On a sunny day (Fri, 7 Oct 2022 11:02:32 +0100) it happened Martin Brown <'''newspam'''@nonad.co.uk> wrote in <thotfq$lku$1@gioia.aioe.org>:>On 06/10/2022 12:37, Jeroen Belleman wrote: >> >> P.S. At 30MHz, the wavelength is 10m. > >Fence post error in my mental arithmetic - I usually observed in the >radar bands between 2.7GHz and 31GHz. > >Most impressive image I ever made was VLA Cass A epoch 1984 at 5GHz >(6cm). It was the longest observing time spent on a single object. >(there is now a movie of it expanding of which that is the first frame) > >https://www.sciencephoto.com/media/332250/view/radio-photo-of-supernova-remnant-cassiopeia-a > >I don't like the official stock image though - too soot and whitewash >for my taste it has lost all the intricate nebulosity inside. The raw >image was originally made at 2048 square which was right at the limits >of what was possible on the AIPS hardware at the time.I found this today o nspace.com: https://www.space.com/high-velocity-clouds-supernova-ursae-majoris
A Photon's Perspective on Life
Started by ●October 5, 2022
Reply by ●October 7, 20222022-10-07
Reply by ●October 7, 20222022-10-07
On 2022-10-07 12:02, Martin Brown wrote: [...]> > Most impressive image I ever made was VLA Cass A epoch 1984 at 5GHz > (6cm). It was the longest observing time spent on a single object. > (there is now a movie of it expanding of which that is the first > frame) > > https://www.sciencephoto.com/media/332250/view/radio-photo-of-supernova-remnant-cassiopeia-a > > I don't like the official stock image though - too soot and > whitewash for my taste it has lost all the intricate nebulosity > inside. The raw image was originally made at 2048 square which was > right at the limits of what was possible on the AIPS hardware at the > time. >Nice work! Congrats. Do you have a link to that movie? The one I found seems to be in the X-ray domain. Jeroen Belleman
Reply by ●October 12, 20222022-10-12
On 07/10/2022 14:13, Jeroen Belleman wrote:> On 2022-10-07 12:02, Martin Brown wrote: > [...] >> >> Most impressive image I ever made was VLA Cass A epoch 1984 at 5GHz >> (6cm). It was the longest observing time spent on a single object. >> (there is now a movie of it expanding of which that is the first >> frame) >> >> https://www.sciencephoto.com/media/332250/view/radio-photo-of-supernova-remnant-cassiopeia-a >> >> I don't like the official stock image though - too soot and >> whitewash for my taste it has lost all the intricate nebulosity >> inside. The raw image was originally made at 2048 square which was >> right at the limits of what was possible on the AIPS hardware at the >> time. >> > > Nice work! Congrats. Do you have a link to that movie? The one I > found seems to be in the X-ray domain.The trick we used was to operate the VLA slightly out of band to observe at 4 frequencies with an average of 5GHz but scaled so that we pushed the imaging field to be 4x bigger than the instrument was designed for. Oversampling 4x moves the diffraction rings out by the same factor. The correlator gain settings were interesting too it is rather bright. The movie seems to have gone. I suspect the person who maintained it may have moved into Xrays and I can't see it anywhere online now. They were also involved in the Chandra 3D modelling of Cass A. I'm surprised that it is no longer online - I expected them to add another frame every ~5 years for as long as the VLA was still operational at that frequency. My ancient page about my part in those observations is online here: https://www.nezumidemon.co.uk/astro/radio/cassa.html But the link to the movie link now points at thin air. The wayback machine has only one snapshot which failed "Not found" :( I might have a personal copy of it in my old archives but it will take some finding as I can't remember what the filename is called. I will ask the person who used to maintain it and cross fingers for a reply. -- Regards, Martin Brown
Reply by ●October 12, 20222022-10-12
Martin Brown <'''newspam'''@nonad.co.uk> wrote:> The movie seems to have gone. I suspect the person who maintained it may > have moved into Xrays and I can't see it anywhere online now.Internet Archive Wayback Machine? https://archive.org/ -- MRM
Reply by ●October 12, 20222022-10-12
On 12/10/2022 18:27, Mike Monett VE3BTI wrote:> Martin Brown <'''newspam'''@nonad.co.uk> wrote: > >> The movie seems to have gone. I suspect the person who maintained it may >> have moved into Xrays and I can't see it anywhere online now. > > Internet Archive Wayback Machine? > https://archive.org/Sadly it only has one copy of a 404 not found response. -- Regards, Martin Brown
Reply by ●October 12, 20222022-10-12
Martin Brown <'''newspam'''@nonad.co.uk> wrote:> On 12/10/2022 18:27, Mike Monett VE3BTI wrote: >> Martin Brown <'''newspam'''@nonad.co.uk> wrote: >> >>> The movie seems to have gone. I suspect the person who maintained it may >>> have moved into Xrays and I can't see it anywhere online now. >> >> Internet Archive Wayback Machine? >> https://archive.org/ > > Sadly it only has one copy of a 404 not found response.It may not have been online long enough. I guess it takes a while to scan though the internet, especially if you don't have the number of servers that google has. -- MRM
Reply by ●October 13, 20222022-10-13
On 13/10/2022 00:33, Mike Monett VE3BTI wrote:> Martin Brown <'''newspam'''@nonad.co.uk> wrote: > >> On 12/10/2022 18:27, Mike Monett VE3BTI wrote: >>> Martin Brown <'''newspam'''@nonad.co.uk> wrote: >>> >>>> The movie seems to have gone. I suspect the person who maintained it may >>>> have moved into Xrays and I can't see it anywhere online now. >>> >>> Internet Archive Wayback Machine? >>> https://archive.org/ >> >> Sadly it only has one copy of a 404 not found response. > > It may not have been online long enough. I guess it takes a while to scan > though the internet, especially if you don't have the number of servers that > google has.It was there for decades but the researcher hosting the MPEG has moved on and the movie hasn't :( I didn't imagine it. I found the paper: https://www.researchgate.net/publication/234201111_Cas_A_-_the_movie Unfortunately the data products link on Simbad also leads nowhere :( I suspect most of them have retired by now and X-rays are sexier. -- Regards, Martin Brown
Reply by ●October 13, 20222022-10-13
Martin Brown <'''newspam'''@nonad.co.uk> wrote:>> It may not have been online long enough. I guess it takes a while to >> scan though the internet, especially if you don't have the number of >> servers that google has. > > It was there for decades but the researcher hosting the MPEG has moved > on and the movie hasn't :( I didn't imagine it. I found the paper: > > https://www.researchgate.net/publication/234201111_Cas_A_-_the_movie > > Unfortunately the data products link on Simbad also leads nowhere :( > I suspect most of them have retired by now and X-rays are sexier. > > -- > Regards, > Martin BrownThe wayback machine was launched in 2001. Cas A - the movie is dated April 1996, so it was not captured in the archive. -- MRM
Reply by ●October 13, 20222022-10-13
On 13/10/2022 12:32, Mike Monett VE3BTI wrote:> Martin Brown <'''newspam'''@nonad.co.uk> wrote: > >>> It may not have been online long enough. I guess it takes a while to >>> scan though the internet, especially if you don't have the number of >>> servers that google has. >> >> It was there for decades but the researcher hosting the MPEG has moved >> on and the movie hasn't :( I didn't imagine it. I found the paper: >> >> https://www.researchgate.net/publication/234201111_Cas_A_-_the_movie >> >> Unfortunately the data products link on Simbad also leads nowhere :( >> I suspect most of them have retired by now and X-rays are sexier. >> >> -- >> Regards, >> Martin Brown > > The wayback machine was launched in 2001. > > Cas A - the movie is dated April 1996, so it was not captured in the archive.But it was still around until at least 2012. -- Regards, Martin Brown
Reply by ●October 13, 20222022-10-13
