If you need illustrations or just beautiful images, please download the images and movies we have prepared for you instead.

We require that you:

If you download these data, we require that you:

1. Do not propagate the data to your colleagues. Instead, refer them to this site. The data will be available from this or an equivalent location on the web for a long time;
2. Refer to this paper when you publish your results: G. B. Scharmer, B. V. Gudiksen, D. Kiselman, M. G. Löfdahl & L. H. M. Rouppe van der Voort, 2002, "Dark cores in sunspot penumbral filaments", Nature 420, pp. 151-153.
3. Include the following sentence in a footnote to the paper title or in the Acknowledgments: "The Swedish 1-m Solar Telescope is operated on the island of La Palma by the Institute for Solar Physics of the Royal Swedish Academy of Sciences in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.";
4. Send us preprints and offprints.

Targets

• 22 May 2002: NOAA active region 9957 at μ=0.99
• 15 July 2002: NOAA active region 10030 at μ=0.96

Note that the field of view (FOV) is different in all the image channels from 15 July. The largest FOV is from a Megaplus 4.2 camera. The smaller FOV is from a Megaplus 1.6 camera. The smallest FOV is from a Megaplus 1.6 camera equipped with a phase-diversity sensor. The image scale is the same, though.

Single images

gband_22May2002_AR9957_1.fits (8.2 MByte)
430.5 nm (bandwidth = 1.2 nm) G-band, exposure time is 4 ms, 11:33 UT, Corrected for theoretical telescope and detector MTF, Pixel scale: 0.041 arcsec per pixel.

gcont_15Jul2002_AR10030_357.fits (3.0 Mbyte)
436.4 nm (bandwidth = 1.1 nm) G-band continuum, exposure time = 5 ms, 11:34 UT, Corrected for theoretical telescope and detector MTF, Pixel scale: 0.041 arcsec per pixel.

c4877_15Jul2002_AR10030_323.fits (8.2 MByte)
487.7 nm (bandwidth = 8 nm), exposure time = 13 ms, 11:34 UT, Corrected for theoretical telescope and detector MTF, Pixel scale: 0.041 arcsec per pixel.

gband_15Jul2002_AR10030_631-634.fits (1.3 MByte)
430.5 nm (bandwidth = 1.2 nm) G-band, exposure time is 6 ms, 11:34 UT, Corrected for Phase-Diversity estimated OTF, Pixel scale: 0.041 arcsec per pixel.

PD restored data cubes

All these data cubes contain Phase Diversity (PD) restored G-band images, 22 sec cadence, see gband_15Jul2002_AR10030_631-634.fits above for details. These files are pretty large.

ANA fz files can be read into ANA with a "restore" command and into IDL using the f0/fz commands defined in SolarSoft.

Reduction pipe line:

1. corrected for bias and dark current
2. flat-field corrected
3. post-processed with Joint Phase-Diverse Speckle (see Löfdahl & Scharmer 2002)
4. corrected for diurnal field rotation
5. rigid aligned (bi-cubic interpolation)
6. destretched (bi-cubic interpolation)
7. subsonic Fourier filtered: modulations > 4 km/s suppressed
8. every frame in the cube is scaled between 0-255

• For a quick look on your screen: gband_pd_15Jul2002.extended.fullFOV.mpg. Mpeg movie, 1h23m movie, 12:28:52 - 13:51:38, 43,5 MByte.
• For dynamical studies and better quality viewing on your screen (just the best part) with data processing software like IDL or ANA: gband_15Jul2002_AR10030.cube.fits. FITS cube, 28m, 13:03:12 - 13:31:14, 47.6 MByte. See above for how to read it into IDL.
• For dynamical studies and better quality viewing on your screen (entire sequence) with your favorite data processing software: gband_pd_15Jul2002.extended.fullFOV.cube. ANA fz format data cube, 1h23m, 12:28:52 - 13:51:38, 110 MByte.
• For quantitative frame by frame measurements: The whole 1.5 h sequence, gzipped tar archives with single images in separate ANA fz files. See above for how to read them into IDL. These images are not aligned or otherwise processed to run as a movie, i.e. these frames have only been through the first 3 steps in the reduction pipe line. See above items for movies!

gband_pd_15Jul2002.part1.tar.gz, 40.3 MBytes. 93 frames, 22 sec cadence, 12:28:53 - 13:03:03 UT.
gband_pd_15Jul2002.part2.tar.gz, 33.0 MBytes. 76 frames, 22 sec cadence, 13:03:12 - 13:31:14 UT. Best quality part. Corresponds to movie cube gband_15Jul2002_AR10030.cube.fits above.
gband_pd_15Jul2002.part3.tar.gz, 21.5 MBytes. 52 frames, 22 sec cadence, 13:31:36 - 13:51:38 UT.

Full field-of-view data cube

A sequence of false-color tiff files that can be assembled into a movie using your favorite image processing software. Gzipped tar-archives, uncompressed sizes less than 650 MBytes for easy CDrom archiving.

Frames 1-59 (compressed: 386 MBytes)
Frames 60-119 (compressed: 432 MBytes)
Frames 120-179 (compressed: 443 MBytes)
Frames 180-239 (compressed: 424 MBytes)
Frames 240-284 (compressed: 287 MBytes)

The field of view corresponds to that of c4877_15Jul2002_AR10030_323.fits above. The processing is similar to that of the PD restored movie above, except that the images are only corrected for the theoretical MTF of the telescope and the detector, and not for any seeing effects.

Telescope and camera info

• Clear aperture: 0.97 m,
• Focal length: 20.3 m, re-imaging lens gives 0''.041/pixel image scale
• CCD detectors: KAF4200 and KAF1600, pixel size 9.0 μm, 100% fill.

Papers written on these data

• G. B. Scharmer, B. V. Gudiksen, D. Kiselman, M. G. Löfdahl & L. H. M. Rouppe van der Voort, 2002, Dark cores in sunspot penumbral filaments, Nature 420, pp. 151-153.
• L. H. M. Rouppe van der Voort, M. G. Löfdahl, D. Kiselman, & G. B. Scharmer, Penumbral structure at 0''.1 resolution I. General appearance and power spectra, submitted to A&A.

Papers describing the telescope and methods used

• G. B. Scharmer, K. Bjelksjö, T. Korhonen, B. Lindberg & B. Petterson, The 1-meter Swedish solar telescope, in Proc. SPIE Keil & Avakyan, eds., Innovative Telescopes and Instrumentation for Solar Astrophysics, volume 4853-47 of Proc. SPIE, 2002. In press.
• G. B. Scharmer, P. Dettori, M. G. Löfdahl & M. Shand, Adaptive optics system for the new Swedish solar telescope, in Keil & Avakyan, eds., Innovative Telescopes and Instrumentation for Solar Astrophysics, volume 4853-52 of Proc. SPIE, 2002. In press.
• M. G. Löfdahl and G, B. Scharmer. Phase diverse speckle inversion applied to data from the Swedish 1-meter solar telescope, in Stephen Keil and Sergey Avakyan, editors, Innovative Telescopes and Instrumentation for Solar Astrophysics, volume 4853-54 of Proc. SPIE, 2002. In press.
• P. Dettori and G. Hosinsky, The Swedish solar telescope control system, in Lewis, ed., Advanced Telescope and Instrumentation Control Software II, volume 4848-65 of Proc. SPIE, 2002. In press.
• M G. Löfdahl, Multi-frame blind deconvolution with linear equality constraints, in Bones, Fiddy, & Millane, eds., Image Reconstruction from Incomplete Data II, volume 4792-21 of Proc. SPIE, 2002. In press.