nov 27th 2008southwold and reydon society from southwold skies to the universe - a journey through...

Nov 27th 2008 Southwold and Reydon Society

FROM SOUTHWOLD SKIES TO THE UNIVERSE

- a journey through space astronomy

Michael Rowan-Robinson


Atmospheric transmission

first detection of electromagnetic radiation outside the optical band:

Herschel (1800) detectedinfrared radiation from the sun


Radio astronomy•1933 Karl Jansky, detected Milky Way at radio wavelengths•1940s Grote Reber, mapped the Milky Way• 1945, John Hey, discovered point sources• 1955-65 Cambridge, Parkes, surveyed the sky and catalogued extragalactic radio sources - radio-galaxies and quasars• 1967 discovery of pulsars


X-ray astronomy from space

•1948 T.R.Burnight detects X-rays from sun using V2•1962 Giacconi detects X-ray binary Sco-X1 using Aerobee rocket•1963 Boyer detects Crab Nebula in X-rays (rocket)•1965 first extragalactic X-ray source (M87, Byram, rocket)•1970 Uhuru X-ray satellite maps sky at 2-20 KeV

The Uhuru satellite before launch

many subsequent X-ray missions, through to Chandra and XMM, both launched in 1999


Uhuru detected X-rays from compact sources in binary systems (white dwarfs, neutron stars, black holes), from quasars (massive black holes) and from very hot gas in clusters of galaxies (100 million degree)


Kitt Peak, Arizona, 1974, my first observing run


JCMT 1987


first submillimetre survey of the sky, using JCMT. several very luminous galaxies found - galaxies in the midst of their main star and heavy element formation.


1983 saw the launch ofIRAS, the Infrared Astronomical Satellite, which made the first all-sky survey at infrared wavelengths, from 10-100 microns

IRAS


The launch of IRAS


IRAS - the infrared ‘cirrus’

south celestial pole

emission from clouds of interstellar dust in our Galaxy


IRAS - star forming regions

constellation OrionLMC, the Large Magellanic Cloud


IRAS discovered ultraluminous infrared galaxies, forming stars 100-1000 times faster than our Galaxy, probably caused by mergers between two galaxies

this is an image of Arp 220

Uultraluminous infrared galaxies


IRAS - dust debris disks

IRAS also discovered dust debris disks around stars, confirmed by imaging with the Hubble Space Telescope, evidence for planetary systems in formation. Today over 300 exoplanets are known.


IRAS

the IRAS all-sky survey of infrared point-sources: white: star-forming regions, blue: red giant stars, green: galaxies


the William Herschel Telescope on La Palma, used to follow up IRAS galaxies


Mapping the Universe


Large scale structureThe 3-dimensionalThe 3-dimensional distribution ofdistribution of galaxies showsgalaxies shows structure on structure on different scales.different scales.

This can be usedThis can be used to estimate theto estimate the average density average density of the universe.of the universe.In dimenionlessIn dimenionless units:units:

~ 0.27 ~ 0.27


How much matter is there in the universe ?

The light elements D, He, LiThe light elements D, He, Li are generated from nuclearare generated from nuclear reactions about 1 minutereactions about 1 minute after the Big Bang. Theafter the Big Bang. The abundances turn out to abundances turn out to depend sensitively on thedepend sensitively on the density of ordinary matterdensity of ordinary matter in the universe.in the universe.

density ~ 4.10density ~ 4.10-28 -28 kg/cu m kg/cu m bb ~ 0.04 ~ 0.04


Evidence for Dark Matterthe speed at which starsthe speed at which starsorbit round a galaxy pointsorbit round a galaxy pointsto the existence of a haloto the existence of a haloof dark matter. of dark matter. sensitive surveys showsensitive surveys showthat this can not be due to that this can not be due to stars, or gas.stars, or gas.


Evidence for Dark Matter 2

images of clustersimages of clustersof galaxies withof galaxies withHST show arcsHST show arcsdue to gravitationaldue to gravitationallensing. These canlensing. These canbe used to weighbe used to weighthe cluster. Again,the cluster. Again,the cluster isthe cluster isdominated by darkdominated by darkmatter.matter.

Abell 2218


Need for Dark Matter

So there is far more matter (So there is far more matter (~ 0.27 ) ~ 0.27 ) out there than can be accounted for by out there than can be accounted for by the stuff we are made of (the stuff we are made of (bb ~ 0.04). ~ 0.04).

85% of the matter in the universe is 85% of the matter in the universe is ‘dark’ matter (the neutralino ?)‘dark’ matter (the neutralino ?)

Particle Physicists hope to detect this at Particle Physicists hope to detect this at the Large Hadron Colliderthe Large Hadron Collider


Audit of the mass-energy of the Universe:

4% ordinary matter

23% dark matter

73% dark energyDark en


History of the universe

Nov 27th 2008 Southwold and Reydon SocietySPITZER, 2003


IC1396, the Elephant’s Trunk- a dark globule inside an emission nebula

- a pair of newly formed stars have created a cavity

- the animation shows how the appearance changes from the optical, where dust absorbs light to the infrared where the dust radiates


QuickTime™ and aMPEG-4 Video decompressor

are needed to see this picture.


infrared emission from debris along a comet orbit


Sombrero galaxy- end-point of a galaxy merger


Two interacting galaxies


Visible and infrared images of the star-forming galaxy Messier 82


two new European Space Agency missions due for launch in April 2009

PlanckHerschel


Keck and VLT(Very Large Telescopes)


James Webb Space Telescope how to detect z = 10 galaxies ?

nov 27th 2008southwold and reydon society from southwold skies to the universe - a journey through...

Documents

clusters of galaxies

luminous galaxies

infrared cirrus

infrared wavelengths

point sources

iras galaxiesmapping

neutron stars

haloof dark matter