A SPEctra Clustering Tool for the exploration of large spectroscopic surveys. Philipp Schalldach (HU Berlin & TLS Tautenburg, Germany)
|
|
- Herbert Armstrong
- 6 years ago
- Views:
Transcription
1 A SPEctra Clustering Tool for the exploration of large spectroscopic surveys Philipp Schalldach (HU Berlin & TLS Tautenburg, Germany)
2 Working Group Helmut Meusinger (Tautenburg, Germany) Philipp Schalldach (Berlin & Tautenburg, Germany) Aick in der Au (Munich, Germany) Mike Newholm (London, UK) Jesko Schwarzer (Bonn, Germany) Frank Pertermann (Tautenburg, Germany) Jörg Brünecke (Leipzig, Germany)
3 Content Scientific aim of ASPECT General procedure Data pools SOM algorithm for clustering SDSS spectra Methods for the analysis of SOMs Application: Search for unusual objects Next steps Summary
4 Aim Astronomy is a data intensive science with a growth rate of ~ 0.5 PB accessible data per year (Berriman & Groom 2011) ASPECT refers to a tool chain for the analysis of large data pools. The main module utilizes an artificial neural network algorithm called Kohonen mapping that projects higher dimensional input data into a 2-dimensional grid (self-organising map = SOM). The resulting SOM allows the user to browse efficiently through huge data collections and to select certain types of (e.g. rare) objects. ASPECT is able to compute SOMs for the spectra of up to one million objects (and more in the near future).
5 General Procedure Via a learn rate and a neighbourhood function an adaption of a neural network layer to actual spectral data is being achieved The result at this step is a table-like grid in which every cell/neuron represents an object. Main feature: similar objects are located in similar areas of the SOM. The resulting SOM can be analysed by eye or by blending in additional internal or external data. In der Au, Meusinger, Schalldach, et al., 2012, Astron. & Astrophys. 547, A115
6 General Procedure Example: SOM for sin functions of different peridicity
7 General Procedure Example: evolution over a SOM of > 1 Million Spectra
8 Data Pools Main observables (so far): spectra from the Sloan Digital Sky Survey (SDSS) data releases DR4 to DR10 - The SDSS is an photometric and spectral observation campaign - conducted at Apache Point Observatory, New Mexico meter telescope (120-megapixel camera, pair of spectrographs) Other data has also been processed either during development processes or within scientific evaluation processes including but not refraining to - CoRoT lighcurves for the purpose of exoplanet search - BATSE lightcurves for the purpose of identifying GRBs - Different types of data from near-industrial research Yet, best results up to date achieved with SDSS spectroscopic data.
9 SDSS Spectra SDSS spectra (as well as imaging data) is available from the SDSS Data Archive Server via several means, including search masks, SQL database interfaces and raw access to folder structures mainly in fits file format. ASPECT works with raw spectral data points being extracted from fits files and folded by several factors to increase on computation performance. Each spectrum along with several parameters are written into a single binary file that can be processed by the main component of the tool chain. The additional parameters (redshift,emission line-measurements, object type as determined by the SDSS pipeline) are not used within the computations, yet in the subsequent analysis of the SOM. For purpose of identification the SDSS nomenclature of identifying a spectrum via its MJD, plate ID, and fiber ID are being kept.
10 SDSS Spectra Credits: Sloan Digital Sky Survey
11 SOMs SOMs produce a similarity graph (usally in 2D) from high dimensional input data SOM key ingredients to emerge topographical organized maps: (1) broad casting of input into an n-dimensional map (2) selection of a winner (3) adaption of n-dimensional map in the spatial neighbourhood of the winner
12 SOM Algorithm for Clustering Spectra Ø Initalize network for instance take input spectra in randomized order Ø For each learning step: present training data (in our case all input spectra to cluster) in randomized order Ø For each input spectrum: find best matching spectrum in the network with smallest error (using euclidian distance between spectra) on collision (more than one input spectrum hit the same network cell) take input spectrum with smaller error, store other in collision list adapt best matching spectrum and the neigbourhood cells repeat steps for all spectra in collision list (search only in non occupied cells) change learn rate and adaption radius for new learning step
13 SOM Algorithm for Clustering Spectra Neigbourhood function: Actually used neighbourhoodfunction: exp(-sqrt(dx²+dy²)/2sigma²)
14 SOM Algorithm for Clustering Spectra Learn rate (eta) and Radius (sigma) change over training phase (t=0..1) Network adaption:
15 Spectral Icon Map Icon map of SDSS spectra of low-redshift galaxies Each pixel of the SOM corresponds to an object and can be represented by an iconised version of the spectrum. The inspection of the icon map is an efficient tool to - get an overview of the variety of spectral types -select objects of a given type -search for rare, unusual objects
16 Blending in Parameters Aside from the icon map, other parameters such as redshift, photometric data, line indices etc. can be plotted into the grid via color coding This enables for a general overview of the datapool in terms of its parameter space.
17 Using Interfaces The actual cells of the grid can be linked to other data pools or other means of computing as well. The key feature of similar spectra being located close to each other within the SOM ought to be preserved. Icon map Picture map
18 Using Interfaces In order to get more detailed information on the objects in the SOM, a html interface links to the SDSS database and therewith also to other data archives (SIMBAD, NED) as well as crossreferences to publications (ADS).
19 Application: Search for Unusual Quasars How to find rare, unusual objects in a SOM? Due to the intrinsic properties of the Kohonen-mapping algorithm, ASPECT tends to cluster unusual spectra at one or several spots regarding the overall composition of the datapool. These areas can be easily identified via visual inspection, parameter maps, or tracking of priorly defined objects.
20 Application: Search for Unusual Quasars Quasar = QSO (quasi stellar object) Actively accreting super-massive black hole in the center of a galaxy Nearby matter (gas clouds, stars, planets,...) in the distance range of lightyears is getting sucked into the black hole Angular momentum generates an accretion disc with luminosity higher than billions of stars Very far away, high redshifts but still visible because of its high luminosity Schematic view of a quasar, Credits: NASA / CXC / M.Weiss
21 Application: Search for Unusual Quasars Binning Quasars into redshift-bins of width 0.1. About 80 Kohonen-Maps clustered by ASPECT. Visual analysis yields ~ 1000 unusual Quasars of different types: - strong unusual absorption lines - weak emission lines - strong iron emission - very red spectra - miscellaneous As well as several extremely peculiar spectra that probably represent special evolutionary stages (e.g. very young quasars) Meusinger, Schalldach, Scholz, et al., 2012, Astron. & Astrophys. 541, A77
22 Application: Search for Unusual Quasars Composite spectra as compared to the composite spectrum of ordinary quasars. a ) Unusually red spectra b ) Unusual broad absorption lines c ) Weak emission lines
23 Currents What s being worked on Preparation for SDSS DR12 (> 2 million spectra) Adaption of ASPECT to FPGAs (floating point gate arrays) Adaption of ASPECT to GPUs (crunching the numbers with graphic cards) Enriching complementary Interfaces and other software tools for better navigation on huge Kohonen-Maps (> 1 million objects) Looking for other types of rare / difficult to identify objects such as post-starburst galaxies or carbon stars in order to find limiting constraints and model fitting parameters Using ASPECT for other types of data, such as lightcurves
24 Summary ASPECT is able to cluster voluminous samples of spectra by means of SOMs. We created a topological map of more than spectra from the SDSS DR4 (In der Au et al. 2012) to illustrate the capability of ASPECT. A larger SOM for ~ 1 million spectra from the SDSS DR7 was computed; the analysis is in progress. A large number of smaller SOMs were computed for special object types and were successfully used for the search for unusual quasars (Meusinger et al. 2012; Meusinger & Balafkan 2014). Improvements of ASPECTs will enable to compute a SOM for the > 2 million spectra from the SDSS DR12 (end of 2014).
25 Thank you all for your time and patience. Fin.
Introduction to the Sloan Survey
Introduction to the Sloan Survey Title Rita Sinha IUCAA SDSS The SDSS uses a dedicated, 2.5-meter telescope on Apache Point, NM, equipped with two powerful special-purpose instruments. The 120-megapixel
More informationData Release 5. Sky coverage of imaging data in the DR5
Data Release 5 The Sloan Digital Sky Survey has released its fifth Data Release (DR5). The spatial coverage of DR5 is about 20% larger than that of DR4. The photometric data in DR5 are based on five band
More informationROSAT Roentgen Satellite. Chandra X-ray Observatory
ROSAT Roentgen Satellite Joint facility: US, Germany, UK Operated 1990 1999 All-sky survey + pointed observations Chandra X-ray Observatory US Mission Operating 1999 present Pointed observations How do
More informationIntroduction to SDSS -instruments, survey strategy, etc
Introduction to SDSS -instruments, survey strategy, etc (materials from http://www.sdss.org/) Shan Huang 17 February 2010 Survey type Status Imaging and Spectroscopy Basic Facts SDSS-II completed, SDSS-III
More informationReal Astronomy from Virtual Observatories
THE US NATIONAL VIRTUAL OBSERVATORY Real Astronomy from Virtual Observatories Robert Hanisch Space Telescope Science Institute US National Virtual Observatory About this presentation What is a Virtual
More informationActive Galaxies and Galactic Structure Lecture 22 April 18th
Active Galaxies and Galactic Structure Lecture 22 April 18th FINAL Wednesday 5/9/2018 6-8 pm 100 questions, with ~20-30% based on material covered since test 3. Do not miss the final! Extra Credit: Thursday
More informationD4.2. First release of on-line science-oriented tutorials
EuroVO-AIDA Euro-VO Astronomical Infrastructure for Data Access D4.2 First release of on-line science-oriented tutorials Final version Grant agreement no: 212104 Combination of Collaborative Projects &
More informationDesign and implementation of the spectra reduction and analysis software for LAMOST telescope
Design and implementation of the spectra reduction and analysis software for LAMOST telescope A-Li Luo *a, Yan-Xia Zhang a and Yong-Heng Zhao a *a National Astronomical Observatories, Chinese Academy of
More informationThe phenomenon of gravitational lenses
The phenomenon of gravitational lenses The phenomenon of gravitational lenses If we look carefully at the image taken with the Hubble Space Telescope, of the Galaxy Cluster Abell 2218 in the constellation
More informationLecture Outlines. Chapter 25. Astronomy Today 7th Edition Chaisson/McMillan Pearson Education, Inc.
Lecture Outlines Chapter 25 Astronomy Today 7th Edition Chaisson/McMillan Chapter 25 Galaxies and Dark Matter Units of Chapter 25 25.1 Dark Matter in the Universe 25.2 Galaxy Collisions 25.3 Galaxy Formation
More informationQuasars and Active Galactic Nuclei (AGN)
Quasars and Active Galactic Nuclei (AGN) Astronomy Summer School in Mongolia National University of Mongolia, Ulaanbaatar July 21-26, 2008 Kaz Sekiguchi Hubble Classification M94-Sa M81-Sb M101-Sc M87-E0
More informationBlack Holes and Active Galactic Nuclei
Black Holes and Active Galactic Nuclei A black hole is a region of spacetime from which gravity prevents anything, including light, from escaping. The theory of general relativity predicts that a sufficiently
More informationLARGE QUASAR GROUPS. Kevin Rahill Astrophysics
LARGE QUASAR GROUPS Kevin Rahill Astrophysics QUASARS Quasi-stellar Radio Sources Subset of Active Galactic Nuclei AGNs are compact and extremely luminous regions at the center of galaxies Identified as
More informationQuestion 1. Question 2. Correct. Chapter 16 Homework. Part A
Chapter 16 Homework Due: 11:59pm on Thursday, November 17, 2016 To understand how points are awarded, read the Grading Policy for this assignment. Question 1 Following are a number of distinguishing characteristics
More informationSDSS Data Management and Photometric Quality Assessment
SDSS Data Management and Photometric Quality Assessment Željko Ivezić Princeton University / University of Washington (and SDSS Collaboration) Thinkshop Robotic Astronomy, Potsdam, July 12-15, 2004 1 Outline
More informationStudying galaxies with the Sloan Digital Sky Survey
Studying galaxies with the Sloan Digital Sky Survey Laboratory exercise, Physics of Galaxies, Spring 2017 (Uppsala Universitet) by Beatriz Villarroel *** The Sloan Digital Sky Survey (SDSS) is the largest
More informationOther stellar types. Open and globular clusters: chemical compositions
Other stellar types Some clusters have hotter stars than we find in the solar neighbourhood -- O, B, A stars -- as well as F stars, and cooler stars (G, K, M) Hence we can establish intrinsic values (M
More informationAstronomical Techniques
Astronomical Techniques Spectrographs & Spectroscopy Spectroscopy What is spectroscopy? A little history. What can we learn from spectroscopy? Play with simple spectrographs. Basic optics of a spectrograph.
More informationActive Galaxies & Quasars
Active Galaxies & Quasars Normal Galaxy Active Galaxy Galactic Nuclei Bright Active Galaxy NGC 5548 Galaxy Nucleus: Exact center of a galaxy and its immediate surroundings. If a spiral galaxy, it is the
More informationThe SDSS Data. Processing the Data
The SDSS Data Processing the Data On a clear, dark night, light that has traveled through space for a billion years touches a mountaintop in southern New Mexico and enters the sophisticated instrumentation
More informationSearching for Needles in the Sloan Digital Haystack
Searching for Needles in the Sloan Digital Haystack Robert Lupton Željko Ivezić Jim Gunn Jill Knapp Michael Strauss University of Chicago, Fermilab, Institute for Advanced Study, Japanese Participation
More informationData Management Plan Extended Baryon Oscillation Spectroscopic Survey
Data Management Plan Extended Baryon Oscillation Spectroscopic Survey Experiment description: eboss is the cosmological component of the fourth generation of the Sloan Digital Sky Survey (SDSS-IV) located
More informationarxiv: v1 [astro-ph] 12 Nov 2008
Self-Organizing Maps. An application to the OGLE data and the Gaia Science Alerts Łukasz Wyrzykowski, and Vasily Belokurov arxiv:0811.1808v1 [astro-ph] 12 Nov 2008 Institute of Astronomy, University of
More informationChapter 21 Galaxy Evolution. How do we observe the life histories of galaxies?
Chapter 21 Galaxy Evolution How do we observe the life histories of galaxies? Deep observations show us very distant galaxies as they were much earlier in time (old light from young galaxies). 1 Observing
More informationQuasars are supermassive black holes, found in the centers of galaxies Mass of quasar black holes = solar masses
Quasars Quasars are supermassive black holes, found in the centers of galaxies Mass of quasar black holes = 10 6 10 9 solar masses Stars and gas fall into the black hole and shine in an accrecon disk billion
More informationLecture 11 Quiz 2. AGN and You. A Brief History of AGN. This week's topics
Lecture 11 Quiz 2 AGN and You March 25 2003 8:00 PM BPS 1420 1. What system of time do astronomers use rather than the standard day-month-year system? 2. In that system, how long would it be between noon
More informationThe Star Formation Observatory (SFO)
Beyond JWST... STScI, Mar 26 27 2009 Slide 1 The Star Formation Observatory (SFO) From Cosmic Dawn to Our Solar System: A Next-Generation UV Optical Space Facility for the Study of Star Formation Rolf
More informationGOODS/VIMOS Spectroscopy: Data Release Version 2.0.1
ESO Phase 3 Data Release Description Data Collection GOODS_VIMOS_SPEC Release Number 1 Data Provider C. Cesarsky Date 10.03.2010 Migrated to Phase 3 infrastructure 08.12.2014 GOODS/VIMOS Spectroscopy:
More informationModern Image Processing Techniques in Astronomical Sky Surveys
Modern Image Processing Techniques in Astronomical Sky Surveys Items of the PhD thesis József Varga Astronomy MSc Eötvös Loránd University, Faculty of Science PhD School of Physics, Programme of Particle
More informationSuper Massive Black Hole Mass Determination and. Categorization of Narrow Absorption Line Quasars Outflows
1 H. James Super Massive Black Hole Mass Determination and Categorization of Narrow Absorption Line Quasars Outflows By Hodari-Sadiki James April 30 th 2012 Abstract We looked at high luminosity quasars
More informationQuasars in the SDSS. Rich Kron NGC June 2006 START CI-Team: Variable Quasars Research Workshop Yerkes Observatory
Quasars in the SDSS Rich Kron 28 June 2006 START CI-Team: Variable Quasars Research Workshop Yerkes Observatory NGC 1068 About 10% of all of the spectra in the SDSS database are of quasars (as opposed
More informationPDF hosted at the Radboud Repository of the Radboud University Nijmegen
PDF hosted at the Radboud Repository of the Radboud University Nijmegen The following full text is a publisher's version. For additional information about this publication click this link. http://hdl.handle.net/2066/84153
More informationOverview of comparison data presented
SUPPLEMENTARY INFORMATION doi:10.1038/nature09452 Overview of comparison data presented In Figure 2, we compare our results with four other data sets chosen to reflect much of the universe in which galaxy
More informationMeasuring Radial Velocities of Low Mass Eclipsing Binaries
Measuring Radial Velocities of Low Mass Eclipsing Binaries Rebecca Rattray, Leslie Hebb, Keivan G. Stassun College of Arts and Science, Vanderbilt University Due to the complex nature of the spectra of
More informationFeeding the Beast. Chris Impey (University of Arizona)
Feeding the Beast Chris Impey (University of Arizona) Note: the box is growing due to cosmic expansion but this is factored out. Heirarchical Structure Active Galactic Nuclei (AGN) Nuclear activity in
More informationAstro-lab at the Landessternwarte Heidelberg. Overview astro-lab & introduction to tasks. Overview astro-lab
Astro-lab at the Landessternwarte Heidelberg Overview astro-lab & introduction to tasks Overview astro-lab Jochen Heidt, April 2018 The astro-lab is offered twice a year. It will always be held during
More informationLecture 9. Quasars, Active Galaxies and AGN
Lecture 9 Quasars, Active Galaxies and AGN Quasars look like stars but have huge redshifts. object with a spectrum much like a dim star highly red-shifted enormous recessional velocity huge distance (Hubble
More informationLarge Scale Structure of the Universe Lab
Large Scale Structure of the Universe Lab Introduction: Since the mid-1980 s astronomers have gathered data allowing, for the first time, a view of the structure of the Universe in three-dimensions. You
More informationGalaxies. The majority of known galaxies fall into one of three major classes: spirals (78 %), ellipticals (18 %) and irregulars (4 %).
Galaxies Collection of stars, gas and dust bound together by their common gravitational pull. Galaxies range from 10,000 to 200,000 light-years in size. 1781 Charles Messier 1923 Edwin Hubble The distribution
More informationFoundations of Astrophysics
Foundations of Astrophysics Barbara Ryden The Ohio State University Bradley M. Peterson The Ohio State University Preface xi 1 Early Astronomy 1 1.1 The Celestial Sphere 1 1.2 Coordinate Systems on a Sphere
More informationThe Sloan Digital Sky Survey
The Sloan Digital Sky Survey Robert Lupton Xiaohui Fan Jim Gunn Željko Ivezić Jill Knapp Michael Strauss University of Chicago, Fermilab, Institute for Advanced Study, Japanese Participation Group, Johns
More informationJodrell Bank Discovery Centre
A-level Physics: Radio Telescopes Consolidation questions For these questions, we will be considering galaxy NGC 660 (below), a rare polar-ring galaxy in the constellation of Pisces. NGC 660 consists of
More information1 Lecture, 2 September 1999
1 Lecture, 2 September 1999 1.1 Observational astronomy Virtually all of our knowledge of astronomical objects was gained by observation of their light. We know how to make many kinds of detailed measurements
More informationDLAs Probing Quasar Host Galaxies. Hayley Finley P. Petitjean, P. Noterdaeme, I. Pâris + SDSS III BOSS Collaboration 2013 A&A
DLAs Probing Quasar Host Galaxies Hayley Finley P. Petitjean, P. Noterdaeme, I. Pâris + SDSS III BOSS Collaboration 2013 A&A 558 111 Outline Feedback mechanisms in QSO host galaxies Strong DLAs at zqso
More information2 F. PASIAN ET AL. ology, both for ordinary spectra (Gulati et al., 1994; Vieira & Ponz, 1995) and for high-resolution objective prism data (von Hippe
AUTOMATED OBJECTIVE PRISM SPECTRAL CLASSIFICATION USING NEURAL NETWORKS F. PASIAN AND R. SMAREGLIA Osservatorio Astronomico di Trieste Via G.B.Tiepolo 11, 34131 Trieste, Italy AND P. HANZIOS, A. DAPERGOLAS
More informationQuasars: Back to the Infant Universe
Quasars: Back to the Infant Universe Learning Objectives! What is a quasar? What spectral features tell us quasars are very redshifted (very distant)? What spectral features tell us they are composed of
More informationASTROPHYSICS. K D Abhyankar. Universities Press S T A R S A ND G A L A X I E S
ASTROPHYSICS S T A R S A ND G A L A X I E S K D Abhyankar Universities Press Contents Foreword vii Preface ix 1 Introduction 1 1.1 ' Astronomy and astrophysics 1 1.2 Importance of astronomy 2 1.3 Methods
More informationBright Quasar 3C 273 Thierry J-L Courvoisier. Encyclopedia of Astronomy & Astrophysics P. Murdin
eaa.iop.org DOI: 10.1888/0333750888/2368 Bright Quasar 3C 273 Thierry J-L Courvoisier From Encyclopedia of Astronomy & Astrophysics P. Murdin IOP Publishing Ltd 2006 ISBN: 0333750888 Institute of Physics
More informationExploiting Sparse Non-Linear Structure in Astronomical Data
Exploiting Sparse Non-Linear Structure in Astronomical Data Ann B. Lee Department of Statistics and Department of Machine Learning, Carnegie Mellon University Joint work with P. Freeman, C. Schafer, and
More informationRick Ebert & Joseph Mazzarella For the NED Team. Big Data Task Force NASA, Ames Research Center 2016 September 28-30
NED Mission: Provide a comprehensive, reliable and easy-to-use synthesis of multi-wavelength data from NASA missions, published catalogs, and the refereed literature, to enhance and enable astrophysical
More informationAstronomy of the Next Decade: From Photons to Petabytes. R. Chris Smith AURA Observatory in Chile CTIO/Gemini/SOAR/LSST
Astronomy of the Next Decade: From Photons to Petabytes R. Chris Smith AURA Observatory in Chile CTIO/Gemini/SOAR/LSST Classical Astronomy still dominates new facilities Even new large facilities (VLT,
More informationThe Sloan Digital Sky Survey. Sebastian Jester Experimental Astrophysics Group Fermilab
The Sloan Digital Sky Survey Sebastian Jester Experimental Astrophysics Group Fermilab SLOAN DIGITAL SKY SURVEY Sloan Digital Sky Survey Goals: 1. Image ¼ of sky in 5 bands 2. Measure parameters of objects
More informationThe Large Synoptic Survey Telescope
The Large Synoptic Survey Telescope Philip A. Pinto Steward Observatory University of Arizona for the LSST Collaboration 17 May, 2006 NRAO, Socorro Large Synoptic Survey Telescope The need for a facility
More informationHOMEWORK - Chapter 17 The Stars
Astronomy 20 HOMEWORK - Chapter 7 The Stars Use a calculator whenever necessary. For full credit, always show your work and explain how you got your answer in full, complete sentences on a separate sheet
More information2019 Astronomy Team Selection Test
2019 Astronomy Team Selection Test Acton-Boxborough Regional High School Written by Antonio Frigo Do not flip over this page until instructed. Instructions You will have 45 minutes to complete this exam.
More informationDoing astronomy with SDSS from your armchair
Doing astronomy with SDSS from your armchair Željko Ivezić, University of Washington & University of Zagreb Partners in Learning webinar, Zagreb, 15. XII 2010 Supported by: Microsoft Croatia and the Croatian
More informationThe SDSS is Two Surveys
The SDSS is Two Surveys The Fuzzy Blob Survey The Squiggly Line Survey The Site The telescope 2.5 m mirror Digital Cameras 1.3 MegaPixels $150 4.3 Megapixels $850 100 GigaPixels $10,000,000 CCDs CCDs:
More informationAstronomy Today. Eighth edition. Eric Chaisson Steve McMillan
Global edition Astronomy Today Eighth edition Eric Chaisson Steve McMillan The Distance Scale ~1 Gpc Velocity L Distance Hubble s law Supernovae ~200 Mpc Time Tully-Fisher ~25 Mpc ~10,000 pc Time Variable
More informationGalaxy Classification
Galaxies Galaxies are collections of billons of stars; our home galaxy, the Milky Way, is a typical example. Stars, gas, and interstellar dust orbit the center of the galaxy due to the gravitational attraction
More informationHow Do I Create a Hubble Diagram to show the expanding universe?
How Do I Create a Hubble Diagram to show the expanding universe? An extremely important topic in astronomy is the expansion of the universe. Although the expanding universe is nearly always discussed in
More informationAstr 5465 Feb. 6, 2018 Today s Topics
Astr 5465 Feb. 6, 2018 Today s Topics Stars: Binary Stars Determination of Stellar Properties via Binary Stars Classification of Binary Stars Visual Binaries Both stars visible Only one star visible Spectroscopic
More informationGalaxies. Galaxy Diversity. Galaxies, AGN and Quasars. Physics 113 Goderya
Galaxies, AGN and Quasars Physics 113 Goderya Chapter(s): 16 and 17 Learning Outcomes: Galaxies Star systems like our Milky Way Contain a few thousand to tens of billions of stars. Large variety of shapes
More informationInternational Olympiad on Astronomy and Astrophysics (IOAA)
Syllabus of International Olympiad on Astronomy and Astrophysics (IOAA) General Notes 1. Extensive contents in basic astronomical concepts are required in theoretical and practical problems. 2. Basic concepts
More informationThe Hertzprung-Russell Diagram. The Hertzprung-Russell Diagram. Question
Key Concepts: Lecture 21: Measuring the properties of stars (cont.) The Hertzsprung-Russell (HR) Diagram (L versus T) The Hertzprung-Russell Diagram The Stefan-Boltzmann Law: flux emitted by a black body
More informationChapter 15 2/19/2014. Lecture Outline Hubble s Galaxy Classification. Normal and Active Galaxies Hubble s Galaxy Classification
Lecture Outline Chapter 15 Normal and Active Galaxies Spiral galaxies are classified according to the size of their central bulge. Chapter 15 Normal and Active Galaxies Type Sa has the largest central
More informationGalaxies over the Latter Half of Cosmic Time
National Aeronautics and Space Administration Galaxies over the Latter Half of Cosmic Time Marc Davis and Sandra M. Faber Taken from: Hubble 2006 Science Year in Review The full contents of this book include
More informationarxiv:astro-ph/ v1 30 Aug 2001
TRACING LUMINOUS AND DARK MATTER WITH THE SLOAN DIGITAL SKY SURVEY J. LOVEDAY 1, for the SDSS collaboration 1 Astronomy Centre, University of Sussex, Falmer, Brighton, BN1 9QJ, England arxiv:astro-ph/18488v1
More informationProtoplanetary discs of isolated VLMOs discovered in the IPHAS survey
Protoplanetary discs of isolated VLMOs discovered in the IPHAS survey Luisa Valdivielso Casas Collaborators: E. Martín, H. Bouy, E. Solano,J. Drew,R. Greimel 1 IAC - ULL 14 de septiembre 2010 Outline Introduction
More informationOverview: Astronomical Spectroscopy
Overview: Astronomical Spectroscopy or How to Start Thinking Creatively about Measuring the Universe Basic Spectrograph Optics Objective Prism Spectrometers - AESoP Slit Spectrometers Spectrometers for
More informationStars and their properties: (Chapters 11 and 12)
Stars and their properties: (Chapters 11 and 12) To classify stars we determine the following properties for stars: 1. Distance : Needed to determine how much energy stars produce and radiate away by using
More informationSupplementary Information for SNLS-03D3bb a super- Chandrasekhar mass Type Ia supernova
1 Supplementary Information for SNLS-03D3bb a super- Chandrasekhar mass Type Ia supernova SN Location SNLS-03D3bb is located at RA: 14:16:18.920 Dec: +52:14:53.66 (J2000) in the D3 (extended Groth Strip)
More informationActive Galactic Nuclei
Active Galactic Nuclei How were they discovered? How common are they? How do we know they are giant black holes? What are their distinctive properties? Active Galactic Nuclei for most galaxies the luminosity
More informationDistances to Stars. Important as determines actual brightness but hard to measure as stars are so far away
SECTION II: Nature of Stars Astronomers measure properties of Stars Distance Mass Apparent Brightness Surface Temperature Radius Find that some are related Large Mass Large Absolute Brightness We will
More informationChapter 21 Galaxy Evolution. Agenda
Chapter 21 Galaxy Evolution Agenda Announce: Test in one week Part 2 in 2.5 weeks Spring Break in 3 weeks Online quizzes & tutorial are now on assignment list Final Exam questions Revisit Are we significant
More informationSearching for Other Worlds
Searching for Other Worlds Lecture 32 1 In-Class Question What is the Greenhouse effect? a) Optical light from the Sun is reflected into space while infrared light passes through the atmosphere and heats
More informationCharacterization of the exoplanet host stars. Exoplanets Properties of the host stars. Characterization of the exoplanet host stars
Characterization of the exoplanet host stars Exoplanets Properties of the host stars Properties of the host stars of exoplanets are derived from a combination of astrometric, photometric, and spectroscopic
More informationScience with the New Hubble Instruments. Ken Sembach STScI Hubble Project Scientist
Science with the New Hubble Instruments Ken Sembach STScI Hubble Project Scientist 1 Hubble Has Improved Over Time Servicing missions have improved Hubble s vision. Hubble sees farther and with greater
More informationAstronomy C SSSS 2018
Astronomy C SSSS 2018 Galaxies and Stellar Evolution Written by Anna1234 School Team # Names 1 Instructions: 1. There are pictures of a number of galaxies in this test. However, as the DSO list for 2019
More informationFlagging Bad Data in Imaging
Flagging Bad Data Flagging Bad Data in Imaging Observations are never perfect, due to observing conditions e.g., bad seeing, moonlight, the solar wind, clouds, airplanes, cosmic rays, telescope malfunctions
More informationOur Galaxy. Milky Way Galaxy = Sun + ~100 billion other stars + gas and dust. Held together by gravity! The Milky Way with the Naked Eye
Our Galaxy Milky Way Galaxy = Sun + ~100 billion other stars + gas and dust Held together by gravity! The Milky Way with the Naked Eye We get a special view of our own galaxy because we are part of it!
More informationData challenges of the Virtual Observatory in Time Domain Astronomy
Data challenges of the Virtual Observatory in Time Domain Astronomy Ada Nebot Gomez-Moran Astronomical Data Analysis Software & Systems Nov. 11-15 2018 Time Domain Astronomy The study of variability of
More informationM31 - Andromeda Galaxy M110 M32
UNIT 4 - Galaxies XIV. The Milky Way galaxy - a huge collection of millions or billions of stars, gas, and dust, isolated in space and held together by its own gravity M110 M31 - Andromeda Galaxy A. Structure
More informationHubble s Law and the Cosmic Distance Scale
Lab 7 Hubble s Law and the Cosmic Distance Scale 7.1 Overview Exercise seven is our first extragalactic exercise, highlighting the immense scale of the Universe. It addresses the challenge of determining
More informationUsing Spitzer to Observe the Solar System
Using Spitzer to Observe the Solar System Sean Carey Spitzer Science Center 47 th DPS meeting 09 November 2015 SJC - 1 Spitzer Space Telescope NASA s Infrared Great Observatory Launched on 25 August 2003
More informationAstronomy 102: Stars and Galaxies Examination 3 April 11, 2003
Name: Seat Number: Astronomy 102: Stars and Galaxies Examination 3 April 11, 2003 Do not open the test until instructed to begin. Instructions: Write your answers in the space provided. If you need additional
More informationQSO ABSORPTION LINE STUDIES with the HUBBLE SPACE TELESCOPE
QSO ABSORPTION LINE STUDIES with the HUBBLE SPACE TELESCOPE COLORADO GROUP: JOHN STOCKE, MIKE SHULL, JAMES GREEN, STEVE PENTON, CHARLES DANFORTH, BRIAN KEENEY Results thus far based on: > 300 QSO ABSORBERS
More informationVera Genten. AGN (Active Galactic Nuclei)
Vera Genten AGN (Active Galactic Nuclei) Topics 1)General properties 2)Model 3)Different AGN-types I. Quasars II.Seyfert-galaxies III.Radio galaxies IV.young radio-loud AGN (GPS, CSS and CFS) V.Blazars
More informationAstronomy 10 Test #2 Practice Version
Given (a.k.a. `First ) Name(s): Family (a.k.a. `Last ) name: ON YOUR PARSCORE: `Bubble your name, your student I.D. number, and your multiple-choice answers. I will keep the Parscore forms. ON THIS TEST
More informationQuasars and AGN. What are quasars and how do they differ from galaxies? What powers AGN s. Jets and outflows from QSOs and AGNs
Goals: Quasars and AGN What are quasars and how do they differ from galaxies? What powers AGN s. Jets and outflows from QSOs and AGNs Discovery of Quasars Radio Observations of the Sky Reber (an amateur
More informationGrowth of structure in an expanding universe The Jeans length Dark matter Large scale structure simulations. Large scale structure
Modern cosmology : The Growth of Structure Growth of structure in an expanding universe The Jeans length Dark matter Large scale structure simulations effect of cosmological parameters Large scale structure
More informationAstr 2310 Thurs. March 3, 2016 Today s Topics
Astr 2310 Thurs. March 3, 2016 Today s Topics Chapter 6: Telescopes and Detectors Optical Telescopes Simple Optics and Image Formation Resolution and Magnification Invisible Astronomy Ground-based Radio
More informationChapter 17. Active Galaxies and Supermassive Black Holes
Chapter 17 Active Galaxies and Supermassive Black Holes Guidepost In the last few chapters, you have explored our own and other galaxies, and you are ready to stretch your scientific imagination and study
More informationScience with large imaging surveys
Science with large imaging surveys Hiranya V. Peiris University College London Science from LSS surveys: A case study of SDSS quasars Boris Leistedt (UCL) with Daniel Mortlock (Imperial) Aurelien Benoit-Levy
More informationGalaxies. With a touch of cosmology
Galaxies With a touch of cosmology Types of Galaxies Spiral Elliptical Irregular Spiral Galaxies Spiral Galaxies Disk component where the spiral arms are Interstellar medium Star formation Spheroidal
More informationAge of the Universe Lab Session - Example report
Age of the Universe Lab Session - Example report FS 17 Prof. George Lake Assistant: Mischa Knabenhans Office: Y11-F-74, e-mail: mischak@physik.uzh.ch http://www.ics.uzh.ch/~mischak/teaching/universe.html
More informationCHEMICAL ABUNDANCE ANALYSIS OF RC CANDIDATE STAR HD (46 LMi) : PRELIMINARY RESULTS
Dig Sites of Stellar Archeology: Giant Stars in the Milky Way Ege Uni. J. of Faculty of Sci., Special Issue, 2014, 145-150 CHEMICAL ABUNDANCE ANALYSIS OF RC CANDIDATE STAR HD 94264 (46 LMi) : PRELIMINARY
More informationLecture Outlines. Chapter 24. Astronomy Today 8th Edition Chaisson/McMillan Pearson Education, Inc.
Lecture Outlines Chapter 24 Astronomy Today 8th Edition Chaisson/McMillan Chapter 24 Galaxies Units of Chapter 24 24.1 Hubble s Galaxy Classification 24.2 The Distribution of Galaxies in Space 24.3 Hubble
More informationMulti-wavelength Astronomy
astronomy Multi-wavelength Astronomy Content What do we measure Multi-wavelength approach Data Data Mining Virtual Observatory Hands on session Larmor's formula Maxwell's equations imply that all classical
More informationSDSS-IV and eboss Science. Hyunmi Song (KIAS)
SDSS-IV and eboss Science Hyunmi Song (KIAS) 3rd Korea-Japan Workshop on Dark Energy April 4, 2016 at KASI Sloan Digital Sky Survey 2.5m telescopes at Apache Point Observatory (US) and Las Campanas Observatory
More informationGamma-Ray Astronomy. Astro 129: Chapter 1a
Gamma-Ray Bursts Gamma-Ray Astronomy Gamma rays are photons with energies > 100 kev and are produced by sub-atomic particle interactions. They are absorbed by our atmosphere making observations from satellites
More information