.fz File Will Not Open

[Rick_N.]

Hello, I have tried several times to open a file that I know opens in other programs. I am wondering if the .fz file type prevents this. AIJ responds that: "This does not appear to be a FITS file."

The original FITS file is from the DECam NEO survey and was taken in April 2014. Its name is:
 
c4d_140423_023007_ooi_VR_v1.fits.fz

but it is a 300 MByte file. I can Dropbox it if needed.

Any help appreciated as it means I can get the magnitude for a probable SN.

[karenacollins]

If you are not running AIJ 3.4.0.xx, please update to the latest version (the daily build is recommended).

If that doesn't resolve the problem, we would need a copy of the file to investigate.

Karen

[Rick_N.]

Yes, v3.4 does now open the file. However, I am now having problems finding the coordinates in that image.

Can I send you the file so you can see what is happening and that I am not mad? I can share it to an email address; as I say it is a large file (300mb), but I think it would be worthwhile. It is also a file with 60 HDUs, which is the most I've seen on any FITS file.

Perhaps you could send me an email address through whatever means?

The link to CTIO DECam NEO is "DECam NEO: A sensitive, wide-field search for Near-Earth Objects" http://www.ctio.noao.edu/noao/node/7604

Their archive is available through the NOIRLab search page, but this is stress-inducing:
https://astroarchive.noirlab.edu/portal/search/?sort=caldat#/search-form

Thankyou for your help :)

[karenacollins]

Yes, send a link to karenacollins atatat outlook dotdot com.

[Rick_N.]

OK have done. You need to be a Dropbox member, but you probably already know this

The coordinates are:
RA/DEC:   13:56.06.14  -16:47:33.4
RA/DEC:   209.025583  -16.792611

[karenacollins]

Hi Rick,

There are multiple possible sources of the problem. The first is that the ra/dec reference location is given at pixel 13422.2, 6306.333 (CRPIX1, CRPIX2). That location should correspond to RA=208.7410277581, Dec = -16.33504840526 (CRVAL1, CRVAL2), which is similar to the coordinates you provided below. However, the image that opens for me is 2046 x 4094, so the reference location would be off of the image. I'm not sure if this is an inconsistency caused by the multiple HDUs, or if it is intended to be that way. Another potential issue is that the TPV projection is being used in the WCS headers. Unfortunately, AIJ does not currently support that projection type (there's an unobvious note about that in the white information line below the image display menus). I've re-plate-solved the image using astrometry.net, which uses coordinates AIJ has been well tested against and get roughly RA = 13:53:40, Dec = 15:25:40 near the center of the field. This is the same as I get from the original image too. I'm thinking that the coordinates reported are correct, but maybe the portion of the image you are interested in is in one of the other HDUs?? Unfortunately, AIJ v3.4 currently only supports the image in the first image HDU encountered. A possible solution is to try to extract the portion of the image you need to a single HDU fits file using a different tool. In the longer term, we are working on an AIJ v5 release. We should be able to support multiple headers in that version eventually, but we can't provide a fix immediately.

Karen

[Rick_N.]

Thankyou for your time and effort. Using other software, the problem is as you describe: the coordinates are outside the given image. Apparently, the probable SN was found using Aladin, but I have yet to locate it with that either! I will struggle on  ... Look forward to v5