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Broad O VI Emission Wings From Active Stars

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15 Oct 2008 Still with HST, HI, OI and CII were discovered in the far UV, ii) a low-resolution (R=2000) long-slit spectrograph covering the same

Future Directions in Ultraviolet Spectroscopy

    Ultraviolet Spectroscopy

     A conference inspired by the accomplishments of the

     Far Ultraviolet Spectroscopic Explorer Mission

     Future Directions in

    The Future Directions in Ultraviolet Spectroscopy conference is sponsored by the

    Astrophysics Division of the National Aeronautics and Space Administration’s

    Science Mission Directorate, (NASA HQ) and the Canadian Space Agency (CSA).

    Additional support has been provided by the French Space Agency, Centre

    National d'Etudes Spatiales (CNES).

    A Conference Inspired by the Accomplishments of the 1

    Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

A Conference Inspired by the Accomplishments of the 2

Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

    Future Directions in Ultraviolet Spectroscopy

    October 20-22, 2008

    Annapolis, Maryland

    Final Program

    October 15, 2008

Sunday, October 19, 2008

17:00 19:00 Registration and Opening Reception

Monday, October 20, 2008

Session I, Chair and Provocateur: B. Savage

     9:00 C. Danforth (I) Finding "Missing" Baryons in the Local Universe?

     9:30 T. Tripp (I) New Results on O VI Absorbers, Warm-Hot Intergalactic Gas, and

     Feedback

    10:00 A. Narayanan (C) Probing the WHIM Gas Through Ne VIII Absorption

    10:15 Discussion

10:30 11:00 Coffee Break and Poster Viewing

Session II, Chair and Provocateur: C. Howk

    11:00 R. Lallement (I) Local Interstellar Medium: New Perspectives

    11:30 D. Bowen (I) The Distribution of Hot Gas in the Disk of the Milky Way

    12:00 V. Dixon (C) FUSE Observations of O VI Emission from the Milky Way

     and Beyond

    12:15 Discussion

12:30 13:30 Lunch and Poster Viewing

Session III, Chair and Provocateur: T. Heckman

    13:30 A. Aloisi (I) A UV Perspective of Starburst Galaxies

    14:00 G. Kriss (I) FUSE Observations of Active Galactic Nuclei and Prospects for the

     Future

    14:30 N. Lehner (C) The Magellanic System - Accretion, Feedback

    14:45 Discussion

15:00 15:30 Coffee Break and Poster Viewing

Session IV, Chair and Provocateur: A. Fullerton

    15:30 R. Prinja (I) Mass Loss from Hot Stars

    16:00 K. Werner (I) Abundances in Hot Evolved Stars

    16:30 N. Walborn (C) Systematics of Magellanic Cloud OB Spectra from FUSE

    16:45 Discussion

Invited talks (I) 30 minutes, including discussion

    Contributed talks (C) 15 minutes, including discussion

A Conference Inspired by the Accomplishments of the 3

    Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

    Tuesday, October 21, 2008

Session V, Chair and Provocateur: C. Froning

     9:00 K. Long (C) Disks, Winds, and White Dwarfs in Cataclysmic Variables

     9:15 S. Engle (C) The Secret FUV/X-ray Lives of Cepheids

     9:30 K. France (C) Far-UV Studies of H2 Emission from Photodissociation Regions

     9:45 V. Lebouteiller (C) Metal enrichment in the neutral gas of blue compact dwarfs 10:00 S. Mathur (C) Super-solar metallicity in AGNs measured with FUSE

    10:15 Discussion

    10:40 11:15 Coffee Break and Poster Viewing

Session VI, Chair and Provocateur: J. Linsky

    11:15 C. Oliveira (I) D/H Observations: Present Understanding and Future Perspectives 11:45 G. Steigman (I) Tracking The Post-BBN Evolution Of Deuterium

    12:15 Discussion

    12:30 13:30 Lunch and Poster Viewing

Session VII, Chair and Provocateur: C. Grady

    13:30 E. Guinan (I) The Sun in Time: Effects of the Young Sun's Radiation

    14:00 A. Brown (I) The Ultraviolet Environment of Protoplanetary Systems

    14:30 A. Gomex de Castro (C) The formation of planetary disks and winds

    14:45 15:15 Coffee Break and Poster Viewing

15:15 A. Vidal-Madjar (I) Ultraviolet Studies of Extra-Solar Planets

    15:45 A. Roberge (I) Gas in Protoplanetary and Debris Disks

    16:15 C. Martin-Zaidi (C) H in the circumstellar environments of Herbig Ae/Be stars 2

    16:30 Discussion

18:00 - 20:00 Conference Dinner (included with registration)

    W. Oegerle (I) After Dinner Remarks

    Director Astrophysics Division NASA GSFC

Wednesday, October 22, 2008

Session VIII, Chair and Provocateur: J. Morse

     9:00 M. Shull (I) The Cosmic Origins Spectrograph and the Future of UV Astronomy

     9:30 C. Martin (I) The Galaxy Evolution Explorer: Results and Future Implications 10:00 S. McCandliss (C) Essential observations of the Lyman continuum

    10:15 10:45 Coffee Break and Poster Viewing

10:45 K. Werner (C) WSO/UV - Ultraviolet mission for the next decade

    11:00 J. Green (I) Future Ultraviolet Observatories

    11:30 M. Postman (I) Future of UV Astronomy

    12:00 Discussion

12:30 Lunch

14:00 End of Conference

A Conference Inspired by the Accomplishments of the 4

    Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

    Oral Presentations & Discussions

    Monday, October 20, 2008

Session I, The Nearby Inter-Galactic Medium

    Dr. Blair D Savage University Wisconsin, Madison

    savage@astro.wisc.edu

     Provocateur

     10/20/2008 9:00:00 AM

Finding "Missing" Baryons in the Local Universe?

    Dr. Charles W Danforth University of Colorado

    danforth@casa.colorado.edu

    Simulations predict that shocks from large scale structure formation and galactic winds have reduced fraction of baryons in the warm, photoionized phase (the Lya Forest) from nearly 100% in the early universe to less than 50% today. Some of the remaining Invited Talk baryons are predicted to lie in the warm-hot ionized medium (WHIM) phase at T=105-

    107 K, but the quantity remains a highly tunable parameter of the models. Modern UV 10/20/2008 9:00:00 AM spectrographs we have allowed us unprecedented access to both the Lya Forest and

    potential WHIM tracers in the local universe. Several independant groups have

    constructed large catalogs far-UV absorbers along multiple AGN sight lines. There is general agreement between the surveys that the warm, photoionized phase makes up 30% of the baryon budget at z~0. Another 10% can be accounted for in collapsed structures. However, interpretation of the ~100 high-ion (OVI, etc) absorbers at z<0.4 is more

    controversial. These species are readily created in the shocks expected to exist in the IGM but they can also be created via photoionization and thus not represent WHIM

    material.

    I review here the results from several large IGM surveys and discuss the evidence for photoionized vs. WHIM OVI. Given the observational evidence and theoretical

    expectations, I argue that most of the observed OVI absorbers represent shocked gas at T~105.5 rather than photoionized gas and are thus valid tracers of the WHIM phase.

    Given this assumption, enriched gas at T=105-6 can account for ~10% of the baryon

    budget at z=0. The remaining 50% of the "missing" baryons may reside in gas T>106 or in metal-poor regions. Finally, I discuss ways in which COS data can expand the legacy of FUSE and STIS to solve the photo/shock OVI debate and account for additional

    WHIM baryons.

A Conference Inspired by the Accomplishments of the 5

    Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

    A High-Resolution Survey of Low-Redshift QSO Absorption Lines: New Results on O VI Absorbers, Warm-Hot Intergalactic Gas, and Feedback

    Dr. Todd M Tripp University of Massachusetts

    tripp@fcrao1.astro.umass.edu

    Currently, two broad questions are driving observational and theoretical studies of the low-redshift intergalactic medium: (1) Are the missing baryons located in the "warm-hot" Invited Talk intergalactic medium (WHIM) at the present epoch? Hydrodynamic cosmological simulations predict that as the universe evolves and large-scale structures grow, 10/20/2008 9:30:00 AM

    intergalactic gas accretes into increasingly deeper potential wells, and a substantial amount of intergalactic material is shock heated. By z = 0, the simulations predict that 20 - 50% of the baryons are shock heated to temperatures of 1e5 - 1e7 K, the so-called WHIM. This is purported to be a robust prediction from these popular simulations, but is there any observational evidence of the WHIM? (2) How do galaxies affect their surroundings, and how do surroundings affect their galaxies? Processes grouped under the rubric of "feedback" (e.g., supernova- or AGN-driven outflows) are often invoked to solve problems in galaxy evolution, but observational constraints on feedback are still quite limited. Conversely, theorists have suggested that gas accretion is more complex than previously thought and occurs in "cold" and "hot" flavors.

     To provide observational constraints relevant to these topics, we have been conducting a high-resolution spectroscopic study of the low-redshift IGM using QSO absorption lines. This talk will summarize several new results from this survey, with a focus on QSO absorption systems detected in the O VI doublet. The O VI doublet is frequently detected in low-z QSO spectra, but it will be shown that the absorbers have some surprising properties, e.g., the gas is often cooler than expected (T << 1.0e5 K), sometimes quite enriched with metals (in some cases approaching solar metallicity), and rather far from luminous galaxies.

Probing the WHIM Gas Through Ne VIII Absorption

    Dr. Anand Narayanan University of Wisconsin

    Bart P. Wakker, Blair D. Savage

    anand@astro.wisc.edu

    We report the detection of Ne VIII in the intergalactic medium at z=0.32566 in the FUSE spectrum of the z=0.6460 quasar 3C263. The Ne VIII 770 feature is detected at a significance of 2.9 sigma. This is a conservative limit since the measurement also takes Contributed Talk into account the continuum placement and fixed pattern noise errors. Additionally, O III, 10/20/2008 10:00:00 AM

    O IV and N IV are detected at the same velocity as Ne VIII. The rest-frame equivalent width of the Ne VIII 770 feature is Wr=50.7+/-17.5 mA, with an apparent column density of log N(Ne VIII)=14.02(-0.18 +0.13) and b(Ne) = 67.3+/-4.1 km/s. The Ne VIII 780 line is heavily contaminated by Ly-gamma at z =0.089. The rest-frame equivalent widths of the other lines are Wr(O III 832)=96.5 ? 14.1 mA, Wr(O IV 788)=79.8+/-12.9 mA and Wr(N IV 765)=87.9+/-18.8 mA. The low ionization O II 834 line is not detected, with a 3 sigma upper limit of 21 mA.

    A Conference Inspired by the Accomplishments of the 1

    Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

    Using photoionization models, we show that the Ne VIII traces gas of a different density and temperature compared to the moderately ionized species. A single phase model of photoionized gas within a column density range of log N(HI)=14.6-16.2 cm-2, log n~-3.83 cm-3, and a metallicity range of [Z/H]=0.09 to -1.78, can explain the observed O II, O III, O IV and N IV. However, for this range of metallicity, the models require a log n~-6 cm-3 in order to reproduce the observed N(Ne VIII). Alternatively, collisional ionization in a hot gas can also generate the observed N(NeVIII). This would require temperatures in excess of 105 K, making this system an interesting probe of the shock-heated warm-hot intergalactic medium (WHIM). COS observations will provide better constrains on the physical nature of this multiphase system through coverage of associated O VI and H I lines.

Session II, The Interstellar Medium

    Dr. Chris Howk Univesity of Notre Dame

    jhowk@nd.edu

     Provocateur

     10/20/2008 11:00:00 AM

Local Interstellar Medium: New Perspectives

    Dr. Rosine Lallement Service d'Aéronomie /IPSL/UVSQ

    Rosine.Lallement@aerov.jussieu.fr

    I will discuss some recent results on the local interstellar gas distribution : -titanium absorption measurements and updated correlations between deuterium and metals. -dense gas distribution inferred from optical absorption data. -recent modeling of X-ray emission Invited Talk following charge exchange between solar wind high ions and interstellar neutrals, induced contamination of the soft-X ray background and consequences for the Local 10/20/2008 11:00:00 AM

    Cavity hot gas. -comparison of X-ray data with high ions from FUSE (Welsh et al): both suggest a lack of hot gas at small distance of the galactic plane in the local cavity. I will discuss the need for new high resolution soft X-ray, UV and optical data.

A Conference Inspired by the Accomplishments of the 2

    Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

    The Distribution of Hot Gas in the Disk of the Milky Way

    Dr. David V Bowen Princeton University

    E. B. Jenkins, T. M. Tripp, K. R. Sembach, B. D. Savage, H. W. Moos

    dvb@astro.princeton.edu

    We review the results of a FUSE-team program designed to characterize the distribution of hot gas in the disk of the Milky Way. By observing OVI absorption lines towards 148 Invited Talk early-type stars at distances of more than 1 kpc, combining our new results with earlier surveys of OVI, and eliminating stars that show conspicuous localized X-ray emission, 10/20/2008 11:30:00 AM

    we find an average OVI mid-plane density of 1.3e-8 cm-3. The density decreases away from the plane of the Galaxy in a way that is consistent with an exponential scale height of 3.2 kpc at negative latitudes or 4.6 kpc at positive latitudes. Average volume densities of OVI along different sight lines exhibit a dispersion of about 0.26 dex, irrespective of the distances to the target stars. This indicates that OVI does not arise in randomly situated clouds of a fixed size and density, but instead is distributed in regions that have a very broad range of column densities, with the more strongly absorbing clouds having a lower space density. Line widths and centroid velocities are much larger than those expected from differential Galactic rotation, but they are nevertheless correlated with distance and OVI column density, which reinforces our picture of a diverse population of hot plasma regions that are ubiquitous over the entire Galactic disk. The velocity extremes of the OVI profiles show a loose correlation with those of very strong lines of less ionized species, supporting a picture of a turbulent, multiphase medium churned by shock-heated gas from multiple supernova explosions.

FUSE Observations of O VI Emission from the Milky Way and Beyond

    Dr. W. Van Dyke Dixon Johns Hopkins University

    R. Sankrit (USRA)

    wvd@pha.jhu.edu

    Observers using the Far Ultraviolet Spectroscopic Explorer (FUSE) have detected emission in the 1032 and 1038 A resonance lines of the lithium-like O VI ion from a variety of sources in the Milky Way and Magellanic Clouds, including planetary nebulae, Contributed Talk supernova remnants, superbubbles, and the diffuse interstellar medium. Observed line 10/20/2008 12:00:00 PM

    intensities span three orders of magnitude, from a few thousand line units (photons/s/cm2/sr) for the faintest interstellar sight lines (a limit set by the detection threshold of FUSE) to a few million line units for the brightest supernova remnants. In this talk, we review these results, highlighting some unexpected discoveries -- such as the detection of collisionally-excited O VI in several planetary nebulae and of photoionized O VI around a hot white dwarf -- and pointing out some general conclusions about O VI emission that run contrary to our initial expectations. We discuss the scientific questions that could be addressed by a next-generation survey of O VI emission.

    This work is supported by NASA grant NAS5-32985 to the Johns Hopkins University.

A Conference Inspired by the Accomplishments of the 1

    Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

Session III, Galaxies and Active Galactic Nuclei

    Dr. Tim Heckman Johns Hopkins University

    heckman@pha.jhu.edu

     Provocateur

    10/20/2008 1:30:00 PM

A UV Perspective of Starburst Galaxies

    Dr. Alessandra Aloisi Space Telescope Science Institute

    aloisi@stsci.edu

    Starbursts are an important component of both the low- and high-redshift Universe. Thanks to their proximity, local starbursts constitute a perfect laboratory where to test our ideas about star formation, evolution of massive stars, physics and chemical evolution of Invited Talk the ISM. This type of studies is also fundamental in order to better understand star-

    10/20/2008 1:30:00 PM formation phenomena in more distant galaxies, the connection between the low- and high-z universe and the processes involved in the origin and evolution of galaxies, including mergin, accretion and feedback. The rest-frame UV spectral range provides unique insights into the starburst phenomenon by offering unique diagnostic tools for investigating the properties of the hot massive stars and the different ISM phases. I will review several key results from past UV observations of nearby starburst galaxies, including FUSE observations, and I will give an overview of the open issues that can only be addressed by the next generation of UV observatories.

    FUSE Observations of Active Galactic Nuclei and Prospects for the Future Dr. Gerard Kriss Space Telescope Science Institute

    gak@stsci.edu

    Over its 8-year lifetime, the Far Ultraviolet Spectroscopic Explorer observed over 200 hundred active galactic nuclei (AGN). Many of these observations were campaigns dedicated to AGN science, including coordinated observations with other observatories Invited Talk such as Chandra, XMM-Newton, and the Hubble Space Telescope. However, most

    10/20/2008 2:00:00 PM observations were part of large samples of nearby AGN that served as background probes of gas in the interstellar medium, the Galactic halo and the local intergalactic medium. These large samples and the dedicated campaigns have broadly advanced our understanding of the far-ultraviolet continuum of AGN and the ubiquitous outflows of photoionized gas from their active nuclei. The bright, nearby, lower-luminosity AGN A Conference Inspired by the Accomplishments of the 2

    Far Ultraviolet Spectroscopic Explorer Mission

Future Directions in Ultraviolet Spectroscopy

    observed with FUSE generally have bluer continua than their higher luminosity counterparts observed with HST, and the spectral shapes are broadly consistent with accretion disk models. More than half of the Type 1 AGN observed with FUSE show blueshifted intrinsic absorption by the O VI doublet, indicative of highly ionized outflows from the central nuclear regions. I will give an overview of these observations, and interpret them in the context of winds from accretion disks and thermally driven winds originating from the obscuring torus, with an eye toward what observational capabilities are needed in the future to understand the role of outflows in the structure and evolution of AGN, and their impact on their environments.

    The Magellanic System - Accretion, Feedback: What have we learnt from FUSE? Prof. Nicolas Lehner University of Notre Dame

    nlehner@nd.edu

    Characterizing the infall and outflow of gas and metals in galaxies is crucial for understanding the evolution of galaxies and the intergalactic medium. The study of these phenomena in local galaxies provides the most robust diagnostic tests for models of tidal interaction, galactic winds, and accretion of primordial material onto galaxies, which are Contributed Talk 10/20/2008 2:30:00 PM important for piecing together the history of matter and metals in the Universe. The Magellanic System with its high-velocity complexes connected to the Magellanic Clouds provides a laboratory where the techniques of gas-phase absorption line spectroscopy can be used to study the gas toward many individual stars and QSOs. Many of the FUV spectra show significant blueshifted and redshifted interstellar absorption relative to the systemic velocities of the SMC and LMC, signatures of outflow and infall in these galaxies. FUSE provides the largest and highest quality LMC/SMC database in the FUV and has truly open the door to new sciences and discoveries in these galaxies. I discuss how present (and future) observations in the UV bandwith have changed our view of these nearby galaxies and what can we learn from it for the higher redshift Universe.

A Conference Inspired by the Accomplishments of the 2

    Far Ultraviolet Spectroscopic Explorer Mission

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