1 / 14

UV Spectroscopy of Star-Forming Galaxies

UV Spectroscopy of Star-Forming Galaxies. Alessandra Aloisi (ESA/STScI). Star-Forming Galaxies in the Local Universe. M31. SF is ongoing in nearby Sp and Irr Starbursts mostly in dwarfs & interacting/ merging galaxies. SMC. NGC 5253. Antennae.

arch
Download Presentation

UV Spectroscopy of Star-Forming Galaxies

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. UV Spectroscopy of Star-Forming Galaxies Alessandra Aloisi (ESA/STScI)

  2. Star-Forming Galaxies in the Local Universe M31 • SF is ongoing • in nearby • Sp and Irr • Starbursts • mostly in • dwarfs & • interacting/ • merging galaxies SMC NGC 5253 Antennae

  3. Star-Forming Galaxies in the High-z Universe HDF-N • Merging of galaxies • predicted by • hierarchical scenarios • Population of • star-forming and • interacting galaxies • observed at z 1 • (e.g., LBGs) HDF-S MS 1512-cB58

  4. Probing Nearby Star-Forming Galaxies • Laboratories to test • SF, evolution of • massive , & ISM • Easy targets where • to infer SF history, • chemical & physical • evolution • Low-z templates for • the high-z Universe Sextans A NGC 5253 & MS 1512-cB58 Dolphin et al. 2003 Tremonti et al. 2001

  5. UV Spectroscopy • SF young , massive, hot  rest-frame UV • HST optical for z > 2-3 • JWST 1-5 for z > 4-5 • Rest-frame UV rich • in transitions of • abundant ions/atoms • emission & • absorption • ISM absorption NGC 7714 González Delgado et al. 1999

  6. Absorption (Emission) Lines NGC 5253: stellar clusters • Broad low resolution • FWHM > 100 km/s • Spectral evolution • synthesis models SB99 •  regime •  age •  SFR •  extinction • Many studies •  HUT • HST • FUSE • GALEX Tremonti et al. 2001

  7. ISM Absorption Lines • Narrow high resolution • FWHM ~ 5-15 km/s • Physics, chemistry, • & kinematics •  molecular gas -T=102-3K •  neutral gas -T=102-3 K •  ionized gas -T=104 K •  coronal gas -T=105-6 K • Pilot studies •  HST/GHRS & STIS • NUV (1200-3200 Å) •  FUSE • FUV (900-1200 Å) M83: HUT (4 Å/pixel) & FUSE (0.04 Å/pixel) Leitherer et al. 2002

  8. Molecular Gas (H2) • FUSE band < 1120 Å rich in • H2 absorption lines • No detection of H2 in SBs & BCDs • N(H2) < 1015 cm-2 I Zw 18 Vidal-Madjar et al. 2000 H2 in dense clouds - ƒ< 1 H2 in diffuse ISM destroyed ? SB MW Hoopes et al. 2004 (submitted)

  9. Neutral Gas Thuan et al. 1997 • Few studies with GHRS • FUSE suitable for most • abundant species – H I, O I, • Ar I, Si II, P II, C II, N I, & Fe II • 3 BCDs studied in detail: • I Zw 18, I Zw 36, & Mkn 59 • ~ 25 SBs & BCDs will be • analyzed in the future SBS 0335-052 I Zw 18 H I more metal-poor than H II ? Aloisi et al. 2003

  10. Ionized Gas & Dust • Need of STISin addition to FUSE: • Ionization • C I,C II, C III, C IV Fe II, Fe III • Si II, Si III, Si IV Al II, Al III • Depletion • Zn & Mn - Fe Fe-peak elements • S - Si & O  elements • F  in star-forming galaxies -  < 0 • lower fluxes in STIS than in FUSE • only NGC 1705 with Echelle data

  11. GHRS & STIS Spectra of NGC 1705 STIS E140M 0.015 Å/pixel - 4 km/s Vázquez et al. (2004) GHRS G140L 0.56 Å/pixel - 140 km/s Heckman & Leitherer (1997) Sahu & Blades (1997) Sahu (1998)

  12. Coronal Gas • FUSE provides access to • O VI1032, 1038 doublet • O VIabsorption in few SBs • voutflow = 102-3 km/s • Only NGC 1705 modeled Outflow of hot gas through holes in a fragmented superbubble shell Heckman et al. 2001

  13. Requirements for the VLST • Abundances, ionization, depletion, • kinematics, & physics of ISM • wide UV spectral range 900-3200 Å • Saturation, multiple components, weaker lines • high-resolution R = 20,000-50,000 • v = 15-5 km/s • More SBs + normal SF galaxies & • reddened galaxies + fainter QSOs + higher z • flux limit F << 10-16erg/sec cm2Å@1400 Å • Spatial sampling of ISM • long slit , MOS, or integral field spectroscopy

  14. Conclusions • Emerging picture for ISM in nearby Universe will: • 1. help in understanding chemical & physical • evolution of local SF galaxies • 2. complement picture for Ly systems at higher z: • local / low z high z • (dusty) SF regions inactive regions • ISM in galaxy cores galaxy halos & IGM • serve as template for high-z SF galaxies - LBGs

More Related