ASSESSING THE MILKY WAY SATELLITES ASSOCIATED WITH THE SAGITTARIUS DWARF SPHEROIDAL GALAXY

By D. Law, S. Majewski. 2010

183 citations recorded by the source corpus.

Numerical models of the tidal disruption of the Sagittarius (Sgr) dwarf galaxy have recently been developed that for the first time simultaneously satisfy most observational constraints on the angular position, distance, and radial velocity trends of both leading and trailing tidal streams emanating from the dwarf. We use these dynamical models in combination with extant three-dimensional position and velocity data for Galactic globular clusters and dSph galaxies to identify those Milky Way satellites that are likely to have originally formed in the gravitational potential well of the Sgr dwarf, and have been stripped from Sgr during its extended interaction with the Milky Way. We conclude that the globular clusters Arp 2, M 54, NGC 5634, Terzan 8, and Whiting 1 are almost certainly associated with the Sgr dwarf, and that Berkeley 29, NGC 5053, Pal 12, and Terzan 7 are likely to be as well (albeit at lower confidence). The initial Sgr system therefore may have contained five to nine globular clusters, corresponding to a specific frequency SN = 5–9 for an initial Sgr luminosity MV = −15.0. Our result is consistent with the 8 ± 2 genuine Sgr globular clusters expected on the basis of statistical modeling of the Galactic globular cluster distribution and the corresponding false-association rate due to chance alignments with the Sgr streams. The globular clusters identified as most likely to be associated with Sgr are consistent with previous reconstructions of the Sgr age–metallicity relation, and show no evidence for a second-parameter effect shaping their horizontal branch morphologies. We find no statistically significant evidence to suggest that any of the recently discovered population of ultrafaint dwarf galaxies are associated with the Sgr tidal streams, but are unable to rule out this possibility conclusively for all systems.

Subfields: Astronomy and Astrophysics, Education, Instrumentation

View Paper: https://www.semanticscholar.org/paper/5a22d80e97d1e2c28690823f5c0e3fc5d7f6ee10

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Citations in the corpus

Chemical tagging with APOGEE: Discovery of a large population of N-rich stars in the inner Galaxy (2016, background): “…is abundant evidence for the formation of the Galactic halo itself, and that of the nearest giant spiral galaxy, Andromeda, through accretion of satellite galaxies (e.g., Searle & Zinn 1978; Ibata et al. 1994; Belokurov et al. 2006b; Law & Majewski 2010; Ibata et al. 2014; Gilbert et al. 2014).”
Proper motions and dynamics of the Milky Way globular cluster system fromGaiaDR2 (2018, background): “…distinct populations, for instance, the 6 clusters associated with the Sagittarius stream (confirming some of the candidate members suggested in Law & Majewski 2010), or the group of outer halo clusters with little net rotation and high radial action, identified in Myeong et al. (2018).”
SAGITTARIUS II, DRACO II AND LAEVENS 3: THREE NEW MILKY WAY SATELLITES DISCOVERED IN THE PAN-STARRS 1 3π SURVEY (2015, unknown): “The fact that it lies 40–45 kpc behind Sgr dSph rules out a direct connection between the two satellites but a comparison with the Law & Majewski (2010b) N-body model for the Sgr stream (Figure 5) reveals that Sgr II is located at the expected distance of model particles from the trailing arm of…”
The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way (2012, background): “As the radial velocity of NGC 5053 in the Galactic standard of rest is only 34 km/s (Law & Majewski 2010), it is reasonable to assume that the orbit is not aligned closely with the line of sight and that the tail therefore is seen more from its side than along its extend. c© 2012 RAS, MNRAS 000,…”
Gaia EDR3 view on galactic globular clusters (2021, methodology): “This connection was explored in a number of papers, e.g., Law & Majewski (2010b), Bellazzini et al. (2020), Arakelyan et al. (2020); however, these studies all relied on the old model of the Sgr stream from Law & Majewski (2010a), which was conceived before the more recent observations of its…”
A MegaCam Survey of Outer Halo Satellites. III. Photometric and Structural Parameters (2018, background): “It has been suggested in the past that Boötes II may be associated with the Sagittarius dwarf galaxy (Koch et al. 2009a).”
Mass and shape of the Milky Way’s dark matter halo with globular clusters from Gaia and Hubble (2018, methodology): “…run our algorithm i) with the full sample of GCs but also ii) excluding the four clusters Arp 2, Palomar 12, Terzan 7 and Terzan 8 that have been associated to the Sagittarius dwarf according to the dynamical analysis of Law & Majewski (2010) and have been recently confirmed by Sohn et al. (2018).”
A Gaia DR2 view of the open cluster population in the Milky Way (2018, background): “In order to reconstruct the overall shape of our Galaxy, it is necessary to estimate distances to astronomical objects that we use as tracers, and to study their distribution.”
The formation and assembly history of the Milky Way revealed by its globular cluster population (2018, background): “This projected metallicity is ∆[Fe/H] ∼ 0.3 dex lower than the metallicity of the young (τ = 3–8 Gyr), low-mass (M < 105 M ) GC population of Sagittarius (Law & Majewski 2010), confirming the known result that Sagittarius has a current metallicity higher than expected for its relatively low mass…”
The bifurcated age–metallicity relation of Milky Way globular clusters and its implications for the accretion history of the galaxy (2013, methodology): “…has only one old GC, while the LMC and SMC, and particularly Sagittarius are known to have extended cluster AMRs of 3 Gyrs or more (Glatt et al. 2008; Law & Majewski 2010; 10 The notable exception is Ruprecht 106 at [Fe/H]= −1.78 and 10.75 Gyr in this plot, however as discussed in §2 the…”