DOCSLIB.ORG

Dust Evolution in Galaxy Cluster Simulations

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Dust Evolution in Galaxy Cluster Simulations Università degli Studi di trieste Dipartimento di Fisica Divisione di Astrofisica Dust Evolution in Galaxy Cluster Simulations PhD Candidate: Supervisor: Eda Gjergo Dr. Gian Luigi Granato School Coordinator: Co-Supervisor: Livio Lanceri Dr. Giuseppe Murante School Coordinator: Academic Advisor: Livio Lanceri Prof. Stefano Borgani January 30, 2019 Doctoral Thesis Academic Year 2017:2018 Cycle XXXI Dust Evolution in Galaxy Cluster Simulations EDA GJERGO Department of Physics Division Astrophysics University of Trieste Trieste, Italy 2018 Dust Evolution in Galaxy Cluster Simulations EDA GJERGO Department of Physics, Astrophysics Division University of Trieste © EDA GJERGO, 2018. PhD Candidate: Eda Gjergo Supervisor: Dr. Gian Luigi Granato, INAF Astronomical Observatory of Trieste Referee: Prof. Alessandro Bressan, SISSA International School for Advanced Studies Referee: Prof. Manolis Plionis, Aristotle University of Thessaloniki Doctoral Thesis 2018:2019 Department of Physics Astrophysics Division University of Trieste Via Bazzoni 2, Trieste, 34143 Telephone +39 040 3199 133 Email [email protected] A thesis submitted in fulfillment of the requirements for the degre of Doctor Philosophiae in Physics Typeset in LATEX Trieste, Italy 2018 iv Abstract Gaseous astrophysical media are splattered with solid agglomerates of molecules we call cosmic dust. Dust ranges in size between a few Angstroms and a few microns. While dust accounts only for one percent of the mass in the interstellar medium (ISM) of a Milky Way-like galaxy, it reprocesses about a third of its starlight, mostly in the UV and optical bands, and reemits it in the infrared. It is almost impossible to interpret correctly the spectral energy distribution (SED) of a galaxy without accounting for dust in some way. Dust affects not only the observation but also the evolution of galaxies. In fact, its surface is a catalyst for the formation of molecules, most important of which is H2. These molecules are efficient gas coolants and accelerate the gravitational collapse of molecular clouds, the cradles for star formation. Observations, in particular, are quite sensitive to dust properties such as compo- sition and grain size. A need emerges to include dust within theoretical models of galaxy and galaxy cluster evolution. The INAF Astronomical Observatory of Trieste, among other things, has developed a custom state-of-the-art cosmological N-body simulation of galaxy clusters based on the GADGET-3 code. The code cal- culates dynamics with a tree-Particle-Mesh method, where the simulated ‘particles’ actually represent massive ensembles of substances of different types, specifically dark matter, gas, stars, and black holes. The interactions between gas particles are treated with Smoothed-Particle Hydrodynamics, there is also star formation, radiative cooling, stellar and active galactic nuclei (AGN) feedback, and chemical evolution by stellar nucleosynthesis. Adding dust to this framework however has not been feasible until now. Tracing the continuous grain size (or its discrete approximation) would burden with ad- ditional dimensions the already heavy particle structure and calculations, slowing down the runs to impractical rates. Dust was instead treated in post processing v Abstract (Granato et al., 2015), and its properties were assumed a priori. Then Hirashita (2015) proposed an approximation. Instead of computing the grain size continuum, he postulated that dust grains are divided between large (nominally 0.1µm) and small (nominally 0.01µm). He therefore adapted a comprehensive one-zone dust evolution model (Asano et al., 2013) to this approximation. The binary grain size distribution was selected for both observational and modeling reasons. When dust grains are produced in the envelopes of evolved stars or in supernova remnants, the dominant size is around 0.1µm. In the ISM however, smaller dust is often just as prevalent or at times even dominant. This suggests that ISM evolution alters the grain size distribution. The phenomenon is captured in the modeling. Some processes are most efficient on one grain size over the other, or at times they have opposite effects on each size domain. We successfully adapted the Hirashita(2015) model to our custom GADGET-3 cos- mological zoom-in simulation code, specifically we embedded the model so that each simulated gas particle will trace, on top of the usual gas elements obtained from stel- lar and supernovae yields, also small and large dust grains. We tested our method on 14 15 four massive ( two M200 ≥ 3 × 10 M and two M200 ≥ ×10 M ) galaxy clusters. We also improved on previous dust production routines, which assumed a fixed dust condensation efficiency for each element. Instead, we form the two most representa- tive dust species observed in nature: carbonaceous dust and astrophysical silicates, based on the element abundance produced by stellar or supernovae yields. At the peak of star formation activity at z & 3 when proto-clusters start to assemble, we find that the gas particles in our simulations are rich in dust, as expected. In order to test the impact of dust processes on dust growth other than stellar production, we ran simulations with dust production and destruction alone, without any grain-gas or grain-grain interactions. Dust is enhanced by a factor of two to three due to the processes occurring in the ISM. We investigated variations of the model through different runs to understand the interdependence of all the processes. We were able to reproduce the dust abundance to metallicity relations observed in local galaxies, however we under-produced the dust content of galaxy clusters around z . 0.5 observed by IRAS, Planck, and Herschel observations. This discrepancy can be mended only by assuming a lower sputtering efficiency, which erodes dust grains in the hot Intracluster Medium (ICM). The abundance of the two dust species, silicates and carbonaceous dust, is also slightly different from the Milky Way average, and from the common values adopted in calculations of dust reprocessing. These differences may have a strong impact on the predicted SED. This method lays the vi Abstract groundwork for further developments, such as cosmological simulations of single galaxies, , or the refinement of radiative cooling routines with H2 catalysis on grain surfaces. vii Abstract viii Dedication I am indebted to a long list of mentors and friends which have inspired me and will continue to do so for many years to come. First of all, I would like to thank my primary supervisor Gian Luigi Granato for disciplining my enthusiasm into a more attentive, careful, and critical approach to scientific research. I am grateful for his painstaking guidance over these years, and for the constructive discussions. I appreciate Giuseppe Murante’s generosity in sharing his knowledge and for always finding the time to help everyone. I owe him a great deal of my improvements in computing. I am lucky to have been inspired by Stefano Borgani’s humble excellence and passion for cosmological research. I benefited from fruitful conversations with PierLuigi Monaco who impressed me with a sharp and clear mind. Special thanks to Francesca Matteucci who, while not an official supervisor, has been a pillar of strength to me with her warmth, passionate character, and dynamic scientific in- tuition. I value the support and optimism I received from her through thick and thin. Thanks to Steve Kuhlmann, for being beyond a supervisor, a dear friend, for in- troducing me to the world of research with countless opportunities. Thank you for believing in my potential and for encouraging me to pursue a career in Astro- physics. Thanks to Arthur Lubin for inspiring me with his resilience, charisma, love of mathematics, and ability to always let me see and seek the big picture. Thanks to Yurii Shylnov for being one of the most honest, humble, yet excellent professors I have ever had. Thanks to Salman Habib, Katrin Heitmann, Sergei Shandarin, for the scientific perspicacity and thought-provoking conversations. Thanks to Fabio Pasian for encouraging me to apply to the PhD program in the first place. Thanks to Cinthia Ragone-Fuguera, Gabriella de Lucia, Gabriele Cescutti, Andrea Biviano, Emiliano Sefusatti, Emiliano Munari, Elena Rasia, Barbara Sartoris, Fabio Fontanot, Veronica Biffi, Umberto Maio, David Goz, Alex Saro, and Marta Spinelli for galvanizing my scientific curiosity with the arrays of research fields and person- alities they havex exposed me to. Thanks to my fellow PhD students who showed me excellence does not come at the cost of a balanced life, but because of it. Thanks ix Dedication to my friends Emanuele Spitoni, Fiorenzo Vincenzo, Lorenzo Gioannini, Carlo De Masi, Valeria Grisoni, Anna Zoldan, Chiara Moretti, Luigi Bassini, Federico Rizzo, Paolo Simonetti, Dan Eckhart, and Angela Faust, whom between jokes, intellec- tual curiosity, authenticity, and originality, brought fun into my days, softened my quarter-life crisis, and affected my outlook on important issues. Thanks to my dearest friends Carlo e Zina Magnelli, Linda Corsi, and Maria Luisa Princivalli, whose wisdom, optimism, affection, knowledge, and spiritual generosity brightened my life when I needed it most. You are like family. Margherita Hack, your memory lives within me every day. You showed me a way of being I aspire to master, with your relentless dedication, pure heart, minimalist lifestyle, scientific enterprise, devotion to humanity, to nature, to fairness. Thank you for having opened your heart to me and for believing in me from the very start. Dear Aldo de Rosa, I treasure you more than you could remember in your last years. I will never forget how nurturing, affectionate, and encouraging you’ve been to me, and how you helped me grow in between jokes and tease. I owe any and all of my achievements to my mother, who raised me to value integrity, kindness, justice, and excellence, and who devoted every ounce of herself to help me grow every day. Thank you for your unconditional love and positivity, for your trust and encouragement.
Load more

Recommended publications
  • Arxiv:1802.01597V1 [Astro-Ph.GA] 5 Feb 2018 Born 1991)
    Astronomy & Astrophysics manuscript no. AA_2017_32084 c ESO 2018 February 7, 2018 Mapping the core of the Tarantula Nebula with VLT-MUSE? I. Spectral and nebular content around R136 N. Castro1, P. A. Crowther2, C. J. Evans3, J. Mackey4, N. Castro-Rodriguez5; 6; 7, J. S. Vink8, J. Melnick9 and F. Selman9 1 Department of Astronomy, University of Michigan, 1085 S. University Avenue, Ann Arbor, MI 48109-1107, USA e-mail: [email protected] 2 Department of Physics & Astronomy, University of Sheffield, Hounsfield Road, Sheffield, S3 7RH, UK 3 UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ, UK 4 Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin, Ireland 5 GRANTECAN S. A., E-38712, Breña Baja, La Palma, Spain 6 Instituto de Astrofísica de Canarias, E-38205 La Laguna, Spain 7 Departamento de Astrofísica, Universidad de La Laguna, E-38205 La Laguna, Spain 8 Armagh Observatory and Planetarium, College Hill, Armagh BT61 9DG, Northern Ireland, UK 9 European Southern Observatory, Alonso de Cordova 3107, Santiago, Chile February 7, 2018 ABSTRACT We introduce VLT-MUSE observations of the central 20 × 20 (30 × 30 pc) of the Tarantula Nebula in the Large Magellanic Cloud. The observations provide an unprecedented spectroscopic census of the massive stars and ionised gas in the vicinity of R136, the young, dense star cluster located in NGC 2070, at the heart of the richest star-forming region in the Local Group. Spectrophotometry and radial-velocity estimates of the nebular gas (superimposed on the stellar spectra) are provided for 2255 point sources extracted from the MUSE datacubes, and we present estimates of stellar radial velocities for 270 early-type stars (finding an average systemic velocity of 271 ± 41 km s−1).
    [Show full text]
  • 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
    [Show full text]
  • Arxiv:1803.10763V1 [Astro-Ph.GA] 28 Mar 2018
    Draft version October 10, 2018 Typeset using LATEX default style in AASTeX61 TRACERS OF STELLAR MASS-LOSS - II. MID-IR COLORS AND SURFACE BRIGHTNESS FLUCTUATIONS Rosa A. Gonzalez-L´ opezlira´ 1 1Instituto de Radioastronomia y Astrofisica, UNAM, Campus Morelia, Michoacan, Mexico, C.P. 58089 (Received 2017 October 20; Revised 2018 February 20; Accepted 2018 February 21) Submitted to ApJ ABSTRACT I present integrated colors and surface brightness fluctuation magnitudes in the mid-IR, derived from stellar popula- tion synthesis models that include the effects of the dusty envelopes around thermally pulsing asymptotic giant branch (TP-AGB) stars. The models are based on the Bruzual & Charlot CB∗ isochrones; they are single-burst, range in age from a few Myr to 14 Gyr, and comprise metallicities between Z = 0.0001 and Z = 0.04. I compare these models to mid-IR data of AGB stars and star clusters in the Magellanic Clouds, and study the effects of varying self-consistently the mass-loss rate, the stellar parameters, and the output spectra of the stars plus their dusty envelopes. I find that models with a higher than fiducial mass-loss rate are needed to fit the mid-IR colors of \extreme" single AGB stars in the Large Magellanic Cloud. Surface brightness fluctuation magnitudes are quite sensitive to metallicity for 4.5 µm and longer wavelengths at all stellar population ages, and powerful diagnostics of mass-loss rate in the TP-AGB for intermediater-age populations, between 100 Myr and 2-3 Gyr. Keywords: stars: AGB and post{AGB | stars: mass-loss | Magellanic Clouds | infrared: stars | stars: evolution | galaxies: stellar content arXiv:1803.10763v1 [astro-ph.GA] 28 Mar 2018 Corresponding author: Rosa A.
    [Show full text]
  • Multiple Stellar Populations in Magellanic Cloud Clusters. VI. A
    Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 1 March 2018 (MN LATEX style file v2.2) Multiple stellar populations in Magellanic Cloud clusters.VI. A survey of multiple sequences and Be stars in young clusters A. P.Milone1,2, A. F. Marino2, M. Di Criscienzo3, F. D’Antona3, L.R.Bedin4, G. Da Costa2, G. Piotto1,4, M. Tailo5, A. Dotter6, R. Angeloni7,8, J.Anderson9, H. Jerjen2, C. Li10, A. Dupree6, V.Granata1,4, E. P.Lagioia1,11,12, A. D. Mackey2, D. Nardiello1,4, E. Vesperini13 1Dipartimento di Fisica e Astronomia “Galileo Galilei”, Univ. di Padova, Vicolo dell’Osservatorio 3, Padova, IT-35122 2Research School of Astronomy & Astrophysics, Australian National University, Canberra, ACT 2611, Australia 3Istituto Nazionale di Astrofisica - Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio Catone, Roma, Italy 4Istituto Nazionale di Astrofisica - Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova, IT-35122 5 Dipartimento di Fisica, Universita’ degli Studi di Cagliari, SP Monserrato-Sestu km 0.7, 09042 Monserrato, Italy 6 Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA 7 Departamento de Fisica y Astronomia, Universidad de La Serena, Av. Juan Cisternas 1200 N, La Serena, Chile 8 Instituto de Investigacion Multidisciplinar en Ciencia y Tecnologia, Universidad de La Serena, Raul Bitran 1305, La Serena, Chile 9Space Telescope Science Institute, 3800 San Martin Drive, Baltimore, MD 21218, USA 10 Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia 11Instituto de Astrof`ısica de Canarias, E-38200 La Laguna, Tenerife, Canary Islands, Spain 12Department of Astrophysics, University of La Laguna, E-38200 La Laguna, Tenerife, Canary Islands, Spain 13Department of Astronomy, Indiana University, Bloomington, IN 47405, USA Accepted 2018 February 27.
    [Show full text]
  • 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).
    [Show full text]
  • Wolf–Rayet Star
    Wolf–Rayet star Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon. The spectra indicate very high surface enhancement of heavy elements, depletion of hydrogen, and strong stellar winds. Their surface temperatures range from 30,000 K to around 200,000 K, hotter than almost all other stars. They were previously called W-type stars referring to their spectral classification. Classic (or Population I) Wolf–Rayet stars are evolved, massive stars that have completely lost their outer hydrogen and are fusing helium or heavier elements in the core. A subset of the population I WR stars show hydrogen lines in their spectra and are known as WNh stars; they are young extremely massive stars still fusing hydrogen at the core, with helium and nitrogen exposed at the surface by strong mixing and radiation-driven Hubble Space Telescope image of nebula M1-67 mass loss. A separate group of stars with WR spectra are the around Wolf–Rayet star WR 124. central stars of planetary nebulae (CSPNe), post asymptotic giant branch stars that were similar to the Sun while on the main sequence, but have now ceased fusion and shed their atmospheres to reveal a bare carbon-oxygen core. All Wolf–Rayet stars are highly luminous objects due to their high temperatures—thousands of times the bolometric luminosity of the Sun (L☉) for the CSPNe, hundreds of thousands L☉ for the Population I WR stars, to over a million L☉ for the WNh stars —although not exceptionally bright visually since most of their radiation output is in the ultraviolet.
    [Show full text]
  • A Large and Homogeneous Sample of Cmds of LMC Stellar Clusters
    Extragalactic Star Clusters fA U Symposium Series, Vol. 207, 2002 Doug Geisler, Eva K. Grebel, and Dante Minniti, eds. A Large and Homogeneous Sample of CMDs of LMC Stellar Clusters Enzo Brocato Osservatorio Astronomico di Teramo, Via Maggini, 1-64100 Teramo, Italy, (email: [email protected]) Elisa Di Carlo Osservatorio Astronomico di Teramo, Via Maggini, 1-64100 Teramo, Italy, (email: [email protected]) Abstract. We present the photometric results of 21 stellar clusters of the Large Magellanic Cloud. The WFPC2 images were retrieved from the HST archive. Simple stellar populations in a large spread of age are well rep- resented in the sample of color-magnitude diagrams shown here. 1. Introduction and data reduction LMC stellar clusters represent an appealing opportunity of probing our under- standing of stellar populations in a wide range of age. Clearly, one of the most powerful tools for this purpose is to study their CMDs. The HST collected a number of images all along the years and we decided to use the archive facility 'to derive a set of homogeneous CMDs for the LMC clusters. All the images were retrieved from the HST archive as observed with the WFPC2 camera in the filters F450W and F555W. DAOPHOT II (Stetson 1987) was used to obtain the instrumental magnitudes. We followed Dolphin (2000) to derive the calibrated magnitudes and colors. We find good agreement (within ~ 0.1 mag) between our data and the results of Sarajedini (1998) for the common clusters NGC 2155, SL 663, and NGC 2121. We performed an additional check of our photometry by comparing our data of NGC 2257 to the ground based photometry by Walker (1989).
    [Show full text]
  • Mass Segregation in Young LMC Clusters I. 1
    CORE Metadata, citation and similar papers at core.ac.uk Provided by CERN Document Server Mass segregation in young LMC clusters I. 1 2001 Mon. Not. R. Astron. Soc. 000, 000–000 (2001) Mass segregation in young compact star clusters in the Large Magellanic Cloud: I. Data and Luminosity Functions R. de Grijs?, R.A. Johnson , G.F. Gilmore and C.M. Frayn Institute of Astronomy, University of Cambridge,† Madingley Road, Cambridge CB3 0HA Accepted —. Received —; in original form —. ABSTRACT We have undertaken a detailed analysis of HST/WFPC2 and STIS imaging observa- tions, and of supplementary wide-field ground-based observations obtained with the NTT of two young ( 10 25 Myr) compact star clusters in the LMC, NGC 1805 and NGC 1818. The ultimate∼ goal− of our work is to improve our understanding of the degree of primordial mass segregation in star clusters. This is crucial for the interpretation of observational luminosity functions (LFs) in terms of the initial mass function (IMF), and for constraining the universality of the IMF. We present evidence for strong luminosity segregation in both clusters. The LF slopes steepen with cluster radius; in both NGC 1805 and NGC 1818 the LF slopes reach a stable level well beyond the clusters' core or half-light radii. In addition, the brightest cluster stars are strongly concentrated within the inner 4Rhl. The global cluster LF, although strongly nonlinear, is fairly∼ well approximated by the core or half-light LF; the (annular) LFs at these radii are dominated by the segregated high-luminosity stars, however. We present tentative evidence for the presence of an excess number of bright stars surrounding NGC 1818, for which we argue that they are most likely massive stars that have been collisionally ejected from the cluster core.
    [Show full text]
  • Large Magellanic Cloud Stellar Clusters
    A&A 374, 523–539 (2001) Astronomy DOI: 10.1051/0004-6361:20010711 & c ESO 2001 Astrophysics Large Magellanic Cloud stellar clusters I. 21 HST colour magnitude diagrams?;?? E. Brocato1;2,E.DiCarlo1;3, and G. Menna1 1 Osservatorio Astronomico di Collurania, Via M. Maggini, 64100 Teramo, Italy 2 Istituto Nazionale di Fisica Nucleare, LNGS, L'Aquila, Italy 3 Area di ricerca in Astrogeofisica, L'Aquila, Italy e-mail: brocato, [email protected] Received 22 June 2000 / Accepted 9 March 2001 Abstract. We present WFPC2 photometry of 21 stellar clusters of the Large Magellanic Cloud obtained on images retrieved from the Hubble Space Telescope archive. The derived colour magnitude diagrams (CMDs) are presented and discussed. This database provides a sample of CMDs representing, with reliable statistics, simple stellar populations with a large spread of age. The stars in the core of the clusters are all resolved and measured at least down to the completeness limit; the magnitudes of the main sequence terminations and of the red giant clump are also evaluated for each cluster, together with the radius at half maximum of the star density. Key words. Galaxy: globular clusters: general { galaxies: evolution { galaxies: Magellanic Clouds 1. Introduction 1998), iii) to evaluate the age of the oldest clusters in this galaxy (Walker 1989, 1990, 1992, 1993a,b; Testa et al. The Large Magellanic Cloud (LMC) offers a unique oppor- 1995; Brocato et al. 1996; Olsen et al. 1998) and iv) tunity to investigate bright populous stellar systems span- to study the luminosity function of MC clusters (Mateo ning a wide range of age and located at a distance short 1988).
    [Show full text]
  • THE MAGELLANIC CLOUDS NEWSLETTER an Electronic Publication Dedicated to the Magellanic Clouds, and Astrophysical Phenomena Therein
    THE MAGELLANIC CLOUDS NEWSLETTER An electronic publication dedicated to the Magellanic Clouds, and astrophysical phenomena therein No. 127 — 1 February 2014 http://www.astro.keele.ac.uk/MCnews Editor: Jacco van Loon Editorial Dear Colleagues, friends, It is my pleasure to present you the 127th issue of the Magellanic Clouds Newsletter. It’s been a little quieter, blame the holidays, bless you. Other distractions of life, perhaps. No worries: The Clouds will be up there for a while still. Plenty on supernova remnants though, and evolved stars and their remnants in general. Check out a fantastic opportunity to work with an inspiring scientist in an amazing team at the Space Telescope Science Institute! The next issue is planned to be distributed on the 1st of April. Have an intense but safe 2014. Editorially Yours, Jacco van Loon 1 Refereed Journal Papers Optical spectra of 5 new Be/X-ray Binaries in the Small Magellanic Cloud and the link of the supergiant B[e] star LHA 115-S 18 with an X-ray source Grigoris Maravelias1, Andreas Zezas1,2,3, Vallia Antoniou3,4 and Despoina Hatzidimitriou5 1University of Crete, Physics Department & Institute of Theoretical & Computational Physics, Heraklion, Greece 2Foundation for Research and Technology-Hellas, Institute of Electronic Structure & Laser, Heraklion, Greece 3Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA 4Iowa State University, Department of Physics & Astronomy, Ames, IA, USA 5University of Athens, Department of Physics, Section of Astrophysics, Astronomy, and Mechanics, Athens, Greece The Small Magellanic Cloud (SMC) is well known to harbor a large number of High-Mass X-ray Binaries (HMXBs).
    [Show full text]
  • Arxiv:0705.3464V1
    DRAFT VERSION JUNE 22, 2021 Preprint typeset using LATEX style emulateapj v. 08/22/09 SURFACE BRIGHTNESS PROFILES FOR A SAMPLE OF LMC, SMC AND FORNAX GALAXY GLOBULAR CLUSTERS E. NOYOLA Astronomy Department, University of Texas at Austin, TX 78712 and Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraçe 85748, Garching K. GEBHARDT Astronomy Department, University of Texas at Austin, TX 78712 Draft version June 22, 2021 ABSTRACT We use Hubble Space Telescope archival images to measure central surface brightness profiles of globular clusters around satellite galaxies of the Milky Way. We report results for 21 clusters around the LMC, 5 around the SMC, and 4 aroundthe Fornaxdwarf galaxy. The profiles are obtained using a recently developed technique based on measuring integrated light, which is tested on an extensive simulated dataset. Our results show that for 70% of the sample, the central photometric points of our profiles are brighter than previous measurements using star counts with deviations as large as 2 mag/acrsec2. About 40% of the objects have central profiles deviating from a flat central core, with central logarithmic slopes continuously distributed between -0.2 and -1.2. These results are compared with those found for a sample of Galactic clusters using the same method. We confirm the known correlation in which younger clusters tend to have smaller core radii, and we find that they also have brighter central surface brightness values. This seems to indicate that globular clusters might be born relatively concentrated, and that a profile with extended flat cores might not be the ideal choice for initial profiles in theoretical models.
    [Show full text]
  • Spectroscopy of Binaries in Globular Clusters
    Spectroscopy of Binaries in Globular Clusters Dissertation for the award of the degree “Doctor rerum naturalium” (Dr.rer.nat.) of the Georg-August-Universität Göttingen within the doctoral program PROPHYS of the Georg-August University School of Science (GAUSS) submitted by Benjamin David Giesers from Oldenburg Göttingen, 2019 Thesis Commitee Prof. Dr. Stefan Dreizler Sonnenphysik und Stellare Astrophysik, Institut für Astrophysik, Georg-August-Universität Göttingen, Germany Dr. Sebastian Kamann Star formation and stellar populations, Astrophysics Research Institute, Liverpool John Moores University, United Kingdom Dr. Tim-Oliver Husser Stellare Astrophysik, Institut für Astrophysik, Georg-August-Universität Göttingen, Germany Members of the Examination Board Reviewer: Prof. Dr. Stefan Dreizler Sonnenphysik und Stellare Astrophysik, Institut für Astrophysik, Georg-August-Universität Göttingen, Germany Second Reviewer: Prof. Dr. Ulrich Heber Stellare Astrophysik, Dr. Karl Remeis Sternwarte, Friedrich-Alexander-Universität Erlangen- Nürnberg, Germany Further members of the Examination Board: Dr. Saskia Hekker Stellar Ages and Galactic Evolution, Max-Planck-Institut für Sonnensystemforschung, Göttin- gen, Germany Prof. Dr. Wolfram Kollatschny Extragalaktische Astrophysik, Institut für Astrophysik, Georg-August-Universität Göttingen, Germany Prof. Dr. Wolfgang Glatzel Sonnenphysik und Stellare Astrophysik, Institut für Astrophysik, Georg-August-Universität Göttingen, Germany PD Dr. Jörn Große-Knetter Kern- und Atomphysik, II. Physikalisches Institut, Georg-August-Universität Göttingen, Ger- many Date of the oral examination: 13 December 2019 Abstract The natural constants in the universe are adjusted so that dense and massive star forming re- gions can end up in gravitational bound star clusters, called globular clusters. These objects are found in all galaxies and are building blocks of galaxies and the universe. The kinematic properties of globular clusters cannot be explained by that of a population consisting only of single stars.
    [Show full text]