Recent content by Ikaros

Based on what type of data it is, I think you're correct. Thanks.

Hi all, Consider the scatter plot below (example only): The bottom subplot looks like a residual plot (y-x), but it's over (1+x). I'm hoping someone can explain what this is and the benefit of it. Thanks

Along the same lines, I've seen a few "mass selected galaxies" as well. So I'm assuming that the researcher has selected a pool of galaxies using wavelength (above example) or mass (this example) as the criteria. Can anyone confirm?

Hi all, I'm hoping a pretty simple question. When I read about researchers working on galaxy surveys, they often state they're working on "XX-band selected galaxies". For example, D.J.B. Smith et al. performed analysis on a large number of 250μm-selected galaxies at z < 0.5. Is this as...

Thanks for making your first post just for me, CSteinhardt! You cleared up everything I was uncertain on, very helpful.

Thanks for the reply, Drakkith. That appears to be it. I've been playing in a public catalog and after subtracting V magnitudes from U and J from V, I get a plot that resembles the ones I've been looking at. There's a clearly defined upper-left region, which apparently relates to quiescent...

Hi all, I was hoping someone could give me an overview of what a U-V vs V-J plot is and how it's used to categorise galaxies. I believe it's relates to flux observations of galaxies through different photometric band filters. So U-V is the restframe magnitude with a filter from the...

Thanks Dick. I should be practicing my Dirac notation more... ##\left< { f }|{ \hat { B } }|{ g } \right> ={ \left< { g }|{ \hat { B } }|{ f } \right> }^{ * }## As for ##B^*##, it is the Hermitian conjugate. In this case, I probably should be using the dagger notation ##{ B }^{ \dagger...

Hi Dick and thanks for your reply. I don't see any flaw in the reasoning, but I'm hoping my solution above conveys this clearly.

I've sought assistance from others regarding the above, and everyone believes it's okay . However, I'd love some feedback in this thread on my approach.

Homework Statement If B is Hermitian, show that BN and the real, smooth function f(B) is as well. Homework Equations The operator B is Hermitian if \int { { f }^{ * }(x)Bg(x)dx= } { \left[ \int { { g }^{ * }(x)Bf(x) } \right] }^{ * } The Attempt at a Solution Below is my...

Thanks for the tip. That looks like the way to go.

A poor choice of word by me, but I did account for the polarisation components due to the wave's orientation by averaging the Fresnel coefficients in my attempt above. I note an error in my opening post as the wave should be E=Ecos\alpha\hat{s}+Esin\alpha\hat{p}. The wave is alinged by...

Homework Statement A homework problem asks me to find the Fresnel coefficient for a linearly polarised plane wave, which is incident under an angle theta, whose electric field vector can be given as: E=Ecos\hat{s}+Esin\hat{p} \hat{s} and \hat{p} are the unit vectors for s-polarised and...

Nice work. Looks good to me. \omega _f = \omega _i \frac{{r_i^2 }}{{r_f^2 }} = 0.55\frac{{0.22^2 }}{{0.15^2 }} = 1.18{\rm{rad}} \cdot {\rm{s}}^{ - 1}