The formation and evolution of Andromeda IX

Hedieh Abdollahi; Atefeh Javadi; Mohammad Taghi Mirtorabi; Elham Saremi; Habib Khosroshahi; Jacco Th. van Loon; Iain McDonald; Elahe Khalouei; Sima T. Aghdam; Maryam Saberi

arXiv · 2302.07599

The formation and evolution of Andromeda IX

Hedieh Abdollahi·Atefeh Javadi·Mohammad Taghi Mirtorabi·Elham Saremi·Habib Khosroshahi·Jacco Th. van Loon·Iain McDonald·Elahe Khalouei·Sima T. Aghdam·Maryam Saberi

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Abstract

Local Group (LG), the nearest and most complete galactic environment, provides valuable information on the formation and evolution of the Universe. Studying galaxies of different sizes, morphologies, and ages can provide this information. For this purpose, we chose the And\,IX dSph galaxy, which is one of the observational targets of the Isaac Newton Telescope (INT) survey. A total of 50 long-period variables (LPVs) were found in And\,IX in two filters, Sloan $i'$ and Harris $V$ at a half-light radius of 2.5 arcmin. The And\,IX's star formation history (SFH) was constructed with a maximum star formation rate (SFR) of about $0.00082\pm0.00031$ M$_\odot$ yr$^{-1}$, using LPVs as a tracer. The total mass return rate of LPVs was calculated based on the spectral energy distribution (SED) of about $2.4\times10^{-4}$ M$_\odot$ yr$^{-1}$. The distance modulus of $24.56_{-0.15}^{+0.05}$ mag was estimated based on the tip of the red giant branch (TRGB).

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Hedieh Abdollahi, Atefeh Javadi, Mohammad Taghi Mirtorabi, Elham Saremi, Habib Khosroshahi, Jacco Th. van Loon, Iain McDonald, Elahe Khalouei, Sima T. Aghdam, Maryam Saberi. 2023-02-15. The formation and evolution of Andromeda IX. https://arxiv.org/abs/2302.07599

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