1. Thessaloniki, Oct 3rd 2009 Cool dusty galaxies: the impact of the Herschel mission Michael Rowan-Robinson Imperial College London

2. Thessaloniki, Oct 3rd 2009 Cool dusty galaxies: the impact of the Herschel mission To set the scene for the Herschel far infrared and submillimetre mission, I’m going to talk first about some of the key discoveries from the IRAS and Spitzer missions

3. Thessaloniki, Oct 3rd 2009 1983 saw the launch of IRAS, the Infrared Astronomical Satellite, which made the first all-sky survey at infrared wavelengths, from 10-100 microns IRAS

4. Thessaloniki, Oct 3rd 2009 IRAS - the infrared ‘cirrus’ south celestial pole emission from clouds of interstellar dust in our Galaxy, the infrared ‘cirrus’

5. Thessaloniki, Oct 3rd 2009 IRAS - star forming regions constellation Orion LMC, the Large Magellanic Cloud

6. Thessaloniki, Oct 3rd 2009 IRAS discovered ultraluminous infrared galaxies, forming stars 100-1000 times faster than our Galaxy, probably caused by mergers between two galaxies this is an HST image of Arp 220 Uultraluminous infrared galaxies

7. Thessaloniki, Oct 3rd 2009 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.

8. Thessaloniki, Oct 3rd 2009 IRAS the IRAS all-sky survey of infrared point-sources: white: star-forming regions, blue: red giant stars, green: galaxies. IRAS detected 60,000 dusty, star-forming glaxies over the whole sky.

9. Thessaloniki, Oct 3rd 2009 SPITZER, 2003

10. Thessaloniki, Oct 3rd 2009 LMC star formation in our nearest neighbour, the Large Magellanic Cloud, seen at infrared wavelengths

11. Thessaloniki, Oct 3rd 2009 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

12. Thessaloniki, Oct 3rd 2009

13. infrared emission from debris along a comet orbit

14. Thessaloniki, Oct 3rd 2009 SINGS - Spitzer Nearby Galaxy Survey 75 nearby galaxies detailed studies of their gas, dust, and star- formation rate M81

15. Thessaloniki, Oct 3rd 2009 visible (HST) and infrared (Spitzer) images of M51, the ‘Whirlpool’ galaxy

16. Thessaloniki, Oct 3rd 2009 Sombrero galaxy

17. Thessaloniki, Oct 3rd 2009 Two interacting galaxies

18. Thessaloniki, Oct 3rd 2009 Visible and infrared images of the star-forming galaxy Messier 82

19. Thessaloniki, Oct 3rd 2009 High-redshift galaxies with Spitzer Egami et al 2005: z ~ 6.7 lensed galaxy with M = 10 9 M o, stellar age at least 50 Myr Spitzer is only an 85-cm telescope, but it can detect the most distant galaxies known

20. Thessaloniki, Oct 3rd 2009 SWIRE (Spitzer Wide-Area IR Extragalactic Survey) I’ve been mainly involved with SWIRE, a survey of ~50 square degrees of the sky at 3.6-160 microns. We found 1.5 million galaxies and have used their optical and near infrared colours to estimate their distances, and hence their luminosities, star-formation rates, stellar masses and dust masses

21. Thessaloniki, Oct 3rd 2009 optical templates for photometric redshifts t These are the galaxy templates we use for estimating the redshift of the galaxies (Rowan-Robinson et al 2008)

22. Thessaloniki, Oct 3rd 2009 Over 1 million photometric redshifts This shows the kind of performance we achieve, a comparison of our photometric redshifts with spectroscopic redshifts 5 optical bands, + 3.6, 4.5  m

23. Thessaloniki, Oct 3rd 2009 SPITZER-IRS spectra of ULIRGs detailed infrared spectra of some ultraluminous infrared galaxies (ULIRGs), and our models for these we need Herschel to test the behaviourof these galaxies at submillimetre wavelengths (Farrah et al, 2008) our infrared templates

24. Thessaloniki, Oct 3rd 2009 star-formation rate v. redshift whole SWIREcatalogue strong selection effects consistent with strong rise to z = 1.5 (RR et al 2008)

25. Thessaloniki, Oct 3rd 2009 star formation history as a function of redshift The Infrared Space Observatory (1996- 9) showed a steep rise in the star- formation rate to z = 1 submm surveys and surveys with Spitzer show flat behaviour from z = 1 - 2.5 very uncertain at z > 2-3 Herschel surveys will detect thousands of high-redshift star- forming galaxies

26. Thessaloniki, Oct 3rd 2009 SOURCE COUNTS AT 24 microns to understand the numbers of sources as a function of brightness, different tyes of galaxy need to undergo different evolutionary histories M82 cirrus dust tori

27. Thessaloniki, Oct 3rd 2009 COUNTS AT 8-1100  m, ir background Predicted counts from 8 1100 microns, comparison with observed counts at 160, 850 and 1100 microns, and with integrated background spectrum (Rowan-Robinson 2009) Integrated background spectrum 160  m 850  m 1100  m

28. Thessaloniki, Oct 3rd 2009 HERSCHEL SPACE OBSERVATORY Herschel launch May 14th 2009, now in orbit at L2 Science demonstration phase started two weeks ago

29. Thessaloniki, Oct 3rd 2009 HERSCHEL SPACE OBSERVATORY Composite of M51 with PACS array

30. Thessaloniki, Oct 3rd 2009 HERSCHEL SPACE OBSERVATORY SPIRE images of M66 and M74

31. Thessaloniki, Oct 3rd 2009 HERSCHEL SPACE OBSERVATORY SPIRE images of M74 (and high redshift galaxies ?) at 250, 350, 500  m

32. Thessaloniki, Oct 3rd 2009 Messier83 background galaxies very clear on latest image,of M83

33. Thessaloniki, Oct 3rd 2009 Herschel view of the Milky Way

34. Thessaloniki, Oct 3rd 2009 European-ELT: 2017 Proposed 43-m, segmented mirror, working at 0.6-23 microns. Will allow us to image exoplanets, take their spectra, and to see the very first galaxies in the universe, at redshift > 10