Dr. Tigran Khanzadyan (NUIG)

Looking at the Universe through Infrared

Spectacles

Overview• Discovery of Infrared

• Waves and frequencies

• Infrared in our life

• Infrared Astronomy and it’s limitations

• Hidden Universe revealed

• Types of Infrared and the actual discoveries

• Future of Infrared Astronomy

Infrared?

• What do you associate with this name?

Infrared?

• What do you associate with this name?

Night Vision?

Infrared?

• What do you associate with this name?

Night Vision?

Missile guidance system?

Infrared?

• What do you associate with this name?

Night Vision?

Missile guidance system?

How about the weather?

Discovery of Infrared

Discovery of Infrared

• In 1800 Herschel made the discovery of “calorific rays" during his famous experiment.

Sir Frederick William Herschel(1738-1822)

Discovery of Infrared

• In 1800 Herschel made the discovery of “calorific rays" during his famous experiment.

• “Calorific rays” were later renamed infrared rays - which means below red (from the Latin infra, "below")

Sir Frederick William Herschel(1738-1822)

Herschel’s Experiment

Herschel’s Experiment

Herschel’s Experiment

Herschel’s Experiment

Herschel’s Experiment

Herschel’s Experiment

in 1 min

Herschel’s Experiment

in 1 min

in 2 min

Herschel’s Experiment

in 1 min

in 2 min in 3 min

Herschel’s Experiment

in 1 min

in 2 min in 3 min

In the beginning all 3 thermometers show 76 F

Final readings are: thermometer 1 = 80Fthermometer 2 = 83Fthermometer 3 = 86F ?!

Herschel’s measurements

Herschel’s measurements

• He measured the temperatures of the violet, blue, green, yellow, orange and red light and noticed that all of the colours had temperatures higher than in the beginning.

Herschel’s measurements

• He measured the temperatures of the violet, blue, green, yellow, orange and red light and noticed that all of the colours had temperatures higher than in the beginning.

• But the temperature of the colours increased from the violet to the red part of the rainbow - interesting!

Herschel’s measurements

• He measured the temperatures of the violet, blue, green, yellow, orange and red light and noticed that all of the colours had temperatures higher than in the beginning.

• But the temperature of the colours increased from the violet to the red part of the rainbow - interesting!

• He then measured the temperature just beyond the red portion of the rainbow in a region apparently devoid of sunlight - highest of all!

Right, but why?

Right, but why?• It was strange that temperature in the shade

was higher than that of under the direct sun light.

Right, but why?• It was strange that temperature in the shade

was higher than that of under the direct sun light.

• Herschel then concluded that some other sort of light which can-not be seen is causing this temperature rise.

Right, but why?• It was strange that temperature in the shade

was higher than that of under the direct sun light.

• Herschel then concluded that some other sort of light which can-not be seen is causing this temperature rise.

• He then discovered that this “invisible” light or radiation can be reflected, refracted, absorbed and transmitted just like the visible light.

Right, but why?• It was strange that temperature in the shade

was higher than that of under the direct sun light.

• Herschel then concluded that some other sort of light which can-not be seen is causing this temperature rise.

• He then discovered that this “invisible” light or radiation can be reflected, refracted, absorbed and transmitted just like the visible light.

• So there is an invisible light beyond the red!

Waves ...

• Waves can be slow or fast and therefore can be more or less frequent - we call it frequency of the waves.

Waves ...

• Waves can be slow or fast and therefore can be more or less frequent - we call it frequency of the waves.

• When the waves are small they are more frequent and when the waves are big they are less frequent.

Waves ...

• Waves can be slow or fast and therefore can be more or less frequent - we call it frequency of the waves.

• When the waves are small they are more frequent and when the waves are big they are less frequent.

• We say that the frequency of waves is inversely proportional to the size of waves.

Waves ...

• Waves can be slow or fast and therefore can be more or less frequent - we call it frequency of the waves.

• When the waves are small they are more frequent and when the waves are big they are less frequent.

• We say that the frequency of waves is inversely proportional to the size of waves.

• We know that the light is also a wave, and every wave has it’s height and length.

Waves ...

Wavelength and Frequency

Wavelength and Frequency

• Wavelength is the distance between individual waves (e.g. from one peak to another). Visible light - 400 to 700 billionths of a meter - or 400 to 700 nanometers (nm).

Wavelength and Frequency

• Wavelength is the distance between individual waves (e.g. from one peak to another). Visible light - 400 to 700 billionths of a meter - or 400 to 700 nanometers (nm).

• The frequency is the number of waves which pass a point in space each second. Visible light - 430 trillion waves per second (red) to 750 trillion waves per second (violet).

Wavelength and Frequency

• Wavelength is the distance between individual waves (e.g. from one peak to another). Visible light - 400 to 700 billionths of a meter - or 400 to 700 nanometers (nm).

• The frequency is the number of waves which pass a point in space each second. Visible light - 430 trillion waves per second (red) to 750 trillion waves per second (violet).

• Light waves are waves of energy and the amount of energy in a wave is proportional to its frequency.

Electromagnetic spectra

Electromagnetic spectra

• We see only tiny portion of the spectra - the visible part.

Electromagnetic spectra

• We see only tiny portion of the spectra - the visible part.

• InfraRed is below the Red since it’s waves are less frequent that of the Red light.

Electromagnetic spectra

• We see only tiny portion of the spectra - the visible part.

• InfraRed is below the Red since it’s waves are less frequent that of the Red light.

• Infrared spans from 0.7 micrometers to about 350 micrometers (μm)

Present Day Infrared

Present Day Infrared• Archeology, Animal Studies, Geology, Vegetation

and Soil, Meteorology, Oceanography … Astronomy!

Present Day Infrared• Archeology, Animal Studies, Geology, Vegetation

and Soil, Meteorology, Oceanography … Astronomy!

• In Arts and History - reconstruction works

Present Day Infrared• Archeology, Animal Studies, Geology, Vegetation

and Soil, Meteorology, Oceanography … Astronomy!

• In Arts and History - reconstruction works

• Health & Safety - environmental monitoring, Medicine, Fire Fighting, Search and Rescue, Military, Law Enforcement

Present Day Infrared• Archeology, Animal Studies, Geology, Vegetation

and Soil, Meteorology, Oceanography … Astronomy!

• In Arts and History - reconstruction works

• Health & Safety - environmental monitoring, Medicine, Fire Fighting, Search and Rescue, Military, Law Enforcement

• Commercial applications - Maintenance of Mechanical Systems, Electrical Systems, Heat Loss in Structures, Navigation, Food Industry

Infrared Astronomy?

Infrared Astronomy?• All objects emit infrared radiation.

Infrared Astronomy?• All objects emit infrared radiation.

• Infrared Astronomy is the detection and study of the infrared radiation (heat energy) emitted from objects in the Universe.

Infrared Astronomy?• All objects emit infrared radiation.

• Infrared Astronomy is the detection and study of the infrared radiation (heat energy) emitted from objects in the Universe.

• So, Infrared Astronomy involves the study of just about everything in the Universe.

Infrared Astronomy?• All objects emit infrared radiation.

• Infrared Astronomy is the detection and study of the infrared radiation (heat energy) emitted from objects in the Universe.

• So, Infrared Astronomy involves the study of just about everything in the Universe.

• We need powerful infrared detectors, but there is a dilemma - everything around us radiates in infrared how we are going to “see” what’s out there?

Cryogenics

Cryogenics• So we need to keep our detectors

somewhere cold to prevent the surrounding heat.

Cryogenics• So we need to keep our detectors

somewhere cold to prevent the surrounding heat.

• Here comes the Cryogenics - means "the production of freezing cold".

Cryogenics• So we need to keep our detectors

somewhere cold to prevent the surrounding heat.

• Here comes the Cryogenics - means "the production of freezing cold".

• All infrared detectors are placed in the cryostats and cooled down.

Cryogenics• So we need to keep our detectors

somewhere cold to prevent the surrounding heat.

• Here comes the Cryogenics - means "the production of freezing cold".

• All infrared detectors are placed in the cryostats and cooled down.

• Now-days we cool down the detectors up-to 10 Kelvin (-442 F)!

Cryogenics• So we need to keep our detectors

somewhere cold to prevent the surrounding heat.

• Here comes the Cryogenics - means "the production of freezing cold".

• All infrared detectors are placed in the cryostats and cooled down.

• Now-days we cool down the detectors up-to 10 Kelvin (-442 F)!

Our Atmosphere

Our Atmosphere

• Water vapours prevent us from detecting the radiation coming from the space in most of the infrared bands.

Solution?

Solution?We could build the

observatories in dry and high places like Muna Kea

and many others.

Solution?We could build the

observatories in dry and high places like Muna Kea

and many others.

We could use balloons, rockets

and aircrafts to go even higher

Solution?We could build the

observatories in dry and high places like Muna Kea

and many others.

We could use balloons, rockets

and aircrafts to go even higher

Or we could rise above

the atmosphere IRAS MSXISO SPITZER

Constellation of Orion

Constellation of Orion

Jupiter

Jupiter

Hubble Space Telescope

Orion NebulaOMC-1

Hubble Space Telescope

Orion NebulaOMC-1

Sombrero Galaxy - M104

Sombrero Galaxy - M104

Why we need Infrared in Astronomy?

Why we need Infrared in Astronomy?

• By observing Infrared radiation the hidden Universe can be revealed (as we observed a minute ago).

Why we need Infrared in Astronomy?

• By observing Infrared radiation the hidden Universe can be revealed (as we observed a minute ago).

• Infrared range is quite wide compared to the visible light therefore we can potentially find more objects of interest.

Why we need Infrared in Astronomy?

• By observing Infrared radiation the hidden Universe can be revealed (as we observed a minute ago).

• Infrared range is quite wide compared to the visible light therefore we can potentially find more objects of interest.

• There are many objects in Universe which can only be seen through the infrared “spectacles”.

Types of Infrared

Solar System Objectsand extraterrestrial

system

Stellar Nurseriesand related objects

Other galaxies

Future of Infrared Astronomy

Future of Infrared Astronomy

• Even though we have an enormous success with the past and current Infrared telescopes on the ground and in the space we still have many unanswered questions and problems.

Future of Infrared Astronomy

• Even though we have an enormous success with the past and current Infrared telescopes on the ground and in the space we still have many unanswered questions and problems.

• At the moment there are several planned space missions which we will use to fill the gaps in our knowledge of universe, but surely future will present us with the new challenges and mysteries and we will plan more future missions.

• Herschel discovered the Infrared Light.

• Presently Infrared technology is widely used in every-day life.

• Infrared Astronomy reveals the hidden universe.

• Different types of objects can be studied using the Infrared Technology advancing our knowledge of the universe.

• Future of Infrared Astronomy is promising!

Thank you!Questions?