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Antonia M. Varela, Casiana Muñoz-Tuñón Instituto de Astrofísica de Canarias 1-2 july 2002

IMAGE QUALITY, METEOROLOGY AND ISOPLANATISM AT THE ORM. Antonia M. Varela, Casiana Muñoz-Tuñón Instituto de Astrofísica de Canarias 1-2 july 2002 www.iac.es/project/sitesting/site.html Astronomical Quality of the Canarian Observatories, 2001, CMT Ed.

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Antonia M. Varela, Casiana Muñoz-Tuñón Instituto de Astrofísica de Canarias 1-2 july 2002

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  1. IMAGE QUALITY, METEOROLOGY AND ISOPLANATISM AT THE ORM Antonia M. Varela, Casiana Muñoz-Tuñón Instituto de Astrofísica de Canarias 1-2 july 2002 www.iac.es/project/sitesting/site.html Astronomical Quality of the Canarian Observatories, 2001, CMT Ed. Astronomical Site Evaluation in the Visible and Radio Range, 2002, Vernin, Zouhair, CMT Eds. Sky Quality Group-IAC

  2. http://www.iac.es/eno/folleto.htm EUROPEAN NORTHERN OBSERVATORIES (ENO) • Historical perspective • Sky background • Meteorological Parameters • Image Quality and atmospheric turbulence • IR and UV sky quality; water vapour content • Atmospheric Transmision • High technology Programmes... Sky Quality Group-IAC

  3. /www.iac.es/project/sitesting/site.html Varela and Muñoz-Tuñón Sky Quality Group-IAC

  4. Who we are? Casiana Muñoz-Tuñón (IAC) PI Albar García de Gurtubai (IAC) Observer Antonia M. Varela (IAC) Researcher Collaborators: Jean Vernin (Département d’Astrophysique de Niza) Jesús Jiménez Fuensalida, Sergio Chueca and Claudia Hoegeman(IAC) Chris Benn (Isaac Newton Group, La Palma) Sky Quality Group-IAC

  5. Why Canary Islands? Geographical factors: • Lat. 28ºN, Long.16-17ºW • Visibility of North Hemisphere and part of Southern • Far from tropical storms Climatological conditions: • Trade winds+cold current • Troposphere above the cloud level Altitude: • 2400 m, above the inversion layer • Dry wind regimes (trade winds) • Transparent atmosphere. • Clouds level covering light contamination www.iac.es/sitesting/isalas.html Sky Quality Group-IAC

  6. EUROPEAN NORTHERN OBSERVATORY (ENO) The ORM on La Palma and the OT on Tenerife, combine world class facilities for night and solar time studies. There are telescopes and astronomical instruments from 60 institutions (19 countries) that together with the scientific and technical facilities of the IAC (Tenerife), constitute the ENO, shortly to be boosted by the coming into service in 2004 of the 10.4m optical-infrared GTC and with the facilities of the Joint Astrophysics Centre (La Palma). Observing time is offered to the European astronomical community under the auspices of the European Comission of the European Union. Sky Quality Group-IAC

  7. Useful Observing Time • 73% (from 10 years-4.2 m W.H.T.) • 79% (from CAMC, 1984:1994, Sarazin, 1985) • 78% (from Murdin, 1985) Muñoz-Tuñón, Vernin & Varela A&A Suppl. Ser. 125, 183 (1997) Also important, classify them, photometric or spectroscopic Long data-base (Carlsberg, GONG) Sky Quality Group-IAC

  8. NUMBER OF PHOTOMETRIC NIGHTS (from CAMC) http://ww.iac.es/proyect/sitesting/site.html 76% 60% 47% 39.5% Ardeberg & Murdin, 1983: 59% Sky Quality Group-IAC

  9. www.iac.es/project/sitesting/fondo_brillo.html Sky background Sky spectrum www.iac.es/project/sitesting/fondo_brillo.html SKY QUALITY PROTECTION LAW Spain, national law Hawaii, council law .... IAU Commission http://www.iac.es/proyect/otpc/ Sky Quality Group-IAC

  10. M.A. Guerrero et al., 1998, New Astron. Reviews, 42, 529-532 In summer over 75% of the nights are free of dust, while at other times of the year over 90% are dust free. Extinction in V is less than 0.2mag on observing nights over approximately 88% of the nights, and k>0.5 mag only occurs less than 1% of the nights. The modal value is 0.11 mag/airmass in both cases.The vertical line indicates the extinction coefficient limit for dusty nights (0.153 mag/airmass) Sky Quality Group-IAC

  11. Long term (routine) measurements DIMMS GSMs SCIDAR microthermal probes (equipped masts) mass (??) Intensive campaigns Balloon launchings All possible resources wavefront sensors SCIDAR+DIMMs+masts seeing prediction models. Image quality and Atmospheric turbulence Sky Quality Group-IAC

  12. Differential Image Motion Monitor (accurate, absolute and reproducible data) Sarazin & Roddier, 1990, A&A, 227, 294. (ESO DIMM) Vernin & Muñoz-Tuñón, 1995, PASP, 107, 265 (DA/IAC DIMM) Used by, GTC, TNG, O. Sierra Nevada, Calar Alto, ING, INAOE (la Negra, Cananea), UNAM(Spedro M)... Next, Morocco, France & Spain DIMM Tower designed by the Galileo team Sky Quality Group-IAC

  13. Automatic Weather Stations (AWS) Mahoney, Muñoz-Tuñón & Varela, New Astronomy Reviews, 1998 Sky Quality Group-IAC

  14. Site assesments campaigns at the Canarian ObservatoriesObservatorio del Teide (OT) Tenerife Island OT Nowcasting seeing and meteorology at the OT. Varela, Muñoz-Tuñón, Gurtubai. Astronomical Society of the Pacific Vol 266 (2002). Vernin, Zouhair, Muñoz-Tuñón Eds. Sky Quality Group-IAC

  15. OT TELESCOPIC FACILITIES Themis VTT CST IAC 80 Solar Laboratory Tenerife Experiment OGS Sky Quality Group-IAC

  16. Site Assessments campaigns at ORM NOT, WHT, TNG and GTC. Future at “Degollada del hoyo verde” Sky Quality Group-IAC

  17. Gran Telescopio de Canarias 10.4m (GTC) www.gtc.iac.es Sky Quality Group-IAC

  18. Degollada del Hoyo Verde-ORM (La Palma) Sky Quality Group-IAC

  19. Advanced Technology Solar Telescope, ATST (NSO) • ATST is a 4m aperture solar telescope • Next major astronomy NSF project after ALMA • Leaded by National Solar Observatory. Aimed for 2010 • Site candidates are • Big Bear , California. • Haleakala, Hawaii • ORM, La Palma, Canary Islands, Spain • Panguitch Lake, Utah • Sacramento Peak, New Mexico • Site Testing instruments are: • Seeing monitor (S-DIMM, scintillometer array, Cloud cover) • Sky Brightness Monitor (Mini-coronagraph, Water vapor meter, Dust monitor) Sky Quality Group-IAC

  20. Sobotka et al., ApJL, 447, L133 (1995). Shand y Sharmer, Astron.Rev., 42, 481 (1998). 25% de una imagen de 2000x2000 pixels de la superficie del Sol en la banda G (430 nm) tomada en el SVST (La Palma). La marca representa 1 arcsec (equivalente a 725 km en la superficie del Sol). 611x559 pixels de 0.062 arcsec. Sky Quality Group-IAC

  21. Long term statistics at ORM. From april to december 1997. 50%, seeing is better than 0.58”. Ehgamberdiev, S.A. et al., A&A Suppl. Ser.145, 293 .../project/sitesting/tabla_seeing.html Sky Quality Group-IAC

  22. ORM-GTC Site Sky Quality Group-IAC

  23. Seasonal Seeing DependenceMuñoz-Tuñón, Vernin & Varela, 1997, A&AS, 125, 183. Data gathered at the TNG site Annual variation of the scale height and frequency of the sea clouds in Tenerife. (Font-Tullot, 1956) Sky Quality Group-IAC

  24. NE and < V > ~ 2-6m/s ± 2-3m/s Different wind-vector patterns are associated to local orographical effects (N-NE) Nighttime GTC: Mahoney. Muñoz-Tuñón, Varela (1998) CAMC (1996-1999)and NOT: Varela, Muñoz-Tuñón, Gurtubai (2002), in preparation Consistent with Brandt & Wöhl (1982), Brandt & Righini (1985) and Jabiri et al., 2001. Sky Quality Group-IAC

  25. Wind conditions are important for new telescopes design... Nocturnal and daytime WRs (ORM) Muñoz-Tuñón, Varela, Mahoney New Astron. Revs., 42, 417. Data from the ORM-GTC Campaign (1995/1996). Ndata=367766 points.(day and night) (1data/minute) Wind gusts are the maximun wind velocity recorded for every 10s time interval. If 40 km/h would be the practical limit of operation...the useful time is 95%. CMT, 2002, ASP, conf, Ser.,vol266. Sky Quality Group-IAC

  26. Statistical Meteorological Results IIORM (NOT Site) Sky Quality Group-IAC

  27. SEISMICITY The ORM is located in a degree 7 zone (seismic resistence regulation NCSE 94), which corresponds to a horizontal acceleration of 0.08 g. Contrary of what happens on other volcanic islands, e.g. Hawaii, earth-quakes are very rare in Canaries. The Canarian Archipelago is relatively old, 3 to 4 million years, and therefore seismicity is not a problem to be taken into account (Anguita & Hernán, J. of Vulcanology and geothermal res, 103, 1, 2000). From the long-term record gathered by the National Seismology Network registered earth-quakes are sparse and of very low intensity as compared, for example, with those recorded in northern Chile. (Muñoz-Tuñón C., ASP Conf. Ser., 2002) The Departemento de Geología de la Univ. La Laguna (Tenerife) and the Station of Vulcanology of Canary Islands plan a micro-seismicity campaign in july 2002 at the OWL candidate site (ORM). Sky Quality Group-IAC

  28. Research we are now: Measuring the Isoplanatism o from the atmospheric scintillation Current techniques for CN2 are not suitable for continous monitoring. SCIDAR: statistical analysis of atmospheric scintillation by double stars: larger than 1m telescopes and severe constraints on the detector sensitivity (Tokovinin, 2002). Although the vertical resolution of single-stars profilers is worse compared with SCIDAR, the availability of bright single stars and the small size of required apertures make this approach very attractive.  is readily estimated from the SCINTILLATION index of single stars through a small aperture (< 10cm). ADVANTAGE: 10 YEARS OF MONITORING SEEING AND SCINTILLATION AT THE ORM. Sky Quality Group-IAC

  29. From o -5/3= 114.7 l-2 cos-8/3(z) dh CN2(h) h 5/3 (2) Loos & Hogge,1979 Fried, 1982 J. Krause-Polstorff, 1993 Ziad et al,, 2000 Sarazin and Tokovinin, 2001 s I2= = s = 9.62 l -2 dh CN2(h) P(h)(3) o -5/3=A s-3/5(sec z)-8/5 where A is a function of CN2(h) and P(h,D,) or weighting function. Methodology has been proved by using CN2(h) (Vernin, Muñoz-Tuñón, Avila, 1995) and scintillation measured at the same period of time. Concentric circular-annular apertures (Tokovinin, 2002): P(h,D,)= 1/(1- 2)2  0  df f-8/3 sin2 (hf2) [2J1(Df)/ Df - 2(2J1( Df)/  Df )]2 Being P(h, D<10cm)  h 5/6 P(h, D>10cm)  h 2 P(h, D=10cm,  = 0.4)  h 5/3 (Ziad et al., 2000) Sky Quality Group-IAC IAC, 14 June ´02, A.M. Varela

  30. BIAS EXPOSURE TIME CONSTRAINT: Last equation assumes infinitely small exposure time, but time is finite, introducing non negligible bias in the isoplanatic angle calculation. Ziad et al., 2000 Sarazin and Tokovinin, 2001 Tokovinin, 2002 (1) R= s()/s(0) (2) Integration of stellar light during  is equivalent to spatial smoothing of the scintillation pattern over a distance V , assuming a single turbulent layer with constant V s() from P(h, , V) With  = 5ms, V > 35 m/s at 10 km: R > .5 Sarazin and Tokovinin (2001) found that RV(h) /R0.5V200mb~ .995, and R (5ms) > .7 (PARSCA campaign. Paranal). Sky Quality Group-IAC IAC, 14 June ´02 A.M. Varela

  31. A=.290as R< 0.4 for V= 17.5m/s R= 0.59 for V= 10m/s R= 0.85 for V= 5m/s  = 0.2 D=10cm Mean and median 0  3.4as 0 > 3.0as for 60% 0 < 2.0as for 18% Isoplanatic angle(´´)/R Sky Quality Group-IAC

  32. ... current research works: R calibration by using most realistic parameters  = 0 D = 6cm V profiles from (SCIDAR, ballons) Seeing vs Isoplanatism short-term fluctuations stability statistical behaviour Seasonal dependence (tropopause center variations, jet stream) Sky Quality Group-IAC

  33. From ESPAS Site Summary Series: No.CN2 SITEAO(as) No.Nights ORM 1.3-1.6*(1.22,1.29,1.64,2.39) 8-11 PARANAL 1.9-2.4 19-12 MAIDANAK 2.5 9 PACHON 2.1-2.1-2.9 40-22-8 S:PEDRO MARTIR 1.7 11 ? *Masciadri et al. (A&A, 2001). BUT: Need of continous statistical values of AO Temporal sampling. Number of flights/night From DIMM scintillations data: AO ~ 2-3as (SQG). Sky Quality Group-IAC

  34. GSM web In the coming years: GONG web SQG web • G. Scidar (September 2002): Fuensalida et al. and Vernin • GSM (August or September 2002): A. Ziad and F. Martin • Isoplanatism from Scintillation Single Stars (DIMM) • Wind profiles from INM: Chueca et al. and Sarazin. • Seeing forecasting (2003): Masciadri et al. • Recent Site campaigns: • (A) Degollada del Hoyo Verde • (B) ATST • (C) OWL 100m (near MAGIC)? • (D) EURO 50 (Hoyo Verde) ? (C) (B) (A) Sky Quality Group-IAC

  35. Programmes for optimizing Astronomical observing and capitalizing on the quality of our skies: First sodium laser beacon at ORM (http://op.ph.ic.ac.uk/jkt_lgs/) The LGS project is framed within the EuropeanCommunity Programme. Observing the sodium beacon from the JKT, 163 m from the launch site. The image shows the long streak through the sodium layer created by laser. With brighter emissions from those parts of the layer more abundant in sodium (Michaille et al., 2000). The sodium density measured in summer was 1.6 109 atoms/cm2. The typical height of the sodium layer is about 90km. Michaille et. al, 2000 First detection at the OT, 5 Dec. 2001. J.J.Fuensalida et al. Sky Quality Group-IAC

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