English

Central star formation in an early-type galaxy I~Zw~81 in the Bootes void

Astrophysics of Galaxies 2022-12-28 v1

Abstract

The origin of star-formation in customarily passively evolving early-type massive galaxies is poorly understood. We present a case study of a massive galaxy, I~Zw~81, inside the Bootes void. The void galaxy is known to host an active galactic nuclei (AGN). Our detailed 2D decomposition of the surface brightness distribution in the CanadaCanada FranceFrance HawaiiHawaii TelescopeTelescope (CFHTCFHT) g- and r-bands revealed multiple structural components such as a nuclear point source, a bar, a ring, and an inner exponential disk followed by an outer low surface brightness (LSB) disk. I~Zw~81 turns out to be a disk-dominated galaxy with lenticular morphology. The modelling of the multi-wavelength spectral energy distribution (SED) shows that the galaxy is star-forming (SF), and belongs to the blue cloud. We find that the optical (g-r) color of the bar is bluer than the disks, and the far- and near-ultraviolet emission inside the galaxy observed with Ultraviolet Imaging Telescope (UVIT) onboard {\em AstroSat} is concentrated in the central few kpc region enclosing the bar. The strong bar might be playing a pivotal role in driving the gas inflow and causing SF activity in tandem with the minor merger-like interactions as evident from the deep CFHTCFHT data. The low-luminosity AGN is insufficient to quench the central SF. The results are peculiar from the standpoint of a massive barred lenticular galaxy.

Keywords

Cite

@article{arxiv.2211.04043,
  title  = {Central star formation in an early-type galaxy I~Zw~81 in the Bootes void},
  author = {Divya Pandey and Kanak Saha and Ananta C. Pradhan and Sugata Kaviraj},
  journal= {arXiv preprint arXiv:2211.04043},
  year   = {2022}
}

Comments

Accepted for publication in ApJ