Spectroscopic study of the peculiar galaxy IC 883

• Published in: Astronomy letters Vol. 42; no. 4; pp. 215 - 227
• Main Authors: Yakovleva, V. A., Merkulova, O. A., Karataeva, G. M., Shalyapina, L. V., Yablokova, N. V., Burenkov, A. N.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-04-2016; Springer Nature B.V
• Subjects: Astronomy; Astrophysics; Astrophysics and Astroparticles; Dispersions; Dwarf galaxies; Fabry-Perot interferometers; Galaxies; Kinematics; Observations and Techniques; Physics; Physics and Astronomy; Spectroscopic analysis; Spectroscopy; Spirals; Stars & galaxies; Stellar populations; interacting galaxies—kinematics; galaxies; groups of galaxies; structure
• ISSN: 1063-7737; 1562-6873
• DOI: 10.1134/S1063773716040071

We analyze new optical spectroscopic observations obtained at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences with the SCORPIO focal reducer (in the modes of a Fabry–Perot interferometer (FPI) and long-slit spectroscopy) and the Multi-Pupil Fiber Spectrograph for the galaxy IC 883. We have confirmed that the main body of the galaxy rotates around its minor axis. The positions of the dynamical axes of the stellar and gaseous components have been found to differ by ~10°. The velocities in the SE tail do not correspond to the circular rotation around the galaxy’s minor axis. This structure is probably a fragment of an unwound curved spiral arm. Regions with high velocity dispersions and peculiarities in the velocity fields have been found along the minor axis. Our study of the age and metallicity of the galaxy’s stellar population has shown that the mean values of these parameters in the stellar disk, except for the central region (
r
≤ 5ʺ), are ≈1 Gyr and ≈−0.4 dex, respectively. Both young (2−5 × 10
8
yr) and old (5−10 × 109 yr) stellar populations are present in the circumnuclear region. Our analysis of the spectroscopic data for the bright feature 8ʺ south of the nucleus coincident in position with a compact X-ray source has shown that this is apparently a dwarf galaxy or a remnant of a companion galaxy. Our FPI observations in the Hα emission line and direct images have revealed a region of ionized gas that together with the already known structures along the minor axis forms a clumpy tidal structure of ionized gas pulled from the companion galaxy. The results of our study confirm the previously proposed hypothesis that the observed peculiar structures were formed by the merger of two galaxies. However, it can be said that IC 883 does not belong to the class of polar-ring galaxies.