Stellar content of nearby galaxies. II - The Local Group dwarf elliptical galaxy M32

1989 ◽  
Vol 98 ◽  
pp. 1285 ◽  
Author(s):  
Wendy L. Freedman
1990 ◽  
Vol 99 ◽  
pp. 149 ◽  
Author(s):  
Christine D. Wilson ◽  
Barry F. Madore ◽  
Wendy L. Freedman

1978 ◽  
Vol 77 ◽  
pp. 227-236
Author(s):  
G. Burbidge

The term “nearby galaxies” is not very precise. If we restrict ourselves to galaxies within the local group, we are really only talking about our Galaxy, M31 and M33. Since the Galactic Center has been reviewed extensively by Oort in Annual Reviews (1977), and I feel that there is nothing exceptional to say about the nuclei of M31 and M33 as far as phenomena other than their stellar content and central dynamics are concerned, to discuss interesting properties we must consider more distant objects. If we go out to the distance of the Virgo cluster, we already include objects such as NGC 5128, M82 and M87. Each of these galaxies shows or was claimed to show evidence of different kinds of violent nuclear activity. Indeed, it is obvious that within the volume occupied by the supercluster (whether or not it is really a physical entity) there must be many galaxies in which nuclear activity can be detected.


1999 ◽  
Vol 118 (2) ◽  
pp. 862-882 ◽  
Author(s):  
D. Martínez-Delgado ◽  
C. Gallart ◽  
A. Aparicio

2018 ◽  
Vol 14 (S344) ◽  
pp. 161-177 ◽  
Author(s):  
Denise R. Gonçalves

AbstractThe Local Group contains a great number of dwarf irregulars and spheroidals, for which the spectroscopy of individual stars can be obtained. Thus, the chemical evolution of these galaxies can be traced, with the only need of finding populations spanning a large age range and such that we can accurately derive the composition. Planetary nebulae (PNe) are old- and intermediate-age star remnants and their chemical abundances can be obtained up to 3-4 Mpc. H ii regions, which are brighter and much easily detected, represent galaxies young content. PNe and H ii regions share similar spectroscopic features and are analysed in the same way. Both are among the best tracers of the chemical evolution allowing to draw the chemical time line of nearby galaxies. The focus in this review are the PN and H ii region populations as constraints to the chemical evolution models and the mass-metallicity relation of the local universe.


1983 ◽  
Vol 104 ◽  
pp. 255-258
Author(s):  
R. D. Davies

A measurement of the motion of the Local Group of galaxies through the Universe provides an indication of their peculiar motion relative to the Hubble flow consequent upon the gravitational influence of the local large scale mass inhomogeneities. This motion can be measured either relative to the cosmic microwave background at z ∼ 1000 or relative to the background or nearby (z ∼ 0.01) galaxies. The interpretation of published measurements is subject to some uncertainty. As an example, the Local Group motion derived from optical studies of nearby galaxies (Rubin et al. 1976) differs from that derived from radio frequency measurements of the dipole anisotropy in the microwave background. (Boughn et al. 1981, Gorenstein & Smoot 1981).


1999 ◽  
Vol 193 ◽  
pp. 459-469
Author(s):  
Donald F. Figer ◽  
Sungsoo S. Kim ◽  
Mark Morris ◽  
Eugene Serabyn

The three massive clusters in the Galactic Center are not only the most massive young clusters in the Galaxy, but they harbor more Wolf-Rayet stars than any other starburst region in the Local Group. An understanding of their stellar content will be valuable for extending models to starburst regions in other galaxies. We present HST-NICMOS images, luminosity functions, and color-magnitude diagrams of two of these: the Quintuplet and Arches clusters. The images allow the detection of stars over 6 magnitudes fainter than ever before and reveal previously undetected multiple star systems. For the first time, we clearly identify the main sequence in the Quintuplet cluster, and we extend earlier detections of the main sequence in the Arches cluster to Minitial < 10 M⊙. We estimate that the Arches cluster has an initial mass function slope which is greater than the Salpeter value. Given their stellar content, the Galactic Center clusters provide both the best nearby examples of super star clusters and the best nearby locale in which to investigate WR phenomena in starburst galaxies and galactic nuclei. We discuss the content of the Galactic Center clusters, with a particular emphasis on how they compare to other massive clusters of the local group. We expect that many of the massive stars in the Galactic Center will soon evolve to become WR stars, and eventually become supernovae at a rate of ∼ 1 per 20 000 years for the next several Myr. We note that our preliminary N-body simulations suggest that such dense clusters are short-lived in the strong tidal field of the Galactic Center, consistent with the fact that no older dense clusters are seen in the central 50 pc. This implies a star formation rate of 5(10−3) M⊙ yr−1 in the Galactic Center.


2014 ◽  
Vol 10 (S312) ◽  
pp. 201-202 ◽  
Author(s):  
Zhou Fan ◽  
Yanbin Yang

AbstractThe recent studies show that the formation and evolution process of the nearby galaxies are still unclear. By using the Canada France Hawaii Telescope (CFHT) 3.6m telescope, the PanDAS shows complicated substructures (dwarf satellite galaxies, halo globular clusters, extended clusters, star streams, etc.) in the halo of M31 to ~150 kpc from the center of galaxy and M31-M33 interaction has been studied. In our work, we would like to investigate formation, evolution and interaction of M31 and M33, which are the nearest two spiral galaxies in Local Group. The star cluster systems of the two galaxies are good tracers to study the dynamics of the substructures and the interaction. Since 2010, the Xinglong 2.16m, Lijiang 2.4m and MMT 6.5m telescopes have been used for our spectroscopic observations. The radial velocities and Lick absorption-line indices can thus be measured with the spectroscopy and then ages, metallicities and masses of the star clusters can be fitted with the simple stellar population models. These parameters could be used as the input physical parameters for numerical simulations of M31-M33 interaction.


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