Deciphering Galactic Halos: A Detailed Review of Star Formation in NGC 5128 (Cen A)

Abdollahi, M.; Aghdam, S. T.; Javadi, A.; Hashemi, S. A.; van Loon, J. Th.; Khosroshahi, H.; Hamedani Golshan, R.; Saremi, E.; Saberi, M.

Abstract

NGC 5128 (Centaurus A), the closest giant elliptical galaxy outside the Local Group to the Milky Way, is one of the brightest extragalactic radio sources. It is distinguished by a prominent dust lane and powerful jets, driven by a supermassive black hole at its core. Using previously identified long-period variable (LPV) stars from the literature, this study aims to reconstruct the star formation history (SFH) of two distinct regions in the halo of NGC 5128. These regions reveal remarkably similar SFHs, despite being located about 28 kpc apart on opposite sides of the galaxy’s center. In Field 1, star formation rates (SFRs) show notable increases at approximately 800 Myr and 3.8 Gyr ago. Field 2 exhibits similar peaks at these times, along with an additional rise around 6.3 Gyr ago. The increase in SFR around 800 Myr ago is consistent with earlier research suggesting a merger event. Since no LPV catalog exists for the central region of NGC 5128, we focused our investigation on its outer regions, which has provided new insights into the complex evolutionary history of this cornerstone galaxy. The SFH traced by LPVs supports a scenario in which multiple events of nuclear activity have triggered episodic, jet-induced star formation.

Citation

Abdollahi, M., Aghdam, S. T., Javadi, A., Hashemi, S. A., van Loon, J. T., Khosroshahi, H., …Saberi, M. (in press). Deciphering Galactic Halos: A Detailed Review of Star Formation in NGC 5128 (Cen A). Communications of the Byurakan Astrophysical Observatory, 71(2), 345-350. https://doi.org/10.52526/25792776-24.71.2-345

• Journal Article Type: Article
• Acceptance Date: Dec 27, 2024
• Online Publication Date: Dec 27, 2024
• Deposit Date: Jan 13, 2025
• Publicly Available Date: Jan 13, 2025
• Journal: Communications of the Byurakan Astrophysical Observatory
• Electronic ISSN: 2579-2276
• Peer Reviewed: Peer Reviewed
• Volume: 71
• Issue: 2
• Pages: 345-350
• DOI: https://doi.org/10.52526/25792776-24.71.2-345
• Public URL: https://keele-repository.worktribe.com/output/1047033