TY - JOUR
T1 - Revisiting the relation between the number of globular clusters and galaxy mass for low-mass galaxies
AU - Zaritsky, Dennis
N1 - Publisher Copyright:
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2022/6/1
Y1 - 2022/6/1
N2 - Using a new method to estimate total galaxy mass (MT) and two samples of low-luminosity galaxies containing measurements of the number of globular clusters (GCs) per galaxy (NGC), we revisit the NGC-MT relation using a total of 203 galaxies, 157 of which have MT ≤ 1010 M⊙. We find that the relation is nearly linear, NGC α MT0.92 ± 0.08 down to at least MT ∼108.75 M⊙. Because the relationship extends to galaxies that average less than one GC per galaxy and to a mass range in which mergers are relatively rare, the relationship cannot be solely an emergent property of hierarchical galaxy formation. The character of the radial GC distribution in low-mass galaxies, and the lack of mergers at these galaxy masses, also appears to challenge models in which the GCs form in central, dissipatively concentrated high-density, high-pressure regions and are then scattered to large radius. The slight difference between the fitted power-law exponent and a value of one leaves room for a shallow MT-dependent variation in the mean mass per GC that would allow the relation between total mass in GCs and MT to be linear.
AB - Using a new method to estimate total galaxy mass (MT) and two samples of low-luminosity galaxies containing measurements of the number of globular clusters (GCs) per galaxy (NGC), we revisit the NGC-MT relation using a total of 203 galaxies, 157 of which have MT ≤ 1010 M⊙. We find that the relation is nearly linear, NGC α MT0.92 ± 0.08 down to at least MT ∼108.75 M⊙. Because the relationship extends to galaxies that average less than one GC per galaxy and to a mass range in which mergers are relatively rare, the relationship cannot be solely an emergent property of hierarchical galaxy formation. The character of the radial GC distribution in low-mass galaxies, and the lack of mergers at these galaxy masses, also appears to challenge models in which the GCs form in central, dissipatively concentrated high-density, high-pressure regions and are then scattered to large radius. The slight difference between the fitted power-law exponent and a value of one leaves room for a shallow MT-dependent variation in the mean mass per GC that would allow the relation between total mass in GCs and MT to be linear.
KW - galaxies: formation
KW - galaxies: star clusters: general
KW - globular clusters: general
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U2 - 10.1093/mnras/stac1072
DO - 10.1093/mnras/stac1072
M3 - Article
AN - SCOPUS:85133008875
VL - 513
SP - 2609
EP - 2614
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 2
ER -