Everyone is familiar with the explosive antics of starburst galaxy M82. The Hubble Space Telescope has taken some awesome images of M82 showcasing its hydrogen-alpha emissions fanning out from the nucleus, a process thought to have been initiated by a close encounter with galaxy M81 beaucoup years ago. The Chiefland 14.5-inch RC has visited M82 earlier this year recording 6 hours of (clear filter) luminance data, 8 hours of 2X2 binned RGB data mixed with a dash (10 hours) of 2X2 binned hydrogen-alpha data through a 6nm bandpass Astrodon H-a filter. The comparison images of RC and Hubble is attached as “M82Mosaic1”. The Hubble trumps the Chiefland RC image but, interestingly, the faint blue tail extending off the bottom of M82 in the L(Ha)RGB RC image is not see in the Hubble. We dub this faint blue extension “Binky’s Tail” (named after our dog Binky). Is this blue filament part of the hydrogen-alpha fan burst? This seems unlikely since it is blue in the RGB data and the H-a data didn’t pick it up. Or is this integrated flux nebula (high galactic cirrus nebula) that is prevalent in this area as popularized by Steve Mandel. He names this nebula Mandel-Wilson 3 or “Volcano Nebula” and is thought to be reflected light from our galaxy on dust above the plane of our galaxy. Streaks of this faint nebula can be seen in the 6 hour luminance frame in “M82Mosaic2” along with Binky’s Tail. Neither of these features shows up in the hydrogen-alpha image at the bottom of “M82Mosaic2”. Long color exposures of this high galactic cirrus by Jordi Gallego (see APOD link below) actually show this dust to be more bluish-gray than red. My RC hydrogen-alpha image is grainy because the filter has a narrow bandpass (therefore, letting little light through), is binned at 2X2 to help gather photons at slow f/9. Also, the SBIG STL-11K camera is not the most red sensitive camera on the planet! Nevertheless, the 10 hour H-a image picked up something not seen on the “deeper” luminance image — a “cap-shaped” shell of H-a data. A bit of research on the net disclosed an article “H-a Emission 11 Kiloparsecs Above M82” by Devine and Bally in Astrophysical Journal, 1999. A link is attached below if you want to read the whole great article (2.45MB to download PDF). They describe a H-a “cap” northwest of M82 and they imaged it with the Kitt Peak 4 meter telescope in 1997. “M82Mosaic3” shows the KPNO image next to the Chiefland RC image. In the KPNO image, the H-a emission can nearly be traced all the way from the galaxy to the cap. The Chiefland RC image cannot boast that damage! I put forth the challenge for someone at the Village to go deeper on M82 and “Trace to the Cap”! Perhaps someday, I can pull that off with my colder (less noise), more red sensitive Apogee 16803 CCD camera which should be operational this Fall! The H-a cap is about 10 arcmin. out from the nucleus of M82 so the Hubble image and my 24-hour exposure L(Ha)RGB image in “M82Mosaic1” don’t include the area. I will write the author John Bally, who is still at Univ. of Colorado, for new insights into this fascinating H-a cap 10 years later!
http://apod.nasa.gov/apod/ap080512.html — Deep Integrated Flux image around M81-82 in APOD by Jordi Gallego
http://www.iop.org/EJ/abstract/0004-637X/510/1/197 – Devine and Bally article abstract – no images
http://www.iop.org/EJ/article/0004-637X/510/1/197/38794.web.pdf?request-id=03624ceb-e72a-4c99-9eb7-780e06b20c1d — PDF (2.45MB) but worth it!