"Looking at the Universe through Infrared Spectacles" is public out-reach lecture given on Galway Astronomy Festival 2009. It took place in Westwood House Hotel, January 30th 2009, Galway, Ireland

1. Dr.Tigran Khanzadyan (NUIG)
Looking at the Universe
through Infrared
Spectacles

2. 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

3. Infrared?
• What do you associate with this name?

4. Infrared?
• What do you associate with this name?
NightVision?

5. Infrared?
• What do you associate with this name?
NightVision?
Missile guidance system?

6. Infrared?
• What do you associate with this name?
NightVision?
Missile guidance system?
How about the weather?

7. Discovery of Infrared

8. Discovery of Infrared
• In 1800 Herschel made
the discovery of
“calorific rays" during
his famous experiment.
Sir Frederick William Herschel
(1738-1822)

9. 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)

10. Herschel’s Experiment

11. Herschel’s Experiment

12. Herschel’s Experiment

13. Herschel’s Experiment

14. Herschel’s Experiment

15. Herschel’s Experiment
in 1 min

16. Herschel’s Experiment
in 1 min
in 2 min

17. Herschel’s Experiment
in 1 min
in 2 min in 3 min

18. 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 = 80F
thermometer 2 = 83F
thermometer 3 = 86F ?!

19. Herschel’s
measurements

20. 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.

21. 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!

22. 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!

23. Right, but why?

24. Right, but why?
• It was strange that temperature in the shade
was higher than that of under the direct sun
light.

25. 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.

26. 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.

27. 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!

28. Waves ...

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

30. • 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 ...

31. • 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 ...

32. • 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 ...

33. Wavelength and
Frequency

34. 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).

35. 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).

36. 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.

37. Electromagnetic spectra

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

39. 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.

40. 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)

41. Present Day Infrared

42. Present Day Infrared
• Archeology, Animal Studies, Geology,Vegetation
and Soil, Meteorology, Oceanography …
Astronomy!

43. Present Day Infrared
• Archeology, Animal Studies, Geology,Vegetation
and Soil, Meteorology, Oceanography …
Astronomy!
• In Arts and History - reconstruction works

44. 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

45. 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

52. Infrared Astronomy?

53. Infrared Astronomy?
• All objects emit infrared radiation.

54. 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.

55. 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.

56. 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?

57. Cryogenics

58. Cryogenics
• So we need to keep our detectors
somewhere cold to prevent the
surrounding heat.

59. 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".

60. 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.

61. 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)!

62. 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)!

63. Our Atmosphere

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

65. Solution?

66. Solution?
We could build the
observatories in dry and
high places like Muna Kea
and many others.

67. 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

68. 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

69. Constellation of Orion

70. Constellation of Orion

76. Jupiter

77. Jupiter

78. Hubble Space
Telescope
Orion Nebula
OMC-1

79. Hubble Space
Telescope
Orion Nebula
OMC-1

83. Sombrero Galaxy - M104

84. Sombrero Galaxy - M104

86. Why we need Infrared
in Astronomy?

87. Why we need Infrared
in Astronomy?
• By observing Infrared radiation the hidden
Universe can be revealed (as we observed a
minute ago).

88. 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.

89. 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”.

90. Types of Infrared

91. Solar System Objects
and extraterrestrial
system

98. Stellar Nurseries
and related objects

108. Other galaxies

113. Future of Infrared
Astronomy

114. 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.

115. 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.

117. • 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!

118. Thank you!
Questions?