Physical Galaxy Pairs and Their Effects on Star Formation
  We present 776 truly physical galaxy pairs, 569 of them are close pairs and
208 false pairs from Karachentsev (1972) and Reduzzi & Rampazzo (1995)
catalogues, which contains 1012 galaxy pairs. Also we carried out star
formation activity through the far-infrared emission (FIR) in physical (truly)
interacting galaxies in some galaxy pairs and compared them with projection
(optical) interacting galaxy pairs. We focused on the triggering of star
formation by interactions and analyzed the enhancement of star formation
activity in terms of truly physical galaxy pairs. The large fraction of star
formation activity is probably due to the activity in the exchange of matter
between the truly companions. The star formation rate (SFR) of galaxies in
truly galaxy pairs is found to be more enhanced than the apparent pairs.
