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Science with SWIFT.

Science with SWIFT. The SWIFT Team: Niranjan Thatte , Matthias Tecza , Fraser Clarke, Tim Goodsall , Lisa Fogarty, Graeme Salter, Susan Kassin . Collaborators: Roger Davies, Ryan Houghton, Nic Scott, Aprajita Verma . What is SWIFT?. 1. QE. 0. 0.7. 1.0. Wavelength ( μm ). 0.235”.

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Science with SWIFT.

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  1. Science with SWIFT. The SWIFT Team: NiranjanThatte, Matthias Tecza, Fraser Clarke, Tim Goodsall, Lisa Fogarty, Graeme Salter, Susan Kassin. Collaborators: Roger Davies, Ryan Houghton, Nic Scott, AprajitaVerma.

  2. What is SWIFT? 1 QE 0 0.7 1.0 Wavelength (μm)

  3. 0.235” 0.160” 0.080” 10.3” × 20.9” 7 7.0” × 14.2” For non-AO observations For NGS /LGS observations For PALM3K observations 3.5” × 7.1”

  4. The Arp147 System.

  5. Arp147 Mihos & Hernquist 1994 Off-axis collision: Gerber et al. 1992

  6. Arp147

  7. Arp 147 Ring Galaxy SFR: 6.5M/yr – 6Myr ETG SFR: 0.1M/yr – 11Myr

  8. Calculated Formation Timescales. Vel:151±7kms-1 Dist:12.8kpc Vel:225±8kms-1 Diam:9.25kpc Timescale for Ring Expansion:<50Myr Angle of collision: 33°-57°

  9. The Coma ETG Sample A221258 A221258 A221258 A221259 A221259 A221343 A221343 NGC4860 Dressler193 • We observed a sample of 14 early-type galaxies in the Coma cluster, selected from the catalogue of Scodeggio+(1998) • Coma is an ideal target for FP observations, containing many nearby ETGs covering a range of masses, all with a common distance • Our sample was evenly divided between 7 logarithmic bins in velocity dispersion, covering the range σ=80-400 kms-1 • Galaxies were typically covered out to ~1 Re, with multiple pointings where necessary UGC8129 A221295 A221256 A221295 PGC44602 A221345 A221345 A221295 A221295 NGC4883 A221345 A221345 A221362 IC4051 UGC8129 IC4011 A221362 A221303 NGC4873 A221354 NGC4886 A221277 A221303 A221277 PGC44533 UGC8129 NGC4867 NGC4889 A221256 NGC4874 NGC4872 A221304 A221277 A221277 A221256 A221256 A221332 A221304 A221304 PGC44662 A221332 A221332 SDSS gri image of the Coma cluster A221332 Slides Courtesy of Nic Scott.

  10. SWIFT Observations NGC4867 • 20 min exposures used to limit impact of cosmic rays • Exposures stacked to give a S/N ratio ~60 within 1 Re • For objects with Re < 5” a nod-on chip observing strategy was used • For larger objects separate sky exposures were taken • For the three largest galaxies with Re > 20” we constructed a mosaic of each object from multiple pointings • Data was reduced using the dedicated SWIFT IRAF pipeline (see Ryan Houghton’s poster) • A sophisticated sky subtraction scheme was used, fitting and subtracting the continuum and emission line components of the sky background separately – the sky line flux is ~100 times that in the absorption features so good sky subtraction is essential • High S/N spectra measured within elliptical apertures of major-axis radius 1 Re were extracted to measure the FP parameters Slides Courtesy of Nic Scott.

  11. Kinematics of Coma ETGs NGC4867 PGC44662 • Voronoibinning (Cappellari & Copin) used to achieve a uniform S/N ~ 40 per spatial bin per Å • The penalized PiXel Fitting code of Cappellari and Emsellem(pPXF) used to extract galaxy kinematics from the Calcium Triplet • For each galaxy we constructed maps of the velocity and velocity dispersion • Quantifying the angular momenta of these galaxies via the λR parameter (Emsellem et al. ) and measuring the FP parameters is currently ongoing NGC4874 NGC4872 NGC4886 IC4011 Slides Courtesy of Nic Scott.

  12. An IFU study of the Fundamental Plane • The Fundamental Plane (FP) is a key diagnostic of early-type galaxy (ETG) evolution • The Virial Theorem predicts a tight relationship between the effective radius (Re), and surface brigthness (Ie) and velocity dispersion (σe) within that radius • To properly measure these quantities we require spatially resolved, 2D spectroscopic data • The tilt of the observed FP compared to the Virial prediction is a key tool in understanding the dark matter content of ETGs – to accurately quantify this tilt we require IFU observations of a sample of ETGs The FP of Jorgensen+96 using long-slit observations of several hundred cluster ETGs Slides Courtesy of Nic Scott.

  13. High Redshift Galaxy Kinematics Bulge+Disc z=0.8 SWIFT Obs: OII at 6755nm OIII at 9125nm Ring z=1.16 SWIFT Obs: OII at 8106nm Eagle z=0.8 SWIFT Obs: OII at 6592nm OIII at 8855nm

  14. The Eagle N N E E Seeing Seeing 13.6’’ 13.6’’ 8.7’’ 8.7’’

  15. The Eagle Flux Velocity Sigma 7’’

  16. Conclusion • SWIFT – many and varied science cases. • IFU data very valuable for its 3D nature. • The future is bright!

  17. Questions.

  18. Science Cases. • Arp147 • Coma • Eagle (high-z) • Aprajita’s Lens? • Mention Ly-alpha?

  19. Coma Text • Veronoi binning (Cappellari & Copin ??) used to achieve a uniform S/N ~ 40 per spatial bin per Å • The penalized PiXel Fitting code of Cappellari and Emsellem (??, pPXF) used to extract galaxy kinematics from the Calcium Triplet • For each galaxy we constructed maps of the velocity and velocity dispersion • Quantifying the angular momenta of these galaxies via the λR parameter and measuring the FP parameters is currently ongoing

  20. Coma Cluster Science • The sample

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