Essendo amministratore di uno dei due forum in cui la discussione si è sviluppata, le ho segnalate a Gabany, chiedendogli se voleva replicare, è stato molto gentile e pronto nel rispondermi, vi posto la sua mail.
Hello Roberto:
Thank you for sending this message! I appreciate the opportunity to contribute to the discussions you have referenced. Even though I am not fluent in Italian, I took a look at the links you mentioned and can tell that there has been a lively discussion that included images by others and some attempts to deconstruct my pictures, too.
So, may I impose upon you to interject the following facts on my behalf.
1. The discovery of star streams around M63 were not announced with haste. Preparation of the scientific paper required over two years of careful data gathering and research. Part of this required the stream to be captured independently with different telescopes, by different imagers.
2. The following image was exposed by Ray Gralak using an FSQ-106. As you can see, the stream is prominent. This image represents about 24 hours of luminance exposure.
Allegato:
securedownload.jpg [ 508.08 KiB | Osservato 883 volte ]
3. The following image was produced with the .8 meter telescope at the McDonald Observatory in Texas:
Allegato:
securedownload1.jpg [ 168.13 KiB | Osservato 883 volte ]
4. Recently, Don Goldman produced an image of M63 that also revealed the stream. Don's picture was produced after our research results were finished but also demonstrates that the stellar stream is real. See :
http://dg-imaging.astrodon.com/gallery/ ... ?imgID=2375. Tony Hallas also produced a deep image of M63 that revealed the stream. See :
http://www.astrophoto.com/M63LRGB.htm6. Here is a list of the research team and the introduction of the team's paper which summarizes our findings. As you can see, there are several distinguished, professional astronomers:
Researchers:
TAYLOR S. CHONIS (Texas Univ),
DAVID MARTÍNEZ-DELGADO (Max Planck Institute for Astronomy),
R. JAY GABANY (Blackbird Observatory),
STEVEN R. MAJEWSKI (Univeristy of Virginia) ,
GARY J. HILL (McDonald Observatory),
RAY GRALAK (Sirius Imaging Observatory),
IGNACIO TRUJILLO (Astrophysical Institute of the Canary Islands)
We present deep surface photometry of a very faint, giant arc-loop feature in the halo of the nearby spiral
galaxy NGC 5055 (M63). This feature is consistent with being a part of the stellar stream of a disrupted dwarf
satellite. This faint feature was first detected in early photographic studies by van der Kruit (1979); in this
work, it is realized to be the result of a recent minor merger through its detection in wide-field, deep images
obtained with a telescope of only 0.16 m aperture. It is clearly confirmed in deep images taken with the 0.5 m
telescope of the BlackBird Remote Observatory and the 0.8 m telescope of the McDonald Observatory. This
low surface brightness (~ 26 mag arcsec-2), arc-like structure around the disk of the galaxy extends 14.00
(~29 kpc projected) from its center, with a projected width of 1.60 (~3.3 kpc). The stream’s morphology is
consistent with that of the visible part of a giant, "great-circle" type stellar stream originating from the recent
accretion of a dwarf satellite in the last few Gyr. The progenitor satellite’s current position and
final fate are not conclusive from our data, although the color of the stream’s stars is consistent with dwarfs
in the Local Group and is redder than the outer faint regions of M63’s disk and stellar halo. Through our
photometric study, we find other low surface brightness "plumes" that, while probably unrelated to the tidal
stream, could be extended spiral features related to the galaxy’s complex spiral structure. We are able to
differentiate between features related to the tidal stream and faint, blue, extended features in the outskirts of
the galaxy’s disk previously detected by the GALEX satellite. With its highly warped HI gaseous disk,
M63 represents one of several recently discovered examples of an isolated spiral galaxy with a warped disk
showing strong evidence of an ongoing minor merger.
7. Finally, it should be noted that the team's results have been subjected to a peer review.
So, although some of the folks participating in these discussions may find it incredible, the streams surrounding M63 are very faint but real.
Thank you, again, for sending this message and thank you for helping me settle the debate with some facts.
Jay
Home
Iscriviti
La Bacheca
F.A.Q.
Login/Logout
