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Galaxy Forum Africa 11 - Petri Galaxy Forum Africa 11 - Petri Presentation Transcript

  • South African AstronomicalFacilities and Galaxy Research Petri Vaisanen - SAAO and SALT
  • Outline ● Astronomy in South Africa ● Astronomical Facilities in SA ● Various galaxy research projects7 Oct 2011 ILOA/ SAAO
  • 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
  • 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
  • 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
  • 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 Oct 2011 ILOA/ SAAO Summer School 7
  • 7 Oct 2011 ILOA/ SAAO
  • 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.
  • 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
  • 91 one-metre segments - with passive and active alignment systems7 October 2011 ILOA/ SAAO
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • MeerKAT – under construction Summer School 18
  • Summer School 19
  • 7 Oct 2011 ILOA/ SAAO
  • 7 Oct 2011 ILOA/ SAAO
  • 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
  • H.E.S.S.Array of 4 telescopesMultiple telescopes allowsstereoscopic reconstructionof shower geometry7 Oct 2011 ILOA/ SAAO Summer School 23
  • 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
  • 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?
  • 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.
  • 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
  • e.g. the Antennea galaxies
  • Star formation density vs. redshiftNormal galaxies LIRGS ULIRGs
  • 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
  • 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
  • SAAO 1.9-m spectroscopy and NOT nb-imaging of starburst galaxies Future: metallicity gradients in interactions with SALT/RSS H_alpha R-band
  • ESO 221-IG0087 Oct 2011 ILOA/ SAAO
  • IRAS 19115-212418 March 2011 Granada
  • IRAS 19115-212418 March 2011 Granada
  • IRAS 19115-2124 – “The Bird”18 March 2011 Granada
  • 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/
  • 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
  • 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
  • Local star-bursting dwarfs (led by Alexei Kniazev, SALT/SAAO)7 Oct 2011 ILOA/ SAAO
  • 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
  • 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)
  • Spectra7 Oct 2011 ILOA/ SAAO
  • 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?
  • University of Witwatersrand (Prof. David Block, Dr. Robert Groess, et al.) Classifying galaxies Modelling galaxies Especially IR galaxies7 Oct 2011 ILOA/ SAAO
  • 7 Oct 2011 ILOA/ SAAO
  • 7 Oct 2011 ILOA/ SAAO
  • Lenticular galaxy formation: An Observers Prospective Sudhanshu Barway South African Astronomical Observatory (SAAO) Ajit K. Kembhavi (IUCAA)Yogesh Wadadekar (NCRA) Y. Divakara Mayya (INAOE)
  • Lenticular GalaxiesLenticular galaxies come in a variety of shapes –Nuclear structuresCentral 10″ x10″ region of galaxies from HST-WFPC2, I band images
  • 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
  • Dr. David Gilbank (SAAO)7 Oct 2011 ILOA/ SAAO
  • 7 Oct 2011 ILOA/ SAAO
  • 7 Oct 2011 ILOA/ SAAO
  • + many post-docs and students [Slides courtesy of Catherine Cress (UWC)]
  • 7 Oct 2011 ILOA/ SAAO
  • 7 Oct 2011 ILOA/ SAAO
  • 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