Graduate school letters of recommendation?

[khfrekek92]

I am currently applying to PhD physics programs across the US and so far my letters of recommendation are from the following: 2 astrophysics professors who I have taken astrophysics classes from, and 1 professor with a physics PhD but taught an upper division scientific writing class to me. Since I'm applying to a physics program, are these references to heavy on the astrophysics side or is that close enough to physics for the admissions committees?
A little about me:
I'm a double major in pre professional physics and applied mathematics with a minor in astronomy.

Thank you!

 

[retro10x]

The point of a reference letter is to show you are ready to do research. The relationship between you and the professor (ex. how well they know your strengths) is more important than what they taught you. A good letter is from someone who has seen you do research or lab work first hand, not someone who only graded your exams. Doing well on exams doesn't mean you will do well in independent research.