Abstract
The Andromeda galaxy is observed to have a system of two large dwarf ellipticals and ~13 smaller satellite galaxies that are currently corotating in a thin plane, in addition to 2 counterrotating satellite galaxies. We explored the consistency of those observations with a scenario where the majority of the corotating satellite galaxies originated from a subhalo group, where NGC 205 was the host and the satellite galaxies occupied dark matter sub-subhaloes. We ran N-body simulations of a close encounter between NGC 205 and M31. In the simulations, NGC 205 was surrounded by massless particles to statistically sample the distribution of the subsubhaloes expected in a subhalo that has a mass similar to NGC 205. We made Monte Carlo samplings and found that, using a set of reference parameters, the probability of producing a thinner distribution of sub-subhaloes than the observed NGC 205 + 15 smaller satellites (thus including the two counter-rotators, but excluding M32) increased from <10-8 for the initial distribution to ~10-2 at pericentre. The probability of the simulated sub-subhaloes occupying the locations of the observed corotating satellites in the line-of-sight velocity versus projected on-sky distance plane is at most 2 × 10-3 for 11 out of 13 satellites. Increasing the mass of M31 and the extent of the initial distribution of sub-subhaloes gives a maximum probability of 4 × 10-3 for all 13 corotating satellites, but the probability of producing the thinness would drop to ~10-3.
| Original language | English |
|---|---|
| Article number | stw1822 |
| Pages (from-to) | 3221-3242 |
| Number of pages | 22 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 462 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Nov 1 2016 |
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All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
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The potential role of NGC 205 in generating Andromeda's vast thin corotating plane of satellite galaxies. / Angus, Garry W.; Coppin, Paul; Gentile, Gianfranco; Diaferio, Antonaldo.
In: Monthly Notices of the Royal Astronomical Society, Vol. 462, No. 3, stw1822, 01.11.2016, p. 3221-3242.Research output: Contribution to journal › Article
TY - JOUR
T1 - The potential role of NGC 205 in generating Andromeda's vast thin corotating plane of satellite galaxies
AU - Angus, Garry W.
AU - Coppin, Paul
AU - Gentile, Gianfranco
AU - Diaferio, Antonaldo
PY - 2016/11/1
Y1 - 2016/11/1
N2 - The Andromeda galaxy is observed to have a system of two large dwarf ellipticals and ~13 smaller satellite galaxies that are currently corotating in a thin plane, in addition to 2 counterrotating satellite galaxies. We explored the consistency of those observations with a scenario where the majority of the corotating satellite galaxies originated from a subhalo group, where NGC 205 was the host and the satellite galaxies occupied dark matter sub-subhaloes. We ran N-body simulations of a close encounter between NGC 205 and M31. In the simulations, NGC 205 was surrounded by massless particles to statistically sample the distribution of the subsubhaloes expected in a subhalo that has a mass similar to NGC 205. We made Monte Carlo samplings and found that, using a set of reference parameters, the probability of producing a thinner distribution of sub-subhaloes than the observed NGC 205 + 15 smaller satellites (thus including the two counter-rotators, but excluding M32) increased from <10-8 for the initial distribution to ~10-2 at pericentre. The probability of the simulated sub-subhaloes occupying the locations of the observed corotating satellites in the line-of-sight velocity versus projected on-sky distance plane is at most 2 × 10-3 for 11 out of 13 satellites. Increasing the mass of M31 and the extent of the initial distribution of sub-subhaloes gives a maximum probability of 4 × 10-3 for all 13 corotating satellites, but the probability of producing the thinness would drop to ~10-3.
AB - The Andromeda galaxy is observed to have a system of two large dwarf ellipticals and ~13 smaller satellite galaxies that are currently corotating in a thin plane, in addition to 2 counterrotating satellite galaxies. We explored the consistency of those observations with a scenario where the majority of the corotating satellite galaxies originated from a subhalo group, where NGC 205 was the host and the satellite galaxies occupied dark matter sub-subhaloes. We ran N-body simulations of a close encounter between NGC 205 and M31. In the simulations, NGC 205 was surrounded by massless particles to statistically sample the distribution of the subsubhaloes expected in a subhalo that has a mass similar to NGC 205. We made Monte Carlo samplings and found that, using a set of reference parameters, the probability of producing a thinner distribution of sub-subhaloes than the observed NGC 205 + 15 smaller satellites (thus including the two counter-rotators, but excluding M32) increased from <10-8 for the initial distribution to ~10-2 at pericentre. The probability of the simulated sub-subhaloes occupying the locations of the observed corotating satellites in the line-of-sight velocity versus projected on-sky distance plane is at most 2 × 10-3 for 11 out of 13 satellites. Increasing the mass of M31 and the extent of the initial distribution of sub-subhaloes gives a maximum probability of 4 × 10-3 for all 13 corotating satellites, but the probability of producing the thinness would drop to ~10-3.
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U2 - 10.1093/mnras/stw1822
DO - 10.1093/mnras/stw1822
M3 - Article
VL - 462
SP - 3221
EP - 3242
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 3
M1 - stw1822
ER -