General Observations:
- We cannot do X-Ray observations from the ground,
- We need high temperatures for these objects that we want X-Rays from, too low temperatures are not able to produce and emit X-Rays
- Not only do X-Rays penetrate the atmosphere, but much more as their penetration power is very high. This means if we have a telescope for visible light or such, we cannot measure X-Rays with them as the X-Rays simply penetrate through the telescope.
- Many things emit X-Rays, even the moons, which means if we spot X-Rays there must be some energetic reaction happening
- Galaxies produce very large diffused X-Ray
- M87 and some other galaxies blast plasma jets from their nucleus which produce X-Rays because they are incredibly energetic
- Using X-Ray imagery we can see the active regions of the Crab Nebula that we’d never be able to observe optically or using infrared.
- If we could see the Sun in X-Ray we’d be able to observe that the Sun is actually flickering over the period of tens of minutes.
- The energy of the soft X-Ray solar flares come from a region of the sun disc only the size of the sun. But the energy from the more energetic X-Ray solar flares come from deeper in the sun.
- The reason we can see X-Rays from the moon is because it fluoresces from the energy radiated from the sun.
Notes:
We aren’t tackling radio as its too low energy
X-Ray Observations from Space
Rocket experiments started with captured German V2 Rockets (Although the flight lasted for only a few minutes)
- 1948: Solar X-Rays detected (from the solar corona)
- 1962: Bright X-Ray source discovered in Scorpius: the star denoted Sco X-1
- 1963 Isotropic X-Ray background discovered; Extragalactic Sources; X-Ray sources detected in Crab Nebula
- 1966 X-Ray galaxies identified
Satellite Missions
Since 1970 till the current day we have a large amount of satellites that have been launched to observe various objects in X-Rays such as ROSAT SoHo XMM Chandra Such Experimental disoveries are:
A huge number of sources detected (60k by ROSAT)
Many X-Ray binaries were identified (Cygnus X-1, a black hole candidate)
Detailed Observation of solar flares, pulsars, quasars, galaxy clusters, supernovas, galaxies etc
Extra and Athena
To focus our X-Rays for seeing them we cannot reflect them like visible light with mirrors, instread we use slide them across highly conductive materials in a way that mimics a lens, which we call Grazing Incidence Optics
For low energy systems in telescope, Mechanical Collimators are used to block X-Rays from unwanted directions, these are used to shield the sensor from the X-Rays that arent being measured. They use anti-coincidence detectors as well for shielding which will measure at two points, and if the X-Ray penetrates from the wrong side first, they will be electronically removed. This is used more as it is CHEAPER as its less heavy, and that leads to less fuel needed to send it into space. In general shielding is relatively impractical.
A more advanced approach for shielding is Rotating Modulating Collimators, which are two sets of opaque (to X-Ray) slits, and the amount of X-Rays detected will understandably modulate with these rotations. These slits hold a constant angular speed, with the spacecraft which rotates, roughly every 60s
We measure X-Ray photon interacting in a semiconductor crustal (e.g Germanium) which end up releasing one or more electrons which we can them measure using a high voltage connection and measuring current
I got bored so I defined complex fourier in latex.