Articles

High Energy Astronomy: A Telescope is Born


This is VERITAS, a gamma ray observatory
in southern Arizona. You may recognize it from our video a
few months ago, but today we’re here for another reason: the inauguration of a
brand new type of telescope. Behind me is a prototype Schwarzschild-Couder telescope, a gamma ray telescope proposed for the Cherenkov telescope array,
the next-generation observatory for high-energy astronomy. The difference between the Schwarzschild-Couder telescope and a normal Cherenkov telescope is a
normal Cherenkov telescope has one mirror surface reflecting the light onto the
camera, whereas the Schwarzschild-Couder one has two mirrors surfaces, and this
essentially defocuses, also demagnifies the light, allowing you to use smaller
plate scale photo detectors. What this essentially means is we can use smaller
technology, silicon technology much like the difference between an old film
camera and your mobile phone camera. Recently, we talked to one of the project’s
scientists to tell us a little bit more about CTA. CTA is the follow-up
experiment, in some sense, to VERITAS. Large optical reflectors will image the
blue UV Cherenkov light that comes down in air showers when the high-energy
gamma ray interacts in the upper atmosphere, but unlike VERITAS, CTA will consist of many more telescopes — 99 telescopes in
the southern site and then 19 telescopes in the northern site — which will provide
many more views of the shower and lead to much better resolutions, energy and
angular resolution, and much better sensitivity. That means that CTA will be
able to see much fainter sources and more distant sources than VERITAS will
be able to do, or is able to do. The CTA will be composed of three different sizes of
telescopes: large 23 meter dishes, small 4 meter dishes, and then medium 12 meter
telescopes like the one being inaugurated tonight. There are hundreds
of people involved in the project and some of them are here today to view this
prototype. It is not really about the money, not about the companies, it is all
about the people. The project has been going through a number
of difficulties. On a few occasions we have jumped from the cliff without
knowing if the parachute will open, but it is the people’s dedication and an
extraordinary team behind this instrument which made it possible, because every
time people just do a little more, even on the fumes without the money, and this
is what comes out of it. CTA has many different science goals.
With the medium-sized telescope it will be looking at things ranging from
galactic objects like pulsars, supernova remnants, colliding winds, and cosmic ray
acceleration sights in general, all the way up to extra-galactic objects such as
the jets that are coming from the supermassive black holes at the centers
of active galaxies which are accelerating particles to very
close to the speed of light. All of the data that we take will be distributed to the
public at large. I’m hoping that we’ll see something totally new and totally
exciting, and, of course, we don’t know what that is and I’m hoping that that will have
the biggest impact on my work. But I don’t know what it is, of course, because if I knew what it was, it wouldn’t be new. Hi, I’m Matthew.
I’m Michael. And I’m Victoria. Thanks so much for watching
our video about the Cherenkov Telescope Array. Make sure to subscribe so you don’t
miss our live Q&A next week where we’ll be talking about the
making of this video. You can ask questions live during the chat or you
can leave them below in the comments. Thanks so much for watching!

7
Comments

Leave a Reply

Your email address will not be published. Required fields are marked *