scholarly journals The Lowest Metallicity Stars in the LMC: Clues from MaGICC Simulations

Author(s):  
Chris B. Brook ◽  
Maider S. Miranda ◽  
Brad. K. Gibson ◽  
Kate Pilkington ◽  
Greg S. Stinson

AbstractUsing a cosmological hydrodynamical simulation of a galaxy of similar mass to the Large Magellanic Cloud (LMC), we examine the predicted characteristics of its lowest metallicity populations. In particular, we emphasise the spatial distributions of first (Pop III) and second (polluted by only immediate Pop III ancestors) generation stars. We find that primordial composition stars form not only in the central galaxy’s progenitor, but also in locally collapsed subhaloes during the early phases of galaxy formation. The lowest metallicity stars in these subhaloes end up in a relatively extended distribution around the host, with these accreted stars possessing present-day galactocentric distances as great as ~40 kpc. By contrast, the earliest stars formed within the central galaxy remain in the inner region, where the vast majority of star formation occurs, for the entirety of the simulation. Consequently, the fraction of stars that are from the earliest generation increases strongly with radius.

1980 ◽  
Vol 4 (1) ◽  
pp. 90-92
Author(s):  
P. J. McGregor ◽  
A. R. Hyland

The 30 Doradus region offers an excellent opportunity to study cluster formation processes and recent star formation in the Large Magellanic Cloud.


1991 ◽  
Vol 148 ◽  
pp. 15-23 ◽  
Author(s):  
B. E. Westerlund

A vast amount of observational data concerning the structure and kinematics of the Magellanic Clouds is now available. Many basic quantities (e.g. distances and geometry) are, however, not yet sufficiently well determined. Interactions between the Small Magellanic Cloud (SMC), the Large Magellanic Cloud (LMC) and our Galaxy have dominated the evolution of the Clouds, causing bursts of star formation which, together with stochastic self-propagating star formation, produced the observed structures. In the youngest generation in the LMC it is seen as an intricate pattern imitating a fragmented spiral structure. In the SMC much of the fragmentation is along the line of sight complicating the reconstruction of its history. The violent events in the past are also recognizable in complex velocity patterns which make the analysis of the kinematics of the Clouds difficult.


Author(s):  
E. Kontizas ◽  
S. E. Maravelias ◽  
A. Dapergolas ◽  
Y. Bellas-Velidis ◽  
M. Kontizas

1999 ◽  
Vol 190 ◽  
pp. 377-378
Author(s):  
A. Moneti ◽  
R. J. Laureijs ◽  
J.M. van der Hulst ◽  
F. Israel ◽  
P.P. van der Werf

With the detection of strong PAH features and H2 emission in selected knots of the N159, N11A, and 30 Dor regions in the LMC, we present the first results of a study that is part of a coordinated Guaranteed Time ISO programme to investigate star formation in the Magellanic Clouds. The PAH features have different ratios than the ones in Galactic reflection nebulae.


1997 ◽  
Vol 109 ◽  
pp. 292 ◽  
Author(s):  
B. W. Stappers ◽  
J. R. Mould ◽  
K. M. Sebo ◽  
J. A. Holtzman ◽  
J. S., III Gallagher ◽  
...  

1999 ◽  
Vol 190 ◽  
pp. 343-344 ◽  
Author(s):  
T. A. Smecker-Hane ◽  
J. S. Gallagher ◽  
Andrew Cole ◽  
P. B. Stetson ◽  
E. Tolstoy

The Large Magellanic Cloud (LMC) is unique among galaxies in the Local Group in that it is the most massive non-spiral, is relatively gas-rich, and is actively forming stars. Determining its star-formation rate (SFR) as a function of time will be a cornerstone in our understanding of galaxy evolution. The best method of deriving a galaxy's past SFR is to compare the densities of stars in a color-magnitude diagram (CMD), a Hess diagram, with model Hess diagrams. The LMC has a complex stellar population with ages ranging from 0 to ~ 14 Gyr and metallicities from −2 ≲ [Fe/H] ≲ −0.4, and deriving its SFR and simultaneously constraining model input parameters (distance, age-metallicity relation, reddening, and stellar models) requires well-populated CMDs that span the magnitude range 15 ≤ V ≤ 24. Although existing CMDs of field stars in the LMC show tantalizing evidence for a significant burst of star formation that occurred ~ 3 Gyr ago (for examples, see Westerlund et al. 1995; Vallenari et al. 1996; Elson, et al. 1997; Gallagher et al. 1999, and references therein), estimates of the enhancement in the SFR vary from factors of 3 to 50. This uncertainty is caused by the relatively large photometric errors that plague crowded ground-based images, and the small number statistics that plague CMDs created from single Wide Field Planetary Camera 2 (WFPC2) images.


2012 ◽  
Vol 761 (1) ◽  
pp. L5 ◽  
Author(s):  
Stefan C. Keller ◽  
A. Dougal Mackey ◽  
Gary S. Da Costa

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