scholarly journals Two epochs of globular cluster formation from deep field luminosity functions: implications for reionization and the Milky Way satellites

2013 ◽  
Vol 432 (4) ◽  
pp. 3250-3261 ◽  
Author(s):  
Harley Katz ◽  
Massimo Ricotti
Keyword(s):  
Globular Cluster ◽  
Milky Way ◽  
Cluster Formation ◽  
Luminosity Functions

scholarly journals The globular cluster system of the Auriga simulations

2020 ◽  
Vol 496 (1) ◽  
pp. 638-648 ◽  
Author(s):  
Timo L R Halbesma ◽  
Robert J J Grand ◽  
Facundo A Gómez ◽  
Federico Marinacci ◽  
Rüdiger Pakmor ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Milky Way ◽  
Cluster Formation ◽  
Solar Radius ◽  
High Mass ◽  
Formation Model ◽  
The Galaxy ◽  
High Mass Loss ◽  
Globular Cluster System ◽  
Varying Mass

ABSTRACT We investigate whether the galaxy and star formation model used for the Auriga simulations can produce a realistic globular cluster (GC) population. We compare statistics of GC candidate star particles in the Auriga haloes with catalogues of the Milky Way (MW) and Andromeda (M31) GC populations. We find that the Auriga simulations do produce sufficient stellar mass for GC candidates at radii and metallicities that are typical for the MW GC system (GCS). We also find varying mass ratios of the simulated GC candidates relative to the observed mass in the MW and M31 GCSs for different bins of galactocentric radius metallicity (rgal–[Fe/H]). Overall, the Auriga simulations produce GC candidates with higher metallicities than the MW and M31 GCS and they are found at larger radii than observed. The Auriga simulations would require bound cluster formation efficiencies higher than 10 per cent for the metal-poor GC candidates, and those within the Solar radius should experience negligible destruction rates to be consistent with observations. GC candidates in the outer halo, on the other hand, should either have low formation efficiencies, or experience high mass-loss for the Auriga simulations to produce a GCS that is consistent with that of the MW or M31. Finally, the scatter in the metallicity as well as in the radial distribution between different Auriga runs is considerably smaller than the differences between that of the MW and M31 GCSs. The Auriga model is unlikely to give rise to a GCS that can be consistent with both galaxies.

scholarly journals Dynamics of Globular Cluster Systems

1983 ◽  
Vol 100 ◽  
pp. 359-364
Author(s):  
K. C. Freeman
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
Milky Way ◽  
Cluster Formation ◽  
Active Phase ◽  
Chemical Abundance ◽  
Cluster Systems ◽  
Chemical Enrichment ◽  
Wide Range ◽  
The Galaxy

In the Milky Way, the globular clusters are all very old, and we are accustomed to think of them as the oldest objects in the Galaxy. The clusters cover a wide range of chemical abundance, from near solar down to about [Fe/H] ⋍ −2.3. However there are field stars with abundances significantly lower than −2.3 (eg Bond, 1980); this implies that the clusters formed during the active phase of chemical enrichment, with cluster formation beginning at a time when the enrichment processes were already well under way.

scholarly journals Observed Abundance Features and their Implications for Chemical Evolution

2004 ◽  
Vol 21 (2) ◽  
pp. 242-247
Author(s):  
Takuji Tsujimoto ◽  
Toshikazu Shigeyama
Keyword(s):  
Chemical Evolution ◽  
Globular Cluster ◽  
Milky Way ◽  
Galactic Halo ◽  
Cluster Formation ◽  
Abundance Trends ◽  
Nearby Galaxies ◽  
Star Formation Histories ◽  
Chemical Evolution Model ◽  
Shed Light

AbstractWe describe the star formation histories of the Milky Way dwarf spheroidal galaxy and the globular cluster ω Centauri in terms of an inhomogeneous chemical evolution model developed for the Galactic halo. The observed abundance trends seen in neutron-capture elements together with α-elements constrain our models to shed light on the histories of these nearby galaxies and ω Cen. The origin of low-α stars and a new picture of the globular cluster formation scenario induced by cloud–cloud collisions are also presented.

scholarly journals From Young to Old: Spectral Models for Star Cluster Systems

2005 ◽  
Vol 13 ◽  
pp. 187-188
Author(s):  
Uta Fritze – v. Alvensleben ◽  
Peter Anders ◽  
Richard de Grijs
Keyword(s):  
Time Evolution ◽  
Globular Cluster ◽  
Milky Way ◽  
Star Clusters ◽  
Star Cluster ◽  
Cluster Systems ◽  
Luminosity Functions ◽  
Spectral Models ◽  
Model Star ◽  
Two Populations

AbstractEvolutionary synthesis models for star clusters of various metallicities, including gaseous emission during the lifetime of the ionizing stars, are used to model star cluster systems comprising two populations: an old metal-poor globular cluster (GC) population similar to that of the Milky Way halo, and a second GC population of arbitrary metallicity. We investigate the time evolution of color distributions and luminosity functions for the two GC populations and compare with observations of E/SO galaxies. We show that multi-passband data for GC populations give clues to the relative ages and metallicities of the two subpopulations, and help constrain formation scenarios for their parent galaxies.

scholarly journals The SLUGGS survey: measuring globular cluster ages using both photometry and spectroscopy

2019 ◽  
Vol 490 (1) ◽  
pp. 491-501 ◽  
Author(s):  
Christopher Usher ◽  
Jean P Brodie ◽  
Duncan A Forbes ◽  
Aaron J Romanowsky ◽  
Jay Strader ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Near Infrared ◽  
Milky Way ◽  
Cluster Formation ◽  
Optical Photometry ◽  
History Of ◽  
Natural Outcome ◽  
Using Data

ABSTRACT Globular cluster ages provide both an important test of models of globular cluster formation and a powerful method to constrain the assembly history of galaxies. Unfortunately, measuring the ages of unresolved old stellar populations has proven challenging. Here, we present a novel technique that combines optical photometry with metallicity constraints from near-infrared spectroscopy in order to measure ages. After testing the method on globular clusters in the Milky Way and its satellite galaxies, we apply our technique to three massive early-type galaxies using data from the SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey. The three SLUGGS galaxies and the Milky Way show dramatically different globular cluster age and metallicity distributions, with NGC 1407 and the Milky Way showing mostly old globular clusters, while NGC 3115 and NGC 3377 show a range of globular ages. This diversity implies different galaxy formation histories and that the globular cluster optical colour–metallicity relation is not universal as is commonly assumed in globular cluster studies. We find a correlation between the median age of the metal-rich globular cluster populations and the age of the field star populations, in line with models where globular cluster formation is a natural outcome of high-intensity star formation.

scholarly journals On the origin of the helium-rich population in the peculiar globular cluster Omega Centauri

2009 ◽  
Vol 5 (S268) ◽  
pp. 187-188
Author(s):  
Donatella Romano ◽  
M. Tosi ◽  
M. Cignoni ◽  
F. Matteucci ◽  
E. Pancino ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Globular Cluster ◽  
Main Sequence ◽  
Milky Way ◽  
Dwarf Galaxy ◽  
Potential Well ◽  
Galactic Winds ◽  
Supernova Explosions

AbstractIn this contribution we discuss the origin of the extreme helium-rich stars which inhabit the blue main sequence (bMS) of the Galactic globular cluster Omega Centauri. In a scenario where the cluster is the surviving remnant of a dwarf galaxy ingested by the Milky Way many Gyr ago, the peculiar chemical composition of the bMS stars can be naturally explained by considering the effects of strong differential galactic winds, which develop owing to multiple supernova explosions in a shallow potential well.

scholarly journals Globular Cluster and Galaxy Formation: M31, the Milky Way, and Implications for Globular Cluster Systems of Spiral Galaxies

2004 ◽  
Vol 614 (1) ◽  
pp. 158-166 ◽  
Author(s):  
David Burstein ◽  
Yong Li ◽  
Kenneth C. Freeman ◽  
John E. Norris ◽  
Michael S. Bessell ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Globular Cluster ◽  
Milky Way ◽  
Spiral Galaxies ◽  
Cluster Systems

scholarly journals A comparative study of satellite galaxies in Milky Way-like galaxies from HSC, DECaLS, and SDSS

2020 ◽  
Vol 500 (3) ◽  
pp. 3776-3801
Author(s):  
Wenting Wang ◽  
Masahiro Takada ◽  
Xiangchong Li ◽  
Scott G Carlsten ◽  
Ting-Wen Lan ◽  
...  
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Statistical Study ◽  
Satellite System ◽  
Large Scatter ◽  
Local Universe ◽  
Good Representative ◽  
Luminosity Functions ◽  
Satellite Galaxies ◽  
Good Agreement

ABSTRACT We conduct a comprehensive and statistical study of the luminosity functions (LFs) for satellite galaxies, by counting photometric galaxies from HSC, DECaLS, and SDSS around isolated central galaxies (ICGs) and paired galaxies from the SDSS/DR7 spectroscopic sample. Results of different surveys show very good agreement. The satellite LFs can be measured down to MV ∼ −10, and for central primary galaxies as small as 8.5 < log10M*/M⊙ < 9.2 and 9.2 < log10M*/M⊙ < 9.9, which implies there are on average 3–8 satellites with MV < −10 around LMC-mass ICGs. The bright end cutoff of satellite LFs and the satellite abundance are both sensitive to the magnitude gap between the primary and its companions, indicating galaxy systems with larger magnitude gaps are on average hosted by less massive dark matter haloes. By selecting primaries with stellar mass similar to our Milky Way (MW), we discovered that (i) the averaged satellite LFs of ICGs with different magnitude gaps to their companions and of galaxy pairs with different colour or colour combinations all show steeper slopes than the MW satellite LF; (ii) there are on average more satellites with −15 < MV < −10 than those in our MW; (iii) there are on average 1.5 to 2.5 satellites with MV < −16 around ICGs, consistent with our MW; (iv) even after accounting for the large scatter predicted by numerical simulations, the MW satellite LF is uncommon at MV > −12. Hence, the MW and its satellite system are statistically atypical of our sample of MW-mass systems. In consequence, our MW is not a good representative of other MW-mass galaxies. Strong cosmological implications based on only MW satellites await additional discoveries of fainter satellites in extra-galactic systems. Interestingly, the MW satellite LF is typical among other MW-mass systems within 40 Mpc in the local Universe, perhaps implying the Local Volume is an underdense region.

Sign in / Sign up

Export Citation Format

Share Document