Speaker
Description
Since the Laser Interferometer Space Antenna (LISA) project was announced, interest in binary systems of supermassive black holes (SMBHBs) has grown, as it is expected that these systems will be observable with this instrument. In particular, efforts have been made to produce realistic simulations of SMBHBs surrounded by a circumbinary disk (CD), since this specific scenario could be the source of electromagnetic signals caused by dynamic interactions between the binary system and the disk. Furthermore, accretion disks have also been proposed as a means of facilitating the merger of SMBHBs in situations where gravitational radiation or dynamic friction are not strong enough.
Circumbinary accretion and the morphology of the CD have been studied using a wide range of codes and physical setups. However, most previous studies have been conducted using 2D viscous hydrodynamic simulations, which allow for the exploration of a wide range of parameters. Although numerous simulations of SMBHBs have been conducted at various scales, there is not a lot of work looking at the impact a DM halo may have on the circumbinary accretion and morphology. Dark matter (DM) profiles in the central regions at subparsec scales is still widely debated, and some researchers have proposed the DM density to be significantly enhanced at these scales. This sharp morphological feature is called a DM spike.
In this work, we will present the impact of a DM spike potential of different masses and profiles on a system of SMBHBs with a CD. We find that the DM spike can significantly alter the accretion and the formation of an eccentric cavity on the binary system, and we analyze whether the Rossby-Wave Instability can explain the impact of the DM spike on the formation of the cavity. These simulations were carried out using a modified version of RAMSES, a hydrodynamic code with adaptive mesh refinement.