2MASS :The Two Micron All Sky Survey. 2MASS/2MASS :Filters for the Two Micron All Sky Surveyid:2MASS/2MASS.a |
| 2MASS/2MASS.J | 12350.00 | 12350.00 | 12350.00 | 10690.53 | 14208.52 | 1520.26 | 1594.00 | 3.13e-10 | 2MASS | | 2MASS J | | 2MASS/2MASS.H | 16620.00 | 16620.00 | 16620.00 | 14465.17 | 18277.23 | 2410.18 | 1024.00 | 1.13e-10 | 2MASS | | 2MASS H | | 2MASS/2MASS.Ks | 21590.00 | 21590.00 | 21590.00 | 19402.19 | 23810.79 | 2506.19 | 666.80 | 4.28e-11 | 2MASS | | 2MASS Ks | | 2MASS/2MASS.Ks | Filter Description | Filter ID (?) : | 2MASS/2MASS.Ks |
| Description (?) : | 2MASS Ks |
| Phot.System (?) : | 2MASS |
| Detector Type (?) : | Photon counter |
| Band Name (?) : | Ks |
| Obs. Facility (?) : | 2MASS |
| Instrument (?) : | ------ |
| Comments (?) : | ------ |
| | Mathematical properties | Property | Calculated | Specified | Unit | | λref (?) : |
21638.61 | 21590 | (Angstrom) |
| λmean (?) : |
21691.42 | 21590 | (Angstrom) |
| λcen (?) : |
21645.85 | ------- | (Angstrom) |
| λeff (?) : |
21557.65 | 21590 | (Angstrom) |
| λpeak (?) : |
22630.00 | ------- | (Angstrom) |
| λpivot (?) : |
21638.61 | ------- | (Angstrom) |
| λphot (?) : |
21593.57 | ------- | (Angstrom) |
| λmin (?) : |
19402.19 | ------- | (Angstrom) |
| λmax (?) : |
23810.79 | ------- | (Angstrom) |
| Weff (?) : |
2506.19 | ------- | (Angstrom) |
| FWHM (?) : |
2771.26 | ------- | (Angstrom) |
| Af/AV (?) : |
0.125 | ------- | () |
| Fsun (?) : |
8.74 | ------- | (erg/cm2/s/A) |
| Transmission
Data file: ascii, VOTable Reference for filter response:
2MASS at IPAC documentation Transmission components: Filter + Instrument + Atmosphereid:2MASS/2MASS.Ks | | Calibration properties
Vega System | Property | Specified | Calculated | Unit | | Zero Point (?) : |
4.283e-11 |
4.17999e-11 | (erg/cm2/s/A) |
| |
666.8 |
652.85 | (Jy) |
| ZP Type (?) : |
Pogson |
| PhotCal ID (?) : |
2MASS/2MASS.Ks/Vega |
| |
AB System | Property | Specified | Calculated | Unit | | Zero Point (?) : |
------- |
2.32482e-10 | (erg/cm2/s/A) |
| |
------- |
3631.00 | (Jy) |
| ZP Type (?) : |
Pogson |
| PhotCal ID (?) : |
2MASS/2MASS.Ks/AB |
| |
ST System | Property | Specified | Calculated | Unit | | Zero Point (?) : |
------- |
3.631e-9 | (erg/cm2/s/A) |
| |
------- |
56710.58 | (Jy) |
| ZP Type (?) : |
Pogson |
| PhotCal ID (?) : |
2MASS/2MASS.Ks/ST |
| |
Reference for calibration:
Cohen 2003 |
Filter added: 2010-04-17 05:58:55
Last update: 2025-09-04 11:11:27 |
| Filter Plots
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 ≡ filter transmission<p><u>Property info:</u><ul><li><b>Unit</b>:Angstrom<li><b>UCD</b>:em.wl</ul></td></table>',WIDTH,400)){kind=link}
 ≡ filter transmission<br> Vg(λ) ≡ Vega spectrum.<p><u>More info:</u><p>Vega spectrum from calspec database.<ul><li><a href="https://ui.adsabs.harvard.edu/abs/2014PASP..126..711B/abstract" target="_blank">Bohlin, Gordon, & Tremblay (2014)</a>.<li><a href="https://www.stsci.edu/hst/instrumentation/reference-data-for-calibration-and-tools/astronomical-catalogs/calspec" target="_blank">STScI current calspec</a>.<li><a href="morefiles/vega.dat" target="_blank">Vega spectrum file</a> (units: Angstrom erg/cm2/s/A).</ul><p><u>Property info:</u><ul><li><b>Unit</b>:Angstrom<li><b>UCD</b>:em.wl.effective</ul></td></table>',WIDTH,400)){kind=link}
 ≡ filter transmission<p>Equivalent to the horizontal size of a rectangle with height equal to maximum transmission and with the same area that the one covered by the filter transmission curve.<p><u>Property info:</u><ul><li><b>Unit</b>:Angstrom<li><b>UCD</b>:instr.bandwidth<li><b>Utype</b>: <i>photdm:PhotometryFilter.bandwidth.extent.value</i></ul></td></table>',WIDTH,400)){kind=link}
 ≡ filter transmission (energy counter).<br> Vg(λ) ≡ Vega spectrum.<p><i>(T(λ) must be multiplied by λ for photon counting devices)</i><p>F<sub>0,ν</sub>(Jy) = (2.9979246)<sup>-1</sup> 10<sup>5</sup> * λ<sub>ref</sub><sup>2</sup> * F<sub>0,λ</sub>(erg/cm<sup>2</sup>/s/A)<p>In the case that filter owner specifies its own values, they will be the ones provided by the service when queried through the VO.<p><u>Property info:</u><ul><li><b>Unit</b>:Jy<li><b>UCD</b>:phot.flux.density<li><b>Utype</b>: <i>photdm:PhotCal.zeroPoint.flux.value</i></ul></td></table>',WIDTH,400)){kind=link}
 ≡ filter transmission (energy counter).<br> Vg(λ) ≡ Vega spectrum.<p><i>(T(λ) must be multiplied by λ for photon counting devices)</i><p><u>Property info:</u><ul><li><b>Unit</b>:erg/cm2/s/A<li><b>Utype</b>: <i>PhotCal.ZeroPoint</i></ul></td></table>',WIDTH,400)){kind=link}
 ≡ filter transmission<p>f(λ) ≡ flux of the spectrum<p><u>Property info:</u><ul><li><b>UCD</b>:meta.code<li><b>Utype</b>: <i>photdm:PhotometricSystem.detectorType</i></ul></td></table>',WIDTH,400)){kind=link}
 ≡ filter transmission<p><img src=showgraph.php?what=lmean&val=21691.421193139&id=2MASS/2MASS.Ks><p>Filter transmission is transformed to "<i>energy counter</i>" for these calculations, that is, the photon count transmission is multiplied by λ and normalized so that peak transmission is equal to 1.<p><u>Property info:</u><ul><li><b>Unit</b>:Angstrom<li><b>UCD</b>:em.wl</ul></td></table>',STICKY,true,CLOSEBTN,true,WIDTH,400)){kind=link}
 ≡ filter transmission<br> Vg(λ) ≡ Vega spectrum.<p><img src=showgraph.php?what=leff&val=21557.652498909&id=2MASS/2MASS.Ks><p>Filter transmission is transformed to "<i>energy counter</i>" for these calculations, that is, the photon count transmission is multiplied by λ and normalized so that peak transmission is equal to 1.<p><u>More info:</u><p>Vega spectrum from calspec database.<ul><li><a href="https://ui.adsabs.harvard.edu/abs/2014PASP..126..711B/abstract" target="_blank">Bohlin, Gordon, & Tremblay (2014)</a>.<li><a href="https://www.stsci.edu/hst/instrumentation/reference-data-for-calibration-and-tools/astronomical-catalogs/calspec" target="_blank">STScI current calspec</a>.<li><a href="morefiles/vega.dat" target="_blank">Vega spectrum file</a> (units: Angstrom erg/cm2/s/A).</ul><p><u>Property info:</u><ul><li><b>Unit</b>:Angstrom<li><b>UCD</b>:em.wl.effective</ul></td></table>',STICKY,true,CLOSEBTN,true,WIDTH,400)){kind=link}
 ≡ filter transmission<p><img src=showgraph.php?what=lpiv&val=21638.60586223&id=2MASS/2MASS.Ks><p>Filter transmission is transformed to "<i>energy counter</i>" for these calculations, that is, the photon count transmission is multiplied by λ and normalized so that peak transmission is equal to 1.<p><u>Property info:</u><ul><li><b>Unit</b>:Angstrom<li><b>UCD</b>:em.wl</ul></td></table>',STICKY,true,CLOSEBTN,true,WIDTH,400)){kind=link}
 ≡ filter transmission<br> Vg(λ) ≡ Vega spectrum<p><img src=showgraph.php?what=lphot&val=21593.567140056&id=2MASS/2MASS.Ks><p>Filter transmission is transformed to "<i>energy counter</i>" for these calculations, that is, the photon count transmission is multiplied by λ and normalized so that peak transmission is equal to 1.<p><u>More info:</u><p>Vega spectrum from calspec database.<ul><li><a href="https://ui.adsabs.harvard.edu/abs/2014PASP..126..711B/abstract" target="_blank">Bohlin, Gordon, & Tremblay (2014)</a>.<li><a href="https://www.stsci.edu/hst/instrumentation/reference-data-for-calibration-and-tools/astronomical-catalogs/calspec" target="_blank">STScI current calspec</a>.<li><a href="morefiles/vega.dat" target="_blank">Vega spectrum file</a> (units: Angstrom erg/cm2/s/A).</ul><p><u>Property info:</u><ul><li><b>Unit</b>:Angstrom<li><b>UCD</b>:em.wl</ul></td></table>',STICKY,true,CLOSEBTN,true,WIDTH,400)){kind=link}
 ≡ filter transmission<p>Equivalent to the horizontal size of a rectangle with height equal to maximum transmission and with the same area that the one covered by the filter transmission curve.<p><img src=showgraph.php?what=weff&val=2506.1888373448,21645.850699541,1&id=2MASS/2MASS.Ks><p>Filter transmission is transformed to "<i>energy counter</i>" for these calculations, that is, the photon count transmission is multiplied by λ and normalized so that peak transmission is equal to 1.<p><u>Property info:</u><ul><li><b>Unit</b>:Angstrom<li><b>UCD</b>:instr.bandwidth<li><b>Utype</b>: <i>photdm:PhotometryFilter.bandwidth.extent.value</i></ul></td></table>',STICKY,true,CLOSEBTN,true,WIDTH,400)){kind=link}
![(?)](javascript:Tip('<b>A<sub>f</sub>/A<sub>V</sub></b><br><table cellpadding=20><td class=helptd>Ratio between extintion at λ<sub>ref</sub> and visual extintion. <p>Calculated by the service using the extinction law by <a href="http://adsabs.harvard.edu/abs/1999PASP..111...63F" target="_blank">Fitzpatrick (1999)</a> improved by <a href="http://adsabs.harvard.edu/abs/2005ApJ...619..931I" target="_blank">Indebetouw et al (2005)</a> in the infrared. <p><img src="images/extlaw.png"><p>You can download the corresponding <a href=\"getextlaw.php\" target=\"_blank\">data file</a> for the opacity k<sub>λ</sub>. The extinction at each wavelength is calculated as: A<sub>λ</sub> = A<sub>V</sub> * k<sub>λ</sub>/k<sub>V</sub>, where k<sub>λ</sub> is the opacity for a given λ and k<sub>V</sub>=211.4<p><p><u>Property info:</u><ul></ul></td></table>',STICKY,true,CLOSEBTN,true,WIDTH,400)){kind=link}
 ≡ filter transmission.<br> Sun(λ) ≡ Sun spectrum.<p><img src="images/sun.png"><p><p>Filter transmission is transformed to "<i>energy counter</i>" for these calculations, that is, the photon count transmission is multiplied by λ and normalized so that peak transmission is equal to 1.<p><u>More info:</u><p>Sun spectrum from calspec database: sun_reference_stis_002 composed with sun_mod_001 for larger wavelengths.<ul><li><a href="https://ui.adsabs.harvard.edu/abs/2014PASP..126..711B/abstract" target="_blank">Bohlin, Gordon, & Tremblay (2014)</a>.<li><a href="https://www.stsci.edu/hst/instrumentation/reference-data-for-calibration-and-tools/astronomical-catalogs/calspec" target="_blank">STScI current calspec</a>.<li><a href="morefiles/sun.dat" target="_blank">Sun composed spectrum</a> (units: Angstrom erg/cm2/s/A).</ul><p><u>Property info:</u><ul><li><b>Unit</b>:erg/cm2/s/A<li><b>UCD</b>:phot.flux.density</ul></td></table>',STICKY,true,CLOSEBTN,true,WIDTH,400)){kind=link}
 ≡ filter transmission.<br> Vg(λ) ≡ Vega spectrum.<p>F<sub>0,ν</sub>(Jy) = (2.9979246)<sup>-1</sup> 10<sup>5</sup> * λ<sub>ref</sub><sup>2</sup> * F<sub>0,λ</sub>(erg/cm<sup>2</sup>/s/A)<p>Filter transmission is transformed to \"<i>energy counter</i>\" for these calculations, that is, the photon count transmission is multiplied by λ and normalized so that peak transmission is equal to 1.<p>In the case that filter owner specifies its own values, they will be the ones provided by the service when queried through the VO.<p><u>VO PhotDM Utypes</u>: <br><i>PhotCal.MagnitudeSystem.type</i> -> VEGAmag <br><i>PhotCal.ZeroPoint.Flux.value</i> -> F<sub>0</sub><p><u>More info:</u><p>Vega spectrum from calspec database.<ul><li><a href="https://ui.adsabs.harvard.edu/abs/2014PASP..126..711B/abstract" target="_blank">Bohlin, Gordon, & Tremblay (2014)</a>.<li><a href="https://www.stsci.edu/hst/instrumentation/reference-data-for-calibration-and-tools/astronomical-catalogs/calspec" target="_blank">STScI current calspec</a>.<li><a href="morefiles/vega.dat" target="_blank">Vega spectrum file</a> (units: Angstrom erg/cm2/s/A).</ul><p><u>Property info:</u><ul><li><b>UCD</b>:phot.flux.density<li><b>Utype</b>: <i>photdm:PhotCal.ZeroPoint.Flux.value</i></ul></td></table>',STICKY,true,CLOSEBTN,true,WIDTH,400)){kind=link}
