BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Formation of the Andromeda Giant Southern Stream and the ring stru
 ctures in the Andromeda Galaxy
DTSTART;VALUE=DATE-TIME:20230321T112500Z
DTEND;VALUE=DATE-TIME:20230321T114000Z
DTSTAMP;VALUE=DATE-TIME:20241114T092422Z
UID:indico-contribution-189@meetings.aip.de
DESCRIPTION:Speakers: Masao Mori (University of Tsukuba)\nRecent observati
 ons around the M31 have revealed many traces of past interactions with sat
 ellite galaxies. In particular\, the Andromeda Giant Southern Stream (AGSS
 ) in the halo and the double ring structure in the disc have been drawing 
 attention. The AGSS is a giant structure extending more than 100 kpc from 
 the center of M31 and is thought to have been formed in a collision with a
  satellite galaxy about 80 billion years ago (Fardal et al. 2007\; Mori & 
 Rich 2008). On the other hand\, Block et al. (2006) found the double ring 
 structure in M31 made up of gas and dust and argued that the structure was
  formed by a head-on collision of a satellite galaxy\, M32\, around 20 bil
 lion years ago. They conclude that the mass of M32 at the time of the coll
 ision was about one-tenth of the total mass of M31 $\\sim 10^{11} M_\\odot
 $. Moreover\, a model has been proposed by Hammer et al. (2018) in which t
 he AGSS and the double ring structure are formed simultaneously by a major
  merger with the mass of more than $10^{11} M_\\odot$ for the first passag
 e at the large pericentric distance.\nThese situations motivate us to inve
 stigate the possible link between the AGSS and the 10kpc ring structures u
 sing $N$-body/SPH simulations of a miner merger between the M31 and a sate
 llite galaxy with a mass of $10^{10} M_\\odot$. The simulation result succ
 essfully matches the observed features of the AGSS and the 10 kpc rings co
 ncurrently. The stars are smoothly distributed in the galactic disk\, but 
 there are some rings of gas and dust that reproduce the observations.  In 
 addition\, we demonstrate the spatial metallicity distribution of the merg
 er remnants\, assuming the progenitor galaxy's metallicity gradient. The r
 esult remarkably captures the observed features in the AGSS exhibiting non
 -uniform metallicity distribution perpendicular to the AGSS axis (Preston 
 et al. 2021). These results indicate that a minor merger of the massive dw
 arf galaxy is also capable of simultaneously forming the AGSS and the 10 k
 pc ring.\n\nhttps://iaus379.aip.de/event/20/contributions/189/
LOCATION:Haus H\, Telegrafenberg
URL:https://iaus379.aip.de/event/20/contributions/189/
END:VEVENT
END:VCALENDAR