The Universe in the Infrared

The Universe in the Infrared

So, what amazing, astounding new science have we learned with

Spitzer?

Funded by NASA’s Spitzer Science Center

Images courtesy NASA/JPL - Caltech

Pilachowski / August 2005

The Universe in the Infrared

Slide 2

Outline

Solar SystemNearby starsProtostars and protoplanetary

disksGalaxiesThe distant Universe

Pilachowski / August 2005

The Universe in the Infrared

Slide 3

Comet Debris Tails @ 24 m

Comets can have 3 types of tails

gasdustdebris tails

Debris tails are formed from mm to cm sized particles shed by the cometDebris tails follow the orbit of the cometThese are the particles that produce meteor showersDaniel Kirkwood!

Pilachowski / August 2005

The Universe in the Infrared

Slide 4

Vega and Fomalhaut

• Debris disks around nearby stars– both about 25 LY

• Vega’s is huge– Seen face-on– 20 times larger than

the Solar System– Mass 1/3 of Moon’s– Recent collision of

Pluto-sized objects?

• Fomalhaut’s is seen edge-on

Pilachowski / August 2005

The Universe in the Infrared

Slide 5

Alien Asteroid Belt

• A dusty asteroid belt circling the star HD 69830

• Detected from IR emissions from dust

• 25 x the mass of our own asteroid belt

• Or is it a super-comet (Pluto-sized?)– forsterite grains like

Hale-Bopp

Artist’s conception

Pilachowski / August 2005

The Universe in the Infrared

Slide 6

Planets Circling a Brown Dwarf?

• OTS 44 is a brown dwarf– too faint to see in visible light– intermediate between a star and a planet– 15 x mass of Jupiter

• Encircled by a dust disk• Could it harbor planets?

Pilachowski / August 2005

The Universe in the Infrared

Slide 7

Massive Star Embryos Hidden in Dust

Spitzer sees stars forming inside knots of cold dust Infalling material warms, and glows in the infrared

Pilachowski / August 2005

The Universe in the Infrared

Slide 8

How Stars Form

When the center becomes hot and dense enough, it blows away the cocoon, revealing the new star inside

At infrared wavelengths, we can see inside the cocoon as the star forms

Stars form when huge clouds of gas and dust collapse due to gravity

Pilachowski / August 2005

The Universe in the Infrared

Slide 9

A Surprise from Spitzer

Left: optical sky survey image

Right: Spitzer 3-color composite:

• Blue = 3.6 m• Green = 8.0 m• Red = 24 m

The central yellow “star” in the center is a faint, forming star, possibly a brown dwarf.

L1014 is 600 LY distant in the constellation Cygnus

Pilachowski / August 2005

The Universe in the Infrared

Slide 10

The Elephant Trunk: A Nearby Star-Forming Region

hot young protostars embedded in dust

far infrared image

IR composite image

visible

Spitzer reveals protostars forming in the Elephant Trunk Nebula

2,450 LY in Cepheus

Pilachowski / August 2005

The Universe in the Infrared

Slide 11

A New Milky Way Globular Cluster

Distance: 9000 LY Age: ~ 13 Gyr Mass: 300,000 MSun

Toward the constellation Aquila

Pilachowski / August 2005

The Universe in the Infrared

Slide 12

Milky Way Twin: NGC 7331

Pilachowski / August 2005

The Universe in the Infrared

Slide 13

Distant, Dusty Galaxies

Spitzer has found optically invisible galaxies so distant that we see them as they were only 3 billion years after the Big Bang. These galaxies are obscured by silicate dust, suggesting that planets could have formed even at this early time in the history of the Universe.

Higdon et al. 2005, Ap.J., 626, 58Artist’s conception

Pilachowski / August 2005

The Universe in the Infrared

Slide 14

Even more distant galaxies…

At even greater distance, only 2 Gyr after the Big Bang, Spitzer finds super-massive black holes in galaxies shrouded in dust.

X-rays from some of these black hole galaxies are seen with the Chandra X-ray telescope, but they give off too little visible light to be seen with Hubble.

Pilachowski / August 2005

The Universe in the Infrared

Slide 15

Spitzer Continues to Amaze!