The Tully–Fisher Relations of the Eridanus Group of Galaxies

Journal of astrophysics and astronomy

K. S. Dwarakanath2¹  A. Omar1² 

[1] Raman Research Institute, Sadashivanagar, Bangalore 560 080, India.$$;Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263 129, India.$$

关键词: Galaxy: rotation;    luminosity;    linewidth relation;    galaxies: groups;    individual: Eridanus;    radio lines: HI 21 cm-line.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The Tully–Fisher (TF) or the luminosity–linewidth relations of the galaxies in the Eridanus group are constructed using the HI rotation curves and the luminosities in the optical and in the near-infrared bands. The slopes of the TF relations (absolute magnitude 𝑣𝑠 log 2𝑉flat) are -8.6 ± 1.1, -10.0 ± 1.5, -10.7 ± 2.1, and -9.7 ± 1.3 in the R, J, H, and K bands respectively for galaxies having flat HI rotation curves. These values of the slopes are consistent with those obtained from studies of other groups and clusters. The scatter in the TF relations is in the range 0.5–1.1 mag in different bands. This scatter is considerably larger compared to those observed in other groups and clusters. It is suggested that the larger scatter in the TF relations for the Eridanus group is related to the loose structure of the group. If the TF relations are constructed using the baryonic mass (stellar + H${miny I}$ + Helium mass) instead of the stellar luminosity, nearly identical slopes are obtained in the R and in the near-infrared bands. The baryonic TF (baryonic mass 𝑣𝑠 log 2𝑉flat) slope is in the range 3.5–4.1.

【 授权许可】

Unknown