English

Nearby groups of galaxies in the Hercules-Bootes constellations

Astrophysics of Galaxies 2017-06-21 v1 Cosmology and Nongalactic Astrophysics

Abstract

We consider a sample of 412 galaxies with radial velocities VLG<2500V_{\rm LG} < 2500 km s1^{-1} situated in the sky region of RA=13h.0{\rm RA}=13^h\hspace{-0.4em}.\,0 ... 19h.019^h\hspace{-0.4em}.\,0, Dec=+10{\rm Dec}=+10^{\circ} ... +40+40^{\circ} between the Local Void and the Supergalactic plane. One hundred and eighty-one of them have individual distance estimates. Peculiar velocities of the galaxies as a function of Supergalactic latitude SGB show signs of Virgocentric infall at SGB<10SGB < 10^{\circ} and motion from the Local Void at SGB>60SGB > 60^{\circ}. A half of the Hercules-Bootes galaxies belong to 17 groups and 29 pairs, with the richest group around NGC5353. A typical group is characterized by the velocity dispersion of 6767 km s1^{-1}, the harmonic radius of 182182 kpc, the stellar mass of 4.3×1010M4.3 \times10^{10} M_{\odot} and the virial-to-stellar mass ratio of 3232. The binary galaxies have the mean radial velocity difference of 3737 km s1^{-1}, the projected separation of 9696 kpc, the mean integral stellar mass of 2.6×109M2.6\times 10^9 M_{\odot} and the mean virial-to-stellar mass ratio of about 88. The total dark-matter-to-stellar mass ratio in the considered sky region amounts to 3737 being almost the same as that in the Local Volume.

Keywords

Cite

@article{arxiv.1705.01284,
  title  = {Nearby groups of galaxies in the Hercules-Bootes constellations},
  author = {Igor D. Karachentsev and Olga G. Kashibadze and Valentina E. Karachentseva},
  journal= {arXiv preprint arXiv:1705.01284},
  year   = {2017}
}

Comments

11 pages, 5 figures, 4 tables. Accepted to Astrophysical Bulletin