It is currently Mon Jun 27, 2022 5:37 pm

 All times are UTC - 8 hours [ DST ]

 Page 1 of 1 [ 4 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: CR dipole anisotropyPosted: Tue Jun 02, 2015 9:54 am

Joined: Fri Mar 20, 2015 6:44 pm
Posts: 2
Hi,

I've come across a large number of papers that show plots of the "dipole anisotropy", delta, predicted by GALPROP and limits set from data. However, not a single one defines a formula for delta, and nowhere can I find a way to generate this myself from a GALPROP model. Admittedly, part of the problem is the number of places "anisotropic" appears in GALPROP documentation, making it very difficult to google. So can anyone tell me how to do this?

thanks,
Mike

Top

 Post subject: Re: CR dipole anisotropyPosted: Tue Jun 02, 2015 11:19 am

Joined: Wed May 17, 2006 7:02 am
Posts: 285
Location: MPE Garching
galprop does not explictly compute anisotropy, but it follows from the standard formula e.g. equation (1) in http://arxiv.org/abs/1505.02720
But that paper and others also demonstrates that this a far too simple approach, which requires more physics than is in galprop.

_________________
Andy Strong, MPE

Top

 Post subject: Re: CR dipole anisotropyPosted: Thu Jun 04, 2015 7:51 am

Joined: Fri Mar 20, 2015 6:44 pm
Posts: 2
Thanks for the response, but that formula seems far too simple. I'm trying to estimate the CR anisotropy as a function of energy using the galprop output (e.g. figure 8 of http://arxiv.org/pdf/1108.1023.pdf). I've seen a bunch of plots that show the "galprop" prediction for anisotropy, but I haven't been able to find any detail on the calculation

Top

 Post subject: Re: CR dipole anisotropyPosted: Thu Jun 04, 2015 9:33 am

Joined: Wed May 17, 2006 7:02 am
Posts: 285
Location: MPE Garching
That is the standard formula following from the definition of diffusion. But certainly it is too simple, as many papers have pointed out. Probably however it was used in the paper you cite.

_________________
Andy Strong, MPE

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 4 posts ]

 All times are UTC - 8 hours [ DST ]

Who is online

Users browsing this forum: Bing [Bot] and 1 guest

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

Search for:
 Jump to:  Select a forum ------------------ general astrophysics    cosmic rays    gamma rays    interstellar medium    heliospheric modulation    cosmic-ray data galprop general discussion    galprop applications    galprop compilation    galprop debugging    galprop tests    galprop developer    galprop website    galprop features    galprop help    galprop WebRun    2011 GALPROP Workshop: abstracts and discussion other codes    analytical models    semi-analytical models    numerical models    comparisons with galprop    heliospheric modulation