Photometry. La Palma trip 2014 Lecture 2 Prof. S.C. Trager
|
|
- Evelyn Potter
- 6 years ago
- Views:
Transcription
1 Photometry La Palma trip 2014 Lecture 2 Prof. S.C. Trager
2 Photometry is the measurement of magnitude from images technically, it s the measurement of light, but astronomers use the above definition these days This sounds simple, but there are several steps required! We ll focus here on photometry of objects from twodimensional images (detectors) similar (if not all) steps are needed when using singlepixel detectors like photomultiplier tubes
3 The process of photometry 1. Find the location(s) of the object(s) of interest (perhaps all) 2. Determine the background level(s) B of the object(s) (per pixel) 3. Calculate the integrated source intensity I for each object. To do this, sum S counts from N pixels. Then I = S N B
4 The process of photometry 4. Determine the magnitude: m = 2.5 log 10 I + C where C is the photometric zero point 5. Determine the photometric zeropoint(s), airmass correction(s), and color term(s) (if needed) using photometry of standard objects (almost always these are standard stars)
5 Background estimation It is always preferable to find the background as close to the object as possible When measuring magnitudes of compact objects (stars, small galaxies), it is common to determine the background in an annulus around the object object sky annulus
6 Background estimation the annulus is often circular or elliptical, but can be more complicated shape not done when doing surface photometry object sky annulus
7 Background estimation Once the counts in the sky annulus have been measured, compute a histogram of these values then take the mode of the distribution (the most probable value) to determine the background level per pixel #of pixels Mode (peak of this histogram) Median (1/2 above, 1/2 below) Counts Arithmetic mean Because essentially all deviations from the sky are positive counts (stars and galaxies), the mode is the best approximation to the sky.
8 Background estimation For surface photometry, you should fit a constant value or a plane or a surface to blank regions of the image and subtract this from the entire image Note: surface photometry is the measurement of magnitudes per unit area (on the sky)
9 Determining source intensity There are two approaches to this step, depending on need and source type: aperture photometry PSF (fitting) photometry (which we ll skip for now )...and there s also surface photometry, which we ll describe briefly below
10 Aperture photometry In this case, we count the flux from the object and the sky within some aperture typically we use circular apertures for stellar photometry, but the apertures can be arbitrarily shaped for, say, complex galaxies Then the source intensity X is I = aperture I ij B N aperture
11 Aperture photometry Problems... How big should the apertures be? Ideally, you d like to get all of the light from your object... but even stars have very extended images Profile of a stellar image on a photographic plate (King 1971)
12 Aperture photometry Note that a Gaussian profile contains 99% of its light within 10σ 4 FWHM (because FWHM=2.355σ) But! As the aperture grows, S = P aperture I ij increases, but so does Naperture B (because N gets bigger) therefore the noise increases, because N r 2, where r is the radius (size) of the aperture therefore the maximum S/N occurs at some intermediate radius, depending on FWHM
13 Aperture photometry If we restrict size to maximize S/N, we re not measuring all of the flux Either measure and compare all objects through the same aperture...or... Use the fact that the profile is the same for all stars (hopefully!) and measure a bright, well-exposed, unsaturated, isolated star out to 4 FWHM. Then use the magnitude between this aperture and your smaller aperture to correct all the photometry
14 Curve-of-growth analysis 0.05!mag[aper(n+1) - aper(n)] Aperture Radius
15 Aperture photometry More problems... Cosmic rays or bad pixels contaminating your aperture just discard this object why didn t you take multiple images? Nearby stars (or other objects) contaminate your aperture not a problem for sky estimate because we used the mode but if your aperture is contaminated, need to discard object
16 Surface photometry Like aperture photometry on a large scale Determines intensity per unit (angular) area on the sky:!! X SB = I ij B N aperture /area aperture Often use elliptical apertures for this Surface photometry gives light profile and shape information (using parameters of aperture fits)
17 Surface brightness profiles The surface brightness of a galaxy I(x) is the amount of light contained in some small area at a particular point x in an image Consider a square area with a side of length D of a galaxy at distance d. This length will subtend an angle = D/d If the total luminosity of the galaxy in that area is L, then the received flux is F = L/(4 d 2 )
18 So the surface brightness is! I(x) =F/ 2 = L/(4 d 2 )(d/d) 2 = L/(4 D 2 ) which is independent of distance note that this is not true at cosmological distances! The units of I(x) are usually given in L pc 2
19 Often the magnitude per square arcsecond is quoted as the surface brightness:! µ (x) = 2.5 log I (x) + constant In the B-band, the constant is 27 mag/arcsec 2, which corresponds to 1 L pc 2 Thus I B = (µ B 27) L,B pc 2
20 Photometric calibration To determine our photometric zeropoints,! m = 2.5 log 10 I + ZP we need to observe objects usually stars of known magnitudes and colors at many different hour angles
21 Photometric calibration We need to correct three major effects: 1. overall magnitude offset: what magnitude corresponds to, say, one e /s at X=1? 2. color shifts between your filters and the standard stars filters 3. atmospheric extinction note that there will also be different k λ for different-colored stars, because of the width of the broadband filter compared to the slope of k λ and the shape of the stars spectra
22 Color terms
23 Photometric calibration Combining 1) and 2), we have m! true = m 0,inst + b 0 + b 1 c + b 2 c 2 + where c is the color of your object And 3) means V=v 1 +a 0! m 0,inst = m X kx + k 0 cx where c is the color, k is the extinction coefficient, k is the differential color extinction coefficient, and m X is the magnitude observed at airmass X just magnitude zeropoint RMS=0.055
24 Photometric calibration Combining 1) and 2), we have m! true = m 0,inst + b 0 + b 1 c + b 2 c 2 + where c is the color of your object And 3) means V=v inst + c 0 + c 1 X! m 0,inst = m X kx + k 0 cx where c is the color, k is the extinction coefficient, k is the differential color extinction coefficient, and m X is the magnitude observed at airmass X zeropoint and airmass RMS=0.032
25 Photometric calibration Combining 1) and 2), we have m! true = m 0,inst + b 0 + b 1 c + b 2 c 2 + where c is the color of your object And 3) means V=v inst +c 0 +c 1 X+c 2 (B-V)! m 0,inst = m X kx + k 0 cx where c is the color, k is the extinction coefficient, k is the differential color extinction coefficient, and m X is the magnitude observed at airmass X RMS=0.021 zeropoint, airmass, and color
26 Photometric calibration Thus, for a star of known mtrue and c observed at X,! m true = m X + a 0 + a 1 X + a 2 c + a 3 cx + a 4 c 2 + Since each star satisfies this equation, a system of linear polynomial equations exist, and we can invert this system to get our necessary coefficients ai Lists of standard stars can be found in papers by Landolt, Graham, and Stetson, and should be available at any observatory!
27 The photometry Golden Rules Always observe standard stars with colors bracketing the colors of the objects you want to calibrate Always observe standard stars at airmasses spanning the airmasses of your target exposures Only use very clear (photometric) weather! No clouds.
28 The photometry Golden Rules Use blue filters at low X and least moon Save red filters for higher airmasses and more moon Try to work at X<1.5 On big telescopes (>2m) with CCD cameras, standard stars are very easy to saturate Use short exposures to get bright standard stars but not too short to avoid scintillation (>5 10 s) Use longer exposures to get faint standard stars
Imaging Cameras. Imagers can be put at almost any focus, but most commonly they are put at prime focus or at cassegrain.
Imaging Cameras Imagers can be put at almost any focus, but most commonly they are put at prime focus or at cassegrain. The scale of a focus is given by S=206265/(D x f#) (arcsec/mm) Examples: 1. 3m @f/5
More informationStellar Photometry: I. Measuring. Ast 401/Phy 580 Fall 2014
What s Left (Today): Introduction to Photometry Nov 10 Photometry I/Spectra I Nov 12 Spectra II Nov 17 Guest lecture on IR by Trilling Nov 19 Radio lecture by Hunter Nov 24 Canceled Nov 26 Thanksgiving
More informationAperture Photometry with CCD Images using IRAF. Kevin Krisciunas
Aperture Photometry with CCD Images using IRAF Kevin Krisciunas Images must be taken in a sensible manner. Ask advice from experienced observers. But remember Wallerstein s Rule: Four astronomers, five
More informationImaging Cameras. Imagers can be put at almost any focus, but most commonly they are put at prime focus or at cassegrain.
Imaging Cameras Imagers can be put at almost any focus, but most commonly they are put at prime focus or at cassegrain. PanStarrs DES The scale of a focus is given by S=206265/(D x f#) (arcsec/mm) Examples:
More informationPhotometry, PSF Fitting, Astrometry. AST443, Lecture 8 Stanimir Metchev
Photometry, PSF Fitting, Astrometry AST443, Lecture 8 Stanimir Metchev Administrative Project 2: finalized proposals due today Project 3: see at end due in class on Wed, Oct 14 Midterm: Monday, Oct 26
More informationAstronomy 341 Fall 2012 Observational Astronomy Haverford College. CCD Terminology
CCD Terminology Read noise An unavoidable pixel-to-pixel fluctuation in the number of electrons per pixel that occurs during chip readout. Typical values for read noise are ~ 10 or fewer electrons per
More informationPhotometry. Variable Star Photometry
Variable Star Photometry Photometry One of the most basic of astronomical analysis is photometry, or the monitoring of the light output of an astronomical object. Many stars, be they in binaries, interacting,
More informationAstro-photography. Daguerreotype: on a copper plate
AST 1022L Astro-photography 1840-1980s: Photographic plates were astronomers' main imaging tool At right: first ever picture of the full moon, by John William Draper (1840) Daguerreotype: exposure using
More informationTIRCAM2 (TIFR Near Infrared Imaging Camera - 3.6m Devasthal Optical Telescope (DOT)
TIRCAM2 (TIFR Near Infrared Imaging Camera - II) @ 3.6m Devasthal Optical Telescope (DOT) (ver 4.0 June 2017) TIRCAM2 (TIFR Near Infrared Imaging Camera - II) is a closed cycle cooled imager that has been
More informationThis release contains deep Y-band images of the UDS field and the extracted source catalogue.
ESO Phase 3 Data Release Description Data Collection HUGS_UDS_Y Release Number 1 Data Provider Adriano Fontana Date 22.09.2014 Abstract HUGS (an acronym for Hawk-I UDS and GOODS Survey) is a ultra deep
More informationPhotometry using CCDs
Photometry using CCDs Signal-to-Noise Ratio (SNR) Instrumental & Standard Magnitudes Point Spread Function (PSF) Aperture Photometry & PSF Fitting Examples Some Old-Fashioned Photometers ! Arrangement
More informationM67 Cluster Photometry
Lab 3 part I M67 Cluster Photometry Observational Astronomy ASTR 310 Fall 2009 1 Introduction You should keep in mind that there are two separate aspects to this project as far as an astronomer is concerned.
More informationCalibrating VISTA Data
Calibrating VISTA Data IR Camera Astronomy Unit Queen Mary University of London Cambridge Astronomical Survey Unit, Institute of Astronomy, Cambridge Jim Emerson Simon Hodgkin, Peter Bunclark, Mike Irwin,
More informationImaging and Photometry
Imaging and Photometry Ay 122 - Fall 2006 Imaging and Photometry (Many slides today c/o Mike Bolte, UCSC) Now essentially always done with imaging arrays (e.g., CCDs); it used to be with single-channel
More informationCross-Talk in the ACS WFC Detectors. II: Using GAIN=2 to Minimize the Effect
Cross-Talk in the ACS WFC Detectors. II: Using GAIN=2 to Minimize the Effect Mauro Giavalisco August 10, 2004 ABSTRACT Cross talk is observed in images taken with ACS WFC between the four CCD quadrants
More informationPhotometry of the variable stars using CCD detectors
Contrib. Astron. Obs. Skalnaté Pleso 35, 35 44, (2005) Photometry of the variable stars using CCD detectors I. Photometric reduction. Š. Parimucha 1, M. Vaňko 2 1 Institute of Physics, Faculty of Natural
More informationWFC3 TV3 Testing: IR Channel Nonlinearity Correction
Instrument Science Report WFC3 2008-39 WFC3 TV3 Testing: IR Channel Nonlinearity Correction B. Hilbert 2 June 2009 ABSTRACT Using data taken during WFC3's Thermal Vacuum 3 (TV3) testing campaign, we have
More informationObservational Astronomy
Observational Astronomy Instruments The telescope- instruments combination forms a tightly coupled system: Telescope = collecting photons and forming an image Instruments = registering and analyzing the
More informationPhotometric Calibration for Wide- Area Space Surveillance Sensors
Photometric Calibration for Wide- Area Space Surveillance Sensors J.S. Stuart, E. C. Pearce, R. L. Lambour 2007 US-Russian Space Surveillance Workshop 30-31 October 2007 The work was sponsored by the Department
More informationRHO CCD. imaging and observa3on notes AST aug 2011
RHO CCD imaging and observa3on notes AST 6725 30 aug 2011 Camera Specs & Info 76 cm Telescope f/4 Prime focus (3.04 m focal length) SBIG ST- 8XME CCD Camera Kodak KAF- 1603ME Class 2 imaging CCD Built-
More informationCCD reductions techniques
CCD reductions techniques Origin of noise Noise: whatever phenomena that increase the uncertainty or error of a signal Origin of noises: 1. Poisson fluctuation in counting photons (shot noise) 2. Pixel-pixel
More informationSPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA
SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA Instrument Science Report WFC3 2010-08 WFC3 Pixel Area Maps J. S. Kalirai, C. Cox, L. Dressel, A. Fruchter, W. Hack, V. Kozhurina-Platais, and
More informationImage Enhancement (from Chapter 13) (V6)
Image Enhancement (from Chapter 13) (V6) Astronomical images often span a wide range of brightness, while important features contained in them span a very narrow range of brightness. Alternatively, interesting
More informationWISE Photometry (WPHOT)
WISE Photometry () Tom Jarrett & Ken Marsh ( IPAC/Caltech) WISE Science Data Center Review, April 4, 2008 TJ+KM - 1 Overview is designed to perform the source characterization (source position & flux measurements)
More informationTotal Comet Magnitudes from CCD- and DSLR-Photometry
European Comet Conference Ondrejov 2015 Total Comet Magnitudes from CCD- and DSLR-Photometry Thomas Lehmann, Weimar (Germany) Overview 1. Introduction 2. Observation 3. Image Reduction 4. Comet Extraction
More informationWEBCAMS UNDER THE SPOTLIGHT
WEBCAMS UNDER THE SPOTLIGHT MEASURING THE KEY PERFORMANCE CHARACTERISTICS OF A WEBCAM BASED IMAGER Robin Leadbeater Q-2006 If a camera is going to be used for scientific measurements, it is important to
More informationMiCPhot: A prime-focus multicolor CCD photometer on the 85-cm Telescope
Research in Astron. Astrophys. 2009 Vol. 9 No. 3, 349 366 http://www.raa-journal.org http://www.iop.org/journals/raa Research in Astronomy and Astrophysics MiCPhot: A prime-focus multicolor CCD photometer
More informationVAPHOT A Package for Precision Differential Aperture Photometry
VAPHOT A Package for Precision Differential Aperture Photometry HANS J. DEEG 1,, LAURANCE R. DOYLE 3 1 Centro de Astrobiología, INTA, E 8807 Torrejon (Madrid), Spain (hdeeg@bigfoot.com) Instituto de Astrofísica
More informationUNIVERSITY COLLEGE LONDON Department of Physics and Astronomy. An Introduction to Image Processing
UNIVERSITY COLLEGE LONDON Department of Physics and Astronomy UCL Observatory PHAS2130 2015 16.2 An Introduction to Image Processing 1 Introduction Students will have submitted imaging requests to the
More informationACS/WFC: Differential CTE corrections for Photometry and Astrometry from non-drizzled images
SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA Instrument Science Report ACS 2007-04 ACS/WFC: Differential CTE corrections for Photometry and Astrometry from non-drizzled images Vera Kozhurina-Platais,
More informationHIGH SPEED CCD PHOTOMETRY
Baltic Astronomy, vol.j, 519-526, 1995. HIGH SPEED CCD PHOTOMETRY D. O'Donoghue Department of Astronomy, University of Cape Town, Rondebosch 7700, Cape Town, South Africa. Received November 23, 1995. Abstract.
More informationThe predicted performance of the ACS coronagraph
Instrument Science Report ACS 2000-04 The predicted performance of the ACS coronagraph John Krist March 30, 2000 ABSTRACT The Aberrated Beam Coronagraph (ABC) on the Advanced Camera for Surveys (ACS) has
More informationOptical Photometry. The crash course Tomas Dahlen
The crash course Tomas Dahlen Aim: Measure the luminosity of your objects in broad band optical filters Optical: Wave lengths about 3500Å 9000Å Typical broad band filters: U,B,V,R,I Software: IRAF & SExtractor
More informationReflectors vs. Refractors
1 Telescope Types - Telescopes collect and concentrate light (which can then be magnified, dispersed as a spectrum, etc). - In the end it is the collecting area that counts. - There are two primary telescope
More informationARRAY CONTROLLER REQUIREMENTS
ARRAY CONTROLLER REQUIREMENTS TABLE OF CONTENTS 1 INTRODUCTION...3 1.1 QUANTUM EFFICIENCY (QE)...3 1.2 READ NOISE...3 1.3 DARK CURRENT...3 1.4 BIAS STABILITY...3 1.5 RESIDUAL IMAGE AND PERSISTENCE...4
More informationWFCAM Catalogues. Document Number: VDF-SPE-IOA Version 5 02/09/2008. Author: Mike Irwin
WFCAM Catalogues Document Number: VDF-SPE-IOA-00009-0001 Version 5 02/09/2008 Author: Mike Irwin Changes Version 4: The main changes from the previous versions of this document are: a slightly refined
More informationExoplanet Observing Using AstroImageJ
Exoplanet Observing Using AstroImageJ Dennis M. Conti Chair, AAVSO Exoplanet Section Copyright Dennis M. Conti 2017 1 AstroImageJ (AIJ) All-in-one freeware developed and maintained by Dr. Karen Collins
More informationHigh Contrast Imaging using WFC3/IR
SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA WFC3 Instrument Science Report 2011-07 High Contrast Imaging using WFC3/IR A. Rajan, R. Soummer, J.B. Hagan, R.L. Gilliland, L. Pueyo February
More informationSM-2 Seeing Monitor Installation Instructions
SM-2 Seeing Monitor Installation Instructions Santa Barbara Scientific Seeing Monitors SM-1xxx, SM-2xxx The SBS Seeing Monitor includes custom software for measuring the seeing, minute by minute, for 12
More informationWhat an Observational Astronomer needs to know!
What an Observational Astronomer needs to know! IRAF:Photometry D. Hatzidimitriou Masters course on Methods of Observations and Analysis in Astronomy Basic concepts Counts how are they related to the actual
More informationUsing CCDAuto (last update: 06/21/05)
(last update: 06/21/05) (1) Table of Contents I. Overview...3 A. Program...3 B. Observatory...3 i. Specifications...3 ii. Instruments...4 iii. Using the UCI Student Observatory...7 II. Acquiring Calibration
More informationScientific Image Processing System Photometry tool
Scientific Image Processing System Photometry tool Pavel Cagas http://www.tcmt.org/ What is SIPS? SIPS abbreviation means Scientific Image Processing System The software package evolved from a tool to
More informationSuperconducting Transition-Edge Sensors and Superconducting Tunnel Junctions for Optical/UV Time-Energy Resolved Single-Photon Counters
Superconducting Transition-Edge Sensors and Superconducting Tunnel Junctions for Optical/UV Time-Energy Resolved Single-Photon Counters NHST Meeting STScI - Baltimore 10 April 2003 TES & STJ Detector Summary
More informationFLAT FIELD DETERMINATIONS USING AN ISOLATED POINT SOURCE
Instrument Science Report ACS 2015-07 FLAT FIELD DETERMINATIONS USING AN ISOLATED POINT SOURCE R. C. Bohlin and Norman Grogin 2015 August ABSTRACT The traditional method of measuring ACS flat fields (FF)
More informationCCD User s Guide SBIG ST7E CCD camera and Macintosh ibook control computer with Meade flip mirror assembly mounted on LX200
Massachusetts Institute of Technology Department of Earth, Atmospheric, and Planetary Sciences Handout 8 /week of 2002 March 18 12.409 Hands-On Astronomy, Spring 2002 CCD User s Guide SBIG ST7E CCD camera
More informationPhotometric Aperture Corrections for the ACS/SBC
Instrument Science Report ACS 2016-05 Photometric Aperture Corrections for the ACS/SBC R.J. Avila, M. Chiaberge September 30, 2016 Abstract We present aperture correction tables for the Advanced Camera
More informationINTRODUCTION TO CCD IMAGING
ASTR 1030 Astronomy Lab 85 Intro to CCD Imaging INTRODUCTION TO CCD IMAGING SYNOPSIS: In this lab we will learn about some of the advantages of CCD cameras for use in astronomy and how to process an image.
More informationXMM OM Serendipitous Source Survey Catalogue (XMM-SUSS2.1)
XMM OM Serendipitous Source Survey Catalogue (XMM-SUSS2.1) 1 Introduction The second release of the XMM OM Serendipitous Source Survey Catalogue (XMM-SUSS2) was produced by processing the XMM-Newton Optical
More informationA Guide to AstroImageJ Differential Photometry
British Astronomical Association Supporting amateur astronomers since 1890 A Guide to AstroImageJ Differential Photometry Image Display Interface with WASP-12b Target and Comparison Aperture overlay Richard
More informationOptical Imaging. (Some selected topics) Richard Hook ST-ECF/ESO
Optical Imaging (Some selected topics) http://www.stecf.org/~rhook/neon/archive_garching2006.ppt Richard Hook ST-ECF/ESO 30th August 2006 NEON Archive School 1 Some Caveats & Warnings! I have selected
More informationObsAstro Documentation
ObsAstro Documentation Release 0.1 Matthew Craig, Juan Cabanela & Linda Winkler February 18, 2014 Contents 1 Basic image statistics 3 1.1 Before you begin.............................................
More informationObservation Data. Optical Images
Data Analysis Introduction Optical Imaging Tsuyoshi Terai Subaru Telescope Imaging Observation Measure the light from celestial objects and understand their physics Take images of objects with a specific
More informationS.-W. Chang 1, Y.-I. Byun 2, and J. D. Hartman 3 ABSTRACT
A New Method For Robust High-Precision Time-Series Photometry From Well-Sampled Images: Application to Archival MMT/Megacam Observations of the Open Cluster M37 arxiv:53.3375v [astro-ph.im] Mar 25 S.-W.
More informationYou, too, can make useful and beautiful astronomical images at Mees: Lesson 1
You, too, can make useful and beautiful astronomical images at Mees: Lesson 1 Useful references: The Mees telescope startup/shutdown guide: http://www.pas.rochester.edu/~dmw/ast142/projects/chklist.pdf
More informationWFC Zeropoints at -80C
WFC Zeropoints at -80C J. Mack, R. L. Gilliland, J. Anderson, & M. Sirianni May 2, 2007 ABSTRACT Following the recovery of ACS with the side-2 electronics in July 2006, the temperature of the WFC detector
More informationObsAstro Documentation
ObsAstro Documentation Release 0.1 Matthew Craig, Juan Cabanela & Linda Winkler February 18, 2014 Contents i ii Contents: Contents 1 2 Contents CHAPTER 1 Basic image statistics Contents: 1.1 Before you
More informationF/48 Slit Spectroscopy
1997 HST Calibration Workshop Space Telescope Science Institute, 1997 S. Casertano, et al., eds. F/48 Slit Spectroscopy R. Jedrzejewski & M. Voit Space Telescope Science Institute, Baltimore, MD 21218
More informationAstronomical Detectors. Lecture 3 Astronomy & Astrophysics Fall 2011
Astronomical Detectors Lecture 3 Astronomy & Astrophysics Fall 2011 Detector Requirements Record incident photons that have been captured by the telescope. Intensity, Phase, Frequency, Polarization Difficulty
More informationBaseline Tests for the Advanced Camera for Surveys Astronomer s Proposal Tool Exposure Time Calculator
Baseline Tests for the Advanced Camera for Surveys Astronomer s Proposal Tool Exposure Time Calculator F. R. Boffi, R. C. Bohlin, D. F. McLean, C. M. Pavlovsky July 10, 2003 ABSTRACT The verification tests
More informationCHAPTER 6 Exposure Time Calculations
CHAPTER 6 Exposure Time Calculations In This Chapter... Overview / 75 Calculating NICMOS Imaging Sensitivities / 78 WWW Access to Imaging Tools / 83 Examples / 84 In this chapter we provide NICMOS-specific
More informationDifference Image Analysis of the OGLE-II Bulge Data. I. The Method 1. P. R. W o ź n i a k
ACTA ASTRONOMICA Vol. 50 (2000) pp. 421 450 Difference Image Analysis of the OGLE-II Bulge Data. I. The Method 1 by P. R. W o ź n i a k Princeton University Observatory, Princeton, NJ 08544 1001, USA e-mail:
More informationPHYSICS. Chapter 35 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT
PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 35 Lecture RANDALL D. KNIGHT Chapter 35 Optical Instruments IN THIS CHAPTER, you will learn about some common optical instruments and
More informationLecture 5. Telescopes (part II) and Detectors
Lecture 5 Telescopes (part II) and Detectors Please take a moment to remember the crew of STS-107, the space shuttle Columbia, as well as their families. Crew of the Space Shuttle Columbia Lost February
More informationErrata to First Printing 1 2nd Edition of of The Handbook of Astronomical Image Processing
Errata to First Printing 1 nd Edition of of The Handbook of Astronomical Image Processing 1. Page 47: In nd line of paragraph. Following Equ..17, change 4 to 14. Text should read as follows: The dark frame
More informationAchieving milli-arcsecond residual astrometric error for the JMAPS mission
Achieving milli-arcsecond residual astrometric error for the JMAPS mission Gregory S. Hennessy a,benjaminf.lane b, Dan Veilette a, and Christopher Dieck a a US Naval Observatory, 3450 Mass Ave. NW, Washington
More informationVERY LARGE TELESCOPE
EUROPEAN SOUTHERN OBSERVATORY VERY LARGE TELESCOPE NAOS-CONICA Calibration Plan Doc. No. VLT-PLA-ESO-14200-2664 Issue 80 March 03, 2007 N. Ageorges, C. Lidman Prepared..........................................
More informationAstrophysical Techniques Optical/IR photometry and spectroscopy. Danny Steeghs
Astrophysical Techniques Optical/IR photometry and spectroscopy Danny Steeghs Imaging / Photometry background Point source Extended/resolved source Photometry = Quantifying source brightness Detectors
More informationThe iptf IPAC Pipelines: what works and what doesn t (optimally)
The iptf IPAC Pipelines: what works and what doesn t (optimally) Frank Masci & the iptf / ZTF Team ZTF-Photometry Workshop, September 2015 http://web.ipac.caltech.edu/staff/fmasci/home/miscscience/masci_ztfmeeting_sep2015.pdf
More informationTechnical Evaluation Report TAACOS: Target Acquisition with the TA1 Mirror
TAACOS: Target Acquisition with the TA1 Mirror Date: Document Number: Revision: Contract No.: NAS5-98043 CDRL No.: N/A Prepared By: Reviewed By: Reviewed By: Approved By: Approved By: S. Penton, COS Software
More informationComparing Aperture Photometry Software Packages
Comparing Aperture Photometry Software Packages V. Bajaj, H. Khandrika April 6, 2017 Abstract Multiple software packages exist to perform aperture photometry on HST data. Three of the most used softwares
More informationWFPC2 Status and Plans
WFPC2 Status and Plans John Biretta STUC Meeting 12 April 2007 WFPC2 Status Launched Dec. 1993 ~15 yrs old by end of Cycle 16 Continues to operate well Liens on performance: - CTE from radiation damage
More informationAPPENDIX D: ANALYZING ASTRONOMICAL IMAGES WITH MAXIM DL
APPENDIX D: ANALYZING ASTRONOMICAL IMAGES WITH MAXIM DL Written by T.Jaeger INTRODUCTION Early astronomers relied on handmade sketches to record their observations (see Galileo s sketches of Jupiter s
More informationSPIRE Broad-Band Photometry Extraction
SPIRE Broad-Band Photometry Extraction Bernhard Schulz (NHSC/IPAC) on behalf of the SPIRE ICC, the HSC and the NHSC Contents Point Source Photometry Choices Extended gain correction factors Zero-point
More informationSimultaneous Infrared-Visible Imager/Spectrograph a Multi-Purpose Instrument for the Magdalena Ridge Observatory 2.4-m Telescope
Simultaneous Infrared-Visible Imager/Spectrograph a Multi-Purpose Instrument for the Magdalena Ridge Observatory 2.4-m Telescope M.B. Vincent *, E.V. Ryan Magdalena Ridge Observatory, New Mexico Institute
More informationSimulations of the STIS CCD Clear Imaging Mode PSF
1997 HST Calibration Workshop Space Telescope Science Institute, 1997 S. Casertano, et al., eds. Simulations of the STIS CCD Clear Imaging Mode PSF R.H. Cornett Hughes STX, Code 681, NASA/GSFC, Greenbelt
More informationImage analysis. CS/CME/BIOPHYS/BMI 279 Fall 2015 Ron Dror
Image analysis CS/CME/BIOPHYS/BMI 279 Fall 2015 Ron Dror A two- dimensional image can be described as a function of two variables f(x,y). For a grayscale image, the value of f(x,y) specifies the brightness
More informationOmegaCAM calibrations for KiDS
OmegaCAM calibrations for KiDS Gijs Verdoes Kleijn for OmegaCEN & KiDS survey team Kapteyn Astronomical Institute University of Groningen A. Issues common to wide field imaging surveys data processing
More informationSpectral Analysis of the LUND/DMI Earthshine Telescope and Filters
Spectral Analysis of the LUND/DMI Earthshine Telescope and Filters 12 August 2011-08-12 Ahmad Darudi & Rodrigo Badínez A1 1. Spectral Analysis of the telescope and Filters This section reports the characterization
More informationGlobal Erratum for Kepler Q0-Q17 & K2 C0-C5 Short-Cadence Data
Global Erratum for Kepler Q0-Q17 & K2 C0-C5 Short-Cadence Data KSCI-19080-002 23 March 2016 NASA Ames Research Center Moffett Field, CA 94035 Prepared by: Date Douglas Caldwell, Instrument Scientist Prepared
More informationDSLR Photometry. Part 1. ASSA Photometry Nov 2016
DSLR Photometry Part 1 ASSA Photometry Nov 2016 Because of the complexity of the subject, these two sessions on DSLR Photometry will not equip you to be a fully fledged DSLR photometrists. It is hoped
More informationThe Cosmic Microwave Background Radiation B. Winstein, U of Chicago
The Cosmic Microwave Background Radiation B. Winstein, U of Chicago Lecture #1 Lecture #2 What is it? How its anisotropies are generated? What Physics does it reveal? How it is measured. Lecture #3 Main
More informationPuntino. Shack-Hartmann wavefront sensor for optimizing telescopes. The software people for optics
Puntino Shack-Hartmann wavefront sensor for optimizing telescopes 1 1. Optimize telescope performance with a powerful set of tools A finely tuned telescope is the key to obtaining deep, high-quality astronomical
More information"Internet Telescope" Performance Requirements
"Internet Telescope" Performance Requirements by Dr. Frank Melsheimer DFM Engineering, Inc. 1035 Delaware Avenue Longmont, Colorado 80501 phone 303-678-8143 fax 303-772-9411 www.dfmengineering.com Table
More informationCCD PHOTOMETRY OF THE δ SCUTI STAR FG VIRGINIS DURING THE 1995 MULTI-SITE CAMPAIGN
CCD PHOTOMETRY OF THE δ SCUTI STAR FG VIRGINIS DURING THE 1995 MULTI-SITE CAMPAIGN A. STANKOV Institut für Astronomie, Universität Wien, Türkenschanzstraße 17, A-1180 Wien, Austria; E-mail: stankov@astro.univie.ac.at
More informationWFC3/IR Bad Pixel Table: Update Using Cycle 17 Data
Instrument Science Report WFC3 2010-13 WFC3/IR Bad Pixel Table: Update Using Cycle 17 Data B. Hilbert and H. Bushouse August 26, 2010 ABSTRACT Using data collected during Servicing Mission Observatory
More informationAbstract. Preface. Acknowledgments
Contents Abstract Preface Acknowledgments iv v vii 1 Introduction 1 1.1 A Very Brief History of Visible Detectors in Astronomy................ 1 1.2 The CCD: Astronomy s Champion Workhorse......................
More informationWeek 10. Lab 3! Photometric quality. Stamp out those bad points. Finish it.
Week 10 Lab 3! Photometric quality. Stamp out those bad points. Finish it. Lab 4! Great data. Evening sessions this week focus on Lab 3 wrap-up and Lab 4 reducgons. Exams ready for return Read the book!
More informationObserving Guide to Transiting Extrasolar Planets
Observing Guide to Transiting Extrasolar Planets M. Barbieri, C. Lopresti, A. Marchini, R. Papini, and F. Salvaggio e-mail:maueo@gmail.com August 0, 008 Abstract Observing Guide to Transiting Extrasolar
More informationa simple optical imager
Imagers and Imaging a simple optical imager Here s one on our 61-Inch Telescope Here s one on our 61-Inch Telescope filter wheel in here dewar preamplifier However, to get a large field we cannot afford
More informationA PSF-fitting Photometry Pipeline for Crowded Under-sampled Fields. M. Marengo & Jillian Neeley Iowa State University
A PSF-fitting Photometry Pipeline for Crowded Under-sampled Fields M. Marengo & Jillian Neeley Iowa State University What, and Why Developed to extract globular cluster photometry for Spitzer/IRAC Carnegie
More informationWFC3/UVIS Updated 2017 Chip- Dependent Inverse Sensitivity Values
Instrument Science Report WFC3 2017-14 WFC3/UVIS Updated 2017 Chip- Dependent Inverse Sensitivity Values S.E. Deustua, J. Mack, V. Bajaj, H. Khandrika June 12, 2017 ABSTRACT We present chip-dependent inverse
More informationTelescopes and their configurations. Quick review at the GO level
Telescopes and their configurations Quick review at the GO level Refraction & Reflection Light travels slower in denser material Speed depends on wavelength Image Formation real Focal Length (f) : Distance
More informationLimits on Reciprocity Failure in 1.7mm cut-off NIR astronomical detectors
Limits on Reciprocity Failure in 1.7mm cut-off NIR astronomical detectors Wolfgang Lorenzon T. Biesiadzinski, R. Newman, M. Schubnell, G. Tarle, C. Weaverdyck Detectors for Astronomy, ESO Garching, 12-16
More informationGPI INSTRUMENT PAGES
GPI INSTRUMENT PAGES This document presents a snapshot of the GPI Instrument web pages as of the date of the call for letters of intent. Please consult the GPI web pages themselves for up to the minute
More informationAberration Theory and Prototype Mirror Experiments
Aberration Theory and Prototype Mirror Experiments Bruce Holenstein, Rich Mitchell, Dylan Holenstein 2010-2011 Alt-Az Initiative Hawaii Conference on Light Bucket Astronomy 1 Some Light Bucket Aberration
More informationarxiv:astro-ph/ v1 26 Aug 1997
A novel image reconstruction method applied to deep Hubble Space Telescope images arxiv:astro-ph/9708242v1 26 Aug 1997 A. S. Fruchter a and R. N. Hook b a Space Telescope Science Institute 3700 San Martin
More informationPresented by Jerry Hubbell Lake of the Woods Observatory (MPC I24) President, Rappahannock Astronomy Club
Presented by Jerry Hubbell Lake of the Woods Observatory (MPC I24) President, Rappahannock Astronomy Club ENGINEERING A FIBER-FED FED SPECTROMETER FOR ASTRONOMICAL USE Objectives Discuss the engineering
More informationFlat Fields. S. Eikenberry Obs Tech
Flat Fields S. Eikenberry Obs Tech 23 Sep 2014 Review median combination Basic algorithm: Read in im1, im2, im3,, im9 Loop over 1 array dimension, index i Loop over 2 nd dimension, index j imf(i,j)=median([im1(i,j),
More informationCCD Image Calibration Using AIP4WIN
CCD Image Calibration Using AIP4WIN David Haworth The purpose of image calibration is to remove unwanted errors caused by CCD camera operation. Image calibration is a very import first step in the processing
More informationSpectral Line Bandpass Removal Using a Median Filter Travis McIntyre The University of New Mexico December 2013
Spectral Line Bandpass Removal Using a Median Filter Travis McIntyre The University of New Mexico December 2013 Abstract For spectral line observations, an alternative to the position switching observation
More information