24 April 2009

Brooks School

2009: A Big Year for Science!

• 200 years, Darwin’s birth: 12 Feb 1809• 150 years: The Origin of the Species• 400 years: Galileo’s telescope + birth of

modern astronomy (and science):

International Year of Astronomy (IYA) www.astronomy2009.org

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Brooks School

Astronomers learn by looking

24 April 2009

Brooks School

The Electromagnetic Spectrum & Great Observatories

No longer operating

2008: Fermi Gamma Ray Telescope

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Brooks School

Chandra X-ray Observatory

NASA’s X-ray Eye on the Universe

Named for Chandrasekhar, Nobel Laureate

24 April 2009

Brooks School

Chandra Light Path: Grazing Incidence Mirrors

24 April 2009

Brooks School

Launch: 23 July 1999

24 April 2009

Brooks School

Views from Shuttle: “Columbia”

24 April 2009

Brooks School

Chandra’s Orbit: 64 hours

24 April 2009

Brooks School

Chandra’s Orbit in Space

Earth/Moon/ChandraOrbit around Earth

3-day period

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Brooks School

Orion NebulaWhere are Stars Born?

Optical X-ray

24 April 2009

Brooks School

What do we see in X-rays?

• Hottest, most violent sources in the Universe

• Into centers of dense regions, e.g. galactic centers, gas clouds

• Complete picture needs observations at many wavelengths

• Today: tour of source which emit X-rays

24 April 2009

Brooks School

What makes a Star Shine?

• Star burns fuel in its core (fusion: H→Helium)

• Initially fuel is H, star is on Main Sequence “Adult” (e.g. The Sun)

• When H runs out, core heats up and He, burns: “Middle Age” (Giant star)

• When He runs out, it burns heavier elements, e.g. Fe

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Brooks School

Death of a Star• When all fuel runs out, the core collapses• Outer regions of star explode outwards: Supernova• SN shine more brightly than a galaxy for a few hours/days

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Brooks School

SN1987A

• D=150 kly, in LMC• Brightest SN in 400yrs

• Star ~20 Msun

• Chandra Monitoring: 1999→present

• X-rays as SN blast wave encounters equatorial material

• X-ray brightening at least 5-10 yrs more

24 April 2009

Brooks School

Cas A: First Light

CHANDRA X-RAY OBSERVATORYCHANDRA X-RAY OBSERVATORY

1 Msec Deep Image

24 April 2009

Brooks School

Cassiopeia A: Supernova Remnant

X-ray: hot gas, stellar remnantOptical: stars + cool gas/dust

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Crab NebulaCHANDRA HST

24 April 2009

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Actual Chandra First Light

• Point Source to focus: Quasar PKS0637-75, z=0.5

• X-ray Jet visible: 5” long, 200,000 lyrs

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Synchrotron and Inverse Compton Radiation

24 April 2009

Brooks School

X-ray/Radio Jets in Active Galaxies

M87 jet in X-ray, radio and optical D=15 Mpc

24 April 2009

Brooks School

AGN Outbursts and Feedback in Clusters

• X-rays → Gas in clusters: – Site of star-formation– Accretes onto AGN

• Accretion: fuels AGN+feeds outbursts → radio/X-ray jet

• Outburst heats + displaces gas → shocks (kpc)

• Slows cooling + accretion• This Feedback regulates:

– galaxy mass– star formation– AGN growth

M87: nested shocks

MS0735: Radio(red) X-ray(blue)

(600 000 ly)

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Brooks School

Dark Matter: Direct Visualization

• Colliding Galaxy Clusters: – Chandra (pink)

– HST,Magellan (white)

– Dark Matter (blue, measured via gravitational lensing)

• Interpretation:– Drag on gas

– No drag on stars/dark matter

– Gravity due to dark matter clearly separated from baryons (gas)

Bullet cluster

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Bullet Cluster Animation

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Brooks School

NGC 6240: Galaxy with Double X-ray Core

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Brooks School

NGC 6240NGC 6240 Movie Movie

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Brooks School

Cosmology: Structure of the Universe

Distance MeasurementSize of an object

Brightness of an object• Luminosity, L• Flux, F=L/4πr2

• If know L, measure F and determine r

• L determined from observations of many similar sources

r

L

Star

EarthF

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Brooks School

Cosmology with Chandra Observations of Clusters

Optical/X-ray of Abell 85 Growth of Structure: Simulation

Universe is expanding, distance related to velocity

Clusters are too bright → Dark Energy

24 April 2009

Brooks School

Matter and Energy Content of the Universe

Dark Energy: • Anti gravity • Consistent with energy

in the vacuum• Non-zero cosmological

constant in Einstein’s General Relativity

OR• Einstein GR is

wrong/needs updating

24 April 2009

Brooks School

A bit about me!• Dr. Belinda Wilkes, Professional Astrophysicist

(Astronomer)• Smithsonian Astrophysical Observatory,

Cambridge, MA• On contract to NASA to run Chandra X-ray

Observatory (Hubble’s X-ray sister)– Assistant Director, Chandra X-ray Center

• English, BSc (St. Andrews), PhD (Cambridge, UK)• In USA since 1982• Charlotte Garcia’s Mother!

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Closing

http://chandra.harvard.edu

CHANDRA X-RAY OBSERVATORY