Red Supergiants Around the Obscured Open Cluster Stephenson 2 Different
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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. -
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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. -
Sio Maser Emission from Red Supergiants Across the Galaxy: I
Astronomy & Astrophysics manuscript no. 18265-v2 c ESO 2018 November 15, 2018 SiO maser emission from red supergiants across the Galaxy: I. Targets in massive star clusters L. Verheyen⋆, M. Messineo, and K. M. Menten Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, D-53121 Bonn, Germany e-mail: verheyen, messineo, [email protected] Received 2011/ Accepted ABSTRACT Aims. Red supergiants (RSGs) are among the most luminous of all stars, easily detectable in external galaxies, and may ideally serve as kinematic tracers of Galactic structure. Some RSGs are surrounded by circumstellar envelopes detectable by their dust and molecular and, in particular, maser emission. This study consists of a search for maser emission from silicon monoxide (SiO) toward a significant number of RSGs that are members of massive stellar clusters, many of which have only recently been discovered. Further, we aim to relate the occurrence of maser action to properties of the host stars. Methods. Using the IRAM 30 meter telescope, we searched for maser emission in the J = 2 − 1 rotational transition within the first vibrationally excited state of SiO toward a sample of 88 RSGs. Results. With an average rms noise level of 0.25 Jy, we detected maser emission in 15% of the sample, toward most of the sources for the first time in this transition. The peak of the emission provides accurate radial velocities for the RSGs. The dependence of the detection rate on infrared colors supports a radiative pumping mechanism for the SiO masers. Key words. Stars: AGB and post-AGB – circumstellar matter – masers 1. -
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. -
Programme Book
BETELGEUSE WORKSHOP 2012 THE PHYSICS OF RED SUPERGIANTS 26-29 NOVEMBER, 2012 PARIS (FRANCE) PROGRAMME BOOK ii Acknowledgements ...........................................................................................................iv! Scientific3Organizing3Committee .........................................................................................v! Local3Organizing3Committee ...............................................................................................v! Local3information ..............................................................................................................vi! Venue .......................................................................................................................................................................................vi! Public!transportation........................................................................................................................................................vi! Meeting!room ..................................................................................................................................................................... vii! Instructions3for3the3Proceedings ......................................................................................viii! List3of3participants .............................................................................................................ix! Daily3schedule .................................................................................................................xiii! -
Sio and H2O Maser Observations of Red Supergiants in Star Clusters
PASJ: Publ. Astron. Soc. Japan , 1–??, c 2018. Astronomical Society of Japan. SiO and H2O Maser Observations of Red Supergiants in Star Clusters Embedded in the Galactic Disk Shuji Deguchi1, Jun-ichi Nakashima2 Yong Zhang2, Selina S. N. Chong2, Kazutaka Koike1 and Sun Kwok2 1Nobeyama Radio Observatory, National Astronomical Observatory, and Graduate University for Advanced Studies, Minamimaki, Minamisaku, Nagano 384-1305 2Department of Physics, University of Hong Kong, Pokfulam Rd, Hong Kong, China (PASJ 62, No. 2, the April 25 2010 issue in press) (Received 2009 October 9; accepted 2010 February 1) Abstract We present the result of radio observations of red supergiants in the star cluster, Stephenson’s #2, and candidates for red supergiants in the star clusters, Mercer et al. (2005)’s #4, #8, and #13, in the SiO and H2O maser lines. The Stephenson’s #2 cluster and nearby aggregation at the South-West contain more than 15 red supergiants. We detected one at the center of Stephenson’s #2 and three in the south-west aggregation in the SiO maser line, and three of these 4 were also detected in the H2O maser line. The average radial velocity of the 4 detected objects is 96 km s−1, giving a kinematic distance of 5.5 kpc, which locates this cluster near the base of the Scutum-Crux spiral arm. We also detected 6 SiO emitting objects associated with the other star clusters. In addition, mapping observations in the CO J = 1–0 line toward these clusters revealed that an appreciable amount of molecular gas still remains around Stephenson’s #2 cluster in contrast to the prototypical red-supergiant cluster, Bica et al.’s #122. -
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A&A 619, A35 (2018) Astronomy https://doi.org/10.1051/0004-6361/201730717 & c ESO 2018 Astrophysics 86 GHz SiO maser survey of late-type stars in the Inner Galaxy IV. SiO emission and infrared data for sources in the Scutum and Sagittarius-Carina arms, 20◦ < l < 50◦? M. Messineo1,2, ??, H. J. Habing2, L. O. Sjouwerman3, A. Omont4, and K. M. Menten5 1 Key Laboratory for Researches in Galaxies and Cosmology, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026, PR China e-mail: [email protected] 2 Leiden Observatory, PO Box 9513, 2300 RA Leiden, The Netherlands 3 National Radio Astronomy Observatory, PO Box 0, Socorro NM 87801, USA 4 Institut d’Astrophysique de Paris CNRS, 98bis Boulevard Arago, 75014 Paris, France 5 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany Received 1 March 2017 / Accepted 11 May 2018 ABSTRACT We present an 86 GHz SiO (v = 1; J = 2 ! 1) maser search toward late-type stars located within jbj < 0◦:5 and 20◦ < l < 50◦. This search is an extension at longer longitudes of a previously published work. We selected 135 stars from the MSX catalog using color and flux criteria and detected 92 (86 new detections). The detection rate is 68%, the same as in our previous study. The last few decades have seen the publication of several catalogs of point sources detected in infrared surveys (MSX, 2MASS, DENIS, ISOGAL, WISE, GLIMPSE, AKARI, and MIPSGAL). We searched each catalog for data on the 444 targets of our earlier survey and for the 135 in the survey reported here. -
On the Possible Generation of the Young Massive Open Clusters
Astronomy & Astrophysics manuscript no. W100˙AA˙V2 c ESO 2018 November 3, 2018 On the possible generation of the young massive open clusters Stephenson 2 and BDSB 122 by ω Centauri G.M. Salerno1, E. Bica1, C. Bonatto1, and I. Rodrigues2 1 Universidade Federal do Rio Grande do Sul, Departamento de Astronomia CP 15051, RS, Porto Alegre 91501-970, Brazil e-mail: [email protected], [email protected], [email protected], [email protected] 2 IP&D - Universidade do Vale do Para´ıba - UNIVAP, Av. Shishima Hifumi, 2911 - Urbanova, S˜ao Jos´edos Campos 12244-000, SP, Brazil Received –; accepted – ABSTRACT Context. A massive objects such as a globular cluster passing through the disk of a galaxy can trigger star formation. Aims. We test the hypothesis that the most massive globular cluster in the Galaxy, ω Centauri, which crossed the disk approximately 24 ± 2 Myr ago, may have triggered the formation of the open clusters Stephenson 2 and BDSB 122. Methods. The orbits of ω Centauri, Stephenson 2 and BDSB 122 are computed for the three-component model of Johnston, Hernquist & Bolte, which considers the disk, spheroidal and halo gravitational potentials. Results. With the re-constructed orbit of ω Centauri, we show that the latest impact site is consistent, within important uncertainties, with the birth-site of the young massive open clusters BDSB 122 and Stephenson 2. Within uncertainties, this scenario is consistent with the time-scale of their backwards motion in the disk, shock wave propagation and delay for star formation. Conclusions. Together with open cluster formation associated to density waves in spiral arms, the present results are consistent with the idea that massive globular clusters as additional progenitors of open clusters, the massive ones in particular. -
Exploring the Mass Loss Histories of the Red Supergiants
Draft version August 5, 2020 Typeset using LATEX preprint style in AASTeX62 Exploring the Mass Loss Histories of the Red Supergiants∗ Roberta M. Humphreys1 — Greta Helmel1 — Terry J. Jones1 — Michael S. Gordon2 — 1Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455, USA 2USRA-SOFIA Science Center, NASA Ames Research Center, Moffett Field, CA 94035, USA (Received; Revised; Accepted) Submitted to AJ ABSTRACT We report mid- to far-infrared imaging and photomety from 7 to 37µm with SOFIA/FORCAST and 2µm adaptive optics imaging with LBTI/LMIRCam of a large sample of red supergiants (RSGs) in four Galactic clusters; RSGC1, RSGC2=Stephenson 2, RSGC3, and NGC 7419. The red supergiants in these clus- ters cover their expected range in luminosity and initial mass from 9 to more than ≈ 25 M⊙. The population includes examples of very late-type RSGs such as MY Cep which may be near the end of the RSG stage, high mass losing maser sources, yellow hypergiants and post-RSG candidates. Many of the stars and almost all of the most luminous have spectral energy distributions (SEDs) with extended infrared excess ra- diation at the longest wavelengths. To best model their SEDs we use DUSTY with a variable radial density distribution function to estimate their mass loss rates. Our M˙ – luminosity relation for 42 RSGs basically follows the classical de Jager curve, but 5 at luminosities below 10 L⊙ we find a significant population of red supergiants with arXiv:2008.01108v1 [astro-ph.SR] 3 Aug 2020 5 M˙ below the de Jager relation. At luminosities above 10 L⊙ there is a rapid transi- tion to higher mass loss rates that approximates and overlaps the de Jager curve. -
How Should the Progenitors of Iip-Sne Look Like?
HowHow shouldshould thethe progenitorsprogenitors ofof typetype IIII--pp SNeSNe looklook like?like? RedRed supergiantssupergiants inin clustersclusters IgnacioIgnacio NegueruelaNegueruela CaboCabo dede GataGata SeptemberSeptember 20132013 CarlosCarlos GonzGonzáálezlez FernFernáándezndez RicardoRicardo DordaDorda AmparoAmparo MarcoMarco SimonSimon J.J. ClarkClark Outline Red supergiants as SN progenitors Observation vs. theory Constraints from clusters Evidence for substantial evolution during the RSG phase The AGB boundary Can we tell which stars will explode? Exploding RSGs A possible scenario for supernova progenitors (Smith et al. 2011, MNRAS 412, 1522) Distribution of supernova types (Smith et al. 2011, MNRAS 412, 1522) Lower initial mass for a supernova progenitor +1 8.5 -1.5 M Observed supernova progenitors (Smartt 2009, ARA&A 47, 63) Very low mass progenitors L * Observed supernova progenitors (Frasier et al. 2011, MNRAS 417, 1417) Exploding RSGs This may shift up a bit because of circumstellar reddening (Walmswell & Eldridge 2012, MNRAS 419, 2054) Distribution of supernova types (Smith et al. 2011, MNRAS 412, 1522) The theory (Jones et al. 2013, ApJ 772, 150) (Poelarends et al. 2008, ApJ 675, 614) Strong dependence on assumptions but: 9 M for an EC SN 10 M for a CC SN Lower initial mass for a supernova progenitor +1 8.5 -1.5 M Observed supernova progenitors (Smartt 2009, ARA&A 47, 63) RSGs in the Milky Way Red supergiants in clusters and associations (Levesque et al. 2005, ApJ 628, 973) (Levesque et al. 2012, AJ 144, 2) VY CMa Humphreys et. al. 2007, AJ 133, 2716 Geneva evolutionary tracks (Ekström et al. 2012, A&A 537, A146) Distance from radio parallaxes (Zhang et al. -
An Analogue of the Galactic Yellow Hypergiant IRC +10420?
Open Research Online The Open University’s repository of research publications and other research outputs IRAS 18357-0604 – an analogue of the galactic yellow hypergiant IRC +10420? Journal Item How to cite: Clark, J. S.; Negueruela, I. and González-Fernández, C. (2014). IRAS 18357-0604 – an analogue of the galactic yellow hypergiant IRC +10420? Astronomy & Astrophysics, 561, article no. A15. For guidance on citations see FAQs. c [not recorded] 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:10.1051/0004-6361/201322772 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 561, A15 (2014) Astronomy DOI: 10.1051/0004-6361/201322772 & c ESO 2013 Astrophysics IRAS 18357-0604 – an analogue of the galactic yellow hypergiant IRC +10420? J. S. Clark1, I. Negueruela2, and C. González-Fernández2,3 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, Madingly Road, Cambridge, CB3 0HA, UK Received 30 September 2013 / Accepted 10 November 2013 ABSTRACT Context. Yellow hypergiants represent a short-lived evolutionary episode experienced by massive stars as they transit to and from a red supergiant phase. -
Pode Ω Centauri Induzir Formaç˜Ao Estelar No Disco Galáctico?
UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL INSTITUTO DE F´ISICA DEPARTAMENTO DE ASTRONOMIA Pode ! Centauri induzir forma¸c~ao estelar no disco Gal´actico?∗ Gustavo Malta Salerno, Bel., Lic. Disserta¸c~aorealizada sob orienta¸c~aodo Professor Dr. Eduardo Luiz Damiani Bica e apresentada ao Programa de P´os- Gradua¸c~ao do Instituto de F´ısica da UFRGS em preenchimento parcial dos re- quisitos para a obten¸c~aodo t´ıtulode Mestre em F´ısica. Porto Alegre Agosto, 2013 ∗Trabalho parcialmente financiado pelo Conselho Nacional de Desenvolvimento Cient´ıficoe Tecnol´ogico(CNPq). Para Ota, M~aozinha,Manetinha, Cinzinha e Cotoco. Agradecimentos Agrade¸coao Dr. Eduardo Luiz Damiani Bica e ao Dr. Charles Bonatto por todo apoio e orienta¸c~aoque me deram ao longo deste trabalho. Tamb´emagrade¸co`asfam´ıliasFattore e Serres, que me abrigaram sempre que precisei e cuja aten¸c~aojamais poderei retribuir `aaltura. N~aoesquecerei jamais o apoio de Luciano Alexandre Pecetti e sua fam´ılia. Todos os colegas e amigos do Instituto de F´ısica, em especial do Departamento de Astronomia, merecem meus mais sinceros agradecimentos. Aos amigos da Hora Feliz, ao Renato Blumberg de Oliveira e ao Eduardo Balbinot, meus agradecimentos pela companhia, pelo ch´ae pela fogueira. ii Resumo Neste trabalho investigamos um dos processos que pode levar `aforma¸c~aode aglomerados abertos, focando-nos nas intera¸c~oesocorridas durante a passagem de um aglomerado globular atrav´esdo disco Gal´actico, cujos efeitos podem resultar no surgimentos daqueles. Tais intera¸c~oespodem ser uma alternativa aos cen´ariosconvencionais de forma¸c~aoestelar.