Photometric system

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In astronomy, a photometric system is a set of well-defined passbands (or filters), with a known sensitivity to incident radiation. The sensitivity usually depends on the optical system, detectors and filters used. For each photometric system a set of primary standard stars is provided.

The first known standardized photometric system is the Johnson-Morgan or UBV photometric system (1953). At present, there are more than 200 photometric systems.

Photometric systems are usually characterized according to the widths of their passbands:

  • broadband (passbands wider than 30 nm, of which the most widely used is Johnson-Morgan UBV system)
  • intermediate band (passbands between 10 and 30 nm wide)
  • narrow band (passbands less than 10 nm wide)

Photometric letters[edit]

Each letter designates a particular section of the electromagnetic spectrum; most of these sections fall within the region spanning the near-ultraviolet (NUV), the visible and the majority of the near-infrared (NIR).

Indigo and cyan are not standard colors.[1] Orange, yellow, and green fall under visual bands, while violet and purple are under the blue bands. The letters are not standards, but are recognized by common agreement among astronomers and astrophysicists.

Filter Letter Effective Wavelength Midpoint λeff For Standard Filter[2] Full Width Half Maximum[2] (Bandwidth Δλ) Variant(s) Description
Ultraviolet
U 365 nm 66 nm u, u', u* "U" stands for ultraviolet.
Visible
B 445 nm 94 nm b "B" stands for blue.
V 551 nm 88 nm v, v' "V" stands for visual.
G g, g' "G" stands for green (visual).
R 658 nm 138 nm r, r', R', Rc, Re, Rj "R" stands for red.
Near-Infrared
I 806 nm 149 nm i, i', Ic, Ie, Ij "I" stands for infrared.
Z 900 nm[3] z, z'
Y 1020 nm 120 nm y
J 1220 nm 213 nm J', Js
H 1630 nm 307 nm
K 2190 nm 390 nm K Continuum, K', Ks, Klong, K8, nbK
L 3450 nm 472 nm L', nbL'
Mid-Infrared
M 4750 nm 460 nm M', nbM
N 10500 nm 2500 nm
Q 21000 nm[4] 5800 nm[4] Q'

Filters used[edit]

The filters currently being used by other telescopes or organizations.

Units of measurements:

Name Filters Link
2.2 m telescope at La Silla, ESO J = 1.24 μm H = 1.63 μm K = 2.19 μm L' = 3.78 μm M = 4.66 μm N1 = 8.36 μm N2 = 9.67 μm N3 = 12.89 μm 2.2 m telescope at La Silla, ESO[5]
2MASS/PAIRITEL J = 1.25 μm H = 1.65 μm Ks = 2.15 μm Two Micron All-Sky Survey, Peters Automated InfraRed Imaging TELescope
CFHTLS (Megacam) u* = 374 nm g' = 487 nm r' = 625 nm i' = 770 nm z' = 890 nm Canada-France-Hawaii Telescope
Chandra X-ray Observatory LETG = 0.08-0.2 keV HETG = 0.4-10 keV Chandra X-ray Observatory
CTIO J = 1.20 μm H = 1.60 μm K = 2.20 μm L = 3.50 μm Cerro Tololo Inter-American Observatory, a division of NOAO
Cousins RI photometry Rc = 647 nm Ic = 786.5 nm Cousins RI photometry, 1976[6]
DENIS I = 0.79 μm J = 1.24 μm K = 2.16 μm Deep Near Infrared Survey
Eggen RI photometry Re = 635 nm Ie = 790 nm Eggen RI photometry, 1965[7]
FIS N60 = 65.00 μm WIDE-S = 90.00 μm WIDE-L = 145.00 μm N160 = 160.00 μm Far-Infrared Surveyor on board, AKARI space telescope
GALEX NUV = 1800-2750Å FUV = 1400-1700Å GALaxy Evolution Explorer
GOODS (Hubble ACS) B = 435 nm V = 606 nm i = 775 nm z = 850 nm Advanced Camera for Surveys on the Hubble Space Telescope
HAWC Band 1 = 53 µm Band 2 = 88 µm Band 3 = 155 µm Band 4 = 215 µm High-resolution Airborne Wideband Camera for SOFIA[8]
HDF 450 nm 606 nm 814 nm Hubble Deep Field from the Hubble Space Telescope
IRTF NSFCAM J = 1.26 µm H = 1.62 µm K' = 2.12 µm Ks = 2.15 µm K = 2.21 µm L = 3.50 µm L' = 3.78 µm M' = 4.78 µm M = 4.85 µm NASA Infrared Telescope Facility NSFCAM[9]
ISAAC UTI/VLT[10] Js = 1.2 µm H = 1.6 µm Ks = 2.2 µm L = 3.78 µm Brα = 4.07 µm Infrared Spectrometer And Array Camera at Very Large Telescope
Johnson system (UBV) U = 364 nm B = 442 nm V = 540 nm UBV photometric system
OMC Johnson V-filter = 500-580 nm Optical Monitor Camera[11] on INTEGRAL
Pan-STARRS uses the Sloan's g,r,i,z filters plus y = 1005 nm Panoramic Survey Telescope And Rapid Response System
ProNaOS/SPM Band 1 = 180-240 µm Band 2 = 240-340 µm Band 3 = 340-540 µm Band 4 = 540-1200 µm PROgramme NAtional d'Observations Submillerètrique/Systéme Photométrique Multibande, balloon-borne experiment[12]
Sloan u' = 354 nm g' = 475 nm r' = 622 nm i' = 763 nm z' = 905 nm Sloan Digital Sky Survey
SPIRIT III Band B1 = 4.29 μm Band B2 = 4.35 μm Band A = 8.28 μm Band C = 12.13 μm Band D = 14.65 μm Band E = 21.34 μm Infrared camera on Midcourse Space Experiment[13]
Spitzer IRAC 3.6 μm 4.5 μm 5.8 μm 8.0 μm Infrared Array Camera on Spitzer Space Telescope
Spitzer MIPS 24 μm 70 μm 160 μm Multiband Imaging Photometer for Spitzer on Spitzer
Stromvil filters U = 345 nm P = 374 nm S = 405 nm Y = 466 nm Z = 516 nm V = 544 nm S = 656 nm Stromvil photometry
Strömgren filters u = 350 nm v = 411 nm b = 467 nm y = 547 nm β narrow = 485.8 nm β wide = 485 nm Strömgren photometric system
UKIDSS (WFCAM) Z = 882 nm Y = 1031 nm J = 1248 nm H = 1631 nm K = 2201 nm UKIRT Infrared Deep Sky Survey
Vilnius photometric system U = 345 nm P = 374 nm X = 405 nm Y = 466 nm Z = 516 nm V = 544 nm S = 656 nm Vilnius photometric system
VISTA IRC Z = 0.88 μm Y = 1.02 μm J = 1.25 μm H = 1.65 μm Ks = 2.20 μm NB1.18 = 1.18 μm Visible & Infrared Survey Telescope for Astronomy
WISE 3.4 μm 4.6 μm 12 μm 22 μm Wide-field Infrared Survey Explorer
XMM-Newton OM UVW2 = 212 nm UVM2 = 231 nm UVW1 = 291 nm U = 344 nm B = 450 nm V = 543 nm XMM-Newton Optical/UV Monitoring[14]
XEST Survey UVW2 = 212 nm UVM2 = 231 nm UVW1 = 291 nm U = 344 nm B = 450 nm V = 543 nm J = 1.25 μm H = 1.65 μm Ks = 2.15 μm Survey includes the point source of 2MASS with XMM-Newton OM[15]

See also[edit]

References[edit]

  1. ^ Spectral Colors
  2. ^ a b Binney, J.; Merrifield M. Galactic Astronomy, Princeton University Press, 1998, ch. 2.3.2, pp. 53
  3. ^ Gouda, N.; N. Gouda, T. Yano, Y. Kobayashi, Y. Yamada, T. Tsujimoto, T. Nakajima, M. Suganuma, H. Matsuhara, S. Ueda and the JASMINE Working Group (23 May 2005). "JASMINE: Japan Astrometry Satellite Mission for INfrared Exploration". Proceedings of the International Astronomical Union 2004 (IAUC196): 455–468. doi:10.1017/S1743921305001614. 
  4. ^ a b [1] Handbook of Geophysics and the Space Environment 1985, Air Force Geophysics Laboratory, 1985, ed. Adolph S. Jursa, Ch. 25, Table 25-1
  5. ^ A study of the Chamaeleon I dark cloud and T-association. II - High-resolution IRAS maps around HD 97048 and 97300, Assendorp, R.; Wesselius, P. R.; Prusti, T.; Whittet, D. C. B., 1990
  6. ^ ADPS
  7. ^ ADPS
  8. ^ HAWC
  9. ^ NSFCAM
  10. ^ "ISAAC Overview". Paranal Instrumentation. ESO. Retrieved 13 October 2011. 
  11. ^ About INTEGRAL
  12. ^ Calibration of the PRONAOS/SPM submillimeter photometer, F.Pajot et al. 2006
  13. ^ MSXPSC - Midcourse Space Experiment (MSX) Point Source Catalog, V2.3
  14. ^ XMM-Newton SAS: Watchout Page
  15. ^ The XMM-Newton Optical Monitor Survey of the Taurus Molecular Cloud, M.Audard et al. 2006

External links[edit]

  1. Johnson, H. L.; Morgan, W. W. (1953), Fundamental stellar photometry for standards of spectral type on the revised system of the Yerkes spectral atlas, The Astrophysical Journal, vol. 117, pp. 313–352 [2]
  2. The Asiago Database on Photometric Systems
  3. Michael S. Bessell (2005), STANDARD PHOTOMETRIC SYSTEMS, Annual Reviews of Astronomy and Astrophysics vol. 43, pp. 293–336
  4. Infrared portrait of the nearby massive star-forming region IRAS 09002-4732, Apai, D.; Linz, H.; Henning, Th.; Stecklum, B., 2005