The Complex Star Formation History of the Halo of NGC 5128 (Cen A)

• DOI: 10.3847/1538-4357/ad57c0
• Publication Date: 2024-08-23T17:40:47Z
• Authors: Sima T. Aghdam; Atefeh Javadi; Seyedazim Hashemi; Mahdi Abdollahi; Jacco Th. van Loon; Habib Khosroshahi; Roya H. Golshan; Elham Saremi; Maryam Saberi
• Keywords: Star (game theory)

Abstract NGC 5128 (Cen A) is the nearest giant elliptical galaxy and one of brightest extragalactic radio sources in sky, boasting a prominent dust lane jets emanating from its nuclear supermassive black hole. In this paper, we construct star formation history (SFH) two small fields halo 5128: northeastern field (Field 1) at projected distance ∼18.8 kpc center, southern 2) ∼9.9 center. Our method based on identifying long-period variable (LPV) stars that trace their sibling stellar population hence historical due to high luminosity strong variability; identified 395 LPV Field 1 671 2. Even though are ∼28 apart opposite sides they show similar SFHs. 1, rate (SFR) increased significantly around t ∼ 800 Myr 3.8 Gyr 2, SFR considerably Myr, Gyr, 6.3 where lookback time. The increase ∼800 ago agrees with previous suggestions experienced merger SFH reconstructed supports scenario which multiple episodes activity lead episodic jet-induced formation. While there no catalog for central part 5128, applying our outer regions (for first time outside Local Group) has enabled us put constraints complex evolution cornerstone galaxy.