Mr Aditya Manuwal

Galaxies in our Universe are known to be surrounded by haloes of dark matter that have a radially decreasing density profile. It has been decades since the evidence for dark matter began to pour in, but it is still not clear what it is, or how does it relate to properties of galaxies. I am working under the supervision of Dr. Aaron Ludlow, Dr. Adam Stevens and Dr. Aaron Robotham, on studies aimed at exploring how the properties of galaxies relate to their dark matter haloes.

Since the interactions between dark matter and baryons are non-linear by nature, we need to model the involved astrophysical processes self-consistently in order to explore this interplay. To this end, we use the EAGLE suite of hydrodynamical simulations, which are cosmological-scale simulations based on the ΛCDM cosmology. Refer to the following video to know more about the EAGLE simulations:

I work on three projects that address specific scientific questions.

Project I: Dynamical state of a dark matter halo refers to the measure of how far away is the dark matter halo from dynamical equilibrium or virialized state. The first project examines whether and how the dynamical state of dark matter haloes correlates with observable properties of galaxies.

Project II: Neutral atomic hydrogen, due to its large extent, is a good tracer of the underlying potential and halo dynamics. The 21-cm emission spectrum from neutral hydrogen atoms (H I) in galaxies carries combined information about the galaxy’s dynamics and gas mass distribution. Any perturbation in the H I disk is therefore expected to manifest as asymmetry in the 21-cm emission line. Despite the contrary expectation, asymmetric H I lines are the norm, and in the second project I address the origin of these asymmetries. For more info, you can go through this paper, and/or view the following seminar that describes the methodology and some earlier results:

Project III: Star formation in galaxies proceeds in dense molecular clouds, which means that the stellar activity in galaxies is primarily governed by the molecular hydrogen content in their interstellar medium. It is well established that the star formation activity of galaxies evolves with cosmic time, and so does their molecular hydrogen content. However, the studies based on observed galaxies provide conflicting results on whether the molecular hydrogen content of galaxies depends on their environment. It is also not clear whether this dependency changes for galaxies at different epochs. In the third project, I investigate this for the simulated galaxies.

You can follow my research at https://www.researchgate.net/profile/Aditya-Manuwal,

or view my LinkedIn profile at http://www.linkedin.com/in/adimanuwal .

I hope you found this interesting. Thanks for coming!