DOCSLIB.ORG

Download This Article in PDF Format

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Download This Article in PDF Format A&A 623, A129 (2019) Astronomy https://doi.org/10.1051/0004-6361/201833458 & c ESO 2019 Astrophysics Gaia DR 2 and VLT/FLAMES search for new satellites of the LMC?,?? T. K. Fritz1,2, R. Carrera3, G. Battaglia1,2, and S. Taibi1,2 1 Instituto de Astrofisica de Canarias, Calle Via Lactea s/n, 38205 La Laguna, Tenerife, Spain e-mail: [email protected] 2 Universidad de La Laguna, Dpto. Astrofisica, 38206 La Laguna, Tenerife, Spain 3 INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy Received 20 May 2018 / Accepted 13 February 2019 ABSTRACT A wealth of tiny galactic systems populates the surroundings of the Milky Way. However, some of these objects might have origi- nated as former satellites of the Magellanic Clouds, in particular of the Large Magellanic Cloud (LMC). Examples of the importance of understanding how many systems are genuine satellites of the Milky Way or the LMC are the implications that the number and luminosity-mass function of satellites around hosts of different mass have for dark matter theories and the treatment of baryonic physics in simulations of structure formation. Here we aim at deriving the bulk motions and estimates of the internal velocity dis- persion and metallicity properties in four recently discovered distant southern dwarf galaxy candidates, Columba I, Reticulum III, Phoenix II, and Horologium II. We combined Gaia DR2 astrometric measurements, photometry, and new FLAMES/GIRAFFE intermediate-resolution spectroscopic data in the region of the near-IR Ca II triplet lines; this combination is essential for finding potential member stars in these low-luminosity systems. We find very likely member stars in all four satellites and are able to deter- mine (or place limits on) the bulk motions and average internal properties of the systems. The systems are found to be very metal poor, in agreement with dwarf galaxies and dwarf galaxy candidates of similar luminosity. Of these four objects, we can only firmly place +6:8 −1 Phoenix II in the category of dwarf galaxies because of its resolved high velocity dispersion (9:5−4:4 km s ) and intrinsic metallicity spread (0.33 dex). For Columba I we also measure a clear metallicity spread. The orbital pole of Phoenix II is well constrained and close to that of the LMC, suggesting a prior association. The uncertainty on the orbital poles of the other systems is currently very large, so that an association cannot be excluded, except for Columba I. Using the numbers of potential former satellites of the LMC +1:3 11 identified here and in the literature, we obtain for the LMC a dark matter mass of M200 = 1:9−0:9 × 10 M . Key words. proper motions – stars: abundances – galaxies: dwarf – galaxies: kinematics and dynamics 1. Introduction This might be interpreted as a qualitative confirmation of one of the predictions of the ΛCDM hierarchical formation framework. In the Λ cold dark matter (ΛCDM) framework, not only large Recently, about two dozen low-luminosity candidate dwarf galaxies, but also low-mass halos are expected to host their own galaxies were discovered at projected locations in the sky close systems of satellite sub-halos. How many of these will con- to the Magellanic Clouds (Drlica-Wagner et al. 2015; Koposov tain a luminous component depends on several variables, among et al. 2015a, 2018; Martin et al. 2015; Bechtol et al. 2015; which the mass of the host halo, the mass and build-up history Laevens et al. 2015; Torrealba et al. 2018a; Kim & Jerjen 2015; of the sub-halos themselves, and various environmental factors, Kim et al. 2015). This has of course raised the question whether including the strength of the UV-ionizing background (see, e.g., some of these systems might be, or were before infall, part of the review by Bullock & Boylan-Kolchin 2017 and references a satellite system of the Clouds rather than of the Milky Way therein). (MW). Determining how many and which of these dwarf satel- Several low-luminosity galaxies have been detected that lites might have been brought in by the Clouds would give might be physically associated with stellar systems with masses insights into several aspects of galaxy formation in a cosmolog- similar to or lower than that of the LMC (e.g., Antlia A and ical context: in addition to improving the current observational the recently discovered Antlia B around NGC 3109, Sand et al. information on the properties of satellite systems around galax- 2015; Scl-MM-Dw1 around NGC 253, Sand et al. 2014); in ies of lower mass than the MW, it would allow us to further some cases, the “status” of satellite galaxy is guaranteed by the consider the efficiency of galaxy formation at the low-mass end ongoing tidal disruption of such systems (e.g., Rich et al. 2012; (see, e.g., Dooley et al. 2017), and might imply a revision of our Amorisco et al. 2014; Annibali et al. 2016; Toloba et al. 2016). understanding of the properties of the MW satellite system itself in terms of the number of its members as well as its luminosity ? Full Table 2 is only available at the CDS via anonymous ftp and circular velocity function. Identifying which of these dwarf to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc. galaxies in particular might be or have been associated with the u-strasbg.fr/viz-bin/qcat?J/A+A/623/A129 Clouds also provides a direct way to start addressing the effects ?? Based on ESO programs 096.B-0785(A) and 098.B-0419(A). of group preprocessing onto the observed properties of dwarf Article published by EDP Sciences A129, page 1 of 15 A&A 623, A129 (2019) galaxies from the specific perspective of resolved stellar popula- An important general conclusion from these works is that tion studies. knowledge of the systemic radial velocities, combined with sky The number of satellites that could be associated with sys- position and distance, can greatly aid in the identification of pre- tems with stellar masses similar to the Magellanic Clouds has vious Magellanic Cloud satellites. In particular, the most com- been predicted, and in which stellar mass range they should be pelling evidence for association is expected to be provided by found (see, e.g., Dooley et al. 2017). Dooley and collaborators the additional information afforded by knowledge of systemic concluded that there is a dearth of “massive” satellites around proper motions because the accreted galaxies are expected to the Large and Small Magellanic Clouds (LMC and SMC); this share a similar direction of the orbital angular momentum of the could imply a Magellanic Cloud “missing satellite problem”, LMC. although other solutions are possible, such as strong modifica- With the second Gaia mission (Gaia Collaboration 2016) tions to abundance-matching relations (which at the low-mass data release (GDR2; Gaia Collaboration 2018a), the situation end are very uncertain, see, e.g., Garrison-Kimmel et al. 2017; has dramatically improved: not only has the accuracy of the Revaz & Jablonka 2018, and references therein) and strong tidal systemic proper motions of the classical MW dwarf spheroidal stripping. galaxies (dSphs)1 been significantly improved in several cases Several studies have instead focused on predicting which (Gaia Collaboration 2018b), but such determination has finally of the dwarf galaxies found in the surroundings of the MW become possible for dozens of the ultra-faint dwarf galaxies could have been brought in by the Magellanic system (Sales (UFDs; Fritz et al. 2018a; Kallivayalil et al. 2018; Massari & et al. 2011, 2017; Deason et al. 2015; Yozin & Bekki 2015; Helmi 2018; Simon 2018), while before only Segue 1 had a sys- Jethwa et al. 2016). Of these, Deason et al.(2015) used the temic proper motion measurement (Fritz et al. 2018b). All of the ELVIS N-body simulations to identify LMC-mass sub-haloes of above is in a common, absolute reference system. MW/M31-like systems (considering virial masses in the range Kallivayalil et al.(2018, hereafter K18) used the Sales et al. 11 1–3 × 10 M ) and showed that the system of satellites rapidly (2011, 2017) LMC analog to test a possible association with the disperses in phase-space unless the group has infallen recently. LMC for 32 UFDs with MV & −8. For the systems for which The sample of 25 LMC analogs included three dynamical 3D velocities could be obtained, given the additional availability analogs (with similar radial and tangential velocity as observed of published spectroscopic data, they concluded that four (Hor I, for the LMC): the expectations in these cases are that the sub- Car II, Car III, and Hyd I) were former satellites of the Clouds, halos found at z = 0 within ∼50 kpc, or with a 3D velocity dif- while Hyd II and Dra II could be reconciled with a model allow- fering by less ∼50 km s−1, from the original host have a chance ing for a larger dispersion of the tidal debris properties in veloc- higher than 50% to have been part of an LMC-mass group. ity and distance or sky location. Nonetheless, for the whole sample considered together, systems For the systems that lacked either systemic proper motion within 50 kpc and 50 km s−1 of an LMC-mass dwarf at z = 0 and/or radial velocity measurements at the times of the stud- would have a >90% probability of having been former group ies, predictions are provided in several of the works cited above members. under the assumption of a prior physical association to the Mag- Sales et al.(2017) used the LMC analog identified in Sales ellanic system.
Load more

Recommended publications
  • Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects
    Juliana Crestani Ribeiro de Souza Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects Porto Alegre 2017 Juliana Crestani Ribeiro de Souza Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects Dissertação elaborada sob orientação do Prof. Dr. Eduardo Luis Damiani Bica, co- orientação do Prof. Dr. Charles José Bon- ato e apresentada ao Instituto de Física da Universidade Federal do Rio Grande do Sul em preenchimento do requisito par- cial para obtenção do título de Mestre em Física. Porto Alegre 2017 Acknowledgements To my parents, who supported me and made this possible, in a time and place where being in a university was just a distant dream. To my dearest friends Elisabeth, Robert, Augusto, and Natália - who so many times helped me go from "I give up" to "I’ll try once more". To my cats Kira, Fen, and Demi - who lazily join me in bed at the end of the day, and make everything worthwhile. "But, first of all, it will be necessary to explain what is our idea of a cluster of stars, and by what means we have obtained it. For an instance, I shall take the phenomenon which presents itself in many clusters: It is that of a number of lucid spots, of equal lustre, scattered over a circular space, in such a manner as to appear gradually more compressed towards the middle; and which compression, in the clusters to which I allude, is generally carried so far, as, by imperceptible degrees, to end in a luminous center, of a resolvable blaze of light." William Herschel, 1789 Abstract We provide a sample of 170 Galactic Globular Clusters (GCs) and analyse its spatial distribution properties.
    [Show full text]
  • Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-Lat A
    The Astrophysical Journal, 834:110 (15pp), 2017 January 10 doi:10.3847/1538-4357/834/2/110 © 2017. The American Astronomical Society. All rights reserved. SEARCHING FOR DARK MATTER ANNIHILATION IN RECENTLY DISCOVERED MILKY WAY SATELLITES WITH FERMI-LAT A. Albert1, B. Anderson2,3, K. Bechtol4, A. Drlica-Wagner5, M. Meyer2,3, M. Sánchez-Conde2,3, L. Strigari6, M. Wood1, T. M. C. Abbott7, F. B. Abdalla8,9, A. Benoit-Lévy10,8,11, G. M. Bernstein12, R. A. Bernstein13, E. Bertin10,11, D. Brooks8, D. L. Burke14,15, A. Carnero Rosell16,17, M. Carrasco Kind18,19, J. Carretero20,21, M. Crocce20, C. E. Cunha14,C.B.D’Andrea22,23, L. N. da Costa16,17, S. Desai24,25, H. T. Diehl5, J. P. Dietrich24,25, P. Doel8, T. F. Eifler12,26, A. E. Evrard27,28, A. Fausti Neto16, D. A. Finley5, B. Flaugher5, P. Fosalba20, J. Frieman5,29, D. W. Gerdes28, D. A. Goldstein30,31, D. Gruen14,15, R. A. Gruendl18,19, K. Honscheid32,33, D. J. James7, S. Kent5, K. Kuehn34, N. Kuropatkin5, O. Lahav8,T.S.Li6, M. A. G. Maia16,17, M. March12, J. L. Marshall6, P. Martini32,35, C. J. Miller27,28, R. Miquel21,36, E. Neilsen5, B. Nord5, R. Ogando16,17, A. A. Plazas26, K. Reil15, A. K. Romer37, E. S. Rykoff14,15, E. Sanchez38, B. Santiago16,39, M. Schubnell28, I. Sevilla-Noarbe18,38, R. C. Smith7, M. Soares-Santos5, F. Sobreira16, E. Suchyta12, M. E. C. Swanson19, G. Tarle28, V. Vikram40, A. R. Walker7, and R. H. Wechsler14,15,41 (The Fermi-LAT and DES Collaborations) 1 Los Alamos National Laboratory, Los Alamos, NM 87545, USA; [email protected], [email protected] 2 Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden; [email protected] 3 The Oskar Klein Centre for Cosmoparticle Physics, AlbaNova, SE-106 91 Stockholm, Sweden 4 Dept.
    [Show full text]
  • Arxiv:2103.07476V1 [Astro-Ph.GA] 12 Mar 2021
    FERMILAB-PUB-21-075-AE-LDRD Draft version September 3, 2021 Typeset using LATEX twocolumn style in AASTeX63 The DECam Local Volume Exploration Survey: Overview and First Data Release A. Drlica-Wagner ,1, 2, 3 J. L. Carlin ,4 D. L. Nidever ,5, 6 P. S. Ferguson ,7, 8 N. Kuropatkin ,1 M. Adamow´ ,9, 10 W. Cerny ,2, 3 Y. Choi ,11 J. H. Esteves,12 C. E. Mart´ınez-Vazquez´ ,13 S. Mau ,14, 15 A. E. Miller,16, 17 B. Mutlu-Pakdil ,2, 3 E. H. Neilsen ,1 K. A. G. Olsen ,6 A. B. Pace ,18 A. H. Riley ,7, 8 J. D. Sakowska ,19 D. J. Sand ,20 L. Santana-Silva ,21 E. J. Tollerud ,11 D. L. Tucker ,1 A. K. Vivas ,13 E. Zaborowski,2 A. Zenteno ,13 T. M. C. Abbott ,13 S. Allam ,1 K. Bechtol ,22, 23 C. P. M. Bell ,16 E. F. Bell ,24 P. Bilaji,2, 3 C. R. Bom ,25 J. A. Carballo-Bello ,26 D. Crnojevic´ ,27 M.-R. L. Cioni ,16 A. Diaz-Ocampo,28 T. J. L. de Boer ,29 D. Erkal ,19 R. A. Gruendl ,30, 31 D. Hernandez-Lang,32, 13, 33 A. K. Hughes,20 D. J. James ,34 L. C. Johnson ,35 T. S. Li ,36, 37, 38 Y.-Y. Mao ,39, 38 D. Mart´ınez-Delgado ,40 P. Massana,19, 41 M. McNanna ,22 R. Morgan ,22 E. O. Nadler ,14, 15 N. E. D. Noel¨ ,19 A. Palmese ,1, 2 A. H. G. Peter ,42 E. S.
    [Show full text]
  • Dwarf Galaxies 1 Planck “Merger Tree” Hierarchical Structure Formation
    04.04.2019 Grebel: Dwarf Galaxies 1 Planck “Merger Tree” Hierarchical Structure Formation q Larger structures form q through successive Illustris q mergers of smaller simulation q structures. q If baryons are Time q involved: Observable q signatures of past merger q events may be retained. ➙ Dwarf galaxies as building blocks of massive galaxies. Potentially traceable; esp. in galactic halos. Fundamental scenario: q Surviving dwarfs: Fossils of galaxy formation q and evolution. Large structures form through numerous mergers of smaller ones. 04.04.2019 Grebel: Dwarf Galaxies 2 Satellite Disruption and Accretion Satellite disruption: q may lead to tidal q stripping (up to 90% q of the satellite’s original q stellar mass may be lost, q but remnant may survive), or q to complete disruption and q ultimately satellite accretion. Harding q More massive satellites experience Stellar tidal streams r r q higher dynamical friction dV M ρ V from different dwarf ∝ − r 3 galaxy accretion q and sink more rapidly. dt V events lead to ➙ Due to the mass-metallicity relation, expect a highly sub- q more metal-rich stars to end up at smaller radii. structured halo. 04.04.2019 € Grebel: Dwarf Galaxies Johnston 3 De Lucia & Helmi 2008; Cooper et al. 2010 accreted stars (ex situ) in-situ stars Stellar Halo Origins q Stellar halos composed in part of q accreted stars and in part of stars q formed in situ. Rodriguez- q Halos grow from “from inside out”. Gomez et al. 2016 q Wide variety of satellite accretion histories from smooth growth to discrete events.
    [Show full text]
  • Arxiv:1508.03622V2 [Astro-Ph.GA] 6 Nov 2015 – 2 –
    Eight Ultra-faint Galaxy Candidates Discovered in Year Two of the Dark Energy Survey 1; 2;3; 4;5 6;7 6;7 8;4;5 A. Drlica-Wagner ∗, K. Bechtol y, E. S. Rykoff , E. Luque , A. Queiroz , Y.-Y. Mao , R. H. Wechsler8;4;5, J. D. Simon9, B. Santiago6;7, B. Yanny1, E. Balbinot10;7, S. Dodelson1;11, A. Fausti Neto7, D. J. James12, T. S. Li13, M. A. G. Maia7;14, J. L. Marshall13, A. Pieres6;7, K. Stringer13, A. R. Walker12, T. M. C. Abbott12, F. B. Abdalla15;16, S. Allam1, A. Benoit-L´evy15, G. M. Bernstein17, E. Bertin18;19, D. Brooks15, E. Buckley-Geer1, D. L. Burke4;5, A. Carnero Rosell7;14, M. Carrasco Kind20;21, J. Carretero22;23, M. Crocce22, L. N. da Costa7;14, S. Desai24;25, H. T. Diehl1, J. P. Dietrich24;25, P. Doel15, T. F. Eifler17;26, A. E. Evrard27;28, D. A. Finley1, B. Flaugher1, P. Fosalba22, J. Frieman1;11, E. Gaztanaga22, D. W. Gerdes28, D. Gruen29;30, R. A. Gruendl20;21, G. Gutierrez1, K. Honscheid31;32, K. Kuehn33, N. Kuropatkin1, O. Lahav15, P. Martini31;34, R. Miquel35;23, B. Nord1, R. Ogando7;14, A. A. Plazas26, K. Reil5, A. Roodman4;5, M. Sako17, E. Sanchez36, V. Scarpine1, M. Schubnell28, I. Sevilla-Noarbe36;20, R. C. Smith12, M. Soares-Santos1, F. Sobreira1;7, E. Suchyta31;32, M. E. C. Swanson21, G. Tarle28, D. Tucker1, V. Vikram37, W. Wester1, Y. Zhang28, J. Zuntz38 (The DES Collaboration) arXiv:1508.03622v2 [astro-ph.GA] 6 Nov 2015 { 2 { *[email protected] [email protected] 1Fermi National Accelerator Laboratory, P.
    [Show full text]
  • Snake in the Clouds: a New Nearby Dwarf Galaxy in the Magellanic Bridge ∗ Sergey E
    MNRAS 000, 1{21 (2018) Preprint 19 April 2018 Compiled using MNRAS LATEX style file v3.0 Snake in the Clouds: A new nearby dwarf galaxy in the Magellanic bridge ∗ Sergey E. Koposov,1;2 Matthew G. Walker,1 Vasily Belokurov,2;3 Andrew R. Casey,4;5 Alex Geringer-Sameth,y6 Dougal Mackey,7 Gary Da Costa,7 Denis Erkal8, Prashin Jethwa9, Mario Mateo,10, Edward W. Olszewski11 and John I. Bailey III12 1McWilliams Center for Cosmology, Carnegie Mellon University, 5000 Forbes Ave, 15213, USA 2Institute of Astronomy, University of Cambridge, Madingley road, CB3 0HA, UK 3Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA 4School of Physics and Astronomy, Monash University, Clayton 3800, Victoria, Australia 5Faculty of Information Technology, Monash University, Clayton 3800, Victoria, Australia 6Astrophysics Group, Physics Department, Imperial College London, Prince Consort Rd, London SW7 2AZ, UK 7Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia 8Department of Physics, University of Surrey, Guildford, GU2 7XH, UK 9European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany 10Department of Astronomy, University of Michigan, 311 West Hall, 1085 S University Avenue, Ann Arbor, MI 48109, USA 11Steward Observatory, The University of Arizona, 933 N. Cherry Avenue., Tucson, AZ 85721, USA 12Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We report the discovery of a nearby dwarf galaxy in the constellation of Hydrus, between the Large and the Small Magellanic Clouds. Hydrus 1 is a mildy elliptical ultra-faint system with luminosity MV 4:7 and size 50 pc, located 28 kpc from the Sun and 24 kpc from the LMC.
    [Show full text]
  • Eight Ultra-Faint Galaxy Candidates Discovered in Year Two of the Dark Energy Survey A
    The Astrophysical Journal, 813:109 (20pp), 2015 November 10 doi:10.1088/0004-637X/813/2/109 © 2015. The American Astronomical Society. All rights reserved. EIGHT ULTRA-FAINT GALAXY CANDIDATES DISCOVERED IN YEAR TWO OF THE DARK ENERGY SURVEY A. Drlica-Wagner1, K. Bechtol2,3, E. S. Rykoff4,5, E. Luque6,7, A. Queiroz6,7,Y.-Y.Mao4,5,8, R. H. Wechsler4,5,8, J. D. Simon9, B. Santiago6,7, B. Yanny1, E. Balbinot7,10, S. Dodelson1,11, A. Fausti Neto7, D. J. James12,T.S.Li13, M. A. G. Maia7,14, J. L. Marshall13, A. Pieres6,7, K. Stringer13, A. R. Walker12, T. M. C. Abbott12, F. B. Abdalla15,16, S. Allam1, A. Benoit-Lévy15, G. M. Bernstein17, E. Bertin18,19, D. Brooks15, E. Buckley-Geer1, D. L. Burke4,5, A. Carnero Rosell7,14, M. Carrasco Kind20,21, J. Carretero22,23, M. Crocce22, L. N. da Costa7,14, S. Desai24,25, H. T. Diehl1, J. P. Dietrich24,25, P. Doel15,T.F.Eifler17,26, A. E. Evrard27,28, D. A. Finley1, B. Flaugher1, P. Fosalba22, J. Frieman1,11, E. Gaztanaga22, D. W. Gerdes28, D. Gruen29,30, R. A. Gruendl20,21, G. Gutierrez1, K. Honscheid31,32, K. Kuehn33, N. Kuropatkin1, O. Lahav15, P. Martini31,34, R. Miquel23,35, B. Nord1, R. Ogando7,14, A. A. Plazas26, K. Reil5, A. Roodman4,5, M. Sako17, E. Sanchez36, V. Scarpine1, M. Schubnell28, I. Sevilla-Noarbe20,36, R. C. Smith12, M. Soares-Santos1, F. Sobreira1,7, E. Suchyta31,32, M. E. C. Swanson21, G. Tarle28, D. Tucker1, V. Vikram37, W. Wester1, Y. Zhang28, and J.
    [Show full text]
  • A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3 Survey', Astrophysical Journal Letters, Vol
    Edinburgh Research Explorer A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3 Survey Citation for published version: Laevens, BPM, Martin, NF, Ibata, RA, Rix, H, Bernard, EJ, Bell, EF, Sesar, B, Ferguson, AMN, Schlafly, EF, Slater, CT, Burgett, WS, Chambers, KC, Flewelling, H, Hodapp, KA, Kaiser, N, Kudritzki, R, Lupton, RH, Magnier, EA, Metcalfe, N, Morgan, JS, Price, PA, Tonry, JL, Wainscoat, RJ & Waters, C 2015, 'A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3 Survey', Astrophysical Journal Letters, vol. 802, no. 2, 18. https://doi.org/10.1088/2041-8205/802/2/L18 Digital Object Identifier (DOI): 10.1088/2041-8205/802/2/L18 Link: Link to publication record in Edinburgh Research Explorer Document Version: Publisher's PDF, also known as Version of record Published In: Astrophysical Journal Letters General rights Copyright for the publications made accessible via the Edinburgh Research Explorer is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policy The University of Edinburgh has made every reasonable effort to ensure that Edinburgh Research Explorer content complies with UK legislation. If you believe that the public display of this file breaches copyright please contact [email protected] providing details, and we will remove access to the work immediately and investigate your claim. Download date: 24. Sep. 2021 The Astrophysical Journal Letters, 802:L18 (6pp), 2015 April 1 doi:10.1088/2041-8205/802/2/L18 © 2015.
    [Show full text]
  • The Rotation of the Halo of NGC6822 Determined from the Radial Velocities of Carbon Stars
    The rotation of the halo of NGC6822 determined from the radial velocities of carbon stars { Graham Peter Thompson { Centre for Astrophysics Research School of Physics, Astronomy and Mathematics University of Hertfordshire Submitted to the University of Hertfordshire in part fulfilment of the requirements of the degree of Master of Philosophy in Astrophysics Supervisor: Professor Sean G. Ryan { April 2016 { Declaration I hereby certify that this dissertation has been written by me in the School of Physics, Astronomy and Mathematics, University of Hertfordshire, Hatfield, Hertfordshire, and that it has not been submitted in any previous application for a higher degree. The core of the dissertation is based on original work conducted at the University of Hertfordshire, and some of the ideas for further work are drawn from topics studied during an earlier Master of Science. All material in this dissertation which is not my own work has been properly acknowledged. { Graham Peter Thompson { ii Acknowledgements I thank Professor Ryan for his invaluable support and patient guidance as my super- visor, throughout this study. His incisive questioning, thoughtful comments, helpful suggestions and, at times, hands-on assistance throughout the study, preparation of a paper to MNRAS and the writing of this dissertation have been invaluable. I thank also Dr Lisette Sibbons, whose work on the spectral classification of carbon stars in NGC 6822 was the genesis of my study. Dr Sibbons was responsible for the acquisition and reduction of the spectra I used in the study. She also provided me with background information related to the stars in the sample, and general advice.
    [Show full text]
  • Detailed Study of the Milky Way Globular Cluster Laevens 3 Nicolas Longeard, Nicolas F
    Detailed study of the Milky Way globular cluster Laevens 3 Nicolas Longeard, Nicolas F. Martin, Rodrigo Ibata, Michelle Collins, Benjamin Laevens, Eric Bell, Dougal Mackey To cite this version: Nicolas Longeard, Nicolas F. Martin, Rodrigo Ibata, Michelle Collins, Benjamin Laevens, et al.. De- tailed study of the Milky Way globular cluster Laevens 3. Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P - Oxford Open Option A, 2019, 490 (2), pp.1498- 1508. 10.1093/mnras/stz2592. hal-03095279 HAL Id: hal-03095279 https://hal.archives-ouvertes.fr/hal-03095279 Submitted on 4 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. MNRAS 490, 1498–1508 (2019) doi:10.1093/mnras/stz2592 Advance Access publication 2019 September 16 Detailed study of the Milky Way globular cluster Laevens 3 Nicolas Longeard,1‹ Nicolas Martin,1,2 Rodrigo A. Ibata,1 Michelle L. M. Collins ,3 Benjamin P. M. Laevens,4 Eric Bell5 and Dougal Mackey6 1CNRS, Observatoire astronomique de Strasbourg, Universite´ de Strasbourg, UMR 7550, F-67000 Strasbourg, France 2Max-Planck-Institut fur¨ Astronomy, Konigstuhl¨ 17, D-69117 Heidelberg, Germany 3Department of Physics, University of Surrey, Guildford, GU2 7XH Surrey, UK 4Institute of Astrophysics, Pontificia Universidad Catolica´ de Chile, Av.
    [Show full text]
  • Arxiv:1508.03622V2 [Astro-Ph.GA] 6 Nov 2015
    SLAC-PUB-16631 Eight Ultra-faint Galaxy Candidates Discovered in Year Two of the Dark Energy Survey 1; 2;3; 4;5 6;7 6;7 8;4;5 A. Drlica-Wagner ∗, K. Bechtol y, E. S. Rykoff , E. Luque , A. Queiroz , Y.-Y. Mao , R. H. Wechsler8;4;5, J. D. Simon9, B. Santiago6;7, B. Yanny1, E. Balbinot10;7, S. Dodelson1;11, A. Fausti Neto7, D. J. James12, T. S. Li13, M. A. G. Maia7;14, J. L. Marshall13, A. Pieres6;7, K. Stringer13, A. R. Walker12, T. M. C. Abbott12, F. B. Abdalla15;16, S. Allam1, A. Benoit-L´evy15, G. M. Bernstein17, E. Bertin18;19, D. Brooks15, E. Buckley-Geer1, D. L. Burke4;5, A. Carnero Rosell7;14, M. Carrasco Kind20;21, J. Carretero22;23, M. Crocce22, L. N. da Costa7;14, S. Desai24;25, H. T. Diehl1, J. P. Dietrich24;25, P. Doel15, T. F. Eifler17;26, A. E. Evrard27;28, D. A. Finley1, B. Flaugher1, P. Fosalba22, J. Frieman1;11, E. Gaztanaga22, D. W. Gerdes28, D. Gruen29;30, R. A. Gruendl20;21, G. Gutierrez1, K. Honscheid31;32, K. Kuehn33, N. Kuropatkin1, O. Lahav15, P. Martini31;34, R. Miquel35;23, B. Nord1, R. Ogando7;14, A. A. Plazas26, K. Reil5, A. Roodman4;5, M. Sako17, E. Sanchez36, V. Scarpine1, M. Schubnell28, I. Sevilla-Noarbe36;20, R. C. Smith12, M. Soares-Santos1, F. Sobreira1;7, E. Suchyta31;32, M. E. C. Swanson21, G. Tarle28, D. Tucker1, V. Vikram37, W. Wester1, Y. Zhang28, J. Zuntz38 (The DES Collaboration) arXiv:1508.03622v2 [astro-ph.GA] 6 Nov 2015 This material is based upon work supported by the U.S.
    [Show full text]
  • On the Nature of Ultra-Faint Dwarf Galaxy Candidates I: Des1, Eridanus Iii and Tucana V
    DRAFT VERSION DECEMBER 7, 2017 Typeset using LATEX twocolumn style in AASTeX61 ON THE NATURE OF ULTRA-FAINT DWARF GALAXY CANDIDATES I: DES1, ERIDANUS III AND TUCANA V BLAIR C. CONN,1 HELMUT JERJEN,1 DONGWON KIM,1 AND MISCHA SCHIRMER2 1Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia 2Gemini Observatory, Casilla 603, La Serena, Chile ABSTRACT We use deep Gemini/GMOS-S g;r photometry to study the three ultra-faint dwarf galaxy candidates DES1, Eridanus III (Eri III) and Tucana V (Tuc V). Their total luminosities, MV (DES1) = -1:42±0:50 and MV (Eri III) = -2:07±0:50, and mean metallicities, +0:21 +0:19 [Fe/H] = -2:38-0:19 and [Fe/H] = -2:40-0:12, are consistent with them being ultra-faint dwarf galaxies as they fall just outside the 1-sigma confidence band of the luminosity-metallicity relation for Milky Way satellite galaxies. However, their positions in the size-luminosity relation suggests that they are star clusters. Interestingly, DES1 and Eri III are at relatively large Galactocentric distances with DES1 located at DGC = 74±4 kpc and Eri III at DGC = 91±4 kpc. In projection both objects are in the tail of gaseous filaments trailing the Magellanic Clouds and have similar 3D-separations from the Small Magellanic Cloud (SMC): ∆DSMC;DES1 = 31.7 kpc and ∆DSMC;Eri III = 41.0 kpc, respectively. It is plausible that these stellar systems are metal-poor SMC satellites. Tuc V represents an interesting phenomenon in its own right. Our deep photometry at the nominal position of Tuc V reveals a low-level excess of stars at various locations across the GMOS field without a well-defined centre.
    [Show full text]