It is existential for all non-expandist cosmologists in this forum to prove that cosmic time dilation does not exists. Until recently, quasars and supernovaes were shown to be devoid of cosmic time dilation, however for SNies this has recently been questioned by a DES study. As such it is existential to perform a better analysis with the highest redshift supernovaes otherwise static universes would be simply 100% falsified. You might not realize it, but this is the highest priority issue in non-orthodox cosmology. To help with this quest, I need to contact Dr Crawford, one can get his email via the button “view email” here https://arxiv.org/abs/1711.11237 https://arxiv.org/show-email/b3a46a20/1711.11237 However since I do not have an arxiv account I cannot get it. Note that Crawford is retired but he could still give insightful answers, moreover he recently (2 years ago?) signed a petition with members of the ACG group about arxiv censorship. Thanks in advance, I promise I will be respectful of his time and not spam him with too many questions.
Edit: I have made an arxiv account and was able to get his email, nevermind
This is a pretty low effort comment on my part, but he seems to be accused of using data translated to the rest-frame, where time dilation would already be removed:
https://www.physicsforums.com/threads/lack-of-time-dilation-in-type-1a-supernova.946267/
Crawford is literally the one pointing out SALT2 rest frame remove the info. His analysis of raw light curves and absolute magnitudes bypass this.
Do you have a link to the raw data?
It is detailed in section 2 of the paper 2.2 Raw type Ia supernovae light curves The dataset is B14 Crawford detail each Metadata associated with a supernova, you can also see the files table 1
So I’m not sure I understand The paper for the B14 dataset compilation (2011) https://arxiv.org/abs/1104.1443 Link to https://tspace.library.utoronto.ca/handle/1807/25390 While it contains SNLS I’m not sure where is the link for the full B14 dataset Thankfully the files Crawford used are explicitly stated table 1
But then he says he used the data from the “SNANA” website which is from SDSS. https://arxiv.org/abs/0908.4274
Link to SNANA http://www.sdss.org/supernova/SNANA.html And the link is dead yay But it might be available on webarchive? There is a classic version of the sdss website https://classic.sdss.org/supernova/aboutsupernova.php It mentions snana And gives another SNANA link which is also dead http://snana.uchicago.edu/ So SNANA is a software package as discussed on sncosmo https://github.com/sncosmo/sncosmo/issues/197 And indeed here is the new SNANA repository https://github.com/RickKessler/SNANA I suppose the software allows to download the files of table 1. Datasets seems to be available here for snana https://zenodo.org/record/4015325
Here is the installation guide https://github.com/RickKessler/SNANA/blob/master/doc/snana_install.pdf
To use a curve fitter like SALT2 there is also the sncosmo python library.
Trying to compile the dataset Crawford used sounds tedious, and is a low priority for me at the moment. Since you have his email, perhaps you can request it directly from him.
eta I’m downloading SNDATA_ROOT-PUBLIC-2020-07-11.tar.gz now. But I think that’s only one part of his full dataset.
Even if you did not manage to find the B14 full dataset, by far the most important subdataset of light curves is SNLS. Which is probably this https://tspace.library.utoronto.ca/handle/1807/26549
For processing the light curves, the sncosmo python package should be the most user friendly even though Crawford used SNANA.
The reason why SNLS is most important is because it goes to high redshift and has a decent number of supernovae (Cf table 1), the hubble ones are low numbered and the sdss ones are low redshift.
The main goal would be to reproduce figure 2 of Crawford paper and also to a lower extent figure 3.
If you could that would be groundbreaking as, as I said previously cosmic time dilation is the biggest crisis in cosmology by far.
I will send him an email if we don’t manage to find the data of table 1 after a few days.
David Crawford has a profile in ResearchGate. There is a listing of some of his papers there and his email.
https://www.researchgate.net/profile/David-Crawford-6
I found his email but thanks yes it’s also possible to DM him on researchgate.
The video I posted used observed frame data, and there’s also this:
https://arxiv.org/abs/astro-ph/0504481
Which has no mention of SALT.
So I downloaded SNDATA ROOT PUBLIC and indeed all the light curves files of table 1 are listed under the lcmerge folder e.g. JLA2014_SNLS.LIST Now the question is how to process .LIST files
That LIST file is just a text document that contains the file names of the rest of the directory:
The actual goodies are in the .dat files.
The .dat files have a MJD, that’s your julian date. A difference of 1 between records should be 1 day.