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Appendix A: Comments on individual objects

The field around galaxies CGCG 97-114, CGCG 97-120 and CGCG 97-125 deserves special attention. Each one of them shows H $\alpha$ emission. However CGCG 97-120 is not listed in Table 4 because its radial velocity, 5595 km s^-1, (de Vaucouleurs 1991) is out of the transmitance window of the on-band filter. Instead, CGCG 97-114 and CGCG 97-125 have very similar velocities lying in our filter range: 8293 km s^-1 (de Vaucouleurs 1991) and 8271 km s^-1 (Haynes et al. 1997) respectively. If these galaxies form a sub-group within Abell 1367 ( $<\,V\,>\, = 6500$ km s^-1), this entity must have a very high velocity dispersion. The group coincides in position with the X-ray cluster center (Donnelly et al. 1998). CGCG 97-120 is a very H I deficient galaxy (def(H I) = 0.9, Chincarini et al. 1983), indicating that it has passed through the cluster center, while CGCG 97-125 is not (def(H I) = -0.21, Haynes et al. 1997). No H I measurement is available for CGCG 97-114,because it lies close (in space and in velocity) to CGCG 97-125.

In between CGCG 97-120 and CGCG 97-125 we found two emission-line dwarf galaxies 114454+194733 and 114451+194713 (labeled as F.O. but not included in our list because its S/N ratio is lower than 5) (see Fig. .2) which were already revealed by Sakai et al. (2001). For both galaxies a spectroscopic follow-up gave velocities about 8100 km s^-1, consistent with those of CGCG 97-114 and CGCG 97-125, indicating that they are probably associated with these galaxies.

In addition, our net frame shows the presence of some H $\alpha$ emission bridging CGCG 97-114 and CGCG 97-125. Two bright H $\alpha$ knots are detected near CGCG 97-125 followed by a filamentary structure near the bright star between the two galaxies. This structure probably indicates a tidal interaction between the two galaxies, consistently with the shells of 1 $^\prime$ diameter seen in the off-band image around CGCG 97-125. In fact N-body simulations (Quinn 1984; Seguin 1996) confirm Schweizer (1980) suggestion that shells around early type galaxies result from galaxy collisions. It is not yet possible to decide whether 114454+194733 and F.O. are tidal dwarfs of CGCG 97-125 or patches of star-forming gas stripped from it.

$\begin{figure} \par\includegraphics[width=17cm,clip]{MS2087fA1a.eps} \end{figure}$

Figure A.1: Net H $\alpha$ images of the selected galaxies. Blue contours correspond to the continuum image.

$\begin{figure} \par\includegraphics[width=17cm,clip]{MS2087fA1b.eps} \end{figure}$

Figure A.1: continued.

$\begin{figure} \par\includegraphics[width=17cm,clip]{MS2087fA1c.eps} \end{figure}$

Figure A.1: continued.

$\begin{figure} \par\includegraphics[width=17cm]{MS2087fA1d.eps} \end{figure}$

Figure A.1: continued.

$\begin{figure} \par\includegraphics[width=17cm]{MS2087fA1e.eps} \end{figure}$

Figure A.1: continued.

$\begin{figure}\par\includegraphics[width=8cm,clip]{MS2087fA2a.eps} \includegraph... ...p]{MS2087fA2b.eps} \includegraphics[width=8cm,clip]{MS2087fA2c.eps} \end{figure}$

Figure A.2: Detailed net H $\alpha$ , on-band and off-band images of F.O. 18.

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