ASTR 3520 Perceptions and Instrumentation II: Spectroscopy.


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Outline John Bally C323A Duane 492 5786 john.bally@colorado.edu bally@casa.colorado.edu Office hours: Th after class (2:00 PM) Wed (2:00 PM) Adam Ginsburg C329 Duane 303 667 3805 adam.ginsburg@colorado.edu Off
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Slide 1

ASTR 3520 Observations & Instrumentation II: Spectroscopy Lecture 1 Introduction

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Overview John Bally C323A Duane 492 5786 john.bally@colorado.edu bally@casa.colorado.edu Office hours: Th after class (2:00 PM) Wed (2:00 PM) Adam Ginsburg C329 Duane 303 667 3805 adam.ginsburg@colorado.edu Office Hours: Mon, Tues 11:00 AM or by arrangement Student & Teacher Introductions:

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Organization Review course structure, substance, and Syllabus Observing Projects: Stellar, nebular spectroscopy, semester ventures, labs, homework. Apache Point Observatory Field Trip: - 5 - 6 days/4 - 5 evenings - Covered by Course Fees - VLA, NSO, APO - Last week of Oct. (relies on upon TAC) Observing Proposals for Semester venture due end of Sept. 24" Observing Groups 5 bunches/3 to 4 each. - Each gathering must have finally 1 experienced spectator Start spectrograph outline (once-over softly)

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Spectroscopy: Astronomy => Astrophysics Light as a wave marvel:  = c Geometrical optics => wave optics Diffraction  ~ /D Interference: n  = D sin  n = 1,2,3,… Deep bits of knowledge into the way of particles, atoms: Discrete wavelengths => Discrete vitality levels Electrons stable just in specific circles. Obstruction of electron waves!  = h/p = h/mv :de Broglie waves All matter has wave-like conduct on adequately little scale!

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Spectrograph Focal Plane collimator camera locator Dispersing component Slit Telescope Spectrograph

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SBO Spectrograph outline Slit & Decker: Restrict approaching light Spatial bearing versus Ghostly bearing Collimator & Camera: Transfer picture of opening onto indicator. Grinding: Disperse light: scattering => phantom determination What decides ghastly determination & scope? - Slit-width - Grating properties: N forests , request number - Camera/collimator amplification (central length proportion) - Detector pixel size and number of pixels.

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Types of Spectroscopy Electromagnetic Waves: Emission, ingestion Visual, close IR., FIR, Radio, UV/X-beam, gamma-beam - Solids, fluids, gasses, plasmas - Emission, retention - Spectral line, sub-atomic groups, continua: - Thermal (~LTE, blackbody, dark body): - Non-warm (masers, synchrotron, … ) - Electronic, vibrational, rotational moves. - Effects of B (Zeeman), E ( Stark), movement (Doppler), weight (impacts), common life-time (line widths) - Radiative Transfer (optical profundity) Other sorts (not secured in this course): NMR Raman Phosprescence/Fluorecence Astro-molecule

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Review of Some Basics c = n x l Angular determination: q = 1.22 l/D radians 206,265" in a radian E = h n F = L/4 p d 2 AZ, El, RA, Dec, Ecliptic, Galactic Siderial time, Hour Angle G = 6.67 x 10 - 8 (c.g.s) c = 3 x 10 cm/sec, k = 1.38 x 10 - 16 h = 6.626 x 10 - 27 m H ~ m proton = 1.67 x 10 - 24 grams m e = 0.91 x 10 - 27 grams eV = 1.602 x 10 - 12 erg Luminosity of Sun = 4 x 10 33 erg/sec Mass of the Sun = 2 x 10 33 grams

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The Physics of EM Radiation Light: l, n - l n = c = 2.998 x 10 cm/s (in vacuum) - E = h n Photon vitality (erg) 1 erg sec - 1 = 10 - 7 Watt h = 6.626 x 10 - 27 (c.g.s) 1 eV = 1.602 x 10 - 12 erg - p = E/c = h/l  Photon force - l = h/p = h/mv deBroglie wavelength Planck Function: B  (T) Emission, retention, continua Discrete vitality levels: Hydrogen

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Refraction: Snell\'s Law: n 1 sin( d 1 ) = n 2 sin( d 2 ) d 1 n 1 n 1 = refractive file in locale 1 n 2 = refractive list in area 2 n = c/v = l vacuum/l medium d 2 n 2

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Basic Lens formulae:

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Basic Mirror formulae:

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L d Diffraction: Light spreads as q = l/d In the `far field\' given by L = d 2/l

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2 opening obstruction Constructive Destructive

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2 opening impedance Anti-reflection covering

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Multi-layer obstruction channel:

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Diffraction grinding:

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Fermat\'s Principle: d(optical way length) = 0 Diffraction grinding: request # wavelength diffraction ang le groove dividing rate ang le

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CCD Imaging Review CCD nuts and bolts - How CCDs work - CCD properties Dark, level, and inclination outlines Image-scales - central length, pixel-scale, FOV Review photometry rudiments - The size framework - Calibration - Atmospheric impacts; Air mass, shading terms

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Subaru 8m (Mauna Kea): Suprime Prime Focus CCD Mosaic 8192 x 8192 pixels utilizing SITe chips (15 m pixels)

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Typical Raw picture With a CCD Cosmic beams Bad pixels stars

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CCDs (Charge-Coupled Device) Properties - Quantum productivity (QE): => 90% - Gain: G = e -/ADU - Dark current: 1 e -/hr to 10 3 e -/sec warm discharge: => Cool to –20 to –150 C - Read Noise: enhancer read-out vulnerability 3 e - to 100 e - per read - Spatial consistency: Bad pixels, sections: ~ << 1% pick up & QE varieties e = h n - E 0

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CCDs Properties - Cosmic Rays: 5 to > 10 3 e - created by each charged molecule more often than not impacts 1 or couple of pixels. non-gaussian charge circulation (not quite the same as stellar picture or PSF) - Well profundity: 5 x 10 4 to 10 6 e - Pixel size: 6 m to 30 m - Array size: 512 x 512 to 4096 x 4096

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Dark current: => cooling

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MOSAIC CCD On KPNO 0.9m Vacuum Dewar LN 2 (77K) Controller Filters & slider

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5 10 0 Charge Transfer V 0 10 0 5

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Charge Coupled Devices (CCDs) Output intensifier

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Charge Coupled Devices (CCDs) Output speaker

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Charge Coupled Devices (CCDs) Read

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Charge Coupled Devices (CCDs) Read

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CCD Corrections/Calibrations Read commotion: inclination outlines - 0 second presentation Dark edges: - Same span as science introduction with screen shut Flat fields: - Dome pads - Twilight pads - Super-sky pads Standard stars - At a few air-masses A = sec (z) = 1/cos(z) z

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CCD Corrections/Calibrations Types of picture blends: IRAF undertaking: imarith image1 (+,- ,*,/) image2 yield imcombine @list_in yield - Average: 1/N S I(n) - Mode: Most basic information esteem - Median: Value in center of extent useful for dismissal of anomalies (e.g CRs) Combine (middle) 3,5,7,… .. An odd # - inclination outlines - level casings

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CCD Corrections/Calibrations Reduction: I(raw) - median(bias) I(reduced) = standard [median(Flat – bias)] Note: Bias can be a Dark if hot pixels/or dim current is expansive

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Flat Field Example star astronomical beam Hot pixels star Bias or dim level Raw science outline star enormous beam star Dark subtracted outline

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Flat Field Example star grandiose beam star vast beam Flat edge

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Flat Field Example inestimable beam Flat edge 1 Normalized, dim subtracted, middle of > 3 level edges

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Flat Field Example enormous beam star Science outline 1 Normalized level edge star Reduced science outline

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Photometry Basics: Vega sizes: m( l ) = - 2.5 log [F( l )/F Vega ( l )] F( l ) = Counts on source F Vega ( l ) = Counts on Vega A = sec (z) = 1/cos(z) z

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Type of Spectra Continuum: - Blackbody: B n (T) - without free, free-bound - Non-warm: Synchrotron radiation - Compton diffusing Line & Band E dipole, B diplole, E quadrupole fine structure, hyperfine structure - electronic moves - vibrational moves - rotational move

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Types of Spectra: Hot, Opaque media Nebulae Stars

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The Planck Function: Black-body radiation (erg s - 1 cm - 2 Hz - 1 2 p sr - 1 ) Wien: B( n ,T) = (2 p h n 3/c 2 ) e - h n/kT Rayleigh-Jeans: B( n ,T) = 2kT/l 2

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The Planck Function: Black-body radiation Wien Rayleigh-Jeans

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Spectrum of Hydrogen (& H-like particles) Ionization (n to unendingness): E = 13.6 eV Transitions: E = h n = E u – E l Ionization at E = 13.6 eV or not as much as l = 912 Angstroms a b g Balmer = R [ 1/n l 2 – 1/n u 2 ] R = 3.288 x 10 15 Hz b a Lyman

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Bohr model: Allowed circles mvr = nh/2 p Coulomb Force: Ze 2/r 2 = mv 2/r Thus, (take out v) r = Ze 2/mv 2 = n 2 h 2/4 p 2 Ze 2 m Energy E = - (1/2) Ze 2/r = - 2 p 2 Z 2 e 4 m/n 2 h 2

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Adam Block: 16" Meade + SBIG ST10E + AO7

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The Orion Nebula (M42)

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Outline & Goals: Tues, 18

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