Galaxy Forum Africa 11 - Petri

1,111 views
1,050 views

Published on

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,111
On SlideShare
0
From Embeds
0
Number of Embeds
443
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Galaxy Forum Africa 11 - Petri

  1. 1. South African AstronomicalFacilities and Galaxy Research Petri Vaisanen - SAAO and SALT
  2. 2. Outline ● Astronomy in South Africa ● Astronomical Facilities in SA ● Various galaxy research projects7 Oct 2011 ILOA/ SAAO
  3. 3. National Astronomical Facilities ☻H.E.S.S.South African Astronomical Observatory (SAAO) ☻HartRAOSouthern African Large Telescope (SALT)Hartebesthoek Radio Observatory (HartRAO)High Energy Stereoscopic System ☻KAT-7 (H.E.S.S.) ☻SAAO + SALTKaroo Array Telescope (MeerKAT) (KAT) XSquare Kilometre Array (SKA) You are here7 Oct 2011 ILOA/ SAAO Summer School 3
  4. 4. South African Astronomical Observatory Mission: to perform research in astronomy; To provide an international facility in Africa for such research; to educate and inform the communityTotal staff: >120Scientists: Physics Astronomy MathematicsEngineers/Technicians Electronics Mechanical Optical ComputerScience Educators History: dates from 1820 HQ: Cape Town, Western Cape7 Oct 2011 ILOA/ SAAO Observing Facilities: Sutherland, Northern Cape Summer School 4
  5. 5. Where is Sutherland and SALT? Sutherland Good dark astronomical site: Aseasonal with 75% nights spectroscopic or better - 50% are photometric Median seeing of 0.9 arcsec (DIMM)SAAO & SALT HQ ~1800 m altitude 7 October 2011 ILOA/ SAAO
  6. 6. SAAO Research Facility Sutherland - Time share: reflecting telescopes: ~20% international 1.9, 1.0, 0.75, 0.5 m, ~20% SA universities + 1.4 m IRSF and several new ~60 % SAAO small and 1.0-m class robotic telescopes7 Oct 2011 ILOA/ SAAO Summer School 6
  7. 7. 7 Oct 2011 ILOA/ SAAO Summer School 7
  8. 8. 7 Oct 2011 ILOA/ SAAO
  9. 9. First light and start of Initial science verificationcommissioning at end of phase in 2006 - 2007.2005. Problems identified….Engineering team left then. Off-sky from April 2009 to August 2010 for a major fix. Re-commissioning of telescope and instruments since then. Back to science operations in mid- 2011.
  10. 10. SALT: A Fixed Elevation Optical-IR Telescope (modelled on the Hobby-Eberly Telescope (HET) in Texas) SALT’s BASIC ATTRIBUTES• 11-m SEGMENTED PRIMARY MIRROR – Spherical Figure – 91 identical hexagonal segments• TELESCOPE FIXED TILT AT 37o – Azimuth (left-right) rotation for pointing only – Reaches 70% of total southern sky and 12.5% of sky at any one time• OBJECTS TRACKED BY “TRACKER” – Tracker contains “Payload” with optics & instruments 7 October 2011 ILOA/ SAAO
  11. 11. 91 one-metre segments - with passive and active alignment systems7 October 2011 ILOA/ SAAO
  12. 12. Annulus of visibilityfor SALT:Annulus represents12.5% of visible sky atany point of timeDeclination range:+10º to -75ºObservation timeavailable = timetaken to crossannulus7 October 2011 ILOA/ SAAO
  13. 13. NGC6864 SALTICAM (built @ SAAO)• CCD camera: 320 to 900 nm range, 10x10 arcmin field-of-view .• UBVRI, uv-340, uv-380, Sloan, Stromgren filters• Time resolution down to 60 ms (slot and frame-transfer mode)• Drift-scanning Has worked well from the beginning 7 October 2011 ILOA/ SAAO 47 Tuc: Lagoon Nebula
  14. 14. RSS: Robert Stobie Spectrograph (formerly PFIS) PI: Ken Nordsieck, University of Wisconsin-Madison• Long slit and multi-object (>100) spectroscopy (320-900 nm, medium resolution, R to 6,000 @ 1 arcsec) over 8’ diameter FoV, UV coverage is rare on large telescopes• Volume Phase Holographic transmission gratings and ‘swinging’ camera enable very flexible Res and wavelength coverage.• Fabry-Perot imaging spectroscopy using double etalons R = 320- 770 (low res.), R = 1250 – 1650 (medium) & 9000 (high)• Imaging polarimetric and spectropolarimetric modes• High Time resolution ~100 ms spectroscopy (charge shuffling, no dead-time) and fast photometry (rare on large telescopes),• Upgrade to near-IR beam (J,H ~2012)7 October 2011 ILOA/ SAAO
  15. 15. RSS: Robert Stobie Spectrograph (formerly PFIS) PI: Ken Nordsieck, University of Wisconsin-Madison• Long slit and multi-object (>100) spectroscopy (320-900 nm, medium resolution, R to 6,000 @ 1 arcsec) over 8’ diameter FoV, UV coverage is rare on large telescopes• Volume Phase Holographic transmission gratings and ‘swinging’ camera enable very flexible Res and wavelength coverage.• Fabry-Perot imaging spectroscopy using double etalons R = 320- 770 (low res.), R = 1250 – 1650 (medium) & 9000 (high)• Imaging polarimetric and spectropolarimetric modes• High Time resolution ~100 ms spectroscopy (charge shuffling, no dead-time) and fast photometry (rare on large telescopes),• Upgrade to near-IR beam (J,H ~2012)7 October 2011 ILOA/ SAAO
  16. 16. Radio AstronomyHartebeesthoek Radio Observatory:26-m dish at Hartebeesthoek: International VLBI network (1960s NASA satellite tracking)SA bidding to host theSquare Kilometre Array (SKA) – KAT-7 (2010) – MeerKAT (2015+) – SKA (2020+)7 Oct 2011 ILOA/ SAAO Summer School 16
  17. 17. Radio AstronomyHartebeesthoek Radio Observatory:26-m dish at Hartebeesthoek: International VLBI network (1960s NASA satellite tracking)SA bidding to host theSquare Kilometre Array (SKA) – KAT-7 (2010) – MeerKAT (2015+) – SKA (2020+)7 Oct 2011 ILOA/ SAAO Summer School 17
  18. 18. MeerKAT – under construction Summer School 18
  19. 19. Summer School 19
  20. 20. 7 Oct 2011 ILOA/ SAAO
  21. 21. 7 Oct 2011 ILOA/ SAAO
  22. 22. Gamma-Ray Astronomy Gamma-Ray: South Africa is a partner in the High Energy Stereoscopic System (H.E.S.S.), based in Namibia And will participate in future gamma-ray observatories, HESS-II7 Oct 2011 ILOA/ SAAO Summer School 22
  23. 23. H.E.S.S.Array of 4 telescopesMultiple telescopes allowsstereoscopic reconstructionof shower geometry7 Oct 2011 ILOA/ SAAO Summer School 23
  24. 24. Number of PhD Astronomers in SA (October 2010) Institution Number Institution Number UCT 29 Wits 4 SAAO 25 UJ 3 UWC 8 UFS 2 UNW 7 UNISA 2 HartRAO 7 Rhodes 1 KAT 6 UZ 1 UKZN 6 101 astronomers (66 in Western Cape) and new posts in UCT, SAAO, UWC,7 Oct 2011 HartRAO, Wits, UNISA, SAAO ILOA/ Rhodes … Summer School 24
  25. 25. Galaxy formation and evolution questions? One of the main unsolved topics of modern astronomy and astrophysics Details regarding star formation and feedback from supernovae, AGN, etc. are complicated How and when did the first galaxies form? How and why are they changing now?
  26. 26. Star formation and dynamics in interacting IR galaxies Petri Väisänen (SAAO / SALT) Alexei Kniazev, Abiy Tekola, Zara Randriamanakoto, Rajin Ramphul Seppo Mattila, Jari Kotilainen, Juha Reunanen, Erkki Kankare (Turku),18 March 2011 Stuart Ryder (AAO), Miguel Perez-Torres (Granada), Granada Angela Adamo (Heidelberg), Goran Ostlin (Stockholm), et al.
  27. 27. Interacting and merging galaxies ● An evolutionary sequence – how is this happening exactly ? gas spirals → starburst / ULIRG → obscured AGN → QSO → elliptical galaxy7 Oct 2011 ILOA/ SAAO
  28. 28. e.g. the Antennea galaxies
  29. 29. Star formation density vs. redshiftNormal galaxies LIRGS ULIRGs
  30. 30. Many questions remain ● Interplay between AGN and star formation, what exactly triggers what? Are the evolutionary transitions causal or coincidental? ● How do the galactic outflows (feedback) affect the evolution? ● WHY are some galaxies LIRGs? ● And WHY are they not ULIRGs? ● How are the processes different at high redshifts?7 Oct 2011 ILOA/ SAAO
  31. 31. AO data of LIRGs ● VLT/NACO and Gemini/Altair NIR adaptive optics programs – High spatial resolution (~0.1”) K-band images of “LIRGs” – 32+8 targets, mostly at 60-120 Mpc, strong AGN excluded, wide range of interaction stages – Data match very well optical HST/ACS LIRG imaging archival data – Complemented by archival Spitzer data and ground based spectroscopy with SALT77Oct 2011 October 2011 ILOA/ SAAO
  32. 32. SAAO 1.9-m spectroscopy and NOT nb-imaging of starburst galaxies Future: metallicity gradients in interactions with SALT/RSS H_alpha R-band
  33. 33. ESO 221-IG0087 Oct 2011 ILOA/ SAAO
  34. 34. IRAS 19115-212418 March 2011 Granada
  35. 35. IRAS 19115-212418 March 2011 Granada
  36. 36. IRAS 19115-2124 – “The Bird”18 March 2011 Granada
  37. 37. RSS data Whats up with the Head ??SALT spectroscopy planned for whole sample Cool gas outflows of 100-400 km/s SAAO77Oct 2011 October 2011 Granada ILOA/
  38. 38. Bird - New data with SINFONI and VISIR ● cont. Pa α~80% of currentSF is in the smallestComponent.Bird is a LIRGbecause of its“Head”Vaisanen, Reunanen,Kotilainen (in prep.) 77Oct 2011 October 2011 ILOA/ SAAO
  39. 39. Super star clusters (SSC) ● Determining spatial distributions of SSCs and determining LFs ● Combining HST data to model ages and masses. Randriamanakoto et al. (in prep)77Oct 2011 October 2011 ILOA/ SAAO
  40. 40. Local star-bursting dwarfs (led by Alexei Kniazev, SALT/SAAO)7 Oct 2011 ILOA/ SAAO
  41. 41. Motivation Young galaxies at high redshifts are too faint to study them in detail. But their local cousins can provide a valuable information on the processes of galaxy formation and early evolution.7 Oct 2011 ILOA/ SAAO
  42. 42. HII in IC4662Distance of 2.5 Mpc.M(B) = -15.5 mag.Isolated galaxy.Previously studied byHidalgo-Games et al. (2001)with 3.6m ESO telescope: ΔV(A-D) = 200 km/s O/H = 0.5 dexWe would like to provedifference in O/H and Bvelocities between D andmain body: A1, A2, B.Measuring metallicities7 Oct 2011 ILOA/ SAAO Kniazev et al. (2010, in ~ 190”x180 Image size preparaion)
  43. 43. Spectra7 Oct 2011 ILOA/ SAAO
  44. 44. HII in IC4662 (4)Region SALT (O/H) 3.6m (O/H) E(B-V)A1 8.13±0.02 8.17±0.06 0.27A2 8.09±0.02 8.17±0.12 0.27D 7.92±0.08 7.70±0.10 0.27B 8.05±0.05 ... 0.24 Evidence for chemical inhomogeneity in a dIrr galaxy? (Kniyazev et al. 2005 for Sextans B) or gradient of abundances?
  45. 45. University of Witwatersrand (Prof. David Block, Dr. Robert Groess, et al.) Classifying galaxies Modelling galaxies Especially IR galaxies7 Oct 2011 ILOA/ SAAO
  46. 46. 7 Oct 2011 ILOA/ SAAO
  47. 47. 7 Oct 2011 ILOA/ SAAO
  48. 48. Lenticular galaxy formation: An Observers Prospective Sudhanshu Barway South African Astronomical Observatory (SAAO) Ajit K. Kembhavi (IUCAA)Yogesh Wadadekar (NCRA) Y. Divakara Mayya (INAOE)
  49. 49. Lenticular GalaxiesLenticular galaxies come in a variety of shapes –Nuclear structuresCentral 10″ x10″ region of galaxies from HST-WFPC2, I band images
  50. 50. Lenticular GalaxiesHow do galaxies form/evolve in different environments?Possible Physical Processeso Mergerso Harassment (high speed encounters)o Strangulation (interactions remove gas, halts star formation)o Ram pressure stripping (cluster medium removes gas, halts SF)o Non-gravitational processes (AGN, SNe) 7 Oct 2011 ILOA/ SAAO
  51. 51. Dr. David Gilbank (SAAO)7 Oct 2011 ILOA/ SAAO
  52. 52. 7 Oct 2011 ILOA/ SAAO
  53. 53. 7 Oct 2011 ILOA/ SAAO
  54. 54. + many post-docs and students [Slides courtesy of Catherine Cress (UWC)]
  55. 55. 7 Oct 2011 ILOA/ SAAO
  56. 56. 7 Oct 2011 ILOA/ SAAO
  57. 57. Summary: South Africa has a 10-m world-class telescope available, fitted with highly versatile instruments. World class facilities coming up in radio. It is a very exciting time to be working with astrophysical research in Africa!7 Oct 2011 ILOA/ SAAO

×