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Theme IV: Nearby Galaxies and the Galactic Center

Lead - G.J. Stacey Cornell University Deputy - W. Vacca USRA. Theme IV: Nearby Galaxies and the Galactic Center. Team Members. Gordon Stacey (Cornell) Formal Lead Science: Far-IR and submm spectroscopy of galaxies, Galactic starformation regions, Galactic Center

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Theme IV: Nearby Galaxies and the Galactic Center

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  1. Lead - G.J. Stacey Cornell University Deputy - W. Vacca USRA Theme IV: Nearby Galaxies and the Galactic Center

  2. Team Members • Gordon Stacey (Cornell) Formal Lead • Science: Far-IR and submm spectroscopy of galaxies, Galactic starformation regions, Galactic Center • Experience: KAO/ISO/JCMT – CSO • Investments: SOFIA (FORCAST/SAFIRE) • Unique Strength: Submm lines, Instrumentation • Bill Vacca (USRA) SOFIA Lead • Science: UV/Optical/Near IR spectroscopy & photometry galaxies, star clusters, massive stars • Experience: HST/Keck/IRTF/Gemini/Spitzer • Investments: SOFIA • Unique Strength: Optical studies, Stellar Populations

  3. Team Members • Sue Madden (CEA/Saclay) • Science: Mid/far-IR and spectroscopy and photometry of galaxies , Galactic star formation regions, Galactic Center • Experience: KAO/ISO (LWS/ISOCAM) • Investments: Herschel (SPIRE/PACS) • Unique Strength: Dwarf Galaxies, Dust continuum • Mark Morris (UCLA) • Science: Multi-wavelength studies of the Galactic Center • Experience: KAO/VLA/HST/Keck/Chandra/Spitzer • Investments: SOFIA • Unique Strength: Galactic Center

  4. Team Members • Linda Tacconi (MPE) • Science: Multi-wavelength spectroscopy of AGN/high z galaxies • Experience: FCRAO/JCMT/VLT/ISO(SWS) Spitzer IRAM Interferometer • Investments: Herschel (PACS) • Unique Strength: Molecular gas in high z galaxies • Mark Wolfire (Maryland) • Science: Theory – PDR/XDR and HII region modeling – Galactic star formation regions, Galactic Center, galaxies • Experience: KAO/ISO/Spitzer • Investments: SOFIA • Unique Strength: Theory, modeling

  5. Activities • Team assembled in April/May • Held several telecons: • Wed at 9 AM (PDT) • June 11, June 18, July 2, July 9, July 15 • Divided ‘Theme’ into 4 major topics (based on ideas from initial telecons and Gordon’s talk at the last review) • Assigned topics to individuals to present (via Powerpoint slides) to the group and lead the discussion • Presentations on 2 topics so far • Responsible person(s) to write up text on topic, incorporating comments from group • We have initial drafts of text on 2 topics

  6. Science Topics within Theme IV • Tracing the ‘Extinction-Free’ Evolution and Star Formation History of Galaxies in the local Universe, at redshifts 0 - 1 (Gordon Stacey) • ‘Low-redshift Cosmology’ • Studying the Circumnuclear Disk and Magnetic Fields of the Galactic Center (Mark Morris) • The GC as a template for AGN • Determining the conditions in the Tori of nearby Active Galactic Nuclei (Mark Wolfire) • Nearby Galaxies (Sue Madden & Bill Vacca) • Feedback (W. Matthews & Pasquale Temi)

  7. Galaxy Spectral Energy Distribution (SED) SOFIA

  8. SOFIA Strengths • Resolving power: • Uniquely high between 5 to 28 and 100 to 700 m (EXES, SAFIRE) • Wavelength coverage: • 9 octaves of wavelength coverage (1 to 700 m) • Covers the peak of dust SED in starburst galaxies • Post-Spitzer, near unique coverage from ~5 m (until JWST, then 28 m) through 60 m (Herschel) • Host of diagnostic lines from 5 to 60 m, including (post Spitzer) SOFIA-unique lines with FORCAST and FIFI-LS: [SIII] 33 m, [SiII] 35 m, [NeIII] 36 m, [OIII] 52 m, [NIII] 57 m

  9. SOFIA’s Regime Ground based windows for [CII] 158 m Evolution of Galaxies at 0 < z < 1 • FIR Fine-Structure lines provide ‘extinction-free’ estimates of strength and hardness of ionizing radiation • Distinguish between stars and AGN in dusty objects (e.g. ULIRGs) • Determine SFR and trace evolution of SFR with z • L([CII])/L(FIR) provides an estimate of size of starburst • Local (regional) starbursts at z~0 to global (galaxy-wide) at z~1 Blain et al 2002 ‘Extinction-corrected’ estimates of SFR/vol. from optical/NIR

  10. Evolution of Galaxies at 0 < z < 1 Near unique niches for studying the epoch from the peak of the star formation per unit volume through to today’s universe z ~ 0 to 1 for [CII] 158 m line – major gas coolant, probes PDRs, G, intensity, size of starburst z ~ 0 to 1 for [NII] 205 m line – probes low density HII regions, proxy for Lyman continuum photons, separates [CII] fraction from ionized gas. z > 2 [OI] 63 m studies – major PDR gas coolant, probes dense PDRs, G, size of starburst SAFIRE is quite competitive with Herschel (especially if SAFIRE is a grating spectrometer – otherwise a next generation spectrometer can fully exploit this sensitivity niche)

  11. Evolution of Galaxies at 0 < z < 1 SOFIA/SAFIRE is uniquely positioned for observations of FIR fine-structure lines (e.g., [OI], [O III], [CII], [NII]) in the critical range 0 < z < 1 Several hundred sources should be accessible from various surveys SOFIA will determine the true SFR history of the local Universe [CII] 158 m 5 detection in 2 hours

  12. Galactic Center: A Local Template for (Active) Galactic Nuclei • Most galaxies contain Super Massive Black Holes at their centers. The GC is the closest example and serves as the local template for more distant (active) galactic nuclei. • How is the SMBH fed? (What are the detailed physical processes involved in accretion onto the BH?) • What are the properties of and conditions in the Circum-nuclear Disk (CND) and how do they affect SF and accretion? • How does CND evolve? • What heats the gas in the GC? • What roles do shocks and turbulence play? • What role does the B field play?

  13. Galactic Center: Circumnuclear Disk Circumnuclear Disk (CND) is a reservoir for material accreting onto the central BH Both star formation and accretion are occurring inside inner edge Properties can be studied with almost all of SOFIA’s instruments Sensitivity is not an issue EXES will provide unique access to pure rotational lines of H2 at 12, 17, and 28 m and distinguish emission from different clouds to determine temps and masses Extensive mapping with SOFIA instruments will allow large scale perspective of events and conditions around a SMBH Large scale mapping can’t be done with Herschel FORCAST 38 m beam KIWC/KAO Latvakoski et al. 1999

  14. Galactic Center: Magnetic Fields 2003 • GC has strong B fields which affect accretion and star formation • Magnetic field measurements using HAWC polarimeter • The 7" beam (@ 60 m) would provide the best measure yet of the GC magnetic field strength • The magnetic field direction in the warmest clouds (including the CND) would be determined from the orientation of the polarization vectors. • Far IR polarimetry with a large FOV and good spatial resolution would be a truly unique capability! 60, 100 m polarimetry with KAO 350 m polarimetry with CSO

  15. Tori of Active Galactic Nuclei • Torus very warm (1000 K), and very dense(~ 107 cm-3)  strong neutral line emission (CO, [OI], H2O) • Typical source @ 100 Mpc: FJ=17-16 ~ 6  10-18 W-m-2 • High-J CO lines are clear signatures and primary coolants of the confining torus – and are very sensitive to the physical conditions of the torus • SOFIA Advantage:CO SED from J ~ 7-6 to J > 58 (46 m)! Artist’s conception of the doughnut shaped torus that confines the emission from an active nucleus (Credit ESA).

  16. Star Formation in Nearby Galaxies  Spitzer/IRAC @ 8 m ≈ SOFIA/FORCAST @ 24 m • How do stars form in galaxies? • The formation of ‘Super Star Clusters’ (SSCs) is major mode of Star Formation in galaxies • All stars in a galaxy may form in SSCs! • ‘Buried’ SSCs are young massive clusters still enshrouded in natal material, invisible in optical/NIR • FORCAST (grisms) and EXES give 3x better spatial resolution than Spitzer • Measure Te, Ne, Z, AV, excitation • Constrain stellar pops/IMF, ages, masses, dust properties • Study winds and feedback from winds on environment • Sensitivity generally not an issue

  17. Schedule July 21 Wed. @ 9am PDT End July / Beg Aug August 13 October 1 • Next telecon (on Nearby Galaxies) • Additional telecons • Collect written drafts on topics • Group will comment on written text • Full (initial) draft of theme document • Revise draft • Prepare PPT slides

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