why look at different frequencies of light? cooler objects are only visible at long wavelengths:...
DESCRIPTION
Radio Telescopes Detects cool gases: H + H H 2 Can detect molecules out in space: oxygen O 2 carbon dioxide CO 2 hydrogen cyanide HCN formaldehyde H 2 CO Ethanol CH 3 COOHTRANSCRIPT
![Page 1: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/1.jpg)
Why look at differentfrequencies of light?
• Cooler objects are only visible at long wavelengths: radio, microwaves, IR.
• Hotter objects are only visible at short wavelengths: UV, X-rays, -rays.
![Page 2: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/2.jpg)
![Page 3: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/3.jpg)
Radio Telescopes
• Detects cool gases: H+ H H2
• Can detect molecules out in space:• oxygen O2
• carbon dioxide CO2
• hydrogen cyanide HCN• formaldehyde H2CO
• Ethanol CH3COOH
![Page 4: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/4.jpg)
Advantages / Problems
• Operates night or day• Atmosphere doesn’t absorb radio waves
• Poorest resolution of any type of light (doesn’t see details well)
• Solution is to make antennas (dishes) VERY large
![Page 5: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/5.jpg)
Arecibo Radio Telescope, Arecibo, Puerto Rico
![Page 6: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/6.jpg)
Puerto Rico
![Page 7: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/7.jpg)
GreenBankTelescope
Green Bank,W.Va.
The dishwould holdFulton Field
![Page 8: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/8.jpg)
Radio Interferometry – a Recipe
• Take 2 (or more) widely separated radio telescopes…
• Electronically blend their signals…• Result is as if you had a telescope with a
diameter equal to the distance between the two separate telescopes.
• VASTLY improves resolution!
![Page 9: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/9.jpg)
Very Large Baseline Array sites across the US. Together thesetelescopes form a huge interferometer.
![Page 10: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/10.jpg)
Infrared (IR) Telescopes• Very similar to visible wavelength
telescopes, except for the detector, called a bolometer.
• IR scopes detect heat from warm gas or warm objects. “Warm” means not hot enough to glow in visible light.
• These scopes must be kept very cold or the heat the scope itself radiates swamps out what they’re looking for.
![Page 11: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/11.jpg)
What kinds of objects?
• IR telescopes “see” warm gas, molecules & dust. In some cases, they can look through cooler dust to see what’s inside the dust clouds!
• Since stars form where there’s lots of dust, these scopes are great for looking inside dusty nebulas where new stars form.
![Page 12: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/12.jpg)
![Page 13: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/13.jpg)
![Page 14: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/14.jpg)
We can’t see everything just invisible wavelengths !!
![Page 15: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/15.jpg)
ISO – theInfraredSpaceObservatory
EuropeanSpaceAgency (ESA)
![Page 16: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/16.jpg)
Orbital Telescopes
• Why put a telescope in orbit?• Gets it above the atmosphere with all its
dust, ozone, water vapor, and CO2 that absorb so much of what we want to see.
• What’s the most famous orbiting telescope?
If you said the Hubble Space Telescopeor HST, you’re right!
![Page 17: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/17.jpg)
![Page 18: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/18.jpg)
HST does detect visible light
• It also detects ultraviolet light.• 2.4 meter mirror = 230,400 eyes!• Resolution is 0.0126 arcsecond or
1 / 3,500,000th of a circle.• We’re used to seeing photos like these!
![Page 19: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/19.jpg)
![Page 20: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/20.jpg)
X-ray & Gamma Telescopes
• “Sees” very hot objects:• Black Holes• Pulsars & Neutron Stars• Supernovas
• VERY good resolution – sees fine details
![Page 21: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/21.jpg)
NGC 4261 – a huge black holeat the center of a distant galaxy
![Page 22: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/22.jpg)
A supernova – an exploding star
![Page 23: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/23.jpg)
What’s left after the explosion – a supernova remnant.
This one’s called Cassiopeia A.
![Page 24: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/24.jpg)
The Crab Nebula in visible light (left) & X-rays (right).
![Page 25: Why look at different frequencies of light? Cooler objects are only visible at long wavelengths: radio, microwaves, IR. Hotter objects are only visible](https://reader036.vdocument.in/reader036/viewer/2022062905/5a4d1ae27f8b9ab059977940/html5/thumbnails/25.jpg)
At the center of the Crab Nebula – a PULSAR