A Catalog of Globular Cluster Systems: What Determines the Size of a Galaxy's Globular Cluster Population?

Harris, William E.; Harris, G. L. H.; Alessi, Matthew

doi:10.1088/0004-637x/772/2/82

Cited by 286 publications

(490 citation statements)

References 98 publications

Supporting

Mentioning

439

Contrasting

Unclassified

Order By: Relevance

“…To do this, we need to estimate the total number of GCs associated with M 33 and LMC-like systems. Harris et al (2013) studied GC populations in a large sample of galaxies and analysed the correlation of the total number of GCs, N GC , with global galaxy properties and type. They find that N GC increases roughly in direct proportion to host galaxy luminosity, with a scatter of a factor of ∼2.5.…”

Section: Icl In Virgo: Nature and Number Of Its Progenitor Galaxiesmentioning

confidence: 99%

The outer regions of the giant Virgo galaxy M 87 Kinematic separation of stellar halo and intracluster light

Longobardi

Arnaboldi

Gerhard

et al. 2015

A&A

137

View full text Add to dashboard Cite

Aims. We present a spectroscopic study of a sample of 287 planetary nebulas (PNs) around the brightest cluster galaxy (BCG) M 87 in Virgo A, of which 211 are located between 40 kpc and 150 kpc from the galaxy centre. With these data we can distinguish the stellar halo from the co-spatial intracluster light (ICL) and study both components separately. Methods. We obtained PN velocities with a high resolution FLAMES/VLT survey targeting eight fields in a total area of ∼0.4 deg 2 . We identified PNs from their narrow and symmetric redshifted λ5007 Å [OIII] emission line, the presence of the second λ4959 Å [OIII] emission line, and the absence of significant continuum. We implement a robust technique to measure the halo velocity dispersion from the projected phase-space to identify PNs associated with the M 87 halo and ICL. Using photometric magnitudes, we construct PN luminosity functions (PNLFs), which are complete down to m 5007 = 28.8. Results. The velocity distribution of the spectroscopically confirmed PNs is bimodal, containing a narrow component centred on the systemic velocity of the BCG and an off-centred broader component, which we identify as halo and ICL, respectively. We find that 243 PNs are part of the velocity distribution of the M 87 halo, while the remaining subsample of 44 PNs are intracluster PNs (ICPNs). Halo and ICPNs have different spatial distributions: the number density of halo PNs follow the galaxy's surface brightness profile, whereas the ICPNs are characterised by a shallower power-law profile, I ICL ∝ R γ with γ in the range [−0.34, −0.04]. No evidence is found for an asymmetry in the halo and ICPN density distributions when the NW and SE fields are studied separately. A study of the composite PN number density profile confirms the superposition of different PN populations associated with the M 87 halo and the ICL, characterised by different PN specific numbers α. We derive α halo = 1.06 × 10 −8 N PN L −1 ,bol and α ICL = 2.72 × 10 −8 N PN L −1 ,bol , respectively. The M 87 halo PNLF has fewer bright PNs and a steeper slope towards faint magnitudes than the ICPNLF, and both are steeper than the standard PNLF for the M 31 bulge. Moreover, the ICPNLF has a dip at ∼1−1.5 mag fainter than the bright cut-off, reminiscent of the PNLFs of systems with extended star formation history, such as M 33 or the Magellanic clouds. Conclusions. The BCG halo of M 87 and the Virgo ICL are dynamically distinct components with different density profiles and velocity distributions. Moreover, the different α-parameter values and PNLF shapes of the halo and ICL indicate distinct parent stellar populations, consistent with the existence of a gradient towards bluer colours at large radii. These results reflect the hierarchical build-up of the Virgo cluster.

show abstract

Section: Icl In Virgo: Nature and Number Of Its Progenitor Galaxiesmentioning

confidence: 99%

The outer regions of the giant Virgo galaxy M 87 Kinematic separation of stellar halo and intracluster light

Longobardi

Arnaboldi

Gerhard

et al. 2015

A&A

137

View full text Add to dashboard Cite

show abstract

“…In the last decade, Hubble Space Telescope (HST) and ground-based wide-field imaging of hundreds of GC systems has provided us with very detailed information on bimodality (e.g. Dirsch et al 2003;Bassino et al 2006;Peng et al 2006;Harris et al 2006Harris et al , 2013Forbes et al 2011;Kartha et al 2014).…”

Section: Colour Magnitude Relation Of Extragalactic Globular Clustersmentioning

confidence: 99%

The colour–magnitude relation of globular clusters in Centaurus and Hydra

Fensch

Mieske

Müller-Seidlitz

et al. 2014

A&A

View full text Add to dashboard Cite

Aims. We investigate the colour-magnitude relation of metal-poor globular clusters, the so-called blue tilt, in the Hydra and Centaurus galaxy clusters and constrain the primordial conditions for star cluster self-enrichment. Methods. We analyse U, I photometry for about 2500 globular clusters in the central regions of Hydra and Centaurus, based on VLT/FORS1 data. We measure the relation between mean colour and luminosity for the blue and red subpopulation of the globular cluster samples. We convert these relations into mass-metallicity space and compare the obtained GC mass-metallicity relation with predictions from the star cluster self-enrichment model by Bailin & Harris (2009, ApJ, 695, 1082. For this we include effects of dynamical and stellar evolution and a physically well motivated primordial mass-radius scaling. Results. We obtain a mass-metallicity scaling of Z ∝ M 0.27 ± 0.05 for Centaurus GCs and Z ∝ M 0.40 ± 0.06 for Hydra GCs, consistent with the range of observed relations in other environments. We find that the GC mass-metallicity relation already sets in at present-day masses of a few 10 5 M and is well established in the luminosity range of massive MW clusters like ω Centauri. The inclusion of a primordial mass-radius scaling of star clusters significantly improves the fit of the self-enrichment model to the data. The selfenrichment model accurately reproduces the observed relations for average primordial half-light radii r h ∼ 1−1.5 pc, star formation efficiencies f ∼ 0.3−0.4, and pre-enrichment levels of [Fe/H] − 1.7 dex. The slightly steeper blue tilt for Hydra can be explained either by a ∼30% smaller average r h at fixed f ∼ 0.3, or analogously by a ∼20% smaller f at fixed r h ∼ 1.5 pc. Within the selfenrichment scenario, the observed blue tilt implies a correlation between GC mass and width of the stellar metallicity distribution. We find that this implied correlation matches the trend of width with GC mass measured in Galactic GCs, including extreme cases like ω Centauri and M 54. Conclusions. First, we found that a primordial star cluster mass-radius relation provides a significant improvement to the selfenrichment model fits. Second we show that broadened metallicity distributions as found in some massive MW globular clusters may have arisen naturally from self-enrichment processes, without the need of a dwarf galaxy progenitor.

show abstract

“…Observationally, they are useful tracers of old stellar populations because they can be observed at large distances. The number of GCs in a galaxy also correlates linearly with the total host halo mass (Blakeslee et al 1997;Peng et al 2008;Spitler & Forbes 2009;Harris et al 2013), giving a way to estimate the total mass of a galaxy without other information. A recent study by Beasley et al (2016) used kinematics of GCs in the Virgo cluster UDG VCC 1287 to show that the galaxy has an extremely high mass-to-light ratio, consistent with the premise that the number of GCs trace total mass, even in these extreme galaxies.…”

Section: Introductionmentioning

confidence: 99%

A Rich Globular Cluster System in Dragonfly 17: Are Ultra-Diffuse Galaxies Pure Stellar Halos?*

Peng

Lim

2016

ApJL

116

141

View full text Add to dashboard Cite

Observations of nearby galaxy clusters at low surface brightness have identified galaxies with low luminosities, but sizes as large as L å galaxies, leading them to be dubbed "ultra-diffuse galaxies" (UDGs). The survival of UDGs in dense environments like the Coma cluster suggests that UDGs could reside in much more massive dark halos. We report the detection of a substantial population of globular clusters (GCs) around a Coma UDG, Dragonfly 17 (DF17). We find that DF17 has a high GC specific frequency of S N = 26 ± 13. The GC system is extended, with an effective radius of 12″ ± 2″, or 5.6 ± 0.9 kpc at Coma distance, 70% larger than the galaxy itself. We also estimate the mean of the GC luminosity function to infer a distance of -+ 97 14 17 Mpc, providing redshift-independent confirmation that one of these UDGs is in the Coma cluster. The presence of a rich GC system in DF17 indicates that, despite its low stellar density, star formation was intense enough to form many massive star clusters. If DF17ʼs ratio of total GC mass to total halo mass is similar to those in other galaxies, then DF17 has an inferred total mass of ∼1011 M e , only ∼10% the mass of the Milky Way, but extremely dominated by dark matter, with M/L V ≈ 1000. We suggest that UDGs like DF17 may be "pure stellar halos," i.e., galaxies that formed their stellar halo components, but then suffered an early cessation in star formation that prevented the formation of any substantial central disk or bulge.

show abstract

A Catalog of Globular Cluster Systems: What Determines the Size of a Galaxy's Globular Cluster Population?

Cited by 286 publications

References 98 publications

The outer regions of the giant Virgo galaxy M 87 Kinematic separation of stellar halo and intracluster light

The outer regions of the giant Virgo galaxy M 87 Kinematic separation of stellar halo and intracluster light

The colour–magnitude relation of globular clusters in Centaurus and Hydra

A Rich Globular Cluster System in Dragonfly 17: Are Ultra-Diffuse Galaxies Pure Stellar Halos?*

Contact Info

Product

Resources

About