A Kinematic Confirmation of the Hidden Vela Supercluster
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Large Scale Structure in the Local Universe — the 2MASS Galaxy Catalog
Structure and Dynamics in the Local Universe CSIRO PUBLISHING Publications of the Astronomical Society of Australia, 2004, 21, 396–403 www.publish.csiro.au/journals/pasa Large Scale Structure in the Local Universe — The 2MASS Galaxy Catalog Thomas JarrettA A Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125, USA. Email: [email protected] Received 2004 May 3, accepted 2004 October 12 Abstract: Using twin ground-based telescopes, the Two-Micron All Sky Survey (2MASS) scanned both equatorial hemispheres, detecting more than 500 million stars and resolving more than 1.5 million galaxies in the near-infrared (1–2.2 µm) bands. The Extended Source Catalog (XSC) embodies both photometric and astrometric whole sky uniformity, revealing large scale structures in the local Universe and extending our view into the Milky Way’s dust-obscured ‘Zone of Avoidance’. The XSC represents a uniquely unbiased sample of nearby galaxies, particularly sensitive to the underlying, dominant, stellar mass component of galaxies. The basic properties of the XSC, including photometric sensitivity, source counts, and spatial distribution, are presented here. Finally, we employ a photometric redshift technique to add depth to the spatial maps, reconstructing the cosmic web of superclusters spanning the sky. Keywords: general: galaxies — fundamental parameters: infrared — galaxies: clusters — surveys: astronomical 1 Introduction 2003), distance indicators (e.g. Karachentsev et al. 2002), Our understanding of the origin and evolution of the Uni- angular correlation functions (e.g. Maller et al. 2003a), and verse has been fundamentally transformed with seminal the dipole of the local Universe (e.g. -
Observations of New Galaxies in the Zone of Avoidance Using the Arecibo Radio Telescope R
Observations of new galaxies in the Zone of Avoidance using the Arecibo Radio Telescope R. Birdsall, N. Ballering, A. Beardsley, L. Hunt, S. Stanimirovic (Mentor) University of Wisconsin Astronomy Department Abstract: As part of an undergraduate research techniques course, we detected the neutral hydrogen (HI) spectrum of the galaxy SPITZER192404+145632. This galaxy is located in the Zone of Avoidance (ZoA), a region of the large-scale distribution of galaxies that is obscured by our own galactic disk. Using the Arecibo Observatory*, we were able to confirm the infrared detection made by 9 11 Marleau et al. (2008). We find a redshift of z = 0.019, an HI mass of MHI = 1.02 x 10 Mo, and dynamical mass of MT ≈ 3.9 x 10 Mo. Motivation: The Zone of avoidance (ZoA) is located in the night sky in Observations: Analysis: Using the observed spectrum, we calculate the systemic the direction of our galactic disk. Observations of galaxies at optical We observed remotely velocity, distance, rotational velocity, HI mass, and dynamical mass of wavelengths are extremely difficult in this region because of absorption of on October 16, 2008, SPITZER192404+145632. The systemic velocity is found by simply light by the dust in the disk of the Milky Way. Therefore, fewer objects using position switch- evaluating the midpoint velocity of the spectrum. We found vsys = 5800 have been found in the ZoA than in other regions of space (see Figure 1). ing (ON/OFF) observa- km/s. This corresponds to a redshift of z = 0.019. The distance to the Observations in the ZoA with very sensitive infrared and radio telescopes, tions with the L-wide galaxy is determined using Hubble’s Law: present an opportunity for astronomers to discover new galaxies, as receiver of the Arecibo waves at these wavelengths are not absorbed by dust. -
OBSERVATIONS in the ZONE of AVOIDANCE USING ARECIBO OBSERVATORY R.Birdsall, N.Ballering, A.Beardsley, L.Hunt, R.Wilson, S.Stanim
OBSERVATIONS IN THE ZONE OF AVOIDANCE USING ARECIBO OBSERVATORY R.Birdsall, N.Ballering, A.Beardsley, L.Hunt, R.Wilson, S.Stanimi 1. Abstract The Zone of Avoidance is a relatively unknown region of space that lies on the other side of our galactic disk. Previous observations made by other collaborators such as Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) and MIPS Galactic Plane Survey (MIPSGAL) which surveyed the Zone of Avoidance in the infrared spectrum with the Spitzer Space Telescope.[1] Our team decided to focus on target objects observed by the (GLIMPSE) and(MIPSGAL). These two collaborations identified twenty five new objects in the Infrared Spectrum that had the properties of galaxy like objects. For that reason, we used the Arecibo Radio Observatory in the hopes of detecting the radio signal of neutral hydrogen and identifying these objects. This piece focuses on SP192404+1456 2. Zone of Avoidance The Zone of Avoidance is a interesting region of the night sky because very little is known about what occupies that space. The ZOA is the region of the sky that lies beyond in the direction of the Milky Way galactic center. Thus EM radiation sources from the ZOA must make its way through the galactic disk. This makes detection of these galaxies difficult to near impossible. Both GLIMPSE and MIPSGAL where able to detect twenty-five obscure objects in the IR part of the spectrum, but where unable to verify exact source parameters. 1 2 OBSERVATIONS IN THE ZONE OF AVOIDANCE USING ARECIBO OBSERVATORY [2] In Figure 1. we see a spacial map of previous galactic survey's. -
Predicting Structures in the Zone of Avoidance
Mon. Not. R. Astron. Soc. 000, 1–11 (2017) Printed 8 October 2018 (MN LATEX style file v2.2) Predicting Structures in the Zone of Avoidance Jenny G. Sorce1,2⋆, Matthew Colless3, Renee´ C. Kraan-Korteweg4, Stefan Gottlober¨ 2 1Universit´ede Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, France 2Leibniz-Institut f¨ur Astrophysik, 14482 Potsdam, Germany 3Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia 4Department of Astronomy, University of Cape Town, 7700 Rondebosch, South Africa ABSTRACT The Zone of Avoidance (ZOA), whose emptiness is an artifact of our Galaxy dust, has been challenging observers as well as theorists for many years. Multiple attempts have been made on the observational side to map this region in order to better understand the local flows. On the the- oretical side, however, this region is often simply statistically populated with structures but no real attempt has been made to confront theoretical and observed matter distributions. This paper takes a step forward using constrained realizations of the local Universe shown to be perfect substitutes of local Universe-like simulations for smoothed high density peak studies. Far from generating com- pletely ‘random’ structures in the ZOA, the reconstruction technique arranges matter according to the surrounding environment of this region. More precisely, the mean distributions of structures in a series of constrained and random realizations differ: while densities annihilate each other when averaging over 200 random realizations, structures persist when summing 200 constrained realiza- tions. The probability distribution function of ZOA grid cells to be highly overdense is a Gaussian with a 15% mean in the random case, while that of the constrained case exhibits large tails. -
Mapping the Hidden Universe: the Galaxy Distribution in the Zone of Avoidance
Publ. Astron. Soc. Aust., 2000, 17, 6–12. Mapping the Hidden Universe: The Galaxy Distribution in the Zone of Avoidance Renee C. Kraan-Korteweg1 and Sebastian Juraszek2,3 1Departamento de Astronoma, Universidad de Guanajuato, Apartado Postal 144, Guanajuato GTO 36000, Mexico [email protected] 2School of Physics, University of Sydney, NSW 2006, Australia 3ATNF, CSIRO, PO Box 76, Epping, NSW 2121, Australia [email protected] Received 1999 August 26, accepted 1999 October 26 Abstract: Due to the foreground extinction of the Milky Way, galaxies become increasingly faint as they approach the Galactic Equator creating a ‘zone of avoidance’ (ZOA) in the distribution of optically visible galaxies of about 25%. A ‘whole-sky’ map of galaxies is essential, however, for understanding the dynamics in our local Universe, in particular the peculiar velocity of the Local Group with respect to the Cosmic Microwave Background and velocity ow elds such as in the Great Attractor (GA) region. The current status of deep optical galaxy searches behind the Milky Way and their completeness as a function of foreground extinction will be reviewed. It has been shown that these surveys—which in the mean time cover the whole ZOA (Figure 2)—result in a considerable reduction of the ZOA from extinction levels of m m AB =10 (Figure 1) to AB =30 (Figure 3). In the remaining, optically opaque ZOA, systematic HI surveys are powerful in uncovering galaxies, as is demonstrated for the GA region with data from the full sensitivity Parkes Multibeam HI survey (300 ` 332, |b|55, Figure 4). Keywords: zone of avoidance — surveys — ISM: dust, extinction — large-scale structure of universe 1 Introduction presented in an Aito equal-area projection centred on the Galactic plane. -
WALLABY – an SKA Pathfinder H I Survey
University of Louisville ThinkIR: The University of Louisville's Institutional Repository Faculty Scholarship 7-1-2020 WALLABY – an SKA Pathfinder H i survey Bärbel S. Koribalski Australia Telescope National Facility L. Staveley-Smith ARC Centre of Excellence for All-sky Astrophysics T. Westmeier ARC Centre of Excellence for All-sky Astrophysics P. Serra Osservatorio Astronomico di Cagliari K. Spekkens Royal Military College of Canada See next page for additional authors Follow this and additional works at: https://ir.library.louisville.edu/faculty Part of the Astrophysics and Astronomy Commons ThinkIR Citation Koribalski, Bärbel S.; Staveley-Smith, L.; Westmeier, T.; Serra, P.; Spekkens, K.; Wong, O. I.; Lee-Waddell, K.; Lagos, C. D.P.; Obreschkow, D.; Ryan-Weber, E. V.; Zwaan, M.; Kilborn, V.; Bekiaris, G.; Bekki, K.; Bigiel, F.; Boselli, A.; Bosma, A.; Catinella, B.; Chauhan, G.; Cluver, M. E.; Colless, M.; Courtois, H. M.; Crain, R. A.; de Blok, W. J.G.; Dénes, H.; Duffy, A. R.; Elagali, A.; Fluke, C. J.; For, B. Q.; Heald, G.; Henning, P. A.; Hess, K. M.; and Holwerda, Benne W., "WALLABY – an SKA Pathfinder H i survey" (2020). Faculty Scholarship. 476. https://ir.library.louisville.edu/faculty/476 This Article is brought to you for free and open access by ThinkIR: The University of Louisville's Institutional Repository. It has been accepted for inclusion in Faculty Scholarship by an authorized administrator of ThinkIR: The University of Louisville's Institutional Repository. For more information, please contact [email protected]. Authors Bärbel S. Koribalski, L. Staveley-Smith, T. Westmeier, P. Serra, K. Spekkens, O. -
The Unveiling of the Newly Discovered Vela Supercluster 1
The Unveiling of the newly discovered Vela Supercluster ∗ PoS(SSC2015)040 Renée C. Kraan-Korteweg†, Thomas H. Jarrett and Ahmed Elagali Astrophysics, Cosmology and Gravity Centre, University of Cape Town, 7701 Rondebosch, South Africa E-mail: [email protected] Michelle E. Cluver Department of Physics, University of the Western Cape, Bellville, South Africa Maciej Bilicki Astrophysics, Cosmology and Gravity Centre, University of Cape Town, 7701 Rondebosch, South Africa & Leiden Observatory, Leiden University, The Netherlands Matthew M. Colless Research School of Astronomy and Astrophysics, Australian National University, Canberra, Australia Multi-object spectroscopic observations of high density galaxy concentrations were obtained be- tween 2012 and 2014 with SALT, using the multi-object spectrometer (MOS) of the Robert Stobie Spectograph (RSS) on SALT. The goal was to find the missing clusters in an earlier identified ex- tended galaxy overdensity centered at ∼ 18000 km s−1 located at low Galactic latitudes in Vela. Reliable redshifts could be extracted for ∼ 80% of the targeted, highly-obscured galaxies. They were found to have an accuracy of the order of s ∼ 150 km s−1. Of the 13 observed fields, ten revealed clear signatures of galaxy clusters. The majority of the clusters form part of the Vela overdensity. Their distribution also confirmed our suspicion that the Vela overdensity is even more extended and seems to straddle the Galactic Plane. Subsequent multi-fibre spectroscopy with AAOmega+2dF on the Australian Telescope confirmed that these clusters are embedded in a gigantic overdensity of about 20◦ ×20◦ on the sky. The overdensity and its clusters show strong similarities to massive superclusters such as the Shapley Supercluster. -
Annual Report / Rapport Annuel / Jahresbericht 1996
Annual Report / Rapport annuel / Jahresbericht 1996 ✦ ✦ ✦ E U R O P E A N S O U T H E R N O B S E R V A T O R Y ES O✦ 99 COVER COUVERTURE UMSCHLAG Beta Pictoris, as observed in scattered light Beta Pictoris, observée en lumière diffusée Beta Pictoris, im Streulicht bei 1,25 µm (J- at 1.25 microns (J band) with the ESO à 1,25 microns (bande J) avec le système Band) beobachtet mit dem adaptiven opti- ADONIS adaptive optics system at the 3.6-m d’optique adaptative de l’ESO, ADONIS, au schen System ADONIS am ESO-3,6-m-Tele- telescope and the Observatoire de Grenoble télescope de 3,60 m et le coronographe de skop und dem Koronographen des Obser- coronograph. l’observatoire de Grenoble. vatoriums von Grenoble. The combination of high angular resolution La combinaison de haute résolution angu- Die Kombination von hoher Winkelauflö- (0.12 arcsec) and high dynamical range laire (0,12 arcsec) et de gamme dynamique sung (0,12 Bogensekunden) und hohem dy- (105) allows to image the disk to only 24 AU élevée (105) permet de reproduire le disque namischen Bereich (105) erlaubt es, die from the star. Inside 50 AU, the main plane jusqu’à seulement 24 UA de l’étoile. A Scheibe bis zu einem Abstand von nur 24 AE of the disk is inclined with respect to the l’intérieur de 50 UA, le plan principal du vom Stern abzubilden. Innerhalb von 50 AE outer part. Observers: J.-L. Beuzit, A.-M. -
Large-Scale Structures Behind the Southern Milky Way From
Large-Scale Structures Behind the Southern Milky Way from Observations of Partially Obscured Galaxies R.C. Kraan-Korteweg Observatoire de Paris-Meudon, D.A.E.C., 92195 Meudon Cedex, France [email protected] P.A. Woudt Dept. of Astronomy, University of Cape Town, Rondebosch 7700, South Africa P.A. Henning Dept. of Physics and Astronomy, University of New Mexico, Albuquerque, USA Abstract We report here on extragalactic large-scale structures uncovered by a deep optical survey for galaxies behind the southern Milky Way. Systematic visual inspection of the ESO/SRC- ◦ ◦ survey revealed over 10000 previously unknown galaxies in the region 265 ∼<ℓ ∼< 340 , |b| ∼< 10◦. With subsequently obtained redshifts of more than 10% of these galaxies, new structures across the Milky Way are unveiled, such as a filament at v ∼ 2500 km s−1 connecting to the Hydra and Antlia clusters, a shallow extended supercluster in Vela (∼ 6000 km s−1), and a −1 15 nearby (4882 km s ), very massive (M ∼ 2 − 5 · 10 M⊙), rich Coma-like cluster which seems to constitute the previously unidentified center of the Great Attractor. The innermost part of the Milky Way where the foreground obscuration in the blue is m 21 −2 AB ∼> 5 , respectively H I-column densities NH I ∼> 6·10 cm remains fully opaque. In this approximately 8◦ wide strip, the forthcoming blind H I-survey with the multi-beam system at Parkes will provide the only tool to unveil this part of the extragalactic sky. Keywords: galaxies: distances and redshifts - large-scale structure of Universe - surveys arXiv:astro-ph/9611099v1 13 Nov 1996 1 Introduction The Milky Way obscures about 25% of the extragalactic sky. -
A NEW SUPERCLUSTER of GALAXIES a Team of Astronomers
A NEW SUPERCLUSTER OF GALAXIES A team of astronomers from South Africa, the Netherlands, Germany, and Australia announced on November 16 the discovery of a previously unknown major concentration of galaxies in direction to the southern constellation Vela. They’ve dubbed it the Vela supercluster, and it’s one of perhaps 10 million superclusters of galaxies – vast collections of galaxies – the largest structures we know in the universe. The gravitational attraction from this newly found large mass concentration in our cosmic neighbourhood might have an important effect on the motion of our Local Group of galaxies including the Milky Way. It might also help to explain the direction and amplitude of our Local Group’s peculiar velocity with respect to the Cosmic Microwave Background. Generally speaking, superclusters are vast clusters of galaxies spanning up to 200 million light-years across the sky. They’re not isolated in space but exist together with many other smaller concentrations of galaxies, together forming parts of extensive walls of galaxies surrounding large voids in what astronomers call the cosmic web. Superclusters aren’t just big; they are also massive, meaning they have a powerful gravitational pull. They are the most massive known structures in our universe. A nearby supercluster famous for its great mass is the Shapley Supercluster, some 650 million light-years away containing two dozens of massive X-ray clusters for which thousands of Superclusters near Earth. A map of the universe within 500 million light galaxy velocities have been measured. It is years shows most of the major galaxy superclusters that surround our believed to be the largest of its kind in our Virgo supercluster. -
Serendipitious 2MASS Discoveries Near the Galactic Plane
Serendipitous 2MASS Discoveries Near the Galactic Plane: A Spiral Galaxy and Two Globular Clusters Robert L. Hurt, Tom H. Jarrett, J. Davy Kirkpatrick, Roc M. Cutri Infrared Processing & Analysis Center, MS 100-22, California Institute of Technology, Jet Propulsion Laboratory, Pasadena, CA 91125 [email protected], [email protected], [email protected], [email protected] Stephen E. Schneider, Mike Skrutskie Astronomy Program, University of Massachusetts, Amherst, MA 01003 [email protected], [email protected] Willem van Driel United Scientifique Nançay, Obs. de Paris–Meudon, Meudon Cedex, CA 92195, France [email protected] Abstract We present the basic properties of three objects near the Galactic Plane—a large galaxy and two candidate globular clusters—discovered in the Two Micron All Sky Survey (2MASS) dataset. All were noted during spot-checks of the data during 2MASS quality assurance reviews. The galaxy is a late-type spiral galaxy (Sc–Sd), ~11 Mpc distant, at l = 236.82°, b = -1.86°. From its observed angular extent of 6.3' in the near infrared, we estimate an extinction-corrected optical diameter of ~9.5', making it larger than most Messier galaxies. The candidate globular clusters are ~2–3’ in extent and are hidden optically behind foreground extinctions of Av ~18–21 mag at l ~ 10°, b ~ 0°. These chance discoveries were not the result of any kind of systematic search but they do hint at the wealth of obscured sources of all kinds, many previously unknown, that are in the 2MASS dataset. Key words: galaxies: photometry—galaxies: spiral—(Galaxy:) globular clusters: general—surveys—infrared radiation 1. -
The HI Parkes Zone of Avoidance Shallow Survey
Publ. Astron. Soc. Aust., 1999, 16, 35–7 . The HI Parkes Zone of Avoidance Shallow Survey P. A. Henning1, L. Staveley-Smith2, R. C. Kraan-Korteweg3 and E. M. Sadler4 1 Institute for Astrophysics, University of New Mexico, Albuquerque, NM, 87131, USA [email protected] 2 Australia Telescope National Facility, CSIRO, PO Box 76, Epping, NSW 1710, Australia [email protected] 3 Departamento de Astronomia, Universidad de Guanajuato, Guanajuato, GTO, CP 36000, Mexico [email protected] 4 School of Physics, University of Sydney, NSW 2006, Australia [email protected] Received 1998 November 2, accepted 1999 January 22 Abstract: The HI Parkes Zone of Avoidance Survey is a 21 cm blind search with the multibeam receiver on the 64-m radiotelescope, looking for galaxies hidden behind the southern Milky Way. The rst, shallow (15 mJy rms) phase of the survey has uncovered 107 galaxies, two-thirds of which were previously unknown. The addition of these galaxies to existing extragalactic catalogues allows the connectivity of a very long, thin lament across the Zone of Avoidance within 3500 km s1 to become evident. No local, hidden, very massive objects were uncovered. With similar results in the north (the Dwingeloo Obscured Galaxies Survey) our census of the most dynamically important HI-rich nearby galaxies is now complete, at least for those objects whose HI proles are not totally buried in the Galactic HI signal. Tests are being devised to better quantify this remaining ZOA for blind HI searches. The full survey is ongoing, and is expected to produce a catalogue of thousands of objects when it is nished.