POlarization Emission of Millimeter Activity at the Sun: Difference between revisions
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The '''POlarization Emission of Millimeter Activity at the Sun (POEMAS)''' is a solar patrol system composed of two radio telescopes with [[superheterodyne receiver|superheterodyne]] [[polarization (waves)|circular polarization]] receivers at 45 and 90 GHz. Since their [[half power beam width]] is around 1.4°, they observe the full sun. The acquisition system allows to gather 100 values per second at both frequencies and polarizations, with a sensitivity of around 20 [[solar flux units|solar flux units (SFU)]] (1 SFU ≡ 10<sup>4</sup> [[Jansky|Jy]]). The telescope saw [[First light (astronomy)|first light]] in November 2011, and showed excellent performance during two years, when it observed many [[solar flare|flares]].<ref>[http://link.springer.com/article/10.1007%2Fs11207-013-0237-4 Válio, A., Kaufmann, P., Giménez de Castro, C.G., Raulin, J.-P., Fernández, L.O.T., Marún, A., ''POlarization Emission of Millimeter Activity at the Sun (POEMAS): New Circular Polarization Solar Telescopes at Two Millimeter Wavelength Ranges, Solar Phys., 283(2), 651, DOI:10.1007/s11207-013-0237-4]</ref> Since November 2013 is stopped for repairing. The main interest of POEMAS is the observation of [[solar flare]]s in a frequency range where there are very few detectors and fill the gap between [[microwave]]s observed with the [[Radio Solar Telescope Network]] (1 to 15.4 GHz) and submillimeter observations of the [[Solar Submillimeter Telescope]] (212 and 405 GHz). Moreover, POEMAS is the only current telescope capable of carrying on circular polarization [[solar flare]] observations at 90 GHz. (Although, in principle, [[Atacama Large Millimeter Array|ALMA]] band 3 may also observe at 90 GHz with circular polarization<ref>[http://www.almaobservatory.org/en/about-alma/how-does-alma-work/technology/front-end ALMA Front End]</ref>). |
The '''POlarization Emission of Millimeter Activity at the Sun (POEMAS)''' is a solar patrol system composed of two radio telescopes with [[superheterodyne receiver|superheterodyne]] [[polarization (waves)|circular polarization]] receivers at 45 and 90 GHz. Since their [[half power beam width]] is around 1.4°, they observe the full sun. The acquisition system allows to gather 100 values per second at both frequencies and polarizations, with a sensitivity of around 20 [[solar flux units|solar flux units (SFU)]] (1 SFU ≡ 10<sup>4</sup> [[Jansky|Jy]]). The telescope saw [[First light (astronomy)|first light]] in November 2011, and showed excellent performance during two years, when it observed many [[solar flare|flares]].<ref>[http://link.springer.com/article/10.1007%2Fs11207-013-0237-4 Válio, A., Kaufmann, P., Giménez de Castro, C.G., Raulin, J.-P., Fernández, L.O.T., Marún, A., ''POlarization Emission of Millimeter Activity at the Sun (POEMAS): New Circular Polarization Solar Telescopes at Two Millimeter Wavelength Ranges, Solar Phys., 283(2), 651, DOI:10.1007/s11207-013-0237-4]</ref> Since November 2013 is stopped for repairing. The main interest of POEMAS is the observation of [[solar flare]]s in a frequency range where there are very few detectors and fill the gap between [[microwave]]s observed with the [[Radio Solar Telescope Network]] (1 to 15.4 GHz) and submillimeter observations of the [[Solar Submillimeter Telescope]] (212 and 405 GHz). Moreover, POEMAS is the only current telescope capable of carrying on circular polarization [[solar flare]] observations at 90 GHz. (Although, in principle, [[Atacama Large Millimeter Array|ALMA]] band 3 may also observe at 90 GHz with circular polarization<ref>[http://www.almaobservatory.org/en/about-alma/how-does-alma-work/technology/front-end ALMA Front End]</ref>). |
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==Science== |
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POEMAS was designed to ''fill the gap'' between microwaves and submillimeter (less than 1 mm) wavelengths observations of the solar activity. There are a number of different instruments around the world that monitors the sun at microwaves. The [[Nobeyama Radio Heliograph|Nobeyama Radio heliograph (NoRH)]]<ref>[http://adsabs.harvard.edu/abs/1994IEEEP..82..705N Nakajima, H., et al., Proc. IEEE, 82(5),705, 1994</ref><ref>Takano, T., et al., ''An Upgrade of Nobeyama Radioheliograph to a Dual-Frequency (17 and 34 GHz) System'', in ''Coronal Physics from Radio and Space Observations''; Proceedings of the CESRA Workshop held in Nouan le Fuzelier, France 3-7 June 1996, edited by Gerard Trottet, Published by Springer, p.183,(1997)</ref> ([[Nobeyama]], [[Japan]]) makes daily maps at 17 GHz (1.7 cm) with circular left and right polarizations and 34 GHz (8.8 mm), total intensity. The Nobeyama Radio Polarimeters (NoRP)<ref>[http://solar.nro.nao.ac.jp/norp/ Official Site], ([[Nobeyama]],[[Japan]]) is a set of patrol telescopes with receivers from 1 GHz (λ≈30 cm) to 80 GHz ((λ≈3.7 mm) at selected frequencies and circular polarization detection (except at 80 GHz) with full sun disk spatial resolution. The [[Radio Solar Telescope Network|Radio Solar Telescope Network (RSTN)]] is world wide network of telescopes with receivers at selected bands from few hundred MHz (λ≈75 cm) to 15.4 GHz (λ≈2 cm). At the other end of the band, the [[Solar Submillimeter Telescope| Solar Submillimeter Telescope (SST)]] installed at [[Complejo Astronomico El Leoncito]] in [[San Juan Province, Argentina]] observes the sun at 212 GHz (λ≈1.4 mm) and 405 GHz (λ≈0.7 mm). Since there is no observational time overlap between Japan and Argentina, the NoRH and NoRP cannot be used together with SST. Only data from RSTN can be used to analyze flares from 1 to 405 GHz. |
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==References== |
==References== |
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{{Reflist}} |
{{Reflist}} |
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==External Links== |
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* [http://solar.nro.nao.ac.jp/norh Nobeyama Radio Heliograph Official Site] |
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* [http://solar.nro.nao.ac.jp/norp Nobeyama Radio Polarimeters Offcial Site] |
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[[Category:Astronomical instruments]] |
[[Category:Astronomical instruments]] |
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Revision as of 11:50, 21 August 2014
 | This article needs additional citations for verification. (August 2014) |
 POEMAS system installed at CASLEO | |
| Alternative names | POEMAS |
|---|---|
| Part of | Leoncito Astronomical Complex  |
| Location(s) | San Juan Province, Argentina |
| Coordinates | 31°47′56.3″S 69°17′48.1″W / 31.798972°S 69.296694°W |
| Organization | Brazil, Argentina |
| Altitude | 2,491 m |
| Wavelength | 45, 90 GHz (6.7, 3.3 mm) |
| First light | November 2011 |
| Telescope style | 2 Patrol Telescopes with circular polarization detectors |
  Location of POlarization Emission of Millimeter Activity at the Sun (POEMAS) | |
 Related media on Commons | |
The POlarization Emission of Millimeter Activity at the Sun (POEMAS) is a solar patrol system composed of two radio telescopes with superheterodyne circular polarization receivers at 45 and 90 GHz. Since their half power beam width is around 1.4°, they observe the full sun. The acquisition system allows to gather 100 values per second at both frequencies and polarizations, with a sensitivity of around 20 solar flux units (SFU) (1 SFU ≡ 104 Jy). The telescope saw first light in November 2011, and showed excellent performance during two years, when it observed many flares.[1] Since November 2013 is stopped for repairing. The main interest of POEMAS is the observation of solar flares in a frequency range where there are very few detectors and fill the gap between microwaves observed with the Radio Solar Telescope Network (1 to 15.4 GHz) and submillimeter observations of the Solar Submillimeter Telescope (212 and 405 GHz). Moreover, POEMAS is the only current telescope capable of carrying on circular polarization solar flare observations at 90 GHz. (Although, in principle, ALMA band 3 may also observe at 90 GHz with circular polarization[2]).
Science
POEMAS was designed to fill the gap between microwaves and submillimeter (less than 1 mm) wavelengths observations of the solar activity. There are a number of different instruments around the world that monitors the sun at microwaves. The Nobeyama Radio heliograph (NoRH)[3][4] (Nobeyama, Japan) makes daily maps at 17 GHz (1.7 cm) with circular left and right polarizations and 34 GHz (8.8 mm), total intensity. The Nobeyama Radio Polarimeters (NoRP)<ref>Official Site, (Nobeyama,Japan) is a set of patrol telescopes with receivers from 1 GHz (λ≈30 cm) to 80 GHz ((λ≈3.7 mm) at selected frequencies and circular polarization detection (except at 80 GHz) with full sun disk spatial resolution. The Radio Solar Telescope Network (RSTN) is world wide network of telescopes with receivers at selected bands from few hundred MHz (λ≈75 cm) to 15.4 GHz (λ≈2 cm). At the other end of the band, the Solar Submillimeter Telescope (SST) installed at Complejo Astronomico El Leoncito in San Juan Province, Argentina observes the sun at 212 GHz (λ≈1.4 mm) and 405 GHz (λ≈0.7 mm). Since there is no observational time overlap between Japan and Argentina, the NoRH and NoRP cannot be used together with SST. Only data from RSTN can be used to analyze flares from 1 to 405 GHz.
References
- ^ Válio, A., Kaufmann, P., Giménez de Castro, C.G., Raulin, J.-P., Fernández, L.O.T., Marún, A., POlarization Emission of Millimeter Activity at the Sun (POEMAS): New Circular Polarization Solar Telescopes at Two Millimeter Wavelength Ranges, Solar Phys., 283(2), 651, DOI:10.1007/s11207-013-0237-4
- ^ ALMA Front End
- ^ [http://adsabs.harvard.edu/abs/1994IEEEP..82..705N Nakajima, H., et al., Proc. IEEE, 82(5),705, 1994
- ^ Takano, T., et al., An Upgrade of Nobeyama Radioheliograph to a Dual-Frequency (17 and 34 GHz) System, in Coronal Physics from Radio and Space Observations; Proceedings of the CESRA Workshop held in Nouan le Fuzelier, France 3-7 June 1996, edited by Gerard Trottet, Published by Springer, p.183,(1997)