is given in 1987AJ_____94__876O.pdf

My favorite plot of space (zodiacal) background opt-NIR is the one by Michael Lampton (though I think aldering's analysis below is better:

I believe you can take as definitive Greg Aldering's analysis of space background for SNAP aldering01_space_zodi.pdf DO NOT USE without attribution!!! (called the “white paper” elsewhere, probably a section of, or a study for the white paper; the original file was just called zodi.ps).

It is important to understand that the zodi varies depending on angle between sun and pointing. I *think* in the optical it doesn't vary so much, but don't quote me on that. </ul> </ul>

GRBs You should look at GRB General Observing>Slopes explanation of GRB spectral slopes; I use here BAT-like instrument results. Sakamoto+11 says BAT sees low-E PL w/Photon index -1.6 for LGRB. For SGRB, sakamoto says low-E Photon index -1.2 for SGRB, very different results from Nava

The DXRB diffuse X-ray Background is complicated and modern papers point out all sorts of curvatures, etc. Me, I'm a lazy bum and use very very old parameterization Zombeck p. 197 , http://ads.harvard.edu/cgi-bin/bbrowse?book=hsaa&page=197, weirdo units are KeV cm^-2/s/Sr/keV

NA ~ 0.1 keV <E<5 keV (To remind you again: Zombeck parameterization does not cover the soft bump.)

8.5*E^(-.4) 5 keV<E<25 keV

167.*E^(-1.38) 5 keV <E< ~ MeV

(Better parameterizations have a low-E exponential cutoff and all kinds of curvatures, e.g. I(E) = 7.9 E-0.29 exp[-E/41.1 keV] keV cm-2 s-1 sr-1 keV-1 from ~ 5-30 keV. http://www.slac.stanford.edu/econf/C0307282/lec_notes/kahn/kahn1.pdf)

Here are my plots and discussions of how this plays out for choosing energy bands for observations. (It is from my script singu!~/projects/ubat/xethresh.pro).

File:grb_vs_dxrb_spectra.png

So, the DXRB is almost as hard as SGRB up to ~ 25 keV, then it is very steep. Now let's see that in Counts space, which helps visualize results below. File:grbvdxrb_counts.png

How far should I integrate up or down?

X-rays-Observing>Energy Band Selection

The DXRB has a “thermal-ish” bump that dominates from tenths of keV to ~ 3-5 keV. For this reason, you don't want to go below 5 keV, so 5 keV is the obvious lower bound of energy. What do you gain by going to high energy?

If you integrate spectra in count rate space, you see that LGRB rise briskly to ~ 25 keV, then gradually flatten. File:intgd_spectra.png

However, if you make a VERY SIMPLE assumption that the background is dominated by the DXRB (it isn't!! There are particles!!!!) you could make a simple argument that you should integrate to high energies because S/N keeps improving: File:simplified_snr_vs_Emax.png

So, I suspect the particle background spectrum is very hard, and truth is not so optimistic (without active veto). Still, it seems that it should be OK to go all the way up to 100 keV (but recall Chris' caution about being saturated by particle and other events just over your maximum energy threshold; take care with finite resolution and dynamic range).

Note that the SGRB are still rising at the highest energy while the LGRB is flattening.

How far down should one go in energy before this is not favorable increase in S/N?

this from singu!~/projects/xethreshhi2lo.pro

So, its quite clear that you still get photons for BOTH spectra in this idealized picture. I think even HETE got like one SGRB (don't quote me).

Of interest because high-z grb may provide very bright light sources for very high-z Lyman Alpha Forests.

Some papers to check out some day:

http://arxiv.org/abs/1309.1477v1 Observational Requirements for Lyman-alpha Forest Tomographic Mapping of Large-Scale Structure at z ~ 2