Exploring the Mass Loss Histories of the Red Supergiants
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A Massive Association Around the Obscured Open Cluster RSGC3 Tent of the Clusters Is Uncertain.Membershipin RSGC1 and Ste2 2
Astronomy & Astrophysics manuscript no. 16102 c ESO 2018 October 31, 2018 A massive association around the obscured open cluster RSGC3,⋆ I. Negueruela1, C. Gonz´alez-Fern´andez1 , A. Marco1, and J. S. Clark2 1 Departamento de F´ısica, Ingenier´ıa de Sistemas y Teor´ıa de la Se˜nal, Universidad de Alicante, Apdo. 99, E03080 Alicante, Spain e-mail: [email protected] 2 Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK Preprint online version: October 31, 2018 ABSTRACT Context. Four clusters of red supergiants have been discovered in a region of the Milky Way close to base of the Scutum-Crux Arm and the tip of the Long Bar. Population synthesis models indicate that they must be very massive to harbour so many supergiants. If the clusters are physically connected, this Scutum Complex would be the largest and most massive star-forming region ever identified in the Milky Way. Aims. The spatial extent of one of these clusters, RSGC3, has not been investigated. In this paper we explore the possibility that a population of red supergiants could be located in its vicinity. Methods. We utilised 2MASS JHKS photometry to identify candidate obscured luminous red stars in the vicinity of RSGC3. We observed a sample of candidates with the TWIN spectrograph on the 3.5-m telescope at Calar Alto, obtaining intermediate-resolution spectroscopy in the 8000–9000Å range. We re-evaluated a number of classification criteria proposed in the literature for this spectral range and found that we could use our spectra to derive spectral types and luminosity classes. -
A Long-Period Cepheid Variable in the Starburst Cluster Vdbh222 Journal Item
Open Research Online The Open University’s repository of research publications and other research outputs A long-period Cepheid variable in the starburst cluster VdBH222 Journal Item How to cite: Clark, J. S.; Negueruela, I.; Lohr, M. E.; Dorda, R.; González-Fernández, C.; Lewis, F. and Roche, P. (2015). A long-period Cepheid variable in the starburst cluster VdBH222. Astronomy & Astrophysics, 584, article no. L12. For guidance on citations see FAQs. c 2015 ESO https://creativecommons.org/licenses/by-nc-nd/4.0/ Version: Version of Record Link(s) to article on publisher’s website: http://dx.doi.org/doi:10.1051/0004-6361/201527360 Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online’s data policy on reuse of materials please consult the policies page. oro.open.ac.uk A&A 584, L12 (2015) Astronomy DOI: 10.1051/0004-6361/201527360 & c ESO 2015 Astrophysics Letter to the Editor A long-period Cepheid variable in the starburst cluster VdBH222 J. S. Clark1, I. Negueruela2,M.E.Lohr1, R. Dorda2, C. González-Fernández3 ,F.Lewis4,5,andP.Roche5 1 Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK e-mail: [email protected] 2 Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain 3 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK 4 Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK 5 School of Physics & Astronomy, Cardiff University, The Parade, CF24 3AA, Cardiff,UK Received 14 September 2015 / Accepted 21 October 2015 ABSTRACT Context. -
On the Origin of Stellar Associations the Impact of Gaia DR2
BAAA, Vol. 61C, 2020 Asociaci´on Argentina de Astronom´ıa J. Forero-Romero, E. Jimenez Bailon & P.B. Tissera, eds. Proceedings of the XVI LARIM On the origin of stellar associations The impact of Gaia DR2 G. Carraro1 1 Dipartimento di Fisica e Astronomia Galileo Galilei, Padova, Italy Contact / [email protected] Abstract / In this review I discuss different theories of the formation of OB associations in the Milky Way, and provide the observational evidences in support of them. In fact, the second release of Gaia astrometric data (April 2018) is revolutionising the field, because it allows us to unravel the 3D structure and kinematics of stellar associations with unprecedented details by providing precise distances and a solid membership assessment. As an illustration, I summarise some recent studies on three OB associations: Cygnus OB2, Vela OB2, and Scorpius OB1, focussing in more detail to Sco OB1. A multi-wavelength study, in tandem with astrometric and kinematic data from Gaia DR2, seems to lend support, at least in this case, to a scenario in which star formation is not monolithic. As a matter of fact, besides one conspicuous star cluster, NGC 6231, and the very sparse star cluster Trumpler 24, there are several smaller groups of young OB and pre-main sequence stars across the association, indicating that star formation is highly structured and with no preferred scale. A new revolution is expected with the incoming much awaited third release of Gaia data. Keywords / open clusters and associations: general | stars: formation 1. Introduction made of 50 stars or more. They are formed then in the upper part of the molecular cloud mass distribu- Stellar associations (a term introduced by Ambartsum- tion. -
Cygnus OB2 – a Young Globular Cluster in the Milky Way Jürgen Knödlseder
Cygnus OB2 – a young globular cluster in the Milky Way Jürgen Knödlseder To cite this version: Jürgen Knödlseder. Cygnus OB2 – a young globular cluster in the Milky Way. Astronomy and Astrophysics - A&A, EDP Sciences, 2000, 360, pp.539 - 548. hal-01381935 HAL Id: hal-01381935 https://hal.archives-ouvertes.fr/hal-01381935 Submitted on 14 Oct 2016 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. Astron. Astrophys. 360, 539–548 (2000) ASTRONOMY AND ASTROPHYSICS Cygnus OB2–ayoung globular cluster in the Milky Way J. Knodlseder¨ INTEGRAL Science Data Centre, Chemin d’Ecogia 16, 1290 Versoix, Switzerland Centre d’Etude Spatiale des Rayonnements, CNRS/UPS, B.P. 4346, 31028 Toulouse Cedex 4, France ([email protected]) Received 31 May 2000 / Accepted 23 June 2000 Abstract. The morphology and stellar content of the Cygnus particularly good region to address such questions, since it is OB2 association has been determined using 2MASS infrared extremely rich (e.g. Reddish et al. 1966, hereafter RLP), and observations in the J, H, and K bands. The analysis reveals contains some of the most luminous stars known in our Galaxy a spherically symmetric association of ∼ 2◦ in diameter with (e.g. -
16 Aug 2012 E Uegat Rudteosue Pncutrstephenso Cluster Open Obscured the Around Supergiants Red L Am,Spain) Palma, (La Ouain Ohrors Ayrg Eg,Dve Ta.2007 Ages Typical Al
Astronomy & Astrophysics manuscript no. wyffos c ESO 2012 August 17, 2012 Red supergiants around the obscured open cluster Stephenson2,⋆ I. Negueruela1, A. Marco1, C. Gonz´alez-Fern´andez1 , F. Jim´enez-Esteban2,3,4, J. S. Clark5, M. Garcia6,7, and E. Solano2,3 1 Departamento de F´ısica, Ingenier´ıa de Sistemas y Teor´ıa de la Se˜nal, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain e-mail: [email protected] 2 Centro de Astrobiolog´ıa (INTA-CSIC), Departamento de Astrof´ısica, PO Box 78, E-28691, Villanueva de la Ca˜nada, Madrid, Spain 3 Spanish Virtual Observatory, Spain 4 Saint Louis University, Madrid Campus, Division of Science and Engineering, Avda. del Valle 34, E-28003 Madrid, Spain 5 Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK 6 Instituto de Astrof´ısica de Canarias, E-38200 La Laguna, Tenerife, Spain 7 Departamento de Astrof´ısica, Universidad de La Laguna (ULL), E-38206 La Laguna, Tenerife, Spain Preprint online version: August 17, 2012 ABSTRACT Context. Several clusters of red supergiants have been discovered in a small region of the Milky Way close to the base of the Scutum- Crux Arm and the tip of the Long Bar. Population synthesis models indicate that they must be very massive to harbour so many supergiants. Amongst these clusters, Stephenson 2, with a core grouping of 26 red supergiants, is a strong candidate to be the most massive cluster in the Galaxy. Aims. Stephenson 2 is located close to a region where a strong over-density of red supergiants had been found. -
Massive Open Star Clusters Using the VVV Survey III
A&A 564, L9 (2014) Astronomy DOI: 10.1051/0004-6361/201322619 & c ESO 2014 Astrophysics Letter to the Editor Massive open star clusters using the VVV survey III. A young massive cluster at the far edge of the Galactic bar, S. Ramírez Alegría1,2, J. Borissova1,2,A.N.Chené3, E. O’Leary3,P.Amigo1,2, D. Minniti2,4,R.K.Saito5, D. Geisler6, R. Kurtev1,2,M.Hempel2,4, M. Gromadzki1,J.R.A.Clarke1, I. Negueruela7, A. Marco7, C. Fierro1,8, C. Bonatto9, and M. Catelan2,4 1 Instituto de Física y Astronomía, Universidad de Valparaíso, Av. Gran Bretaña 1111, Playa Ancha, Casilla 5030 Valparaíso, Chile e-mail: [email protected] 2 The Millennium Institute of Astrophysics (MAS), Santiago, Chile 3 Gemini North Observatory, USA 4 Pontificia Universidad Católica de Chile, Instituto de Astrofísica, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago, Chile 5 Universidade Federal de Sergipe, Departamento de Física, Av. Marechal Rondon s/n, 49100-000 São Cristóvão SE, Brazil 6 Departamento de Astronomía, Casilla 160-C, Universidad de Concepción, Chile 7 Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante, Spain 8 Escuela Superior de Física y Matemáticas del Instituto Politécnico Nacional, Unidad Profesional Adolfo López Mateos, Mexico 9 Universidade Federal do Rio Grande do Sul, Departamento de Astronomia, CP 15051, RS 91501-970 Porto Alegre, Brazil Received 5 September 2013 / Accepted 11 March 2014 ABSTRACT Context. Young massive clusters are key to map the Milky Way’s structure, and near-infrared large area sky surveys have contributed strongly to the discovery of new obscured massive stellar clusters. -
The Very Reddened Open Clusters Pismis 23 (Lyngå 10) and Stephenson 2?,??
A&A 390, 931–935 (2002) Astronomy DOI: 10.1051/0004-6361:20020716 & c ESO 2002 Astrophysics The very reddened open clusters Pismis 23 (Lyngå 10) and Stephenson 2?;?? S. Ortolani1,E.Bica2,B.Barbuy3,andY.Momany1 1 Universit`a di Padova, Dept. di Astronomia, Vicolo dell’Osservatorio 2, 35122 Padova, Italy e-mail: [email protected] 2 Universidade Federal do Rio Grande do Sul, Dept. de Astronomia, CP 15051, Porto Alegre 91500-970, Brazil e-mail: [email protected] 3 Universidade de S˜ao Paulo, CP 3386, S˜ao Paulo 01060-970, Brazil e-mail: [email protected] Received 15 March 2002 / Accepted 7 May 2002 Abstract. Pismis 23 and Stephenson 2 are two very reddened open clusters, projected close to the Galactic plane. We present VI and JH photometry for Pismis 23 and I and Gunn z for Stephenson 2. We derive a relatively old age of ∼700 Myr for Pismis 23, with a reddening value of E(B−V) = 1:73 and a distance d ≈ 2:6 kpc from the Sun. Stephenson 2 has a clump of red supergiants, indicating a young age of about 20 Myr, somewhat younger and more distant (d ≈ 6 kpc) than recently reported in the literature. The age estimate for such a young object is crucial for the distance estimate. The high reddening of these two clusters relative to predictions from the diffuse interstellar medium at their distances is due to discrete intervening clouds. Key words. open clusters and associations: individual: Pismis 23, Stephenson 2 – stars: Hertzsprung-Russell (HR) and C-M diagrams 1. -
The Cool Supergiant Population of the Massive Young Star Cluster RSGC1
The cool supergiant population of the massive young star cluster RSGC1 Ben Davies (RIT), Don F. Figer (RIT), Casey J. Law (Amsterdam), Rolf-Peter Kudritzki (IfA, Hawaii), Francisco Najarro (CSIC, Madrid), Artemio Herrero (IAC, Spain), John W. MacKenty (STScI) . We present new high-resolution near-IR spectroscopy and OH maser observations to investigate the population of cool luminous stars of the young massive Galactic cluster RSGC1. Using the 2.293micron CO-bandhead feature, we make high-precision radial velocity measurements of 16 of the 17 candidate Red Supergiants (RSGs) identified by Figer et al. We show that F16 and F17 are foreground stars, while we confirm that the rest are indeed physically-associated RSGs. We determine that Star F15, also associated with the cluster, is a Yellow Hypergiant based on its luminosity and spectroscopic similarity to $rho$~Cas. Using the cluster's radial velocity, we have derived the kinematic distance to the cluster and revisited the stars' temperatures and luminosities. We find a larger spread of luminosities than in the discovery paper, consistent with a cluster age 30% older than previously thought (12$pm$2Myr), and a total initial mass of $(3pm1) times 10^{4}$msun. The spatial coincidence of the OH maser with F13, combined with similar radial velocities, is compelling evidence that the two are related. Combining our results with recent SiO and H$_2$O maser observations, we find that those stars with maser emission are the most luminous in the cluster. From this we suggest that the maser-active phase is associated with the end of the RSG stage, when the luminosity-mass ratios are at their highest. -
GIANO-TNG Spectroscopy of Red Supergiants in the Young Star Cluster RSGC3 L
A&A 585, A14 (2016) Astronomy DOI: 10.1051/0004-6361/201526649 & c ESO 2015 Astrophysics GIANO-TNG spectroscopy of red supergiants in the young star cluster RSGC3 L. Origlia1, E. Oliva2, N. Sanna2, A. Mucciarelli3, E. Dalessandro3, S. Scuderi4, C. Baffa2, V. Biliotti2, L. Carbonaro2, G. Falcini2, E. Giani2, M. Iuzzolino2, F. Massi2, M. Sozzi2, A. Tozzi2, A. Ghedina5, F. Ghinassi5, M. Lodi5, A. Harutyunyan5, and M. Pedani5 1 INAF–Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy e-mail: [email protected] 2 INAF–Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy 3 University of Bologna, Physics & Astronomy Dept., Viale Berti Pichat 6-2, 40127 Bologna, Italy 4 INAF–Osservatorio Astrofisico di Catania, via S. Sofia 78, 95123 Catania, Italy 5 INAF–TNG, ORM Astronomical Observatory, 38787 Garafia, TF, Spain Received 1 June 2015 / Accepted 22 September 2015 ABSTRACT Aims. The Scutum complex in the inner disk of the Galaxy has a number of young star clusters dominated by red supergiants that are heavily obscured by dust extinction and observable only at infrared wavelengths. These clusters are important tracers of the recent star formation and chemical enrichment history in the inner Galaxy. Methods. During the technical commissioning and as a first science verification of the GIANO spectrograph at the Telescopio Nazionale Galileo, we secured high-resolution (R ' 50 000) near-infrared spectra of five red supergiants in the young Scutum cluster RSGC3. Results. Taking advantage of the full YJHK spectral coverage of GIANO in a single exposure, we were able to measure several tens of atomic and molecular lines that were suitable for determining chemical abundances. -
Luminous Blue Variables: an Imaging Perspective on Their Binarity and Near Environment?,??
A&A 587, A115 (2016) Astronomy DOI: 10.1051/0004-6361/201526578 & c ESO 2016 Astrophysics Luminous blue variables: An imaging perspective on their binarity and near environment?;?? Christophe Martayan1, Alex Lobel2, Dietrich Baade3, Andrea Mehner1, Thomas Rivinius1, Henri M. J. Boffin1, Julien Girard1, Dimitri Mawet4, Guillaume Montagnier5, Ronny Blomme2, Pierre Kervella7;6, Hugues Sana8, Stanislav Štefl???;9, Juan Zorec10, Sylvestre Lacour6, Jean-Baptiste Le Bouquin11, Fabrice Martins12, Antoine Mérand1, Fabien Patru11, Fernando Selman1, and Yves Frémat2 1 European Organisation for Astronomical Research in the Southern Hemisphere, Alonso de Córdova 3107, Vitacura, 19001 Casilla, Santiago de Chile, Chile e-mail: [email protected] 2 Royal Observatory of Belgium, 3 avenue Circulaire, 1180 Brussels, Belgium 3 European Organisation for Astronomical Research in the Southern Hemisphere, Karl-Schwarzschild-Str. 2, 85748 Garching b. München, Germany 4 Department of Astronomy, California Institute of Technology, 1200 E. California Blvd, MC 249-17, Pasadena, CA 91125, USA 5 Observatoire de Haute-Provence, CNRS/OAMP, 04870 Saint-Michel-l’Observatoire, France 6 LESIA (UMR 8109), Observatoire de Paris, PSL, CNRS, UPMC, Univ. Paris-Diderot, 5 place Jules Janssen, 92195 Meudon, France 7 Unidad Mixta Internacional Franco-Chilena de Astronomía (CNRS UMI 3386), Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile 8 ESA/Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, -
The Inner Resonance Ring of NGC 3081. II. Star Formation, Bar Strength, Disk Surface Mass Density, and Mass-To-Light Ratio
The Inner Resonance Ring of NGC 3081. II. Star Formation, Bar Strength, Disk Surface Mass Density, and Mass-to-Light Ratio Gene G. Byrd – University of Alabama Tarsh Freeman – Bevill State Community College Ronald J. Buta – University of Alabama Deposited 06/13/2018 Citation of published version: Byrd, G., Freeman, T., Buta, R. (2006): The Inner Resonance Ring of NGC 3081. II. Star Formation, Bar Strength, Disk Surface Mass Density, and Mass-to-Light Ratio. The Astronomical Journal, 131(3). DOI: 10.1086/499944 © 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. The Astronomical Journal, 131:1377–1393, 2006 March # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE INNER RESONANCE RING OF NGC 3081. II. STAR FORMATION, BAR STRENGTH, DISK SURFACE MASS DENSITY, AND MASS-TO-LIGHT RATIO Gene G. Byrd,1 Tarsh Freeman,2 and Ronald J. Buta1 Received 2005 July 19; accepted 2005 November 19 ABSTRACT We complement our Hubble Space Telescope (HST ) observations of the inner ring of the galaxy NGC 3081 using an analytical approach and n-body simulations. We find that a gas cloud inner (r) ring forms under a rotating bar perturbation with very strong azimuthal cloud crowding where the ring crosses the bar major axis. Thus, star forma- tion results near to and ‘‘downstream’’ of the major axis. From the dust distribution and radial velocities, the disk rotates counterclockwise (CCW) on the sky like the bar pattern speed. We explain the observed CCW color asym- metry crossing the major axis as due to the increasing age of stellar associations inside the r ring major axis. -
Stellar Activity As a Tracer of Moving Groups⋆⋆⋆
A&A 552, A27 (2013) Astronomy DOI: 10.1051/0004-6361/201219483 & c ESO 2013 Astrophysics Stellar activity as a tracer of moving groups?;?? F. Murgas1, J. S. Jenkins2;3, P. Rojo2, H. R. A Jones3, and D. J. Pinfield3 1 Instituto de Astrofísica de Canarias (IAC), 38205 La Laguna, Tenerife, Spain e-mail: [email protected] 2 Departamento de Astronomía, Universidad de Chile, Casilla Postal 36D, Santiago, Chile 3 Center for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, Herts, AL10 9AB, UK Received 25 April 2012 / Accepted 13 February 2013 ABSTRACT We present the results of a study of the stellar activity in the solar neighborhood using complete kinematics (galactocentric velocities 0 U, V, W) and the chromospheric activity index log RHK. We analyzed the average activity level near the centers of known moving groups using a sample of 2529 stars and found that the stars near these associations tend to be more active than field stars. This supports the hypothesis that these structures, or at least a significant part of them, are composed of kinematically bound, young stars. We confirmed our results by using GALaxy Evolution EXplorer (GALEX) UV data and kinematics taken from the Geneva- Copenhagen Survey for the stars in the sample. Finally, we present a compiled catalog with kinematics and activities for 2529 stars and a list of potential moving group members selected based on their stellar activity level. Key words. stars: activity – stars: kinematics and dynamics – stars: solar-type – solar neighborhood 1. Introduction outflows driven by massive stars, some of the stars that belong to these structures are less affected by the gravitational force of the Moving groups (MGs) are groups of stars distributed across the system.