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| Paper: |
Observable Effects of Tidal Interactions: Markarian Activity in Karachentsev Disk Galaxies |
| Volume: |
230, Galaxy Disks and Disk Galaxies |
| Page: |
437 |
| Authors: |
Byrd, G.; Valtonen, M.; Freeman, T. |
| Abstract: |
The Byrd et al. (1986, 1987) simulation survey determined the tidal perturbation to induce nuclear activity in disk galaxies. We compare simulations and theory to observed Markarian et al. (1978, 1989) activity in Karachentsev's (1981, 1983, 1987) galaxy pairs where both are spirals (SS). About 10% of Markarian (Mrk) galaxies are Seyfert with most of the rest being starburst galaxies with nuclei containing large numbers of OB stars associated with ionized gas (Osterbrock 1989). Karachentsev measured the visual disk diameter, D, for the larger, L, and smaller, S, members along with their radial velocity difference, v, and present-day projected separation on the sky, b. Our simulations and theory predict tidal traits: (1) There should be an excess of SS pairs where both are Mrk over pairs with one active. (2) Mrk activity will be preferentially absent in pairs whose D's are unequal and preferentially present where the D's are equal. (3) <DL+DS> in Mrk pairs should be smaller if the members are equal in size than if they are unequal. (4) Pairs where one or both members are Mrk should have a smaller b.v than where both are normal. All these traits are seen in Karachentsev's SS pairs. The simulations show a several hundred million year delay in the appearance of nuclear activity after perturbation and a similar duration which can explain the weak observational correlation of companion number and activity. A Monte Carlo match to the SS sample assuming Keplerian orbits reaches the same general conclusions as above. |
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