1 / 21

Introduction to and methods of SPACE-based observational astronomy

Introduction to and methods of SPACE-based observational astronomy. 1 st MAGPOP School (Budapest, Aug 23-25 2006). Armando Gil de Paz (Universidad Complutense de Madrid). 3 rd lecture. Today’s lecture. Scheme. Past Missions:. IUE, IRAS, ISO data. Future:.

espen
Download Presentation

Introduction to and methods of SPACE-based observational astronomy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to and methods of SPACE-based observational astronomy 1st MAGPOP School(Budapest, Aug 23-25 2006) Armando Gil de Paz (Universidad Complutense de Madrid) 3rd lecture

  2. Today’s lecture Scheme Past Missions: • IUE, IRAS, ISO data Future: • James Webb Space Telescope (JWST) 1st MAGPOP School(Budapest, Aug 23-25 2006) Space-based Astronomy Tools and Science: • Use of Space-based data • Synergy with ground-based data (e.g. HST-Keck/VLT, JWST-ALMA)

  3. IUE summary: • Partners: Joint NASA, ESA, PPARC mission. 19 years operational (from its launch in 1978 to 1996). • Orbit: Geosynchronous over Atlantic. • Telescope: 45-cm f/15 Ritchey-Chretien Cassegrain. • Instrument: • Echelle spectrograph (1150-1980 ÅÅ, 1800-3350 ÅÅ) with 3” and 10”x20” apertures and high (0.1 Å) and low-resolution (6 Å) modes. Image quality: 2” • Cameras: SWP, LWP (short and long-wavelength prime), & SWR, LWR (redundant cameras). • Archive: 110000 spectra extracted from 104000 IUE images. Maintained at Villafranca tracking station (spectra processed using ESA’s INES software) at http://ines.laeff.esa.es/. A copy is also available through MAST although using an older pipeline version. Past missions: IUE 1st MAGPOP School(Budapest, Aug 23-25 2006)

  4. IUE: Archival Data 1st MAGPOP School(Budapest, Aug 23-25 2006)

  5. IRAS summary: • Partners: Joint project of the US, UK, and the Netherlands. Launched in January 1983. • Orbit: Sun-synchronous near-polar (99o). • Telescope: 57-cm f/9.6 Ritchey-Chretien. • Instruments: Survey Array, CPC, LRS. Past missions: IRAS 1st MAGPOP School(Budapest, Aug 23-25 2006) IRAS focal plane

  6. IRAS: Archival Data 1st MAGPOP School(Budapest, Aug 23-25 2006)

  7. Partners: ESA with the participation of ISAS & NASA. Built by Aerospatiale (now Alcatel). Launched by an Ariane IV in November 1995. Scientific observations were carried out between Feb’96-Apr’98. • Orbit: 24h-period high orbit inside and outside the Van Allen belts. Detectors unusable inside the belts. Past missions: ISO 1st MAGPOP School(Budapest, Aug 23-25 2006)

  8. M51 (ISOCAM LW3 - 14.5 um) • ISOCAM: Two imaging channels with 32×32 arrays operating between 2.5-5.5 um & 4-17 um and 21 filters (11 SW+10 LW). • LWS: It covered the range 43-200 um with R∼200 (R~10000 using Fabry-Pérot etalons). • ISOPHOT: Consists of three subsystems: • ISOPHOT-C, with two photometric cameras covering the range 50-240 um. • ISOPHOT-P, a multi-band, multi-aperture photo-polarimeter @ 3-110 um. • ISOPHOT-S, a dual grating spectro-photometer with R~90 in two simultaneous bands (2.5-5um & 6-12um). • SWS: It covered the range 2.4-45 um with R= 1000-2500 (25000 with FP etalons). ISO: Instruments 1st MAGPOP School(Budapest, Aug 23-25 2006) Points: PHT-C/P PHT-S SWS LWS

  9. ISO: Archival Data 1st MAGPOP School(Budapest, Aug 23-25 2006)

  10. James Webb Space Telescope: Summary Future missions: JWST • Developed by an industrial consortium under NASA’s supervision in collaboration with ESA (mostly for instrument development). • High orbit around the L2 Sun-Earth Lagrange point. Launch ~2013 by an Ariane V rocket. 1st MAGPOP School(Budapest, Aug 23-25 2006)

  11. JWST: Instruments 1st MAGPOP School(Budapest, Aug 23-25 2006)

  12. SPACE-based Astronomy Tools & Science(just a few examples) 1st MAGPOP School(Budapest, Aug 23-25 2006)

  13. ACS PSF NICMOS PSF MIPS PSF PSF photometry: Space-based Astronomy T&S • Critical for crowded fields, Supernova photometry, diffraction-limited images. • Not for use with -even marginally- resolved sources. 1st MAGPOP School(Budapest, Aug 23-25 2006) Procedure: • Determine PSF empirically from field stars, analytically (2D Gaussian, Lorenzt, Moffat) , or Hybrid. • Minimize:

  14. daophot + addstar + daophot • PSF-photometry software: ROMAFOT, STARMAN, DAOPHOT (Stetson 1987), DoPHOT, HSTPHOT • Alternatives: Aperture photometry, Sextractor, TFIT PSF-photometry science (HST CMD of nearby galaxies): Space-based Astronomy T&S 1st MAGPOP School(Budapest, Aug 23-25 2006) Gallart et al. (1999)

  15. GALEX FUV flux vs. HI (texp=30000s) Low background (Poisson statistics): Space-based Astronomy T&S • mean ≠ median ≠ mode • In extreme cases (FUV) most background pixels are zero. GALEX FUV flux vs. HI (texp=100s) GALEX FUV flux vs. HI (texp=1500s) 1st MAGPOP School(Budapest, Aug 23-25 2006) Braine et al. (2006, in prep.)

  16. Z M83 Gil de Paz et al. (2006) Roussel et al. (2005) E/S0 GALEX Optical HI 21cm Boselli et al. (2005) NGC1512 Favored extinction law Gil de Paz et al. (2006); IRX-beta (Meurer et al. 1995, 1999) GALEX Optical HI 21cm New windows: UV Space-based Astronomy T&S • SFR: The UV luminosity (once corrected for extinction) is a good Star Formation Rate tracer (via IMF). Sensitive to very low-levels of SF at low metal abundances (e.g. extended UV). • IRX- law:Since the intrinsic UV slope is approx. constant for continuous SF or smoothly-evolving SF histories, the measured UV slope provides a good estimate of the UV extinction. Good for not heavily extincted objects. • In highly attenuated objects the UV-to-TIR flux ratio can be used. 1st MAGPOP School(Budapest, Aug 23-25 2006) • UV upturn: Unexpected FUV rising flux in evolved stellar populations. First discovered in the nucleus of M31 by the OAO. Emission from BHB stars is suspected. The slope of the integrated CMD is opposite to that seen in the optical.

  17. New windows: IR Space-based Astronomy T&S • SFR: FIR emission due to dust heated by young hot stars: Good measure of the SFR. Advantage: It is extinction free. Disadvantage: Dust also heated by optical photons, especially a longer wavelengths (cooler dust). Thus, the 24 um luminosity provides the best correlation with extinction-corrected H-based SFRs (Calzetti et al. 2006: Pérez-Gonzalez et al. 2006). 1st MAGPOP School(Budapest, Aug 23-25 2006) • UV-to-TIR ratio: The best estimate of the UV extinction. It is almost independent of dust properties, geometry, and SFH (Buat et al. 2005). • MIR diagnostics: The study of the MIR provides important clues on: (1) Formation and excitation conditions of PAHs (2) The relevance of stochastically-heated VSGs (3) The chemical composition of evolved stellar populations (e.g. Silicates feature).

  18. NGC300 Roussel et al. (2005) • Nearby Galaxies: Spitzer + GALEX imaging combined with ground-based corollary data. Some examples: • Roussel et al. (2005) on NGC300 • Dale et al. (2006) on 75 SINGS objects. • Perez-Gonzalez et al. (2006) on M81 • Thilker et al. (2006) on NGC7331. Radial and small-scale properties of extinction, dust temperature, SFR; multi-wavelength SEDs for local templates. Dependence of dust attenuation properties with the clusters’ evolutionary stage. Synergy with ground-based astronomy 1st MAGPOP School(Budapest, Aug 23-25 2006)

  19. Synergy with ground-based astronomy • Cosmological redshift surveys (HST-Keck/VLT): • HST is not optimized for measuring redshifts of faint distant galaxies (just a 2.5m!) • Redshifts have traditionally come from 8-10m telescopes such as Keck, VLT, Gemini… • Unfortunately, most sources in deep imaging surveys with HST (HDF, UDF) are well beyond the spectroscopic limit (IAB~25-26). • Objective of new 30-m class telescopes (TMT,GMT,OWL). 6m 1st MAGPOP School(Budapest, Aug 23-25 2006) photo-z

  20. Synergy with ground-based astronomy • Future surveys (JWST-ALMA-30m synergy): • ALMA will provide an unprecedented sample of very distant galaxies thanks to the negative K-correction. • Targeted JWST programs will allow deriving rest-frame optical properties with superb resolution. • 30m-class telescopes should provide redshifts for ALMA sources with faint molecular-line emission. • … and (in some cases) in 3D using IFUs! 1st MAGPOP School(Budapest, Aug 23-25 2006)

  21. The EndSome notes on the CD-ROM content & Proposal-making practical session 1st MAGPOP School(Budapest, Aug 23-25 2006)

More Related