Zobrazeno 1 - 10
of 26
pro vyhledávání: '"De Kool, Martijn"'
Autor:
Ganguly, Rajib, Brotherton, Michael S., Arav, Nahum, Heap, Sara R., Wisotzki, Lutz, Aldcroft, Thomas L., Alloin, Danielle, Behar, Ehud, Canalizo, Gabriela, Crenshaw, D. Michael, de Kool, Martijn, Chambers, Kenneth, Cecil, Gerald, Chatzichristou, Eleni, Everett, John, Gabel, Jack, Gaskell, C. Martin, Galliano, Emmanuel, Green, Richard F., Hall, Patrick B., Hines, Dean C., Junkkarinen, Vesa T., Kaastra, Jelle S., Kaiser, Mary Elizabeth, Kazanas, Demosthenes, Konigl, Arieh, Korista, Kirk T., Kriss, Gerard A., Laor, Ari, Leighly, Karen M., Mathur, Smita, Ogle, Patrick, Proga, Daniel, Sabra, Bassem, Sivron, Ran, Snedden, Stephanie, Telfer, Randal, Vestergaard, Marianne
Publikováno v:
Astron.J.133:479-488,2007
We present low-resolution ultraviolet spectra of 14 low redshift (z<0.8) quasars observed with HST/STIS as part of a Snap project to understand the relationship between quasar outflows and luminosity. By design, all observations cover the CIV emissio
Externí odkaz:
http://arxiv.org/abs/astro-ph/0610435
Autor:
Arav, Nahum, Kaastra, Jelle, Steenbrugge, Katrien, Brinkman, Bert, Edelson, Rick, Korista, Kirk T., de Kool, Martijn
Publikováno v:
Astrophys.J. 590 (2003) 174-180
We compare X-ray and UV spectroscopic observations of NGC 5548. Both data sets show O VI absorption troughs associated with the AGN outflow from this galaxy. We find that the robust lower limit on the column density of the O VI X-ray trough is seven
Externí odkaz:
http://arxiv.org/abs/astro-ph/0303425
We re-analyze the HST high resolution spectroscopic data of the intrinsic absorber in NGC 5548 and find that the C IV absorption column density is at least four times larger than previously determined. This increase arises from accounting for the kin
Externí odkaz:
http://arxiv.org/abs/astro-ph/0107472
Autor:
Arav, Nahum, de Kool, Martijn, Korista, Kirk T., Crenshaw, D. Michael, van Breugel, Wil, Brotherton, Michael, Green, Richard F., Pettini, Max, Wills, Bev, de Vries, Wim, Becker, Bob, Brandt, W. N., Green, Paul, Junkkarinen, Vesa T., Koratkar, Anuradha, Laor, Ari, Laurent-Muehleisen, Sally A., Mathur, Smita, Murray, Norman
We describe deep (40 orbits) HST/STIS observations of the BALQSO PG 0946+301 and make them available to the community. These observations are the major part of a multi-wavelength campaign on this object aimed at determining the ionization equilibrium
Externí odkaz:
http://arxiv.org/abs/astro-ph/0107414
This is a companion paper to the manuscript entitled: ``HST STIS Observations Of PG 0946+301: The Highest Quality UV Spectrum of a BALQSO'' (Arav et al. 2001; accepted for publication in ApJ). Here we present photoionization-modeling results for ALL
Externí odkaz:
http://arxiv.org/abs/astro-ph/0107415
Autor:
de Kool, Martijn, Arav, Nahum, Becker, Robert H., Gregg, Michael D., White, Richard L., Laurent-Muehleisen, Sally A., Price, Trevor, Korista, Kirk T.
This paper presents an analysis of a Keck HIRES spectrum of the QSO FIRST J104459.6+365605. The line of sight towards the QSO contains two clusters of outflowing clouds that give rise to broad blue shifted absorption lines. The outflow velocities of
Externí odkaz:
http://arxiv.org/abs/astro-ph/0010230
We investigate the thermal stability of the outer layers of accretion discs in which the local viscous energy dissipation rate scales with the pressure as for standard Shakura-Sunyaev discs. By solving for the accretion disc vertical structure using
Externí odkaz:
http://arxiv.org/abs/astro-ph/9903151
Autor:
Arav, Nahum, Becker, Robert H., Laurent-Muehleisen, Sally A., Gregg, Michael D., White, Richard L., de Kool, Martijn
Publikováno v:
Astrophys.J.524:566-571,1999
We find that the depth and shape of the broad absorption lines (BALs) in BALQSO 1603+3002 are determined largely by the fraction of the emitting source which is covered by the BAL flow. In addition, the observed depth of the BALs is poorly correlated
Externí odkaz:
http://arxiv.org/abs/astro-ph/9903140
We analyze HST and ground based spectra of the brightest BALQSO in the UV: PG~0946+301. A detailed study of the absorption troughs as a function of velocity is presented, facilitated by the use of a new algorithm to solve for the optical depth as a f
Externí odkaz:
http://arxiv.org/abs/astro-ph/9810309
We numerically investigate the hydrodynamics of accretion disk reversal and relate our findings to the observed spin-rate changes in the accreting X-ray pulsar GX~1+4. In this system, which accretes from a slow wind, the accretion disk contains two d
Externí odkaz:
http://arxiv.org/abs/astro-ph/9810118