5 10-9, 4.4 10-9, 1.1 10-8, 4.2 10-8 and 2.0 10-7 erg s-1 arcsec-2