Answers to selected exercises

CHAPTER 1

3. (a) 300 GHz; (b) 21 cm. 5. E ˆ 3:98  10À19 J ˆ 2.48 eV. 7. Number of electrons at dynodes 1; 2; 3 ÁÁÁˆ 3†; 9†; 27†; ÁÁÁ: ˆ 31; 32; 33 ÁÁÁand after 10 dynodes it is 310. Thus, Q ˆ 9:46  10À15 C. 8. (a) Æ1,000 counts; (b) 0.1%; p (c) a factor of 4 ˆ 2 (to 0.05%). 9. F 3 ˆ 206,265/128  1.0 ˆ 1,611.45; F  11.725. Lens ˆ 8 the mirror 800. Doublingfocal length implies aberrations are 2 3ˆ 8 times smaller; earliest tele- scopes had longfocal lengths. 10. Readout noise dominates for 1 s; background limits S/N for 100 s.

CHAPTER 2

1. Di€raction-limited angular resolution corresponds to D ˆ 85 m: 206; 265†1:22=D

Angular resolution is 0.003 seconds ofp arc per micron of wavelength. Light- gathering power is only equivalent to 2  10-m ˆ 14.1 m telescope (not 85 m). Interferometry gives huge gain in resolution (85/10 ˆ 8.5). 2. Using1.22 =D, then  ˆ 0.0500 at 2 mm. Linear dimension ˆ (0.0500/206,26500 per rad)  (4.2 lt-yr  6  1012 miles per light-year): linear size ˆ 6.15 million miles. 516 Answers to selected exercises

Baseline of 100 m ˆ 10 better resolution: linear size  615,000 miles or about 2.5 the distance to the Moon. 3. Seeing 0=r0: À6 00 (a) r0 ˆ (0.5  10 m/0.75 )206,265 ˆ 0.14 m; 6=5 (b) r=r0 ˆ (2.2/0.5) ˆ 5.9, thus at 2.2 mm, r ˆ 0.83 m. À6 00 6=5 5. r0 ˆ (0.5  10 m/0.5 )206,265 ˆ 0.21 m; r=r0 ˆ (1.65/0.5) ˆ 4.2, r ˆ 0.86 m; number of sub-apertures D=r†2 ˆ 10=0:86†2 ˆ 134. 6. From 5, r0 ˆ 0.21 m; isoplanatic angle ˆ 0.314r0=H ˆ (0.314  0.21m/ 5,000 m) ˆ 13.2 mrad or 2.7 arcsec. The isokinetic angle is larger by 00 D=r0 ˆ 47.6, thus isokinetic angle ˆ 129.5 .

CHAPTER 3

3. (a) prime focus is faster by (17/5)2ˆ 11.56. (b) Cassegrain is better in practice because the larger plate scale reduces the level of sky background. 4. Tails toward the edges of the ®eld implies coma in the optics. For a simple telescope/camera this could mean a misaligned secondary mirror. 8. FOV ˆ 40.96  34.13 arcminutes or 0.39 square degrees. Number of frames for 100 square degrees is 258. At 20 minutes each this takes 86 hours of observ- ing. One hemisphere is 20,627 square degrees, so to cover this takes 17,720 hours of observing(over 2 years of time). This ®eld of view is too small or the integration time is too long to be useful. 00 0 10. Limit on astigmatism of <0.5 implies FOV 20 . Parameters are R1 ˆ 35 m, R2 ˆ 4.85 m, K1 ˆÀ1.00404, K2 ˆÀ1.64344, and d ˆ 15.204 m. Answers may vary slightly.

CHAPTER 4

No entries.

CHAPTER 5

00 6 2. The f /d ˆ (206,265)dpix=Dtelpix ˆ (206,265 /rad)  (24 mm)/(10 m  10 mm/m) (0.200) ˆ 2.48. Yes, this camera would be challenging. 3.40  3.40. 3. Dcoll ˆ RDtel '=206,265†=2 tan B, R ˆ 20,000, Dtel ˆ 10 m, ' ˆ 0.5: (a) 2 tan B ˆ 0:63†)Dcoll ˆ 77 cm; (b) 2 tan B ˆ 4†)Dcoll ˆ 12 cm. The echelle is more practical. Focal length ˆ 15  Dcoll: (a) 11.55 m. (b) 1.8 m. Answers to selected exercises 517

 4. n ˆ 2.4, A ˆ 30 , c ˆ 2.2 mm, and R ˆ 500 for 2 pixels. Pixel size ˆ 27 mm. Assuming m ˆ 1 (®rst order), T ˆ n À 1† sin A=c ˆ 318 lines per millimeter and EFL ˆ 2dpixR= n À 1† tan A ˆ 33.4 mm. 6. Q ˆ N 0†ÀN 45†=N 0†‡N 45†ˆ2,000 À 1,000=3,000 ˆ‡0:33; U ˆ N 22:5†ÀN 67:5†=N 22:5†‡N 67:5† ˆ 1,800 À 1,200=3,000 ˆ‡0:20; p p ˆ 0:332 ‡ 0:202†ˆ0:39 39%†;

1 À1   ˆ 2 tan U=Q†ˆ15:6 ; p p  N†=N ˆ 1= N ˆ 1= 3000 ˆ 1:8%: 7. R ˆ 20,000 at  ˆ 0.5 mm; an air-spaced etalon of ®nesse 40; ®nd gap d and free 2 spectral range DFSP? DFSP ˆ  =2nd, but 2nd ˆ R=F ˆ 250 mm, giving DFSP ˆ 0.001 mm. 1 8. Scan length ˆ 4 R ˆ (10 mm)(100,000)/4 ˆ 25 cm.

CHAPTER 6

p p Ê 2. n ˆ ng ˆ 4 ˆ 2. Thickness ˆ =4n ˆ 2.2 mm/8 ˆ 0.28 mm (or 2,750 A). 3. Match the followingthree detectors to a 0.2 m telescope and then to an 8 m telescope: for the small telescope seeing ˆ 200 and 1 pixel ˆ 100, for the large telescope seeing ˆ 0.500 and we have 0.2500/pixel. Kodak KAF-4200 CCD with 9 mm pixels in a 2,048  2,048 format: (a) f /d ˆ 9.3, FOV ˆ 340 (b) fd ˆ 0.93, FOV ˆ 8.50. SITe CCD with 22 mm pixels in a 1,024  1,024 format: (a) fd ˆ 22.7, FOV ˆ 170 (b) f /d ˆ 2.27, FOV ˆ 4.270. Hughes-SBRC InSb array with 27 mm pixels in a 1,024  1,024 format: (a) fd ˆ 27.8, FOV ˆ 170 (b) f /d ˆ 2.78, FOV ˆ 4.270. The Kodak CCD cannot be matched to a large telescope unless the scale is reduced to less than 0.100/pixel (FOV ˆ 3.40). 4. Linear size ˆ f and f ˆ 50 mm given ˆ‰1:5 4 1:5†À1†Š=‰ 128† 1:5 ‡ 2† 1:5 À 1†2 2†3Šˆ0:00837 radians Linear size ˆ 418.5 mm  CCD pixel, therefore must use a multi-element lens system. 5. For a 1-second-of-arc diameter blur the focal ratio is given by F 3 ˆ 206,265=128 †ˆ1,611; hence F ˆ 11:724 518 Answers to selected exercises

6. Sagittal image blur due to coma 6000 o€ axis (2.9  10À4 rad) for an f /3 mirror is ˆ 6000/16(3)2ˆ 0.4200. The tail is 3 longer or 1.2500. For f /1.5, the blur is (3/1.5)2ˆ 4 times greater ˆ 1.6700. 7. (a) Diameter of di€raction blur ˆ 2.44 (0.5 mm)(2) ˆ 2.44 mm for f /2 lens at 500 nm. (b) Depth of focus: Df ˆÆ2 F†2 ˆÆ4 mm. 8. Assuming ˆ 24  10À6 KÀ1, Young's modulus E ˆ 10  106 psi and the yield strength of the aluminum strut ˆ 40,000 psi. Since F ˆ EA DL=L† and DL=L ˆ DT, therefore F=A ˆÀ EDT ˆ 50,400 psi. The strut will buckle because the stress exceeds the yield strength. 2 9. A ˆ 5m , " ˆ 5%ˆ 2Fhc, Tc ˆ 77 K: (a) for Th ˆ 300 K, QH ˆ 57 W (b) for Th ˆ 275 K, Qh ˆ 40 W. Add ¯oatingshields or multi-layer insulation. 10. Spectrometer: slit width ˆ w, slit height ˆ h

1 2 AO ˆ 4†Dcoll w=fcoll† h=fcoll† Seeing-limited camera: seeing disk diameter ˆ 

1 2 1 2 2 AO ˆ 4†Dcoll w=fcoll 4  =f coll†

CHAPTER 7

1. See Figures 7.7 and 7.8. Draw the timing diagram very carefully. 4. Inverted operation attracts minority carriers from the channel stops which ®ll surface traps and eliminate dark current. 8. EMCCD gain: with a 40 V clock there is a 1% chance per transfer of creating a second electron by avalanche multiplication. For 600 elements in the register the average gain is G ˆ 1:01†600 ˆ 392.

CHAPTER 8

3. Last pixel has n ˆ 2,048 ‡ 2,048 ˆ 4,096 transfers. CTE ˆ 0.99999, fraction of original charge (Q0) left after n transfers is 0 n 4096 Q ˆ CTE† Q0 ˆ 0:99999† Q0 ˆ 0:9599 or 96%. One can also use 0 À5 Q f1 À n 1 À CTE†gQ0 ˆf1 À 4096 1  10 †gQ0

ˆf1 À 0:04096gQ0 ˆ 0:9590 or 96%. Answers to selected exercises 519 p 5. ``kTC-noise'' ˆ 1=e† kTC† electrons. For T ˆ 150 K, C ˆ 0.5  10À12F, À noise ˆ 201e . p 6. Shot noise on ``pre-¯ash'' ˆ 400 ˆ 20 electrons.p This adds in quadrature with readout noise of 15 electrons. Final noise ˆ f 20†2 ‡ 15†2gˆ25eÀ. 7. Pickingup 50-cycle or 60-cycle harmonics from mains; probably due to a ground- loop.

CHAPTER 9

À 2. V ˆ 0:25†S ‡ 18:75;p linear regression ®t. Gain factor g ˆ 1/0.25 ˆ 4.0e /DN. Readout noise R ˆ g 18.75 ˆ 17.3eÀ. 3. C ˆ 0.1 pF, Asfd ˆ 0.75, n ˆ 16, Vfs ˆ 10 volt, g ˆ 25 electrons/DN. n The total gain is given by Ag ˆ VfsC=2 ge, therefore À12 16 À19 Ag ˆ‰10 0:1  10 †Š=‰2 25† 1:6  10 †Š ˆ 3:81

Dividing Ag by the source follower gain (0.75) gives the gain of the preamp/ postamp combination as 5.09. 5. Flat-®elding is a multiplicative or gain correction. Fringing is an additive term. 00 À 10. Given m ˆ 24, V band, Dtel ˆ 4m,  ˆ 0.30, pix ˆ 0.3 , R ˆ 10e , and Id  0 F ˆ 3:92  10À12  10À0:4 24† WcmÀ2 mmÀ1† 125,600 cm2†  0:55 mm† 0:09 mm† 0:3† 1:99  10À19 J mm† ˆ 9:2eÀ=s Assuming1 00 seeingthen star ¯ux is diluted over n  9 pixels. Average ¯ux ˆ 1eÀ/s/pixel. If sky ˆ 22 magper square arcsecond then 2 À Fsky ˆ 6:3  F  0:3† ˆ 5:2e /s/pixel. Background dominates over signal by about 5 : 1 on average (ignores seeing pro®le). Readout noise ˆ 10eÀ, so equiva- À 2 lent ¯ux ˆ 100e . Must integrate for t > R =Fsky ˆ 100/5.2 ˆ 19.2 s to become background-limited;p p easily achieved, therefore sky-limited. Signal-to-noise ratio  F t= nFsky† ignoresp p signal and readoutp noise; assumes perfect ¯ats. For S/N ˆ 10 then 10 ˆ 9.2 t= (9  5.2), or 1.34 t ˆ 10 and hence t ˆ 55.3 s.

CHAPTER 10

1. Data rate ˆ (number pixels digitized  number of bytes/pixel)/(frame time) ˆ 1M  2=1,0242  10À4 ˆ 0:02 Mbyte/s IR detector data rate is 100/5 ˆ 20 times faster or 0.4 Mbyte/s. For 32 outputs the data rate is 20/32 times slower again (63%) or 0.24 Mbyte/s. 520 Answers to selected exercises

CHAPTER 11

No entries

CHAPTER 12

No entries

CHAPTER 13

1. Wavelengths are much larger. Assuming di€raction-limited angular resolution ˆ 70=D ˆ 70 6cm†= 26  100 cm†ˆ9:70

CHAPTER 14

No entries Appendix A

Powers-of-10 notation

When writingnumbers which are very largeor very small it is useful to introduce a shorthand notation called ``powers of 10'' or scienti®c notation. Thus, instead of writing1,000,000 for 1 million, we write 1 Â 106 and understand this to mean 1 followed by six zeros. Similarly, instead of writing0.000001 for one-millionth, we write 1 Â 10À6 where the minus sign tells us that this number is 1 divided by 1 million. The leadingnumber (mantissa) should be a value between 1 and 10 (e.g.,1.496). Names and symbols are given to the most frequently used powers of 10 as shown below. These names and symbols can be pre®xed to any of the units of measurements given below to infer that the basic unit is to be multiplied by that power of 10. Note the case of the symbol!

Name Symbol Power Name Symbol Power yocto y 10À24 yotta Y 1024 zepto z 10À21 zeta Z 1021 atto a 10À18 exa E 1018 femto f 10À15 peta P 1015 pico p 10À12 tera T 1012 nano n 10À9 giga G 109 micro m 10À6 mega M 106 milli m 10À3 kilo k 103 centi c 10À2 hecto h 102 deci d 10À1 deka da 101 522 Appendix A: Powers-of-10 notation

Notes:

(i) 100 ˆ 1 and in fact N 0 ˆ 1 where N is any number. (ii) N a  N b ˆ N a‡b and N a Ä N b ˆ N aÀb (e.g., 108  102 ˆ 1010). (iii) N a†b ˆ N ab (e.g., 106†2 ˆ 1012). (iv) We use the de®nition of 1 billion as 1,000,000,000 (109) and 1 trillion is 1012.

If x ˆ ay, then the index y is called the logarithm of x to the base a; the logarithm is the number to which the base must be raised to produce the value x. The logarithm (log) of a product is the sum of the individual logs; log cd†ˆlog c†‡log d†. Similarly, the logof a ratio is the di€erence of the logs:log c=d†ˆ log c†Àlog d†. Another useful result is that log cb†ˆb log c†. These rules are needed to understand and manipulate astronomical magnitudes. There are two commonly used bases, the base-10 system (a ˆ 10) and the natural or Naperian system (a ˆ e  2:718); the latter is usually given the symbol ln instead of log. The log(10) ˆ 1, the log(1) ˆ 0, and the log(0.1) ˆÀ1. Decibels (dB) are a logarithmic scale for noise power DP=P and 1dBˆ 10 log DP=P† or, in terms of voltage noise, 1 dB ˆ 20 log DV=V†. When DP=P ˆ 0:5 then dB ˆÀ3.0, and thus the level at which the signal has dropped by 50% is called the ``3 dB point''.

The Greek alphabet alpha beta gamma delta ; D epsilon " zeta  eta  theta  iota  kappa  lambda  mu  nu  xi  omicron o pi  rho  sigma ; S tau  upsilon  phi ' chi psi omega !; O Appendix B

Units of measurement and useful conversions

Quantity SI unit Symbol Length meter m Mass kilogram kg Time second s Electric current ampere A Temperature kelvin K Amount of substance mole mol Luminous intensity candela cd

SI is the SysteÁ me International; sometimes also called the MKS (for meter, kilogram, second) system. See NIST reference: http://physics.nist.gov/cuu/units/ 524 Appendix B: Units of measurement and useful conversions

Quantity Symbol Derived unit Equivalent Force F newton, N 1 N ˆ 1 kgm/s 2 Energy E joule, J 1 J ˆ 1Nmˆ m2 kgs À2 Power P watt, W 1 W ˆ 1 J/s ˆ m2 kgs À3 Electric charge Q coulomb, C 1 C ˆ 1As Potential V volt, V 1 V ˆ 1 J/C ˆ 1 W/A ˆ m2 kgs À3 AÀ1 Capacitance C farad, F 1 F ˆ 1 C/V ˆ mÀ2 kgÀ1 s4 A2 Resistance R ohm, O 1 O ˆ 1V/Aˆ m2 kgs À3 AÀ2 Frequency  hertz, Hz 1 Hz ˆ 1sÀ1 Pressure P pascal, Pa 1 Pa ˆ 1 N/m2ˆ mÀ1 kgs À2

Notes: other units and conversions:

1 micron ˆ 1 micrometer mm†ˆ10À6 m 1 angstrom A†ˆ10À10 m ˆ 10À8 cm ˆ 0:1nm 1 inch in†ˆ2:54 cm ˆ 25:4mm exact† 1cmˆ 0:3937 in 1mˆ 39:37 in 12 in ˆ 1ft 5,280ft ˆ 1 mile mi† 1miˆ 1:6093 km  8=5km 1kmˆ 0:6214 mi  5=8mi 1 nautical mile ˆ 1,852 m 1 ounce oz†ˆ28:3g 1gˆ 0:0353 oz 1kgˆ 2:2046 pound lb† 1lbˆ 0:4536 kg 1 metric ton tonne; t†ˆ1,000 kg ˆ 2,204:6lb 1 liter L†ˆ10À3 m3 ˆ 1,000 cm3 ˆ 1,000 mL A temperature change of 1 degree Kelvin 1K†ˆ1C Celsius† ˆ 1:8F Fahrenheit† Freezingpoint of water ˆ 0C ˆ 273:15 K ˆ 32F Appendix B: Units of measurement and useful conversions 525

1 day d†ˆ24 h ˆ 86,400 s 1 sidereal year yr†ˆ365:256 d ˆ 3:156  107 s 1 erg ˆ 10À7 joule J† 1Jˆ 107 erg 1 calorie cal†ˆ4:186 J 1kWhˆ 3:600  106 J 1 horsepower hp†ˆ550 ft lb=s ˆ 745:7W 1 atmosphere atm†ˆ760 mm Hg ˆ 14:70 lb=in2 ˆ 1:013  105 Pa 1 bar ˆ 105 Pa ˆ 0:9870 atm 1 torr ˆ 1mmHgˆ 133:3Paˆ 1:33 mbar 1 radian ˆ 180= ˆ 57:29583 ˆ 3437:750 ˆ 20626500 100 ˆ 4:848 mrad Notes:

(i) One electronvolt (eV) is the energy gained by an electron of charge e after being accelerated by a potential (V) of 1 volt: 1 eV ˆ e  1Vˆ 1.602  10À19 J (approximately). Alternatively, 1 joule ˆ 6.242  1018 eV. (ii) The product RC of a resistance R and a capacitance C has units of time, and is known as the ``RC time constant''.

Pre®xes for binary multiples In December 1998 the International Electrotechnical Commission (IEC) approved standard names and symbols for pre®xes for binary multiples.

Factor Name Symbol Origin Derivation 210 kibi Ki kilobinary (210)1 kilo (103)1 220 mebi Mi megabinary (210)2 mega (103)2 230 gibi Gi gigabinary (210)3 giga (103)3 240 tebi Ti terabinary (210)4 tera (103)4 250 pebi Pi petabinary (210)5 peta (103)5 260 exbi Ei exabinary (210)6 exa (103)6 526 Appendix B: Units of measurement and useful conversions

Examples:

One kibibit, 1 Kibit ˆ 210 bit = 1024 bit, but one kilobit, 1 kbit ˆ 103 bit ˆ 1,000 bit. One mebibyte, 1 MiB ˆ 220 B ˆ 1,048,576 B, but one megabyte, 1 MB ˆ 106 B ˆ 1,000,000 B. Appendix C

Physical and astronomical constants

Physical constants

Constant Symbol Value Speed of light in vacuum c 2.99792458 Â 108 msÀ1 (exact) Charge on the electron e 1.6022 Â 10À19 C Planck constant h 6.6261 Â 10À34 Js Boltzmann constant k 1.3807 Â 10À23 JKÀ1

À31 Electron mass me 9.1094 Â 10 kg À27 Proton mass mp 1.6726 Â 10 kg 23 À1 Avogadro's number NA 6.0221 Â 10 mol Gas constant R 8.3145 J molÀ1 KÀ1 Gravitational constant G 6.6743 Â 10À11 m3 kgÀ1 sÀ2

À7 À2 Permeability constant 0 4 Â 10 NA (exact) À12 À1 Permittivity constant "0 8.8542 Â 10 Fm Stefan±Boltzmann constant  5.6704 Â 10À8 WmÀ2 KÀ4 Pi  3.14159 Base of natural logs e 2.71828

The constant hc has the value 1.99  10À25 J m, or expressing1 m as 10 6 mm then hc ˆ 1.99  10À19 J mm, or hc ˆ 1.2422 eV mm. 528 Appendix C: Physical and astronomical constants

Astronomical data

6 Mean radius of the Earth RÈ 6.37 Â 10 m

24 Mass of the Earth MÈ 5.98  10 kg Mean Earth±Sun distance ˆ 1 AU* 1.49598  1011 m(93 million miles)

8 Mean radius of the Sun R 6.96 Â 10 m

30 Mass of the Sun M 1.989 Â 10 kg

26 Luminosity of the Sun L 3.827  10 W 1 Lightyear lt-yr 9.4605  1015 m(5.9 trillion miles) 1 Parsec pc 3.0857  1016 m ˆ 3.2616 lt-yr ˆ 206,265 AU*

*AUˆ Astronomical Unit.

Blackbody radiation; the Planck function

2hc2 1 B ˆ WmÀ2 mÀ1 srÀ1  5 ehc=kT À 1†

The maximum of B occurs at max ˆ 2,898/T for max in mm (also called Wien's Displacement Law), or 2h 3 1 B ˆ WmÀ2 HzÀ1 srÀ1  c2 eh=kT À 1†

The maximum of B occurs at max ˆ 58.78T for max in GHz. Note: this is not the same as max=c. Combinations of constants:

2hc2 ˆ 1:191  10À16 Wm2 and hc=k ˆ 1:439  10À2 mK 2h=c2 ˆ 1:4745  10À50 Js3 mÀ2 and h=k ˆ 4:799  10À11 sK

Photon form of Planck Function

Divide B by the photon energy hc=: 2c 1 N ˆ photons sÀ1 mÀ2 mÀ1 srÀ1  4 ehc=kT À 1† To convert to square arcseconds note that 1 steradian ˆ 4.255  1010 arcsec2. The maximum in N occurs at max ˆ 3,670/T for  in mm. Appendix D

Astronomical magnitude scale and relation to lux

In the electro-optical industry the term illuminance is used to describe the amount of light received per unit surface area, and it is measured in a unit called lux. One lux is the illuminance produced by a standard light source of 1 candela at a distance of 1 meter, and 60 candelas is the luminous intensity of a 1 cm2 black body at the temperature of meltingplatinum (2,042 K). One lux is also equivalent to 1 lumen per square meter. Such units are never used in astronomy, but are found in reference to CCD-based cameras intended for low light level television applications. An illuminance of 1 lux is a photon ¯ux of about 3  109 photons/s/mm2 at  ˆ 550 nm, or approximately equivalent to a star of visual magnitude À14. This is roughly equivalent to the full Moon! The brightness in lux of any source in the ``visual'' waveband is

B lux†ˆ10À0:4 mv‡14†

The illuminance of Vega (mv ˆ 0) is only 0.000002 lux. Ordinary hand-held commer- cial TV ``camcorders'', even those with CCDs, operate at frame rates of 1/60th second and are typically designed with 1-inch lenses to image scenes with light levels greater than a few lux (bright moonlight). Intensi®ed CCD systems are capable of imaging with illumination levels as weak as 0.02 lux. While a 2 lux CCD camcorder cannot take images in a room where the illumination level is equivalent to the star Vega, it could actually image the star itself if the lens was removed and the detector attached to a modest telescope. The telescope collects more light and focuses all of the available light onto a single (or small number) of pixels so that the illuminance is increased by several hundred thousand. If the CCD is cooled to allow integration times of many seconds, instead of 1/60th second, then objects can be recorded which are several hundred times fainter still. Appendix E

Basic observational astronomy facts

Coordinates: Positions on the sky are given with reference to the Celestial Equator and the Celestial Poles as shown in Figure A5.1. The coordinates are analogous to longitude and latitude on the Earth's surface and are called Right Ascension (RA or ) and Declination (Dec or ). RA is measured eastwards from the First Point of Aries, an arbitrary marker like the Greenwich meridian, and Dec is measured Æ90 from the Celestial Equator.

Luni-solar precession: The First Point of Aries moves backwards alongthe Celestial Equator at the rate of 50.2 arcseconds per year. Correctingfor this e€ect yields the mean equator and mean equinox.

Nutation: The wobble of the Earth's axis as it precesses. Correction for this e€ect gives the true equator and true equinox. Often, all these corrections are done at the observatory by the telescope control program, but formulas are included in the Astronomical Almanac which is published annually and jointly by the U.K. and the U.S.A. Published coordinates are usually referred to a speci®c equinox such as J2000. For the nearest objects, an additional correction for proper motion (the component of the object's true motion in space at right angles to our line of sight) must be made; the rates are tabulated in surveys of proper motion. The object's true position at the present epoch will depend on the interval of time since the epoch of the tabulated coordinates. To ®nd out when an object is observable you need to convert from RA and Dec to hour angle and zenith distance (or zenith angle) for your latitude. Several basic relationships are given below; it is useful to be familiar with the celestial sphere and basic spherical trigonometry (Green, 1985). 532 Appendix E: Basic observational astronomy facts

Figure E5.1. The celestial sphere and spherical triangle relations. The north celestial pole is at P, and  is the observer's latitude.

Hour angle: The Hour Angle (H) is measured westwards from 0 on the meridian; east is therefore negative and west is positive. In practice, H is given in hours of timeÐand not in degreesÐbecause this gives a more intuitive indication of when the object can be observed; for example, 3 hours east of the meridian (H ˆÀ3 h) means that it will be three hours until that object crosses the meridian. The usual conversion between degree and hours applies: 360 ˆ 24 h; 15 ˆ 1h; 1 ˆ 4 min; 150 ˆ 1 min; 10 ˆ 4s; 1500 ˆ 1s; 100 ˆ 0:067 s Note: Conversions from angle to time on the sky depend on declination (). The interval of time parallel to the RA direction is shortened by the factor cos . On the equator  ˆ 0 and cos  ˆ 1. At the poles  ˆ 90 and cos  ˆ 0.

Zenith distance: ZD or z ˆ 90 À a, where a is called the altitude or elevation angle above the horizon; a ZD > 90 implies that the object is below the horizon.

Azimuth: Azimuth (A) is the compass bearing in degrees measured north through east.

Local sidereal time: LST is the hour of right ascension on the meridian at that moment. Most observatories have a sidereal clock. There are approximately 23 Appendix E: Basic observational astronomy facts 533 hours, 56 minutes, and 4.1 seconds in one sidereal day. The sidereal time at midnight on March 22 is 12 hours, and the LST advances about 2 hours per month. By September 21 the LST is 24 (or 0) hours, and thus this is the RA on the meridian at midnight. In general: LST ˆ RA ‡ HA. LST is tabulated at 0 hours Universal Time for every day of the year in the Astronomical Almanac.

Universal Time is the time on the Greenwich Meridian. Most observatories have a clock keepingUT. Exact UT can be obtained from radio signalsissued by the WWV service.

Julian Date (no connection to the Julian Calendar) is a numerical day count from an arbitrary zero point. Julian Day number is the number of days that have elapsed since noon Greenwich Mean Time on January 1, 4713 bc plus the decimal fraction of a day since the precedingnoon up to the event beingrecorded. Julian Dates are givenin the Astronomical Almanac.

Coordinate transformations: Relationship between Hour Angle (H) and Dec () given azimuth (A) and elevation (a): sin †ˆsin a† sin '†‡cos a† cos '† cos A† cos H†ˆ‰sin a†Àsin † sin '†Š=cos † cos '† and RA ˆ LST À H. Relationship between azimuth (A) and altitude/elevation (a) given the Hour Angle (H) and Dec (): sin a†ˆsin † sin '†‡cos † cos '† cos H† where H ˆ LST À RA cos A†ˆ‰sin †Àsin '† sin a†Š=cos '† cos a† or tan A†ˆsin H†=‰sin '† cos H†Àcos '† tan †Š; and the variation of the parallactic angle (q ˆ angle PXZ) with time is given by tan q†ˆsin H†=‰tan '† cos †Àsin † cos H†Š or sin q†ˆcos '† sin H†=sin † The elevation (or altitude) of the celestial pole above the horizon in degrees is equal to the latitude (') of the site. A plot of airmass (i.e., sec z) vs. time (or HA) will tell you the best time to observe your source. The times of sunset, sunrise, and the position of the Moon are tabulated in the Astronomical Almanac. The times of sunset, sunrise, and twilight are tabulated at 4-day intervals of time and 10-degree intervals of latitude.

References Green, R.M. (1985) Spherical Astronomy, Cambridge University Press, Cambridge, U.K. Roy, A.E.; and Clarke, D. (2003) Astronomy: Principles and Practice, fourth edition, Institute of Physics, Bristol, U.K. Appendix F

Useful statistics

Mean and weighted mean: P x =2† 1 X x ˆ P i i ! x ;ˆ  2 i i 1=i † N where  is the standard deviation of a single observation from thep mean; and N is the number of observations. The standard error of the mean is = N. Variance: P x À x†2 2 ˆ i N À 1 is determined from the sum of the squares of the ``residuals'' or di€erences from the mean. Error in a sum (or di€erence) of two random variables (A and B): A Æ  ; B Æ  A qB 2 2 C ˆ A Æ B†Æ A ‡ B The errors add in quadrature. Error in a ratio of two random variables (A and B): A Æ  ; B Æ  rA B A  2  2 C ˆ Æ C A ‡ B B A B The fractional errors add in quadrature.

The Chi-squared test Compares the observed frequency distribution f xi† of possible measurements xi with the predicted distribution NP xi†, where N is the number of data points and P xi† is 536 Appendix F: Useful statistics the theoretical probability distribution: Xn ‰ f x †ÀNP x †Š2 2 ˆ j j NP x † jˆ1 i The ``reduced'' chi-squared is 2=v, where v is called the ``degrees of freedom'' and is given by N À p, where N is the number of data points and p is the number of parameters determined from those data points.

The Gaussian distribution For a very large number of observations (n) of a random variable, the probability of obtainingthe value x is  1 1 x À x 2 P x; x;†ˆ p exp À  2 2  where the standard deviation  is related to the full width at half maximum (FWHM) of the distribution by FWHM ˆ 2.354, and to the probable error by PE ˆ 0.6745. The probable error corresponds to the range of the variable which contains 50% of the measurements. Error bars giving estimates of  should be applied to all measure- ments. Assumingthat the errors follow a Gaussian distribution, the probability of ®ndingthe variable in the interval Æ1 is 68%. For Æ2:5 it is 98.7%.

The Poisson distribution This is a discrete probability distribution that expresses the probability of a number of events occurringin a ®xed period of time if these events occur with a known average rate and independently of the time since the last event. If the expected number of occurrences in this time interval is , then the probability that there are exactly k occurrences (k being a non-negative integer, k ˆ 0; 1; 2; ...) is equal to keÀ f k;†ˆ k! Here, e is the base of natural logarithms (e ˆ 2.71828...); k is the number of occurrences of an event, the probability of which is given by the function f ; and k! is the factorial of k. The numberp of observed occurrences ¯uctuates about its mean  with a standard deviation k ˆ . These ¯uctuations are called Poisson noise. Index

2dF, two degree ®eld 145±147 AIPS 359 2MASS 101, 420 air, refractivity 48 3-D maps of the Universe 144 airmass 42 51 Pegasi 140 Airy disk, di€raction pattern 30, 471 6dF, six degree ®eld 146 Airy, George 30, 46 AKARI infrared satellite, formerly AB magnitude 333 ASTRO-F 424 Abbe sine condition 206, 433 ALADDIN InSb arrays 409 Abbe, Ernst 206 Allen, David 388 aberration Alpher, Ralph 487 astigmatism 206 aluminum, treatment of 215 coma 91, 205 ampli®er gain 302 spherical 31, 78, 90, 204 ampli®er glow 415 third order 111, 203, 204 analogsignalchain 279 Ables, Harold 329 analog-to-digital converter, ADC 299 absorption bands analog-to-digital unit, ADU 302 A and B bands of oxygen 40 anamorphic magni®cation 170 water vapor 40 Angel, Roger 82, 108, 146 absorption in silicon 188, 189 Anglo-Australian Telescope (AAT) 101 achromatic doublet 89 angular displacement, by wedge or plate acousto-optic spectrometer, AOS 479 202 active galactic nucleus, AGN 121 angular resolution 12, 47 adaptive optics, AO 26, 47, 54, 55, 507 of radio telescopes 468 sky coverage 63 annealing215 system layout 55 antenna gain 471 ADONIS, AO system 61 antenna temperature 470 Advance Camera for Surveys, ACS 72, 444 antennas, types of 471 Advanced CCD Imaging Spectrometer, anti-re¯ection (AR) coating211 ACIS 448, 452 aperture photometry 337 Aikens, Richard 245, 247, 308 aperture synthesis 70, 481, 483±485 538 Index aplanatic Gregorian (AG) telescope 113 background-limited 346 aplanatic, optical system 111 backlash 216 application-speci®c integrated circuit, ASIC backshort 490 286, 512 backside-illuminated CCDs 261 area-solid angle product, also optics, Bacon, Roland 151 Lagrange invariant 87 Baker, Ian 395 Arecibo telescope 474 balanced composite structure, BCS 401 Arens, John Eric 393 Ball Aerospace 444, 446 arrays of PMTs 462 bandgap energy for silicon 289 arti®cal star, see laser guide stars 63 Barnard, E.E. 387 aspheric surface 210 Barth, Aaron 369 Aspin, Colin 396 Bartholin, Rasmus 153 astigmatism 206 baryon acoustic oscillations 150 two-mirror telescope 114 Battson, Don 244 astrometry 120 Bayesian methods 378 astronomical instruments beat frequency 195, 476 designing and building 199 Beattie, David 397 requirements 199 Beckers, Jacques 65 system layout 200 Becklin, Eric 104, 387, 388, 395, 397 Astrophysics Data System, ADS 27 Becklin±Neugebauer (BN) object 387 Atacama Large Millimeter Array, ALMA Beletic, Jim 65 41, 468, 485, 505 Bell Telephone Laboratories 18,19, 467, atmosphere 487 constituents 41 Bennett, Charles 488 scale height 41 beryllium mirror 423, 425 atmospheric Cherenkov telescope 457 Bessel, Friedrich 119 atmospheric dispersion corrector (ADC) 94 Beta Pictoris 128, 129 atmospheric transmission code, ATRAN bias frame 324 389 BigBang487 atmospheric turbulence, time scale 52 nucleosynthesis 139 atmospheric window birefringence 153 infrared 389 bismuth germinate, BGO 455 radio 468 blaze angle 171 atmospheric block diagram 200 absorption 39 blocked column 293 boundary layer 49 blocked impurity band, BIB 395 dispersion 42 blooming, see charge bleeding 292 emission 43 Blouke, Morley 244, 246, 252 extinction 42 Bode, Mike 100 refraction 42 Boksenberg, Alexander 18 thermal emission 44 bolometer 194, 490 transmission 39 Bol'shoi Teleskop Azimutal'ny 4 turbulence 46, 48 Bonn shutters 256, 338 ATV, software 369 BOOMERANG 486 automated imaging telescopes 98 Boston Micromachines Corp 146 avalanche photodiode, APD 70, 507 Bouguer's Law 42 Bowen, Ira 4 Babcock, Horace W. 47, 52 Bragg di€raction 174, 452 back-end, receiver 477 Bragg's Law 451 Index 539

Bredthauer, Dick 247 Centaurus A 121 brightness temperature 470 Center for Adaptive Optics 11 Brodie, Dick 394 Center for High Angular Resolution brown dwarfs 136 Astronomy, CHARA 70 Brown, David 82 Cepheid variables 4, 121 buried-channel CCDs 257 Cerro Paranal 105 Burke, Barry 247 CGRO instrument Burst Alert Telescope, BAT 459 BATSE 458 Burt, David 246 COMPTEL 458 Butler, Paul 140 EGRET 458 byte-swapping358 OSSE 458 Cha€ee, Fred 104 cadmium zinc telluride (CZT) arrays 456, Chajnantor, ALMA site 42, 505 459 Chandra X-ray Observatory, CXRO 290, California and Carnegie Planet Search, 434, 447, 452 CCPS 140 Chandrasekhar, Subrahmanyan 447 California Extremely Large Telescope Channan, Gary 104 (CELT) 110 channel stop 254 Caltech Sub-millimeter Observatory, CSO charge bleeding 292 490, 491 charge transfer eciency 292-295 Cambridge Optical Aperture Synthesis charge-coupled device, CCD 241 Telescope, COAST 71 invention of 241 camera systems 163 charge-coupling 252, 254 Canada±France±Hawaii Telescope, CFHT Cherenkov radiation 8, 461 22 Chi-squared test 535 Canadian Astronomy Data Center, CADC chopping391 27 Chre tien, Henri 92 Cannon, Annie Jump 144 chromatic aberration 207 capacitor 229 lateral 89 Capps, Rich 394 longitudinal 89 carbon ®ber 473 circle of least confusion 90 CASA 359 Clarke, David 101 Casali, Mark 417 CLEAN process 485 Cassegrain, Laurent 78 clock-induced charge 270 CCD, charge-coupled device 19,20,21 clocking254 bias 323 closed-cycle refrigerator 219 charge storage 248 co-adding410 dark current 323 COBE 486, 487 equation 345 coded anode converter, CODACON 443 inventor, Boyle, Willard S. 19,20 coded-mask telescope 435 inventor, Smith, George E. 19,20 Cohen, Judith 142 outputs 256 coherent detector 195 mosaic 22 collectinghorn 472, 474, 475 mountingscheme 221 collimated beam 164 noise 323 Columbus project, see Large Binocular Picturephone 20 Telescope 110 pixels 19 coma 205 preampli®er 230, 231 see aberration 91 celestial sphere 527, 528 Come-on, adaptive optics system 61 540 Index common-user instrumentation 26 cyclic di€erence sets 436 complex refractive index 432 Cygnus A 485, 486 Compton Gamma Ray Observatory, CGRO 71, 457 DAOPHOT, photometry software 366, conduction band 186 338, 340 cone e€ect 507 dark current 287 conic constant 113 dark energy 127 conic sections 91 data archives 27,28 controller design 284 data cube 151 controller types 285 Davis, Ray 7 conversion between hours and degrees 532 dc-coupled preamp 411 convolution 375 decibels 516 Cooke triplet 211 declination axis, see telescope mounts, coolingof CCDs 265 equatorial 95 coolingtime 223 deep depletion CCD 270, 318 Cooper pairs 495 deep imaging in selected ®elds 132 coordinate transformation 529 Deep Near-Infrared Survey, DENIS 101, Copernicus satellite 71 132, 421 copper 215 DEEP2 Redshift Survey 144 CORALIE, spectrograph 140 deferred charge 294 Cornell Caltech Atacama Telescope, CCAT deformable mirror 512 see also adaptive optics 55 coronagraph 127 types of 59 coronene 308 deformable secondary mirrors 60 corrector 93, 94 degreasing, of bearings 218 correlated double-sampling298, 300, 301, DEIMOS 144, 145 413 delay line 443, 444 cosmic microwave background, CMB 154, depletion layer 193 485 deployable integral ®eld unit 508 Cosmic Origins Spectrograph, COS 72 Descartes, Rene 84 cosmic ray 7, 290 detective quantum eciency, DQE 318, particle 461 319, 439 cosmological constant 127 detector COSTAR, Hubble optical corrector 71, 438 capacitance 318 coude focus, see re¯ectingtelescopes, classi®cation 184 stationary foci 92 coherent 185 Crab Nebula (M1) 1 noise-limited 346 polarization 156 performance 32 Craine, Eric 99 photon 184 CRIRES, VLT instrument 418 properties 32 critical angle, for grazing incidence 432 dark current 32 cryogenic lens-holder 416 dynamic range 32 cryogenics and vacuum method 218 linearity 32 cryostat, LN2 226 noise 32 Cuillandre, Jean-Charles 127 quantum eciency 32 Cullum, Martin 308 spectral response 32 curvature sensor 59 temporal response 32 curve of growth 337 thermal 184 cuto€ wavelength 189 deuterium abundance 139 Index 541 diamond machining210 electron±hole pair energy in silicon 449 dichromated gelatine, DCG 173 electronics design 228 Dicke switching476 electron multiplication CCDs 54, 268, 286 Dicke, Robert 476, 487 electron-scanningdevices 17 dielectric constant of silicon 250 ELODIE, spectrograph 140 di€raction emissivity 391 grating 168 encircled energy 31 limit 9, 31 encoder 218 Fraunhofer 46 English Electric Valve (EEV), see e2v Fresnel 46 technologies 246 -limited imaging 133 English yoke, see telescope mounts, Digicon (detector) 19, 445 equatorial 95 Digital Age 5 entrance pupil 88 digital circuitry 234 EPICS 355, 460 digital signal processor, DSP 283 Epps, Harland 211 digitization noise 302, 354 EROS 101 digitized Palomar Observatory Sky Survey ESO Schmidt telescope 123 (DPOSS) 123, 124 etalon 181, 182 digitized sky survey (DSS) 123 e tendue, see area-solid angle product 87 digitized surveys 123 ethernet 354 dipole feed 472, 474 European ELT 111, 503 DIRBE 487 European photon imaging camera, EPIC dispersion, angular and linear 168, 169 448 dispersive power 85 exit pupil 88 distortion 207 Extreme Ultraviolet Explorer, EUVE 438 dithering, of CCD exposures 328, 329, 377 Extremely Large Telescope (ELT) 110 Djorgovski, George 28 extrinsic germanium arrays 403 DMR 487, 488 eye relief 88 dopingmaterials for extrinsic Si and Ge, eye, properties of 11,12,13 table of 191 Doppler E€ect 137 Fabry lens 162 double- and single-sideband 477 Fabry±Perot interferometer 150, 181 down-converters 308, 440 Faint Object Camera (FOC) 18 DQE vs. readout noise and number of Fairchild Semiconductor, Fairchild photons 319 Imaging 242, 245 Draper, Henry 2, 41 false-color 372 drift scanning129, 130, 266, 327, 328 Fano factor 449 DRS Technologies 401, 402 Far Ultraviolet Spectroscopic Explorer, dry ice 218 FUSE 438 fast interface state 298 e2v technologies 246, 460 Faulkes Telescope Project 101 early surveys of the sky 121 Fazio, Giovanni 394, 424 echelle grating 169 Fe55 X-ray absorption in CCDs 450, 451 e€ective area, of antennas 472 Fermat, Pierre 85 E€elsbergradio telescope 473 Fermat's principle 85 Einstein Observatory 446 Fermi level 193 Einstein, Albert 7, 15 Fessenden, Reginald 470 electromagnetic radiation 7 ®bers, optical 146 electron-bombarded CCDs 445 ®eld curvature 207 542 Index

®eld e€ect transistor, FET 232 Full Width Half Maximum, FWHM 30,31 ®eld of view, two-mirror telescope 113 full-well capacity 252 ®eld rotation 95 ®lter wheels 216 GAIA 287, 510 ®lters, UBV 162 Galactic Center 133 ®nesse 182 Galaxy Evolution Explorer Mission, ®nite element analysis 214 GALEX 438 FIRAS 487, 488 galena, see lead sul®de 387 FITS 356 Galileo or Galileo Galilei 1, 77, 502, 513 keywords 357 gallium-doped germanium bolometer 388 Liberator 369 gamma ray 453, 454 ®xed pattern noise 324 burster, GRB 457 Fizeau, Armand Hippolyte 67 Gamow, George 487 Flagsta€ Astrometric Scanning Transit Gaussian distribution 536 Telescope (FASTT) 96 Geary, John 22, 244 FLAIR 146 Gehrels, Neil 461 ¯ash gate 310, 311 Geiger tube 454 ¯at-®eld 306, 307 Genzel, Reinhard 133 sources 327 geosynchronous orbit 437 strategies 325, 326 German mount, see telescope mounts, Flexible Image Transport System, FITS equatorial 95 356 germanium array 403 ¯exible wafer coupling217 germanium solid proportional counters 456 Ghez, Andrea 53, 133 ¯oatingshields 223 Giant Magellan Telescope (GMT) 111, 502 ¯ux from zero-magnitude star 347 Glasse, Alistair 418 focal plane array, FPA 399 GLAST 510 focal ratios, faster and slower 93 Global Network of Automated Telescopes focal reducer 165 (GNAT) 98 forbidden energy gaps, semiconductor 186, Goddard Space Flight Center 490 189 Google Sky 130 Forrest, Bill 394 Graham, James 62, 381, 418 Fourier analysis 53 Gran Telescopio Canarias, GTC 83, 105 Fourier deconvolution 379 gravitational Fourier Transform Spectrometer, FTS 181 lensing150 Fowler sampling413, 414 waves 7 Fowler, Al 394, 396 grazing incidence telescopes 432 Foy, R. 63 Great Attractor 488 FPGA, ®eld programmable gate arrays 286 Great Observatories, NASA's 71 frame transfer CCDs 254 Greek alphabet 522 Fraunhofer lines, F, D, and C 85 Green Bank Telescope, West Virginia 468 Fraunhofer, absorption lines 2 greenhouse gases 40 Fraunhofer, Joseph 2 Greenwood frequency 52 free spectral range 173 Gregory, James 78 Fresnel, Augustin-Jean 46 Grith Observatory 124 Fried parameter, r-naught 51 grisms 176 Fried, David 51 ground loops 234, 280 fringing and sky emission 331, 332 Gunn, Jim 27, 244 Fugate, Bob 48, 63 Gursky, Herbert 22 Index 543

Hadley, John 78 Homestake Gold Mine 7 Haidinger's brush 12 honeycomb mirror 82, 108 Hale telescope 4 Hooke, Robert 78 Hale, George Ellery 3 Hooker telescope 3 half-wave Hooke's law 214 dipole 471 horseshoe mount, see telescope mount, retarder 179 equatorial 95 Hall, Don 388, 397 hot electron bolometer, HEB 481 Hanbury-Brown 483 Houck, Jim 424 Hanbury-Brown and Twiss 69 Hubble constant 138 Hanisch, Robert 29 Hubble Deep Field, HDF 132 hard X-ray 447 Hubble Space Telescope, HST 71, 132, 431, Harwit, Martin 387 438 HAWAII HgCdTe arrays 409 instruments 71 HAWK-I 417 orbit 72 HD209458 125, 126 spherical aberration of 72 heat transfer by radiation 222 Hubble, Edwin 1,3 Heinrich Hertz sub-millimeter telescope 473 Humason, Milton 3 HeisenbergUncertainty Principle, Huygens wavelet 46 di€raction of photons 46 Huygens, Christiaan 15, 46, 78 helium three (3He) refrigerator 491 hybrid array 398 helium-3 systems 219 hybrid structures 397 Henry Draper Catalog144 Hyland, Harry 388 Hereld, Mark 395 Herschel instruments 510 IDL 361, 366-369 Herschel mission 510 Astronomy User's Library 369 Herschel, William 2, 79, 386 IEEE-488 355 Hertz, Heinrich 8 image Hertzsprung±Russell (HR) diagram 121 analysis and processing, principles of 369 HESS 462 enhancement 374 heterodyne 195, 476 formation 29 origin of 470 restoration 378 HgCdTe 400 size, due to di€raction 166 High Energy Astrophysical Observatories, slicer 151 HEAOs 446 smear, from ®eld rotation 95 High Energy Transmission Grating Imaging SpectroPolarimeter, ISP 154 Spectrometer, HETGS 452 imaging spectroscopy 150 High Resolution Camera, HRC 451, 452 immersion gratings 175 high-pass ®lter 375 impurity band conduction 401 high-rho CCD, see deep-depletion CCD indium antimonide 388 270 indium bumps 398 Hill, John 146 infrared array 22 Hipparchus 1, 120 cooling407 Hipparcos satellite 120 dark current 406 Hobby±Eberly Telescope (HET) 92, 101, early development 393 105 linearity 405 Ho€man, Alan 394, 396 noise sources 407 hole 187 quantum eciency 408 in the sky 387 revolution 393 544 Index

Infrared Astronomical Satellite, IRAS 132, James Clerk Maxwell telescope 473, 474, 389 491, 493 infrared astronomy James Webb Space Telescope, JWST 72, history of 386, 387 146, 509 regions 386 orbit of 72 infrared black paint 416 Janesick, James (Jim) 242, 245, 287 infrared instrument 415 Jansky, Karl 467 Infrared Processingand Analysis Center, Japanese National Large Telescope, see IPAC 420 Subaru 106 Infrared Space Observatory, ISO 389 Joint Dark Energy Mission, JDEM 511 infrared window, table of 390 Jorden, Paul 246 infrared-optimized 393 InSb, see indium antimonide 400 Kamiokande Neutrino Observatory 7 INTEGRAL 435, 437, 456 Kandiah, Ken 246 integral ®eld spectroscopy 419 Katzman Automated Imaging Telescope integral ®eld unit, IFU 150, 151 (KAIT) 99 integrated circuit 6 Keck integrating sphere 316 10 m telescopes 80, 94, 502 intensi®ed CCD 442 II laser beacon 66 interference ®lter 182 Interferometer 70, 105 interferometer 66, 134, 181, 482, 483 Observatory 5, 102 baseline 69 Kelvin, Lord 25 delay line 70 Kelvin, scale 25 fringes 68 Kemp modulator 177 intensity 69 Kepler mission 510 phase closure 70 Kepler, Johannes 88 interline transfer CCDs 254 Kepler's third law 141 intermediate frequency 195, 476 kinematic mounts 213 International Celestial Reference Frame Kleinmann, Doug388 (ICRF) 120 International Gemini Telescopes Project 98, Kleinmann±Low Nebula 388 107 KMOS 508 International Ultraviolet Explorer, IUE knife edge test 52 437 Kolmogorov turbulence 49 inversion 287 Kolmogorov, Andrey 49 ion-®guring 102 Krist, John 382 ionizingradiation, on CCD 290 Kristian, Jerry 252 IPCS 18 Kuiper Airborne Observatory 388 IR Kuiper Belt objects 124 array unit cell 399, 400 cameras 416 L2 Lagrange point 72, 509 IRAC instrument on Spitzer 424 L3CCD, see also electron multiplication IRAF 359, 361-366 CCDs 54 IRAM millimeter telescope 473 Labeyrie, Antoine 53, 63, 69 IRAS 389 laminar ¯ow 49 IRCAM, infrared camera 395 Landauer, Fred 242, 244, 308 IRS instrument on Spitzer 424 Large Binocular Telescope 70, 83, 110 isokinetic patch, angle 58 Large Synoptic Survey Telescope (LSST) isoplanatic patch, angle 58 27, 102, 265, 504 Index 545 large telescopes in pre-Keck era, table of magnitude scale 120, 121 80 magnitude system Larkin, James 419 Mould 334 laser guide star AB and STMAG 333 elongation of 65 general 332, 333, 334 monostatic and bistatic projection 64 Kron±Cousins 334, 335 systems 63 SDSS 334 Latham, David 22 Thuan and Gunn 334 lead sul®de (PbS) 387 UBV 334, 335 lead±magnesium±niobate, PMN 59 Vega 333 Leavitt, Henrietta 4 Maksutov telescope, see telescope, hybrid Leighton, Bob 130, 387 93 lensmaker's formula 86 Malin, David 377 Lesser, Mike 310 Marconi, see e2v technologies 247 Lick Observatory AO system 62, 65 Marcus, Steve 245 LIGO 7 Marcy, Geo€ 140 linearity 332 Mare chal approximation 57 Lippershey, Hans 77 Mast, Terry 104 liquid helium 219 matchingto the plate scale 164 materials and properties 213 liquid nitrogen 219 Mather, John 486 Littrow condition 172 Mauna Kea, Hawaii 41 Liverpool Telescope (LT) 100 Max, Claire 61, 65 local oscillator, LO 196, 476 maximum entropy 378, 380 local sidereal time 528 Maxwell, James Clerk 7 logarithms 516 Mayor, Michelle 140 look-up table (LUT) 369 McCarthy, Jim 142 Lord Rosse 79 McCaughrean, Mark 396 Lovell telescope, Jodrell Bank 474 McCreight, Craig 393 Low Energy Transmission Grating McLean, Ian 104 Spectrometer, LETGS 452 Mead, Carver 29 Low light level CCD, L3CCD 268 mechanical design, of instruments 212 Low Resolution Imaging Spectrograph, mechanical shutters 256 LRIS 142 mechanisms 216 Low, Frank 388 median ®ltering376 low-pass ®lter 375 MEDUSA 146 luck imaging 53, 54 MegaCam 127, 265 luminescence 291 megapixel, Mpxl 22 lumogen 308, 440 Meinel, Aden 43 Lunar and Planetary Lab 243 MEMS 145, 380 Luppino, Gerry 266 meniscus mirror 82, 106 Lynds, Roger 245 M87 485, 486 Mersenne relay 210 Messier, Charles 1 MACHO 101 Metachrome 247, 308 Mackay, Craig54, 246, 269, 286, 291 metal oxide semiconductor (MOS) Magdalena Ridge Observatory, MRO 71 capacitor 230 Magellan Telescope 110 metallic re¯ection 432 MAGIC 462 MICHELLE 418 546 Index

Michelson multwavelength milky way 24 interferometer 150 myopia 77 stellar interferometer 69 Michelson, Albert 67, 69 NAOS, AO system 61 microchannel plate, MCP 441 NASA Infrared Telescope Facility 388 micro-electro-mechanical system, MEMS Nasmyth focus, see re¯ectingtelescope, 59 stationary focus 92 microlens array, also lenslet array 151 Nasmyth, James 92 MicroObservatory 99 National Radio Astronomy Observatories, microshutter 146 NRAO 468 microwave kinetic induction detector, near-Earth asteroid 127 MKID 495 Near-Infrared Camera and Multi-Object MIDAS 360 Spectrometer, NICMOS 72 Mills Cross 483 Nelson, Jerry 5, 81, 102 minimum mass, of an extra-solar planet Neugebauer, Gerry 130, 387 141 neutrinos 7 MIPS instrument on Spitzer 403, 424 neutron transmutation doped (NTD) Mira's tail 439 germanium 490, 491 mirrors New Technology Telescope (NTT) 106 parabolic 78 NEWFIRM 417 silver coating108 Newton, Isaac 2, 78 technology of large 82 Niblack, Kurt 394 MIT/Lincoln Labs 247 NICMOS, Hubble Space Telescope mixer 195, 477, 480 instrument 389, 395, 423 MKS system of units 517, 518 NIRSPEC, near-infrared spectrometer for MMT, monolithic and multi-mirror Keck telescope 209, 211, 215, 236, telescope 83 418 modulation transfer function, MTF 32, 208 Nobeyama Radio Observatory 481 Monolithic Mirror Telescope (MMT) 109 nod-and-shu‚e 154 MONSOON 286 nodding392 moonlight 45 node capacitance, of a CCD 297 Moore, Gordon 29 noise 16 Moore's Law 29, 513 equivalent ¯ux density 492, 493 MOS capacitor 249 non-destructive readout 399 mosaics of CCDs 265 Not-a-Number, NaN 367 MOSFET 229 MOSFIRE 213 Oania, Carol 394 motor, servo and stepper 216, 234 observable 7,10 MovingObject and Transient Event Search O'Dell, Bob 244 System (MOTESS) 98 o€-axis parabola, OAP 210 Mt. Everest 42 O€ner relay 211 Mueller matrices 180 OGLE 101 Mullard Observatory 484 OH emission line, see atmospheric emission multi-anode microchannel array, MAMA 43 443, 444, 446 Ohm's law 229 multi-pinned phase (MPP) CCD 262, 287 Oke, Bev 142 multiple layer insulation, MLI 223 Olivier, Scott 61 multiple sodium laser beacons 507 Onaka, Peter 286 Index 547 on-chip binning304 PenÄa, Robert 380 operational ampli®ers, op-amp 232 Penzias, Arno; co-discoverer of cosmic optical design 201 microwave background 487 optical path 85 periodic table of elements, part of 188 optical path di€erence, OPD 31, 207 Petro€, Mike 395, 401 optical power 86 Petzval surface, sum 207 optics phase closure 70 angular magni®cation 87 phasingcamera 104 chief ray 88 phoswich 455 conjugate points 86 photoabsorption 185 Lagrange invariant 87 photocathodes 17 magni®cation 86 photoconduction, photoconductor 185, 191 Newton's equation 87 photoconductive gain 192 spherical mirror equation 86 photodiode 191 thick lenses 86 photoelectric e€ect 13, 15 thin lens equation 85 photoemission 185 orbital speed photography 13,14,15 of the Earth 138 characteristic curve 14 of the Sun 138 hyper-sensitization 14 OrbitingAstronomical Observatory 71 plate density 14 Orias, Geo€ 396 photometer, photoelectric 161 Orion InSb arrays 417 photometric system, table of 335 orthogonal transfer CCD, OTCCD 271, Photometrics, now Roper Scienti®c 245 272 photometry 120 Oschin Schmidt telescope 268 photomultiplier tube 15,16,17 OSIRIS, infrared AO instrument for Keck dynode 16 telescope 419 photon 15 orthogonal transfer CCDs 505 photon transfer outgassing 225, 227 function, gain factor 319, 320 over-scanning305 gain measurement 321, 322 Over-Whelmingly Large (OWL) telescope photovoltaic (photodiode) device 185, 192, 111 400 ozone 40 pick up, electrical noise 280 Pickering, Edward 4 pair production 454 pinhole camera 436 Palomar Observatory Sky Survey (POSS) Pipher. Judith 394 122 pixel sampling164 Palomar Observatory Sky Survey II pixon reconstruction 378, 380 (POSSII) 123 Planck Pan-STARRS 102, 127, 265, 286, 504 function 528 parabolic dish 472 mission 510 paralactic angle 43, 533 Planck, Max 15 paraxial optics 85 plate scale 92, 93, 165 parsec 119 platinum silicide arrays 404 PCI, computer bus 355 Pockels cell 177 Peak-to-Valley, P-V 31 Pogson, Norman 120 Peebles, Jim 487 point spread function, PSF 29,30 548 Index

Poisson radio waveband 469 distribution 536 radiometer equation 476 equation 250 radiometric unit 33 statistics 16 Ramsden circle 88 polar aurora, see atmospheric emission 43 Ramsden, Jesse 88 polar axis, see telescope mounts, equatorial Randall, Dave 396 95 RATAN-600 472 polarimeter 177 ray tracing203, 208 polarimetry 343 Rayleigh back-scattering, see laser guide polarization 152 star 63 linear and circular 179 Rayleigh 44 modulator 153, 177 Criterion 31 transverse wave 152 scattering39 pop-up bolometer 490 Rayleigh, Lord 31, 39 power of ten pre®x 521 Rayner, John 396 power pattern 471 Raytheon Vision Systems, RVS 400, 401, preampli®er, CCD 281 402, 421 precession of the equinoxes 1 RCA 244, 245 precipitable water 41 readout integrated circuit, ROIC 399 pre®xes for binary multiples 525 readout noise 297 pre-¯ash 292 Reber, Grote 467 presbyopia 77 receiver 474 pressure gauge, Pirani and Penning 227 reciprocal linear dispersion 168 prism 175 red leak 334, 335 pro®le ®tting337 redshift 138 proportional counter 454 survey 149 proton impact, on CCD 290 reduction and calibration of CCD data 330 Ptolemy 120 re¯ectingtelescopes Puetter, Rick 378, 380 Cassegrain focus 91 pulse-counting, photon-counting 16 Gregorian focus 91 Purkinje e€ect, see eye 12 Newtonian focus 91 prime focus 91 quanta 15 stationary focus 92 quantum eciency, QE 19 tertiary mirror 92 measurement 316 re¯ection, law of 84 quantum-well infrared photon sensor, re¯ex motion 141 QWIPS 404 refraction, law of 84 quarter-wave refractive index 84 layer 211 Reitsema, Harold 244 retarder 179 remote observing97 quasi-Littrow condition 172 reset or kTC noise 297, 300, 407 Queloz, Didier 140 reset±read±read sampling, see Fowler quenching215 sampling413 queue scheduling98 residual image 287 Quinn, Peter 29 resistor 229 resolvingpower 168 Racine, Rene 79 retarder 178 radiance, irradiance 9, 33 Reticon, Reticon Corporation 19, 247 Index 549 retina 11 segmented mirror 82, 102 cone 11,12 Seidel, Philipp von 204 rod 11,12 semiconductor 6, 186 Reynolds number 49 Semiconductor Technology Associates Richardson±Lucy 378, 380 (STA) 247, 272 Rieke, George 424 semiconductor Rieke, Marcia 395 dopingof 190, 191 Ritchey, George Willis 92 extrinsic 190, 191 Ritchey-Chre tien (RC) telescope 92, 113, intrinsic 186, 188 461 sensor chip assembly, SCA 399 Robert C. Byrd Green Bank telescope, sequencer 283-285 GBT 473 Serrurier truss 96, 97 Robinson, Lloyd 247 Serrurier, Mark U. 96 Rochon, Alex-Marie 144 SExtractor, source extraction software 366 Roddier, FrancË ois 62 Shack±Hartmann sensors 56, 63 Rode, Jon 395 shape factor, of a lens 205 Roentgen satellite, ROSAT 438, 447 SHARC II, sub-millimeter array camera Roper Scienti®c 245 490 rotation matrix 181 Short, James 78 Rowland circle 170, 438 Sibille, FrancË ois 395 Royal Observatory Edinburgh 97, 395 SIDECAR ASIC 287, 410 RS-232 354 sidelobe 471 Ryle, Martin 484 sideral rate 94 signal-to-noise safe handlingof CCD 279 calculation 343 sampling, Nyquist 32 ratio, SNR or S/N 29, 34, 135 Samuel Oschin Schmidt telescope 123 signal±variance plots 322 Sanders, Gary 111 Silicon Imaging Technologies, SITe 247, Savoye, Dick 244 295 scan mode, CCD 99 silicon strip detector 456 Schlieren pattern 52 Simms, Gary 308 Schmidt telescope 93, 206 SIS junction 480, 481 Schmidt, Bernhard 93 sky brightness 391 Schmidt±Cassegrain, see telescope, hybrid Sloan Digital Sky Survey (SDSS) 101, 129, 93 130, 267 Schottky diode 480 ®lter set 336 Schroeder, Dan 111 telescope 101 scintillation counter 455 slow-scanningCCD 264, 265 scintillation of starlight 48 smart focal plane 508 SCSI 355 Smith, Bradford (Brad) 243 SCUBA Smith, Dave 394 galaxies 491, 492 Smith, Gerald (Jerry) 104, 242 sub-millimeter instrument 491 Smoot, George 486 -2 493, 494, 495 Smyth, Charles Piazzi 41 SDSS, Sloan Digital Sky Survey 27 SN1987A 7 passbands and survey limit 336 SNAP 287 seeing Snell, Willebrord 84 see atmospheric turbulence 47 Snell's law, see refraction, law of 84 origin of 48 sodium layer 64 550 Index

SOFIA instruments 422, 423 STARLINK 360 soft X-rays 447 statistics, formulas and de®nitions 535 software 235 STDAS 360 solar blind 439 Steidel, Chuck 142 solar neutrino problem 7 stellar parallax 119 sorption pump 226 Stetson, Peter 340, 366 South African Large Telescope (SALT) 92, Steward Observatory Mirror Lab (SOML) 101, 105 109 space interferometer mission, SIM 511 stigmatism 91 space model 215 Stockman, Pete 154 Space Sciences Lab, Berkeley 442 Stokes parameter 10, 178 Space Telescope Imaging Spectrograph, stop 205 STIS 71, 444 Stover, Richard 317 space telescope 71 StrasbourgAstronomical Data Archive 27 spark chamber 455 Stratospheric Observatory for Infrared special relativity, Doppler formula 138 Astronomy, SOFIA 421 speci®c heat 220 Strehl ratio 47, 208, 431 speckle interferometry 53 Strehl, Karl 47 speckle 53 stressed lap polishing82 spectometer 135 structure function 49 spectra, types of 136 Strutskie, Mike 420 spectrograph sub-array 306 angle 169 Subaru telescope 90, 94 double 142 Sudbury Neutrino Observatory 7 spectrometer 167 summingwell 279 di€raction grating 168 superconductingquantum interference grism 176 device, SQUID 493, 494 prism 175 superconductingtunnel junction, STJ 512 resolution and dispersion 168 superconducting±insulator±superconducting tradeo€ equation 171 (SIS) mixer 195 spectroscope 2 spectroscopy superconductor 495 high resolution 138 supernova, Type Ia 127 medium resolution 142 SuprimeCam, prime focus camera on multi-object 144 Subaru 107 objective prism 144 surface channel CCD 251 slit-less 144 surface speed of light 8 roughness 208, 431 spherical aberration 31, 78, 90, 204 smoothness, accuracy 472, 473 spin-casting109 survey telescope 101 Spitzer Space Telescope, formerly SIRTF SWIFT 435, 437, 456, 459 71, 389, 423, 491 SWIFT's UV Optical Telescope (UVOT) Spitzer, Lyman 71, 423 461 spurious charge 263 SWIFT's X-Ray Telescope (XRT) 460 spurious potential pocket 295 square degrees in whole sky 121 Tektronix 246, 295 Stapelbroek, Dutch 395, 401 Teledyne Imaging Sensors, formerly star ground 280 Rockwell Scienti®c 400 Star®re Optical Range 64 Telesco, Charlie 419 Index 551 telescope transfer noise 297 afocal 88 transition edge sensor, TES 493, 494, 495 astronomical 87 transit, planetary 125 automated imaging 98 T-ReCS 419 basic optical properties 84 Tresch-Fienberg, Richard 394 corrector 93 Trumpler, Robert J. 387 dioptric, catoptric, catadioptric 84 truss 96 doublingtime for aperture size 79 tunable ®lter 182 emissivity 108 TV tubes, includingSEC, SIT, Plumbicon Galilean 88 17 history of 77 twenty-one centimeter line of hydrogen, hybrid 93 21 cm 469 invention of 77 twinkling, see scintillation of starlight 48 Keplerian 87 twisted pair 280 larger than 6.5 m, table of 83 Two Micron All Sky Survey, 2MASS magnifying power 88 130±132 mount Two-Degree Field, 2dF 146 alt-az 94, 95 two-micron sky survey (TMSS) 387 equatorial 94, 95 two-mirror telescope design 111 transit 94, 95 two-phase CCDs 260 re¯ecting78, 90, Tycho catalog120 refractive 87 Tyson, Tony 27, 287, 327 tempering215 Tytler, David 139 Teplitz, Harry 365 Texas Instruments 242, 244, 269 U.S. Naval Observatory 91, 96 thermal B1.0 catalog120 conduction 221 U.K. Infrared Telescope (UKIRT) 96, 97, conductivity 388, 417 integral 222 U.K. Schmidt telescope 123 table of 223 UKIDSS 417, 421 detector 195 Ultralow expansion glass (ULE) 107 thermoelectric cooler 218 Thirty Meter Telescope (TMT) 111, 503 ULTRASPEC 270 Thompson, Rodger 395, 423 uniformity of response 306 Thomson-CSF, now part of e2v units and conversions 523 technologies 247 unsharp mask 377 Three-Mirror Anastigmat, TMA 211 up-the-ramp sampling415 three-phase CCDs 252 Uranus, ®rst CCD image of 243 throughput, see area-solid angle product 87 USB 354 tilt-scanning184 UV (ultraviolet) Time Delay and Integration, TDI 131, 267, regions of the 437 327, 420, 511 detector system 439 timingwaveform 254 -sensitive CCDs 440 Tinney, Chris 140 u±v plane 484 Tiny Tim, HST modelingsoftware by John UV-A, B, and C 40 Krist 382 Titan 420 vacuum Tonry, John 271 chamber 224 total external re¯ection 432 pump 227 552 Index valence band 186 Wien, Wilhelm 25 Vallerga, John 439 Wien's Displacement Law 25 Vee-squared mode 69 Wilkinson, David Todd; WMAP named Vega, absolute ¯ux 347 for 488 VERITAS 462 William Herschel Telescope, WHT 82 Very Large Array, VLA 70, 484 Williams, Bob 132 Very Large Telescope (VLT) 105, 106 Wilson, Robert; co-discoverer of cosmic very large telescope, design of 102 microwave background 487 Very LongBaseline Interferometry, VLBI Wilson, Sir Robert (Bob); father of IUE 134, 483 437 vibration, natural 214 Wimmers, Jim 394 vidicon 17,18 WIYN telescope 272 VIRGO HgCdTe detector, Raytheon's 421 Wizinowich, Peter 65 virtual WMAP, Wilkinson Microwave Anisotropy image 87 Probe 154, 486, 488 observatory 28, 29, 513 Wollaston prism 178 phase CCD 260 visibility 32, 69 Wolter telescope 433 VISTA Wolter, Hans 433 camera 421 work function 15 telescope 102 Wright, Edward 424, 488 VLT Interferometer, VLTI 70 Wright, Gillian 396 Vogt, Steve 139, 140 Wright, Jonathan 246 voltage divider rule 230 Wynne, Charles G. 94 volume phase holographic (VPH) grating Wynn-Williams, Gareth 397 173 Vural, Kadri 395 XMM-Newton observatory 434, 442, 447, VxWorks 355 461 X-ray Walther, Dolores 396 absorption in silicon 449 Wampler scanner 18 collimator 435 warpingharness 102 Watson, Fred 146 Yagi±Uda antenna 472 wavefront error, WFE 31, 208 Young, Erick 403 wavefront sensor, types of 56 Young, Thomas 67 wedge and strip anode 443, 444 Young's modulus 214 Weir, Nick 378 West, Jim 394 Westerbork Synthesis radio telescope 484 ZEMAX 201, 209, 213 Westphal, James (Jim) 242, 244, 287, 308 zenith angle 42 WFCAM 417, 421 zeolite 226 Whipple Observatory 461 Zernike polynomial 57 Wide-®eld Infrared Survey Explorer, WISE table of 58 424 zeropoint 339 Wide-Field/Planetary Camera, WF/PC 71, zodiacal light 45 245, 307 Zone of Avoidance 131

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