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Journal articles on the topic 'Globular clusters: individual(NGC 7006)'

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Published: 4 June 2021

Last updated: 1 February 2022

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1

Buonanno, R., F. F. Pecci, E. Capellaro, S. Ortolani, T. Richtler, and E. H. Geyer. "CCD photometry of globular clusters. IV - NGC 7006." Astronomical Journal 102 (September 1991): 1005. http://dx.doi.org/10.1086/115928.

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2

Dinescu, Dana I., Steven R. Majewski, Terrence M. Girard, and Kyle M. Cudworth. "Orbits of Globular Clusters in the Outer Galaxy: NGC 7006." Astronomical Journal 122, no. 4 (2001): 1916–27. http://dx.doi.org/10.1086/323094.

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3

Wehlau, Amelia, and James M. Nemec. "RR Lyrae Variables in the Second-Parameter Globular Cluster NGC 7006." International Astronomical Union Colloquium 139 (1993): 420. http://dx.doi.org/10.1017/s0252921100118111.

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AbstractThe distant globular cluster NGC7006 was one of the first clusters studied for which the distribution of stars along the horizontal branch of its C-M diagram showed evidence for a “second parameter” in addition to metallicity. Studies of the more than 60 known RR Lyrae stars in this cluster should yield some statistically significant trends or correlations which might help to identify the second parameter. In the first stage of this study (Wehlau, Nemec, Han-Ian $ Rich 1992, AJ, 103, 1583) photographic data from 1984 were combined with previously published data from the 1930's and 1950

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4

Chun, Mun-Suk. "Inhomogeneities in Globular Clusters." Publications of the Astronomical Society of Australia 9, no. 1 (1991): 37–40. http://dx.doi.org/10.1017/s1323358000024826.

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AbstractInhomogeneities in globular clusters are reviewed with the observational evidence for chemical abundance variations from star to star in individual clusters and the large-scale structural variation of clusters. The reality of the radial colour gradient is tested in 47 Tuc (NGC 104). The result shows that the observed radial colour gradient comes from the integration of the calculated colours of individual stars. The cause of this radial colour variation is the result of the concentration of evolved stars and the reddening of the main sequence in the central region. We propose that the

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Geisler, Doug, Taft Armandroff, Gary Da Costa, Myung Gyoon Lee, and Ata Sarajedini. "HST Color-Magnitude Diagrams of Globular Clusters in NGC 185 and NGC 205." Symposium - International Astronomical Union 192 (1999): 231–36. http://dx.doi.org/10.1017/s0074180900204166.

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We present a progress report on our ongoing HST WFPC2 study of globular clusters in NGC 185 and NGC 205. Most of the cluster candidates studied previously only from the ground are indeed globular clusters; however, several candidates turn out to be either foreground stars or background galaxies. In addition, we have discovered one new, previously unsuspected cluster. A complete knowledge of the globular cluster systems in even these nearby galaxies requires high spatial resolution data. We then derive preliminary I, (V – I) color-magnitude diagrams for some of the clusters, as well as for thei

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Held, Enrico V., Luciana Federici, Carla Cacciari, and Vincenzo Testa. "Ages and Metallicities of Globular Clusters in NGC 5128." Symposium - International Astronomical Union 207 (2002): 269–74. http://dx.doi.org/10.1017/s007418090022384x.

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We have obtained multislit spectroscopy of 40 known globular clusters in the nearby peculiar elliptical galaxy NGC 5128 at the ESO NTT telescope. Measurements of metal and hydrogen absorption line indices have been used to estimate the age and metal content of individual clusters. The results have been combined with previous data from multifibre spectroscopy of clusters in the halo of NGC 5128 to study the age and metallicity distribution of the globular cluster system.

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Harris, Gretchen L. H. "NGC 5128: The Giant Beneath." Publications of the Astronomical Society of Australia 27, no. 4 (2010): 475–81. http://dx.doi.org/10.1071/as09063.

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AbstractThis paper reviews what has been learned about the old stellar population of NGC 5128, the only large elliptical galaxy close enough that we can currently observe individual stars as faint as the horizontal branch. Although its galaxy type is still a matter of debate, the uncertainties over distance are now largely resolved; comparison of five stellar distance indicators gives d= 3.8±0.1 Mpc. The globular cluster system, which was once perplexingly invisible, is now known to be predominantly old with a substantial metal-rich component. The globular cluster system (GCS) total population

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Anders, Peter, Uta Fritze –. v. Alvensleben, and Richard de Grijs. "Young Star Clusters: Progenitors of Globular Clusters!?" Highlights of Astronomy 13 (2005): 366–68. http://dx.doi.org/10.1017/s1539299600015987.

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AbstractStar cluster formation is a major mode of star formation in the extreme conditions of interacting galaxies and violent starbursts. Young clusters are observed to form in a variety of such galaxies, a substantial number resembling the progenitors of globular clusters in mass and size, but with significantly enhanced metallicity. From studies of the metal-poor and metal-rich star cluster populations of galaxies, we can therefore learn about the violent star formation history of these galaxies, and eventually about galaxy formation and evolution. We present a new set of evolutionary synth

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Bastian, Nate, Christopher Usher, Sebastian Kamann, et al. "Multiple populations in integrated light spectroscopy of intermediate-age clusters." Monthly Notices of the Royal Astronomical Society: Letters 489, no. 1 (2019): L80—L85. http://dx.doi.org/10.1093/mnrasl/slz130.

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ABSTRACT The presence of star-to-star light-element abundance variations (also known as multiple populations, MPs) appears to be ubiquitous within old and massive clusters in the Milky Way and all studied nearby galaxies. Most previous studies have focused on resolved images or spectroscopy of individual stars, although there has been significant effort in the past few years to look for multiple population signatures in integrated light spectroscopy. If proven feasible, integrated light studies offer a potential way to vastly open parameter space, as clusters out to 10s of Mpc can be studied.

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Smith, Graeme H., Michael M. Briley, and Daniel Harbeck. "A Comparison between Carbon and Nitrogen Abundances of Bright Giants in the Globular Clusters M13, M10, and NGC 7006." Astronomical Journal 129, no. 3 (2005): 1589–95. http://dx.doi.org/10.1086/427714.

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Lardo, C., M. Salaris, N. Bastian, A. Mucciarelli, E. Dalessandro, and I. Cabrera-Ziri. "Chemical inhomogeneities amongst first population stars in globular clusters." Astronomy & Astrophysics 616 (August 2018): A168. http://dx.doi.org/10.1051/0004-6361/201832999.

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Spreads in light element abundances among stars (also known as multiple populations) are observed in nearly all globular clusters. One way to map such chemical variations using high-precision photometry is to employ a suitable combination of stellar magnitudes in the F275W, F336W, F438W, and F814W filters (called the “chromosome map”), to maximise the separation between the different multiple populations. For each individual cluster its chromosome map separates the first population (with metal abundance patterns typical of field halo stars) from the second population (which displays distinctiv

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Husser, Tim-Oliver, Marilyn Latour, Jarle Brinchmann, et al. "A stellar census in globular clusters with MUSE." Astronomy & Astrophysics 635 (March 2020): A114. http://dx.doi.org/10.1051/0004-6361/201936508.

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Aims. We use the spectra of more than 30 000 red giant branch (RGB) stars in 25 globular clusters (GC), obtained within the MUSE survey of Galactic globular clusters, to calibrate the Ca II triplet metallicity relation and derive metallicities for all individual stars. We investigate the overall metallicity distributions as well as those of the different populations within each cluster. Methods. The Ca II triplet in the near-infrared at 8498, 8542, and 8662 Å is visible in stars with spectral types between F and M and can be used to determine their metallicities. In this work, we calibrate the

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Barbuy, B., S. Ortolani, E. Bica, A. Renzini, and M. D. Guarnieri. "Stellar parameters in the bulge cluster NGC 6553." Symposium - International Astronomical Union 189 (1997): 203–6. http://dx.doi.org/10.1017/s0074180900116699.

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Globular clusters in the Galactic bulge form a flattened system, extending from the Galactic center to about 4.5 kpc from the Sun (Barbuy et al. 1997). A study of abundance ratios in these clusters is very important for a more complete understanding of the bulge formation. In this work we present a spectroscopic analysis of individual stars in NGC 6553. This cluster is a key one because it is located at d⊙ ≍ 5.1 kpc, therefore relatively close to us, and at the same time it is representative of the Galactic bulge stellar population: (a) Ortolani et al. (1995) showed that NGC 6553 and NGC 6528

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Vásquez, S., I. Saviane, E. V. Held, et al. "Homogeneous metallicities and radial velocities for Galactic globular clusters." Astronomy & Astrophysics 619 (November 2018): A13. http://dx.doi.org/10.1051/0004-6361/201833525.

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Although the globular clusters in the Milky Way have been studied for a long time, a significant fraction of them lack homogeneous metallicity and radial velocity measurements. In an earlier paper we presented the first part of a project to obtain metallicities and radial velocities of Galactic globular clusters from multiobject spectroscopy of their member stars using the ESO Very Large Telescope. In this paper we add metallicities and radial velocities for a new sample of 28 globular clusters, including in particular globular clusters in the MW halo and the Galactic bulge. Together with our

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Lanzoni, Barbara. "Searching for IMBHs in Galactic globular clusters through radial velocities of individual stars." Proceedings of the International Astronomical Union 10, S312 (2014): 189–96. http://dx.doi.org/10.1017/s1743921315007796.

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AbstractI present an overview of our ongoing project aimed at building a new generation of velocity dispersion profiles ad rotation curves for a representative sample of Galactic globular clusters, from the the radial velocity of hundreds of individual stars distributed at different distances from the cluster center. The innermost portion of the profiles will be used to constrain the possible presence of intermediate-mass black holes. The adopted methodology consists of combining spectroscopic observations acquired with three different instruments at the ESO-VLT: the adaptive-optics assisted,

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Ernandes, H., B. Barbuy, A. Alves-Brito, A. Friaça, C. Siqueira-Mello, and D. M. Allen. "Iron-peak elements Sc, V, Mn, Cu, and Zn in Galactic bulge globular clusters." Astronomy & Astrophysics 616 (August 2018): A18. http://dx.doi.org/10.1051/0004-6361/201731708.

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Aims. Globular clusters are tracers of the history of star formation and chemical enrichment in the early Galaxy. Their abundance pattern can help understanding their chemical enrichment processes. In particular, the iron-peak elements have been relatively little studied so far in the Galactic bulge. Methods. The main aim of this work is to verify the strength of abundances of iron-peak elements for chemical tagging in view of identifying different stellar populations. Besides, the nucleosynthesis processes that build these elements are complex, therefore observational data can help constraini

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Rennó, C., B. Barbuy, T. C. Moura, and M. Trevisan. "Abundances from integrated spectra of 47 Tucanae (NGC 104)." Monthly Notices of the Royal Astronomical Society 498, no. 4 (2020): 5834–54. http://dx.doi.org/10.1093/mnras/staa2697.

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ABSTRACT 47 Tucanae is among the most studied and observed globular clusters, given its proximity. The aim of this work is to study in detail the integrated spectrum of 47 Tucanae, as a template, in order to have a list of reliable lines that are validated for a moderate spectral resolution case. The spectrum of 47 Tucanae is reproduced by computing synthetic spectra, taking into account individual element abundances. The results are compared with other methods. We reproduce the integrated spectrum in the range 4500–9000 Å and derive abundances from individual lines of Na, Mg, Al, Si, Ca, Ti,

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Anders, Peter, Uta Fritze-V. Alvensleben, and Richard de Grijs. "Young Star Clusters: Clues to Galaxy Formation and Evolution." Symposium - International Astronomical Union 217 (2004): 210–11. http://dx.doi.org/10.1017/s0074180900197529.

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Young clusters are observed to form in a variety of interacting galaxies and violent starbursts, a substantial number resembling the progenitors of the well-studied globular clusters in mass and size. By studying young clusters in merger remnants and peculiar galaxies, we can therefore learn about the violent star formation history of these galaxies. We present a new set of evolutionary synthesis models of our GALEV code specifically developed to include the gaseous emission of presently forming star clusters, and a new tool that allows to determine individual cluster metallicities, ages, exti

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Horta, Danny, Ricardo P. Schiavon, J. Ted Mackereth, et al. "The chemical compositions of accreted and in situ galactic globular clusters according to SDSS/APOGEE." Monthly Notices of the Royal Astronomical Society 493, no. 3 (2020): 3363–78. http://dx.doi.org/10.1093/mnras/staa478.

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ABSTRACT Studies of the kinematics and chemical compositions of Galactic globular clusters (GCs) enable the reconstruction of the history of star formation, chemical evolution, and mass assembly of the Galaxy. Using the latest data release (DR16) of the SDSS/APOGEE survey, we identify 3090 stars associated with 46 GCs. Using a previously defined kinematic association, we break the sample down into eight separate groups and examine how the kinematics-based classification maps into chemical composition space, considering only α (mostly Si and Mg) elements and Fe. Our results show that (i) the lo

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Saracino, S., S. Kamann, C. Usher, et al. "Leveraging HST with MUSE – I. Sodium abundance variations within the 2-Gyr-old cluster NGC 1978." Monthly Notices of the Royal Astronomical Society 498, no. 3 (2020): 4472–80. http://dx.doi.org/10.1093/mnras/staa2748.

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ABSTRACT Nearly all of the well-studied ancient globular clusters (GCs), in the Milky Way and in nearby galaxies, show star-to-star variations in specific elements (e.g. He, C, N, O, Na, and Al), known as ‘multiple populations’ (MPs). However, MPs are not restricted to ancient clusters, with massive clusters down to ∼2 Gyr showing signs of chemical variations. This suggests that young and old clusters share the same formation mechanism but most of the work to date on younger clusters has focused on N variations. Initial studies even suggested that younger clusters may not host spreads in other

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Ernandes, H., B. Dias, B. Barbuy, et al. "A MUSE study of the inner bulge globular cluster Terzan 9: a fossil record in the Galaxy." Astronomy & Astrophysics 632 (December 2019): A103. http://dx.doi.org/10.1051/0004-6361/201936431.

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Context. Moderately metal-poor inner bulge globular clusters are relics of a generation of long-lived stars that formed in the early Galaxy. Terzan 9, projected at 4°.12 from the Galactic center, is among the most central globular clusters in the Milky Way, showing an orbit which remains confined to the inner 1 kpc. Aims. Our aim is the derivation of the cluster’s metallicity, together with an accurate measurement of the mean radial velocity. In the literature, metallicities in the range between −2.0 < [Fe/H] < −1.0 have been estimated for Terzan 9 based on color-magnitude diagrams and C

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Longmore, A. J., R. Dixon, I. Skillen, R. F. Jameson, and J. A. Fernley. "Globular Cluster Distances from the RR Lyrae Log (Period) – Infrared Magnitude Relation." International Astronomical Union Colloquium 111 (1989): 273. http://dx.doi.org/10.1017/s0252921100011817.

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AbstractThe log (Period) – infrared (2.2 micron) magnitude relationship has been measured for 7 clusters (M3, M4, M5, M15, M107, ω Cen and NGC 5466). For the clusters where there are several observations for each of the variables, enabling a good mean magnitude to be derived, there is no evidence for scatter in the relation outside observational error. This conclusion applies also to ω Cen, even though the variables observed covered a range of metallicity. It is argued that very accurate relative distances can be obtained which are insensitive to reddening errors and the effects of metallicity

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Lee, Joowon, Jihye Shin, and Sungsoo S. Kim. "Globular Clusters within Dark Matter Halos: Case Studies of 47 Tuc, NGC 1851 and M 15." Proceedings of the International Astronomical Union 12, S316 (2015): 336–37. http://dx.doi.org/10.1017/s174392131500890x.

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AbstractGlobular clusters (GCs) are known to have a very small amount of or no dark matter (DM). Even if GCs are formed in individual DM halos, they must have lost the majority of the DM through dynamical processes such as mass segregation or tidal stripping. Using Fokker-Planck (FP) calculations, we investigate the dynamical evolution of three Galactic GCs with an assumption that they were formed in mini DM halos. We trace the amount of DM of 47 Tuc, NGC 1851, and M 15, which are a ‘disk/bulge’ cluster, an ‘old halo’ cluster, and a ‘young halo’ cluster, respectively. We find that these three

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Lützgendorf, Nora, Markus Kissler-Patig, Karl Gebhardt, et al. "Intermediate-mass black holes in globular clusters: observations and simulations." Proceedings of the International Astronomical Union 10, S312 (2014): 181–88. http://dx.doi.org/10.1017/s1743921315007784.

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AbstractThe study of intermediate-mass black holes (IMBHs) is a young and promising field of research. If IMBHs exist, they could explain the rapid growth of supermassive black holes by acting as seeds in the early stage of galaxy formation. Formed by runaway collisions of massive stars in young and dense stellar clusters, intermediate-mass black holes could still be present in the centers of globular clusters, today. Our group investigated the presence of intermediate-mass black holes for a sample of 10 Galactic globular clusters. We measured the inner kinematic profiles with integral-field s

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Müller, Oliver, Francine R. Marleau, Pierre-Alain Duc, et al. "Spectroscopic study of MATLAS-2019 with MUSE: An ultra-diffuse galaxy with an excess of old globular clusters." Astronomy & Astrophysics 640 (August 2020): A106. http://dx.doi.org/10.1051/0004-6361/202038351.

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The MATLAS deep imaging survey has uncovered a plethora of dwarf galaxies in the low density environment it has mapped. A fraction of them are unusually extended and have low surface brightness. Among these so-called ultra-diffuse galaxies, a few seem to host an excess of globular clusters (GCs). With the integral field unit spectrograph MUSE we have observed one of these galaxies – MATLAS J15052031+0148447 (MATLAS-2019) – located toward the nearby group NGC 5846 and measured its systemic velocity, age, and metallicity, and that of its GC candidates. For the stellar body of MATLAS-2019 we deri

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Cortesi, A., and C. Mendes de Oliveira. "Kinematics of the outskirts of S0 galaxies from PNe and GCs." Proceedings of the International Astronomical Union 11, S321 (2016): 290. http://dx.doi.org/10.1017/s1743921316011376.

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AbstractThe stellar kinematics of the discs of S0 galaxies (as obtained using planetary nebulae, PNe, and integrated stellar light data) is comparable to that of spiral galaxies, with similar flat rotation curves and falling velocity dispersion profiles, but they present a larger amount of random motions. The only other tracer available to probe the kinematics of individual early-type galaxies are globular clusters (GCs). GCs’ formation is intimately connected to a galaxy major star forming event(s) and GCs are, therefore, good proofs of galaxy formation histories. We directly compare a sample

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Lützgendorf, Nora, Markus Kissler-Patig, Karl Gebhardt, et al. "Intermediate-mass black holes in globular clusters: observations and simulations - Update." Proceedings of the International Astronomical Union 12, S316 (2015): 240–45. http://dx.doi.org/10.1017/s1743921315010601.

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AbstractThe study of intermediate-mass black holes (IMBHs) is a young and promising field of research. If IMBH exist, they could explain the rapid growth of supermassive black holes by acting as seeds in the early stage of galaxy formation. Formed by runaway collisions of massive stars in young and dense stellar clusters, intermediate-mass black holes could still be present in the centers of globular clusters, today. We measured the inner kinematic profiles with integral-field spectroscopy for 10 Galactic globular cluster and determined masses or upper limits of central black holes. In combina

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D'Antona, Francesca. "Old and New Tools for Understanding the Evolution of Stars in Clusters." Symposium - International Astronomical Union 207 (2002): 599–609. http://dx.doi.org/10.1017/s007418090022442x.

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The uncertainties in the modelling of some important inputs of stellar evolution must be taken into account for a correct interpretation, both of the HR diagrams of individual stars, and of the integrated colors, of stellar clusters. After a short discussion of Globular Cluster ages, we focus on the problem of convection and discuss the parametrization of convection efficiency and overshooting.Convective efficiency affects the reliability of the giants colors, especially for high metallicity: age - metallicity relations found from integrated colors of clusters must be regarded with caution.Non

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Barbuy, B., H. Ernandes, S. O. Souza, et al. "Gemini/Phoenix H-band analysis of the globular cluster AL 3." Astronomy & Astrophysics 648 (April 2021): A16. http://dx.doi.org/10.1051/0004-6361/202039761.

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Context. The globular cluster AL 3 is old and located in the inner bulge. Three individual stars were observed with the Phoenix spectrograph at the Gemini South telescope. The wavelength region contains prominent lines of CN, OH, and CO, allowing the derivation of C, N, and O abundances of cool stars. Aims. We aim to derive C, N, O abundances of three stars in the bulge globular cluster AL 3, and additionally in stars of NGC 6558 and HP 1. The spectra of AL 3 allows us to derive the cluster’s radial velocity. Methods. For AL 3, we applied a new code to analyse its colour-magnitude diagram. Syn

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Martocchia, S., S. Kamann, S. Saracino, et al. "Leveraging HST with MUSE: II. Na-abundance variations in intermediate age star clusters." Monthly Notices of the Royal Astronomical Society 499, no. 1 (2020): 1200–1211. http://dx.doi.org/10.1093/mnras/staa2929.

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ABSTRACT Ancient (&gt;10 Gyr) globular clusters (GCs) show chemical abundance variations in the form of patterns among certain elements, e.g. N correlates with Na and anticorrelates with O. Recently, N abundance spreads have also been observed in massive star clusters that are significantly younger than old GCs, down to an age of ∼2 Gyr. However, so far N has been the only element found to vary in such young objects. We report here the presence of Na abundance variations in the intermediate age massive star clusters NGC 416 (∼6.5 Gyr old) and Lindsay 1 (∼7.5 Gyr old) in the Small Magellani

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Arellano Ferro, A., I. H. Bustos Fierro, J. H. Calderón, and J. A. Ahumada. "NGC 1261: A TIME-SERIES VI STUDY OF ITS VARIABLE STARS." Revista Mexicana de Astronomía y Astrofísica 55, no. 2 (2019): 337–50. http://dx.doi.org/10.22201/ia.01851101p.2019.55.02.18.

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Time-series VI CCD photometry of the globular cluster NGC 1261 is employed to study its variable star population. A membership analysis of most variables based on Gaia DR2 proper motions and colours was performed prior to the estimation of the mean cluster distance and metallicity. The light curves of the member RR Lyrae were Fourier decomposed to calculate their individual values of distance, [Fe/H], radius and mass. The I band P-L for RR Lyrae stars was also employed. Our best estimates of the metallicity and distance of this Oo I cluster are [Fe/H]ZW =−1.42 ± 0.05 dex and d = 17.2 ± 0.4 kpc

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Barth, Nicholas A., Jeffrey M. Gerber, Owen M. Boberg, Eileen D. Friel, and Enrico Vesperini. "Internal kinematics of M10 and M71." Monthly Notices of the Royal Astronomical Society 494, no. 3 (2020): 4548–57. http://dx.doi.org/10.1093/mnras/staa1019.

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ABSTRACT We present a study of the internal kinematics of two globular clusters, M10 (NGC 6254) and M71 (NGC 6838), using individual radial velocity (RV) measurements obtained from observations using the Hydra multiobject spectrograph on the WIYN 3.5 m telescope. We measured 120 RVs for stars in M10, of which 107 were determined to be cluster members. In M71, we measured 82 RVs and determined 78 of those measurements belonged to cluster members. Using the cluster members, we determine a mean RV of 75.9 ± 4.0 (s.d.) km s−1 and −22.9 ± 2.2 (s.d.) km s−1 for M10 and M71, respectively. We combined

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Schulz, Christine, and Michael Hilker. "From a star cluster ensemble to its formation history." Proceedings of the International Astronomical Union 12, S316 (2015): 263–64. http://dx.doi.org/10.1017/s1743921315008923.

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AbstractThe present-day sample of ultra-compact dwarf galaxies (UCDs) and globular clusters (GCs) around NGC 1399 is interpreted to be composed of individual star cluster (SC) populations. It is assumed that such an SC population forms at a constant star-formation rate (SFR), and its mass distribution is described by the embedded cluster mass function (ECMF) up to the upper limit Mmax. The GCs and UCDs probably formed in interactions of the progenitor galaxies during the assembly of the central Fornax galaxy cluster which is why we use them as tracers of those events. After some corrections, t

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Roth, Martin M., Christer Sandin, Sebastian Kamann, et al. "MUSE crowded field 3D spectroscopy in NGC 300." Astronomy & Astrophysics 618 (October 2018): A3. http://dx.doi.org/10.1051/0004-6361/201833007.

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Aims. As a new approach to the study of resolved stellar populations in nearby galaxies, our goal is to demonstrate with a pilot study in NGC 300 that integral field spectroscopy with high spatial resolution and excellent seeing conditions reaches an unprecedented depth in severely crowded fields. Methods. Observations by MUSE with seven pointings in NGC 300 have resulted in data cubes that are analyzed in four ways: (1) Point spread function-fitting 3D spectroscopy with PampelMUSE, as already successfully pioneered in globular clusters, yields de-blended spectra of individually distinguishabl

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Altner, Bruce. "IUE Investigations at the Core of M 79." Symposium - International Astronomical Union 126 (1988): 501–2. http://dx.doi.org/10.1017/s0074180900042819.

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As a result of their investigation of 27 galactic globular clusters with the ANS satellite van Albada, de Boer and Dickens (1981) classified M 79 (NGC 1904) as an “extremely blue” cluster. It was also found to be a low luminosity x-ray source based on data acquired with the Einstein X-ray Observatory (Grindlay 1981). In this brief paper we discuss the stellar spectra extracted from two short wavelength (SWP) IUE images acquired at the “center of light” of M 79. Discrete peaks in the “spatially resolved”, cross-dispersion profile suggested the presence of at least three hot stars in the large a

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Bruzual, Gustavo A., and Gladis C. Magris. "A Revised Age for the z = 1.55 Galaxy LBDS 53W091." Symposium - International Astronomical Union 183 (1999): 152. http://dx.doi.org/10.1017/s0074180900132322.

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Empirical evidence suggests that the stellar population in LBDS 53W091 is significantly younger than the dominant population in M32. We have used evolutionary population synthesis models to estimate the age of the dominant population in these stellar systems. The age of LBDS 53W091 is in the range from 1 to 2 Gyr and depends on the specific model. Older ages require sub-solar metallicity models. The estimates of the age of the dominant population in M32 range from 3 to 5 Gyr and depend not only on the model but also on the SED of this galaxy used in the fits. The same models predict an age of

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"DYNAMICAL SUBSTRUCTURES OF GALACTIC GLOBULAR CLUSTERS III. NGC 7006." Journal of Astronomy and Space Sciences 22, no. 4 (2005): 363–76. http://dx.doi.org/10.5140/jass.2005.22.4.363.

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