The Outskirts of Cygnus OB2 ⋆
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Spitzer Pipeline Commissioning Observations of DR 6
Spitzer Pipeline Commissioning Observations of DR 6 Sean J. Carey, Jeonghee Rho, William T. Reach, William J. Glaccum, Bidushi Bhattacharya, Mark Lacy, Seppo Laine, Patrick J. Lowrance, Brant O. Nelson, Daniel Stern, Jason A. Surace, Gillian Wilson (Spitzer Science Center) and the IRAC Instrument Team (SAO) Introduction: As part of the Science Verification phase of the In-Orbit Checkout of Spitzer, IRAC observed the HII region DR 6 and the associated infrared cluster DB7 An 8 mm image of a 1.5 by 1.5 degree region centered on (Dutra & Bica 2001). DR 6 is at a distance of 1.0 kpc (Comerón & Torra 2001) . The DR6 from MSX. The HII region is part of the much larger intent of the experiment was to make a representative observation of a region of high structures of the Cygnus X region. Near the HII region are source density and structure similar to observations that will be conducted by general several infrared-dark filaments which are dense molecular observers of Galactic star formation. In addition, these observations provide a stress cores (Carey et al. 1998). test of the IRAC data pipeline and the SSC post-BCD software, including the mosaicer, point source extraction and bandmerging software. Observations: DR 6 was imaged by IRAC using 12s high dynamic range mode on 27 November 2003. High dynamic range observations consist of set of a 0.6s frame and a 12s frame at each pointing. The map is 20 by 10 arcminutes in size with four dithers at each map position. The total integration time per pixel is 43.2 seconds and the map took 20 minutes to complete. -
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. -
The X-Ray Universe 2017
The X-ray Universe 2017 6−9 June 2017 Centro Congressi Frentani Rome, Italy A conference organised by the European Space Agency XMM-Newton Science Operations Centre National Institute for Astrophysics, Italian Space Agency University Roma Tre, La Sapienza University ABSTRACT BOOK Oral Communications and Posters Edited by Simone Migliari, Jan-Uwe Ness Organising Committees Scientific Organising Committee M. Arnaud Commissariat ´al’´energie atomique Saclay, Gif sur Yvette, France D. Barret (chair) Institut de Recherche en Astrophysique et Plan´etologie, France G. Branduardi-Raymont Mullard Space Science Laboratory, Dorking, Surrey, United Kingdom L. Brenneman Smithsonian Astrophysical Observatory, Cambridge, USA M. Brusa Universit`adi Bologna, Italy M. Cappi Istituto Nazionale di Astrofisica, Bologna, Italy E. Churazov Max-Planck-Institut f¨urAstrophysik, Garching, Germany A. Decourchelle Commissariat ´al’´energie atomique Saclay, Gif sur Yvette, France N. Degenaar University of Amsterdam, the Netherlands A. Fabian University of Cambridge, United Kingdom F. Fiore Osservatorio Astronomico di Roma, Monteporzio Catone, Italy F. Harrison California Institute of Technology, Pasadena, USA M. Hernanz Institute of Space Sciences (CSIC-IEEC), Barcelona, Spain A. Hornschemeier Goddard Space Flight Center, Greenbelt, USA V. Karas Academy of Sciences, Prague, Czech Republic C. Kouveliotou George Washington University, Washington DC, USA G. Matt Universit`adegli Studi Roma Tre, Roma, Italy Y. Naz´e Universit´ede Li`ege, Belgium T. Ohashi Tokyo Metropolitan University, Japan I. Papadakis University of Crete, Heraklion, Greece J. Hjorth University of Copenhagen, Denmark K. Poppenhaeger Queen’s University Belfast, United Kingdom N. Rea Instituto de Ciencias del Espacio (CSIC-IEEC), Spain T. Reiprich Bonn University, Germany M. Salvato Max-Planck-Institut f¨urextraterrestrische Physik, Garching, Germany N. -
POSTERS SESSION I: Atmospheres of Massive Stars
Abstracts of Posters 25 POSTERS (Grouped by sessions in alphabetical order by first author) SESSION I: Atmospheres of Massive Stars I-1. Pulsational Seeding of Structure in a Line-Driven Stellar Wind Nurdan Anilmis & Stan Owocki, University of Delaware Massive stars often exhibit signatures of radial or non-radial pulsation, and in principal these can play a key role in seeding structure in their radiatively driven stellar wind. We have been carrying out time-dependent hydrodynamical simulations of such winds with time-variable surface brightness and lower boundary condi- tions that are intended to mimic the forms expected from stellar pulsation. We present sample results for a strong radial pulsation, using also an SEI (Sobolev with Exact Integration) line-transfer code to derive characteristic line-profile signatures of the resulting wind structure. Future work will compare these with observed signatures in a variety of specific stars known to be radial and non-radial pulsators. I-2. Wind and Photospheric Variability in Late-B Supergiants Matt Austin, University College London (UCL); Nevyana Markova, National Astronomical Observatory, Bulgaria; Raman Prinja, UCL There is currently a growing realisation that the time-variable properties of massive stars can have a funda- mental influence in the determination of key parameters. Specifically, the fact that the winds may be highly clumped and structured can lead to significant downward revision in the mass-loss rates of OB stars. While wind clumping is generally well studied in O-type stars, it is by contrast poorly understood in B stars. In this study we present the analysis of optical data of the B8 Iae star HD 199478. -
As the Dome of Twilight Sinks Below The
As the dome of twilight sinks below the horizon, a mechanical corps de ballet starts a slow-motion pirouette with each dancer keeping the unblinking eye of a telescope locked on a single spot in the heavens. Shutters open and ancient photons, ending a journey that may have started before the earth was born, collide with sensors that store an electron to mark that photon's arrival. With the dance in motion the directors sit back to watch the show; another imaging session has begun... Image by Marcus Stevens A Full and Proper Kit An introduction to the gear of astro-photography The young recruit is silly – 'e thinks o' suicide; 'E's lost his gutter-devil; 'e 'asn't got 'is pride; But day by day they kicks him, which 'elps 'im on a bit, Till 'e finds 'isself one mornin' with a full an' proper kit. Rudyard Kipling Like the young recruit in Kipling's poem 'The 'Eathen', a deep-sky imaging beginner starts with little in the way of equipment or skill. With 'older' imagers urging him onward, providing him with the benefit of the mistakes that they had made during their journey and allowing him access to the equipment they've built or collected, the newcomer gains the 'equipment' he needs, be it gear or skills, to excel at the art. At that time he has acquired a 'full and proper kit' and ceases to be a recruit. This paper is a discussion of hardware, software, methods and actions that a newcomer might find useful. It is not meant to be an in-depth discussion of all forms of astro-photography; that would take many books and more knowledge than I have available. -
The E-MERLIN 21 Cm Legacy Survey of Cygnus OB2
This is a repository copy of COBRaS: The e-MERLIN 21 cm Legacy survey of Cygnus OB2. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/162252/ Version: Published Version Article: Morford, JC, Fenech, DM, Prinja, RK et al. (12 more authors) (2020) COBRaS: The e-MERLIN 21 cm Legacy survey of Cygnus OB2. Astronomy & Astrophysics, 637. A64. ISSN 0004-6361 https://doi.org/10.1051/0004-6361/201731379 Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ A&A 637, A64 (2020) https://doi.org/10.1051/0004-6361/201731379 Astronomy c ESO 2020 & Astrophysics COBRaS: The e-MERLIN 21 cm Legacy survey of Cygnus OB2 J. C. Morford1, D. M. Fenech1,2, R. K. Prinja1, R. Blomme3, J. A. Yates1, J. J. Drake4, S. P. S. Eyres5,6, A. M. S. Richards7, I. R. Stevens8, N. J. Wright9, J. S. Clark10, S. -
Useful Constants
Appendix A Useful Constants A.1 Physical Constants Table A.1 Physical constants in SI units Symbol Constant Value c Speed of light 2.997925 × 108 m/s −19 e Elementary charge 1.602191 × 10 C −12 2 2 3 ε0 Permittivity 8.854 × 10 C s / kgm −7 2 μ0 Permeability 4π × 10 kgm/C −27 mH Atomic mass unit 1.660531 × 10 kg −31 me Electron mass 9.109558 × 10 kg −27 mp Proton mass 1.672614 × 10 kg −27 mn Neutron mass 1.674920 × 10 kg h Planck constant 6.626196 × 10−34 Js h¯ Planck constant 1.054591 × 10−34 Js R Gas constant 8.314510 × 103 J/(kgK) −23 k Boltzmann constant 1.380622 × 10 J/K −8 2 4 σ Stefan–Boltzmann constant 5.66961 × 10 W/ m K G Gravitational constant 6.6732 × 10−11 m3/ kgs2 M. Benacquista, An Introduction to the Evolution of Single and Binary Stars, 223 Undergraduate Lecture Notes in Physics, DOI 10.1007/978-1-4419-9991-7, © Springer Science+Business Media New York 2013 224 A Useful Constants Table A.2 Useful combinations and alternate units Symbol Constant Value 2 mHc Atomic mass unit 931.50MeV 2 mec Electron rest mass energy 511.00keV 2 mpc Proton rest mass energy 938.28MeV 2 mnc Neutron rest mass energy 939.57MeV h Planck constant 4.136 × 10−15 eVs h¯ Planck constant 6.582 × 10−16 eVs k Boltzmann constant 8.617 × 10−5 eV/K hc 1,240eVnm hc¯ 197.3eVnm 2 e /(4πε0) 1.440eVnm A.2 Astronomical Constants Table A.3 Astronomical units Symbol Constant Value AU Astronomical unit 1.4959787066 × 1011 m ly Light year 9.460730472 × 1015 m pc Parsec 2.0624806 × 105 AU 3.2615638ly 3.0856776 × 1016 m d Sidereal day 23h 56m 04.0905309s 8.61640905309 -
NGVLA Observations of Dense Gas Filaments in Star-Forming Regions
NGVLA Observations of Dense Gas Filaments in Star-Forming Regions James Di Francesco (NRC Canada, U. Victoria), Jared Keown (U. Victoria), Mike Chen (U. Victoria), Erik Rosolowsky (U. Alberta), Rachel Friesen (NRAO), and the GAS and KEYSTONE teams Background: Herschel and JCMT continuum observations of nearby star-forming regions have revealed that filaments are ubiquitous structures within molecular clouds (André et al. 2014). Such filaments appear to be intimately connected to star formation, with those having column densities of AV > 8 in particular hosting the majority of prestellar cores and protostars in clouds (Könyves et al. 2015). This “threshold” can be explained simply as the result of supercritical cylinder fragmentation (cf. Inutsuka & Miyama 1992). Though gravity and turbulence are likely involved, specifically how star-forming filaments form and evolve in molecular clouds remains unclear. Kinematic probes are needed to understand how mass flows both onto and through filaments, leading to star formation. Current Observations: We show here preliminary results from the recent GAS (PIs: R. Friesen & J. Pineda) and KEYSTONE (PI: J. Di Francesco) surveys that have used the Green Bank Telescope’s K-band Focal Plane Array to map NH3 emission from dense gas in nearby star-forming regions. As a tracer of gas of 3 -3 density > 10 cm , NH3 emission can reveal filament kinematics, dynamics, and kinetic temperatures from line velocities, widths, and ratios, respectively. GAS: Filaments of NGC 1333 in Perseus: KEYSTONE: DR 21 Ridge in Cygnus X North: Figure 1: line velocities (V ; LSR Figure 2 : integrated color scale) of NGC 1333 intensities of NH (1,1) dense gas filaments obtained 3 emission (Moment 0; color from a single-component fit to scale) of the DR 21 Ridge observed NH (1,1) emission. -
Far-Infrared Observations of a Massive Cluster Forming in the Monoceros R2 filament Hub? T
Astronomy & Astrophysics manuscript no. monr2_hobys˙final˙corrected c ESO 2017 December 5, 2017 Far-infrared observations of a massive cluster forming in the Monoceros R2 filament hub? T. S. M. Rayner1??, M. J. Griffin1, N. Schneider2; 3, F. Motte4; 5, V. K¨onyves5, P. Andr´e5, J. Di Francesco6, P. Didelon5, K. Pattle7, D. Ward-Thompson7, L. D. Anderson8, M. Benedettini9, J.-P. Bernard10, S. Bontemps3, D. Elia9, A. Fuente11, M. Hennemann5, T. Hill5; 12, J. Kirk7, K. Marsh1, A. Men'shchikov5, Q. Nguyen Luong13; 14, N. Peretto1, S. Pezzuto9, A. Rivera-Ingraham15, A. Roy5, K. Rygl16, A.´ S´anchez-Monge2, L. Spinoglio9, J. Tig´e17, S. P. Trevi~no-Morales18, and G. J. White19; 20 1 Cardiff School of Physics and Astronomy, Cardiff University, Queen's Buildings, The Parade, Cardiff, Wales, CF24 3AA, UK 2 I. Physik. Institut, University of Cologne, 50937 Cologne, Germany 3 Laboratoire d'Astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, all´eeG. Saint-Hilaire, 33615 Pessac, France 4 Universit´eGrenoble Alpes, CNRS, Institut de Planetologie et d'Astrophysique de Grenoble, 38000 Grenoble, France 5 Laboratoire AIM, CEA/IRFU { CNRS/INSU { Universit´eParis Diderot, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France 6 NRC, Herzberg Institute of Astrophysics, Victoria, Canada 7 Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK 8 Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506, USA 9 INAF { Istituto di Astrofisica e Planetologia Spaziali, via Fosso del Cavaliere 100, I-00133 Roma, Italy 10 -
Data Delivery Document
The CygnusX Legacy Project Data Description: Delivery 1: July 2011 CygnusX team: Joseph L. Hora1 (PI), Sylvain Bontemps2, Tom Megeath3, Nicola Schneider4 , Frederique Motte4, Sean Carey5, Robert Simon6, Eric Keto1, Howard Smith1, Lori Allen7, Rob Gutermuth8, Giovanni Fazio1, Kathleen Kraemer9, Don Mizuno10, Stephan Price9, Joseph Adams11, Xavier Koenig12 1Harvard-Smithsonian Center for Astrophysics, 2Observatoire de Bordeaux, 3University of Toledo, 4CEA-Saclay, 5Spitzer Science Center, 6Universität zu Köln, 7NOAO, 8Smith College, 9Air Force Research Lab, 10Boston College, 11Cornell University, 12Goddard Space Flight Center Table of Contents 1. Project Summary ..................................................................................................................... 3 1.1 IRAC observations ........................................................................................................... 3 1.2 MIPS observations ........................................................................................................... 4 1.3 Data reduction .................................................................................................................. 5 1.3.1 IRAC reduction ......................................................................................................... 5 1.3.2 MIPS reduction ......................................................................................................... 7 2. Point Source Catalog.............................................................................................................. -
Discovery of a Wolf–Rayet Star Through Detection of Its Photometric Variability
The Astronomical Journal, 143:136 (6pp), 2012 June doi:10.1088/0004-6256/143/6/136 C 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A. DISCOVERY OF A WOLF–RAYET STAR THROUGH DETECTION OF ITS PHOTOMETRIC VARIABILITY Colin Littlefield1, Peter Garnavich2, G. H. “Howie” Marion3,Jozsef´ Vinko´ 4,5, Colin McClelland2, Terrence Rettig2, and J. Craig Wheeler5 1 Law School, University of Notre Dame, Notre Dame, IN 46556, USA 2 Physics Department, University of Notre Dame, Notre Dame, IN 46556, USA 3 Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA 4 Department of Optics, University of Szeged, Hungary 5 Astronomy Department, University of Texas, Austin, TX 78712, USA Received 2011 November 9; accepted 2012 April 4; published 2012 May 2 ABSTRACT We report the serendipitous discovery of a heavily reddened Wolf–Rayet star that we name WR 142b. While photometrically monitoring a cataclysmic variable, we detected weak variability in a nearby field star. Low- resolution spectroscopy revealed a strong emission line at 7100 Å, suggesting an unusual object and prompting further study. A spectrum taken with the Hobby–Eberly Telescope confirms strong He ii emission and an N iv 7112 Å line consistent with a nitrogen-rich Wolf–Rayet star of spectral class WN6. Analysis of the He ii line strengths reveals no detectable hydrogen in WR 142b. A blue-sensitive spectrum obtained with the Large Binocular Telescope shows no evidence for a hot companion star. The continuum shape and emission line ratios imply a reddening of E(B − V ) = 2.2–2.6 mag. -
Diffuse X-Ray Emission in the Cygnus OB2 Association
to appear in special issue ApJSS., 2018 Preprint typeset using LATEX style AASTeX6 v. 1.0 DIFFUSE X-RAY EMISSION IN THE CYGNUS OB2 ASSOCIATION. J. F. Albacete Colombo1, J. J. Drake2,E.Flaccomio3,N.J.Wright4, V. Kashyap2,M.G.Guarcello3,K.Briggs5,J.E.Drew6, D. M. Fenech7,G.Micela3, M. McCollough2,R.K.Prinja7,N.Schneider8,S.Sciortino3,J.S.Vink9 1Universidad de R´ıo Negro, Sede Atl´antica, Viedma CP8500, Argentina. 2Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138, U.S.A 3INAF-Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy. 4Astrophysics Group, Keele University, Keele, Staffordshire ST5 5BG, UK. 5Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029, Hamburg, Germany. 6School of Physics, Astronomy & Mathematics, University of Hertfordshire, College Lane, Hatfield, Hertfordshire, AL10 9AB, UK. 7Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK. 8I. Physik. Institut, University of Cologne, D-50937 Cologne, Germany. 9Armagh Observatory and Planetarium, College Hill, Armagh BT61 9DG, Northern Ireland, UK. ABSTRACT We present a large-scale study of diffuse X-ray emission in the nearby massive stellar association Cygnus OB2 as part of the Chandra Cygnus OB2 Legacy Program. We used 40 Chandra X-ray ACIS-I observations covering ∼1.0 deg2. After removing 7924 point-like sources detected in our survey, background-corrected X-ray emission, the adaptive smoothing reveals large-scale diffuse X-ray emission. Diffuse emission was de- tected in the sub-bands Soft [0.5:1.2] and Medium [1.2:2.5], and marginally in the Hard [2.5:7.0] keV band.