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Expected Differences Between AGB Stars in the LMC and the SMC Due to Differences in Chemical Composition
New Views of the Magellanic Clouds fA U Symposium, Vol. 190, 1999 Y.-H. Chu, N.B. Suntzef], J.E. Hesser, and D.A. Bohlender, eds. Expected Differences between AGB Stars in the LMC and the SMC Due to Differences in Chemical Composition Ju. Frantsman Astronomical Institute, Latvian University, Raina Blvd. 19, Riga, LV-1586, LATVIA Abstract. Certain aspects of the AGB population, such as the relative number of M and N stars, the mass loss rates, and the initial masses of carbon- oxygen cores, depend on the initial heavy element abundance Z. I have calculated synthetic populations of AGB stars for different initial Z values taking into consideration the evolution of single and close binary stars. I present the results of population syntheses of AGB stars in clusters as a function of different initial chemical compositions. The relation for the tip luminosity of AGB stars versus cluster age as a function of Z is presented and is used to determine the ages for a number of clusters in the LMC and the SMC, including clusters with no previous age determinations. Population simulations show that for low heavy element abundance (Z = 0.001) few M stars are formed with respect to the number of carbon stars. However, the total number of all AGB stars in clusters is not affected by the initial chemical composition. As a result of the evolution of close binary components after the mass exchange, an increase in the range of limiting values of the thermal pulsing AGB star luminosities is expected. The difference between the maximum luminosity on the AGB of single star and the luminosity of a star after a mass exchange event in a close binary system may be as great as 1 magnitude for very young clusters. -
Publications OFTHK Astronomical Socik-N-Οκτπκ Pacific 101: 570-572, June 1989
Publications OFTHK Astronomical SociK-n-οκτπκ Pacific 101: 570-572, June 1989 A SURVEY FOR RR LYRAE VARIABLES IN FIVE SMALL MAGELLANIC CLOUD CLUSTERS ALISTAIR R. WALKER Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatories* Casilla 603, La Serena, Chile Received 1989 March 15 ABSTRACT Results are presented of a search for RR Lyrae variables in the SMC clusters NGC 121, Lindsay 1, Kron 3, Kron 7, and Kron 44. The techniques used rediscovered the four RR Lyraes in NGC 121, but no variables were found in the other clusters. It is concluded that RR Lyraes do not occur in SMC clusters younger than — 11 Gyr. Key words: star clusters-Magellanic Clouds-variable stars: RR Lyrae stars 1. Introduction Lindsay 1 but did not find any variables; however, the The Small Magellanic Cloud (SMC) contains a number majority of his plates were exposed in times of rather poor of populous clusters in the age range 3-12 Gyr, unlike seeing. A survey of several MC clusters for RR Lyraes was either the Galaxy or the Large Magellanic Cloud (LMC). made, using the Yale 1-m telescope and an image-tube Olszewski (1986) and Olszewski, Schommer, and camera, by Graham and Nemec (1984). They found many Aaronson (1987, henceforth OSA) point out that it should variables in old LMC clusters but none in the two SMC be possible to determine the age of the youngest cluster clusters blinked, NGC 339 and NGC 416. RR Lyraes by a suitable survey for the variables in the Since these surveys, color-magnitude diagrams candidate clusters. -
Properties of Stellar Generations in Globular Clusters and Relations With
Astronomy & Astrophysics manuscript no. carretta c ESO 2018 November 9, 2018 Properties of stellar generations in Globular Clusters and relations with global parameters ⋆ E. Carretta1, A. Bragaglia1, R.G. Gratton2, A. Recio-Blanco3, S. Lucatello2,4, V. D’Orazi2, and S. Cassisi5 1 INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna, Italy 2 INAF-Osservatorio Astronomico di Padova, vicolo dell’Osservatorio 5, I-35122 Padova, Italy 3 Laboratoire Cassiop´ee UMR 6202, Universit`ede Nice Sophia-Antipolis, CNRS, Observatoire de la Cote d’Azur, BP 4229, 06304 Nice Cedex 4, France 4 Excellence Cluster Universe, Technische Universit¨at M¨unchen, Boltzmannstr. 2, D-85748, Garching, Germany 5 INAF-Osservatorio Astronomico di Collurania, via M. Maggini, I-64100 Teramo, Italy Received .....; accepted ..... ABSTRACT We revise the scenario of the formation of Galactic globular clusters (GCs) by adding the observed detailed chemical composition of their different stellar generations to the set of their global parameters. We exploit the unprecedented set of homogeneous abundances of more than 1200 red giants in 19 clusters, as well as additional data from literature, to give a new definition of bona fide globular clusters, as the stellar aggregates showing the presence of the Na-O anticorrelation. We propose a classification of GCs according to their kinematics and location in the Galaxy in three populations: disk/bulge, inner halo, and outer halo. We find that the luminosity function of globular clusters is fairly independent of their population, suggesting that it is imprinted by the formation mechanism, and only marginally affected by the ensuing evolution. We show that a large fraction of the primordial population should have been lost by the proto-GCs. -
Star Clusters As Witnesses of the Evolutionary History of the Small Magellanic Cloud
JENAM, Symposium 5: Star Clusters – Witnesses of Cosmic History Star Clusters as Witnesses of the Evolutionary History of the Small Magellanic Cloud Eva K. Grebel Astronomisches Rechen-Institut 11.0Z9.2e00n8 trum für AstrGroebnel,o JEmNAMie Sy mdp.e 5:r S MUC nStairv Celusrtesrsität Heidelbe0 rg My collaborators: ! PhD student Katharina Glatt ! PhD student Andrea Kayser (both University of Basel & University of Heidelberg) ! Andreas Koch (U Basel & UCLA / OCIW) ! Jay Gallagher, D. Harbeck (U Wisc) ! Elena Sabbi (U Heidelberg & STScI) ! Antonella Nota, Marco Sirianni (STScI) ! Monica Tosi, Gisella Clementini (U Bologna) ! Andrew Cole (U Tasmania) ! Gary Da Costa (ANU) 11.09.2008 Grebel, JENAM Symp. 5: SMC Star Clusters 1 NGC 416 (OGLE) Tracers of the Age-Metallicity Relation: ! Star clusters: ! Easily identifiable. ! Chronometers of intense star formation events. ! Single-age, single-metallicity fossils of local conditions. ! Star clusters in the SMC: ! Clusters formed (and survived) for most of its lifetime " Closely spaced set of age tracers! " Unique property of the SMC. # Milky Way: No comparable set of intermediate-age, populous clusters. # LMC: Age gap at intermediate ages. 11.09.2008 Grebel, JENAM Symp. 5: SMC Star Clusters 2 Cluster-based Age-Metallicity Relation: Photometry Spectroscopy After Da Costa 2002 An inhomogeneous sample: ! Photometric and spectroscopic metallicities from different techniques ! Photometric ages from ground-/space-based data of differing depth 11.09.2008 Grebel, JENAM Symp. 5: SMC Star Clusters 3 Getting Homogeneous Ages and Metallicities: PhD thesis Katharina Glatt ! HST / ACS program to obtain deep CMDs (PI: Gallagher) $ GO 10396, 29 orbits, executed 2005 – 2006. $ 6 populous intermediate-age clusters, 1 globular cluster: NGC 419, Lindsay 38, NGC 416, 339, Kron 3, Lindsay 1, NGC 121. -
The Search for Multiple Populations in Magellanic Cloud Clusters II: the Detection of Multiple Populations in Three Intermediate-Age SMC Clusters?
MNRAS 000,1{7 (2016) Preprint 29 August 2018 Compiled using MNRAS LATEX style file v3.0 The Search for Multiple Populations in Magellanic Cloud Clusters II: The Detection of Multiple Populations in Three Intermediate-Age SMC Clusters? F. Niederhofer1y, N. Bastian2, V. Kozhurina-Platais1, S. Larsen3, K. Hollyhead2, C. Lardo2, I. Cabrera-Ziri2;4, N. Kacharov5, I. Platais6, M. Salaris2, M. Cordero7, E. Dalessandro8;9, D. Geisler10, M. Hilker4, C. Li11, D. Mackey12, and A. Mucciarelli8, 1 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA 2 Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK 3 Department of Astrophysics/IMAPP, Radboud University, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands 4 European Southern Observatory, Karl-Schwarzschild-Straße 2, D-85748 Garching bei Munchen,¨ Germany 5 Max-Planck-Institut fur¨ Astronomie, K¨onigstuhl 17, D-69117 Heidelberg, Germany 6 Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA 7 Astronomisches Rechen-Institut, Zentrum fur¨ Astronomie der Universit¨at Heidelberg, M¨onchhofstraße 12-14, D-69120 Heidelberg, Germany 8 Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, I-40127 Bologna, Italy 9 INAF - Osservatorio Astronomico di Bologna, via Ranzani 1, 40127, Bologna, Italy 10 Departamento de Astronomia, Universidad de Concepcion, Casilla 160-C, Chile 11 Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia 12 Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia Accepted XXX. Received YYY; in original form ZZZ ABSTRACT This is the second paper in our series about the search for multiple populations in Magellanic Cloud star clusters using the Hubble Space Telescope. -
Ngc Catalogue Ngc Catalogue
NGC CATALOGUE NGC CATALOGUE 1 NGC CATALOGUE Object # Common Name Type Constellation Magnitude RA Dec NGC 1 - Galaxy Pegasus 12.9 00:07:16 27:42:32 NGC 2 - Galaxy Pegasus 14.2 00:07:17 27:40:43 NGC 3 - Galaxy Pisces 13.3 00:07:17 08:18:05 NGC 4 - Galaxy Pisces 15.8 00:07:24 08:22:26 NGC 5 - Galaxy Andromeda 13.3 00:07:49 35:21:46 NGC 6 NGC 20 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 7 - Galaxy Sculptor 13.9 00:08:21 -29:54:59 NGC 8 - Double Star Pegasus - 00:08:45 23:50:19 NGC 9 - Galaxy Pegasus 13.5 00:08:54 23:49:04 NGC 10 - Galaxy Sculptor 12.5 00:08:34 -33:51:28 NGC 11 - Galaxy Andromeda 13.7 00:08:42 37:26:53 NGC 12 - Galaxy Pisces 13.1 00:08:45 04:36:44 NGC 13 - Galaxy Andromeda 13.2 00:08:48 33:25:59 NGC 14 - Galaxy Pegasus 12.1 00:08:46 15:48:57 NGC 15 - Galaxy Pegasus 13.8 00:09:02 21:37:30 NGC 16 - Galaxy Pegasus 12.0 00:09:04 27:43:48 NGC 17 NGC 34 Galaxy Cetus 14.4 00:11:07 -12:06:28 NGC 18 - Double Star Pegasus - 00:09:23 27:43:56 NGC 19 - Galaxy Andromeda 13.3 00:10:41 32:58:58 NGC 20 See NGC 6 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 21 NGC 29 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 22 - Galaxy Pegasus 13.6 00:09:48 27:49:58 NGC 23 - Galaxy Pegasus 12.0 00:09:53 25:55:26 NGC 24 - Galaxy Sculptor 11.6 00:09:56 -24:57:52 NGC 25 - Galaxy Phoenix 13.0 00:09:59 -57:01:13 NGC 26 - Galaxy Pegasus 12.9 00:10:26 25:49:56 NGC 27 - Galaxy Andromeda 13.5 00:10:33 28:59:49 NGC 28 - Galaxy Phoenix 13.8 00:10:25 -56:59:20 NGC 29 See NGC 21 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 30 - Double Star Pegasus - 00:10:51 21:58:39 -
Ca II Triplet Spectroscopy of Giants in SMC Star Clusters: Abundances, Velocities and the Age-Metallicity Relation
Ca II Triplet Spectroscopy of Giants in SMC Star Clusters: Abundances, Velocities and the Age-Metallicity Relation G. S. Da Costa Mount Stromlo and Siding Spring Observatories, The Australian National University, Private Bag, Weston Creek Post Office, ACT 2611, Australia Electronic mail: [email protected] and D. Hatzidimitriou Physics Department, University of Crete, P.O. Box 2208, Heraklion 710 03, Crete, Greece Electronic mail: [email protected] ABSTRACT We have obtained spectra at the Ca II triplet of individual red giants in seven SMC star clusters whose ages range from ∼4 to 12 Gyr. The spectra have been used to determine mean abundances for six of the star clusters to a typical precision of 0.12 dex. When combined with existing data for other objects, the resulting SMC age-metallicity relation is generally consistent with that for a simple model of chemical evolution, scaled to the present-day SMC mean abundance and gas mass fraction. Two of the clusters (Lindsay 113 and NGC 339), however, have abundances that are ∼0.5 dex lower than that expected from the mean age-metallicity relation. It is suggested that the formation of these clusters, which have ages of ∼5 Gyr, may have involved the infall of unenriched gas, perhaps from the Magellanic Stream. The spectra also yield radial velocities for the seven clusters. The resulting velocity dispersion is −1 arXiv:astro-ph/9802008v1 2 Feb 1998 16 ± 4 km s , consistent with those of the SMC planetary nebula and carbon star populations. Subject headings: galaxies: abundances — galaxies: individual (SMC) — galaxies: kinematics and dynamics — galaxies: star clusters — Magellanic Clouds Accepted for Publication in The Astronomical Journal – 2 – 1. -
NGC 6535: the Lowest Mass Milky Way Globular Cluster with a Na-O Anti-Correlation??,?? Cluster Mass and Age in the Multiple Population Context
A&A 607, A44 (2017) Astronomy DOI: 10.1051/0004-6361/201731526 & c ESO 2017 Astrophysics NGC 6535: the lowest mass Milky Way globular cluster with a Na-O anti-correlation??,?? Cluster mass and age in the multiple population context A. Bragaglia1, E. Carretta1, V. D’Orazi2; 3; 4, A. Sollima1, P. Donati1, R. G. Gratton2, and S. Lucatello2 1 INAF–Osservatorio Astronomico di Bologna, via Gobetti 93/3, 40129 Bologna, Italy e-mail: [email protected] 2 INAF–Osservatorio Astronomico di Padova, vicolo dell’Osservatorio 5, 35122 Padova, Italy 3 Monash Centre for Astrophysics, School of Physics and Astronomy, Monash University, Melbourne, VIC 3800, Australia 4 Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia Received 7 July 2017 / Accepted 1 August 2017 ABSTRACT To understand globular clusters (GCs) we need to comprehend how their formation process was able to produce their abundance distribution of light elements. In particular, we seek to figure out which stars imprinted the peculiar chemical signature of GCs. One of the best ways is to study the light-element anti-correlations in a large sample of GCs that are analysed homogeneously. As part of our spectroscopic survey of GCs with FLAMES, we present here the results of our study of about 30 red giant member stars in the low-mass, low-metallicity Milky Way cluster NGC 6535. We measured the metallicity (finding [Fe/H] = −1:95, rms = 0.04 dex in our homogeneous scale) and other elements of the cluster and, in particular, we concentrate here on O and Na abundances. -
INFRARED SURFACE BRIGHTNESS FLUCTUATIONS of MAGELLANIC STAR CLUSTERS1 Rosa A
The Astrophysical Journal, 611:270–293, 2004 August 10 A # 2004. The American Astronomical Society. All rights reserved. Printed in U.S.A. INFRARED SURFACE BRIGHTNESS FLUCTUATIONS OF MAGELLANIC STAR CLUSTERS1 Rosa A. Gonza´lez Centro de Radioastronomı´a y Astrofı´sica, Universidad Nacional Autonoma de Me´xico, Campus Morelia, Michoaca´n CP 58190, Mexico; [email protected] Michael C. Liu Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822; [email protected] and Gustavo Bruzual A. Centro de Investigaciones de Astronomı´a, Apartado Postal 264, Me´rida 5101-A, Venezuela; [email protected] Received 2003 November 27; accepted 2004 April 16 ABSTRACT We present surface brightness fluctuations (SBFs) in the near-IR for 191 Magellanic star clusters available in the Second Incremental and All Sky Data releases of the Two Micron All Sky Survey (2MASS) and compare them with SBFs of Fornax Cluster galaxies and with predictions from stellar population models as well. We also construct color-magnitude diagrams (CMDs) for these clusters using the 2MASS Point Source Catalog (PSC). Our goals are twofold. The first is to provide an empirical calibration of near-IR SBFs, given that existing stellar population synthesis models are particularly discrepant in the near-IR. Second, whereas most previous SBF studies have focused on old, metal-rich populations, this is the first application to a system with such a wide range of ages (106 to more than 1010 yr, i.e., 4 orders of magnitude), at the same time that the clusters have a very narrow range of metallicities (Z 0:0006 0:01, i.e., 1 order of magnitude only). -
The Galaxies of the Local Group Sidney Van Den Bergh Index More Information
Cambridge University Press 978-0-521-03743-3 - The Galaxies of the Local Group Sidney van den Bergh Index More information Object Index 30 Doradus, 49, 88, 99, 100, 101, 108, 110, 112–116, DDO 155, 263 121, 124, 131, 134, 135, 139 DDO 187, 263, 279 47 Tucanae, see NGC 104 DDO 210, 5, 7, 194–195, 280, 288 287.5 + 22.5 + 240, 139, 161 DDO 216, 5, 6, 7, 174, 192–194, 280 AE And, 37 DDO 221, 174, 188–191, 280 AF And, see M31V19 DEM 71, 132 Alpha UMi, see Polaris DEM L316, 133 AM 1013-394A, 270, 272 Draco dwarf, 5, 58, 137, 185, 231, 249–252, 256, 259, And I, 5, 234, 235, 236, 237, 242, 280 262, 280 And II, 5, 7, 234, 236, 237, 238, 240, 242, 280 And III, 5, 234, 236, 237, 238, 240, 242, 280 EGB 0419 + 72, 270 And IV, 234 EGB 0427 + 63, see UGC-A92 And V, 5, 7, 237–240, 242, 280 Eridanus, 58, 64, 229 And VI, 5, 7, 240, 241, 242, 280 ESO 121-SC03, 103, 104, 124, 125, 161, 162 And VII, 5, 7, 241, 242, 280 ESO 249-010, 264 Andromeda galaxy, see M31 ESO 439-26, 55 Antlia dwarf, 265–267, 270, 272 Eta Carinae, 37 Aquarius dwarf, see DDO 210 AqrDIG, see DDO 210 F8D1, 2 Arches cluster, see G0.121+0.017 Fornax clusters 1–6, 222, 223, 224 Arp 2, 58, 64, 161, 226, 227, 228, 230, 232 Fornax dwarf 5, 94, 167, 219–226, 231, 256, 259, 260, Arp 220, 113 262, 280 B 327, 24 G 1, 27, 32, 34, 35, 45 BD +40◦ 147, 164 G 105, 35 BD +40◦ 148, 12 G 185, 31 Berkeley 17, 54 G 219, 27, 32 Berkeley 21, 56 G 280, 32 G0.7-0.0, see Sgr B2 C1,20 G0.121 + 0.017, 48 C 107, see vdB0 G1.1-0.1, 49 Camelopardalis dwarf, 241, 242 G359.87 + 0.18, 67 Carina dwarf, 5, 245–247, 256, -
Optical Gravitational Lensing Experiment. Population Effects On
1 The Optical Gravitational Lensing Experiment. Population Effects on the Mean Brightness of the Red Clump Stars ∗ A. U d a l s k i Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland e-mail: [email protected] ABSTRACT We present an empirical test indicating that the mean I-band magnitude of the red clump stars, used as the standard candle in the recent distance determinations to the Magellanic Clouds and other objects, is age independent for intermediate age (2−10 Gyr) stars. Fifteen star clusters of age ≈ 1.5 − 12 Gyr from the LMC and SMC (ESO121SC03, SL663, NGC 2155, NGC 2121, SL388, SL862, NGC 121, L1, KRON3, NGC 416, L113, NGC 339, L11, NGC 419, NGC 411) were observed and their color-magnitude diagrams are presented. The mean I-band brightness of the red clump in these clusters is constant and its mean extinction-free magnitude is: I0 =17.88±0.05 mag and I0 =18.31±0.07 mag at the mean metallicity of −0.8 dex and −1.2 dex for the LMC and SMC clusters, respectively. For older objects (> 10 Gyr) the brightness of the red clump, which converts into the red part of the horizontal branch, fades by about 0.3−0.4 mag, setting an important limitation on the red clump stars method of distance determination. The red clump distance moduli to the Magellanic Clouds from the new independent data set are: m − M = 18.18 ± 0.06 mag and m − M = 18.65 ± 0.08 mag for the LMC and SMC, respectively, in very good agreement with previous determinations. -
Age and Metallicity of Star Clusters in the Small Magellanic Cloud from Integrated Spectroscopy
A&A 520, A85 (2010) Astronomy DOI: 10.1051/0004-6361/200912894 & c ESO 2010 Astrophysics Age and metallicity of star clusters in the Small Magellanic Cloud from integrated spectroscopy B. Dias1,P.Coelho2,B.Barbuy1,L.Kerber1,3, and T. Idiart1 1 Universidade de São Paulo, Dept. de Astronomia, Rua do Matão 1226, São Paulo 05508-090, Brazil e-mail: [bdias;barbuy;idiart;kerber]@astro.iag.usp.br 2 Núcleo de Astrofísica Teórica – Universidade Cruzeiro do Sul, R. Galvão Bueno, 868, sala 105, Liberdade, 01506-000, São Paulo, Brazil e-mail: [email protected] 3 Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna km16, 45662-000 Ilhéus, Bahia, Brazil Received 15 July 2009 / Accepted 17 April 2010 ABSTRACT Context. Analysis of ages and metallicities of star clusters in the Magellanic Clouds provide information for studies on the chemical evolution of the Clouds and other dwarf irregular galaxies. Aims. The aim is to derive ages and metallicities from integrated spectra of 14 star clusters in the Small Magellanic Cloud, including a few intermediate/old age star clusters. Methods. Making use of a full-spectrum fitting technique, we compared the integrated spectra of the sample clusters to three different sets of single stellar population models, using two fitting codes available in the literature. Results. We derive the ages and metallicities of 9 intermediate/old age clusters, some of them previously unstudied, and 5 young clusters. Conclusions. We point out the interest of the newly identified as intermediate/old age clusters HW1, NGC 152, Lindsay 3, Lindsay 11, and Lindsay 113.