The Hubble Space Telescope quasar absorption line key project. I - First observational results, including Lyman-alpha and Lyman-limit systems

1993 ◽  
Vol 87 ◽  
pp. 1 ◽  
Author(s):  
John N. Bahcall ◽  
Jacqueline Bergeron ◽  
Alec Boksenberg ◽  
George F. Hartig ◽  
Buell T. Jannuzi ◽  
...  
Keyword(s):  
Absorption Line ◽  
Hubble Space Telescope ◽  
Space Telescope ◽  
Lyman Alpha

The HST Quasar Absorption-Line Key Project. 8: CCD imaging of Hubble Space Telescope quasar fields

1994 ◽  
Vol 106 ◽  
pp. 646 ◽  
Author(s):  
Sofia Kirhakos ◽  
W. L. W. Sargent ◽  
Donald P. Schneider ◽  
John N. Bahcall ◽  
Buell T. Jannuzi ◽  
...  
Keyword(s):  
Absorption Line ◽  
Hubble Space Telescope ◽  
Space Telescope ◽  
Ccd Imaging

The Hubble Space Telescope quasar absorption line key project. III - First observational results on Milky Way gas

1993 ◽  
Vol 413 ◽  
pp. 116 ◽  
Author(s):  
Blair D. Savage ◽  
Limin Lu ◽  
John N. Bahcall ◽  
Jacqueline Bergeron ◽  
Alec Boksenberg ◽  
...  
Keyword(s):  
Absorption Line ◽  
Milky Way ◽  
Hubble Space Telescope ◽  
Space Telescope

scholarly journals The contribution of quasar absorption outflows to AGN feedback

2020 ◽  
Vol 499 (1) ◽  
pp. 1522-1529
Author(s):  
Timothy R Miller ◽  
Nahum Arav ◽  
Xinfeng Xu ◽  
Gerard A Kriss
Keyword(s):  
Absorption Line ◽  
Active Galactic Nucleus ◽  
Hubble Space Telescope ◽  
Broad Absorption ◽  
Feedback Effects ◽  
Space Telescope ◽  
Central Source ◽  
Broad Absorption Line

ABSTRACT Determining the distance of quasar absorption outflows from the central source (R) and their kinetic luminosity ($\dot{E}_\mathrm{\scriptstyle k}$) is crucial for understanding their contribution to active galactic nucleus (AGN) feedback. Here, we summarize the results for a sample of nine luminous quasars that were observed with the Hubble Space Telescope. We find that the outflows in more than half of the objects are powerful enough to be the main agents for AGN feedback, and that most outflows are found at R > 100 pc. The sample is representative of the quasar absorption outflow population as a whole and is unbiased towards specific ranges of R and $\dot{E}_\mathrm{\scriptstyle k}$. Therefore, the analysis results can be extended to the majority of such objects, including broad absorption line quasars. We find that these results are consistent with those of another sample (seven quasars) that is also unbiased towards specific ranges of R and $\dot{E}_\mathrm{\scriptstyle k}$. Assuming that all quasars have absorption outflows, we conclude that most luminous quasars produce outflows that can contribute significantly to AGN feedback. We also discuss the criterion for whether an outflow is energetic enough to cause AGN feedback effects.

The Hubble Space Telescope quasar absorption line key project. 6: Properties of the metal-rich systems

1994 ◽  
Vol 436 ◽  
pp. 33 ◽  
Author(s):  
Jacqueline Bergeron ◽  
Patrick Petitjean ◽  
W. L. W. Sargent ◽  
John N. Bahcall ◽  
Alec Boksenberg ◽  
...  
Keyword(s):  
Absorption Line ◽  
Hubble Space Telescope ◽  
Space Telescope

The Hubble Space Telescope quasar absorption line key project. II - Data calibration and absorption-line selection

1993 ◽  
Vol 87 ◽  
pp. 45 ◽  
Author(s):  
Donald P. Schneider ◽  
George F. Hartig ◽  
Buell T. Jannuzi ◽  
Sofia Kirhakos ◽  
David H. Saxe ◽  
...  
Keyword(s):  
Absorption Line ◽  
Hubble Space Telescope ◽  
Space Telescope ◽  
Line Selection ◽  
Data Calibration

scholarly journals The Evolution of Neutral Gas in the Universe

2006 ◽  
Vol 2 (S235) ◽  
pp. 440-440
Author(s):  
David Turnshek ◽  
Sandhya Rao ◽  
Eric Monier ◽  
Daniel Nestor ◽  
Anna Quider
Keyword(s):  
Absorption Line ◽  
Hubble Space Telescope ◽  
Reference List ◽  
Space Telescope ◽  
Neutral Gas ◽  
The Universe ◽  
Initial Results ◽  
Gas Component

AbstractWe give references to some of our work on the properties and evolution of the neutral gas component of the Universe (see reference list). The bulk of the observed neutral gas has been detected by identifying intervening damped Lyα (DLA) quasar absorption-line systems with N(H) ≥2 × 1020 atoms cm−2. We also present some initial results from a program to identify DLA absorbers near redshift z = 0.5 using Hubble Space Telescope ACS prism spectra (see Figure 1).

The Hubble Space Telescope Quasar Absorption Line Key Project. XIII. A Census of Absorption‐Line Systems at Low Redshift

1998 ◽  
Vol 118 (1) ◽  
pp. 1-125 ◽  
Author(s):  
Buell T. Jannuzi ◽  
John N. Bahcall ◽  
Jacqueline Bergeron ◽  
Alec Boksenberg ◽  
George F. Hartig ◽  
...  
Keyword(s):  
Absorption Line ◽  
Hubble Space Telescope ◽  
Space Telescope

3D Monte-Carlo Model of Europa's Water Plumes

2021 ◽  
Author(s):  
Audrey Vorburger ◽  
Peter Wurz
Keyword(s):  
Monte Carlo ◽  
Hubble Space Telescope ◽  
Monte Carlo Model ◽  
Line Emission ◽  
True Nature ◽  
Near Surface ◽  
Space Telescope ◽  
Lyman Alpha ◽  
Surface Ocean ◽  
3D Monte Carlo

<p>With the pending launches of JUICE and Europa Clipper within the next three years, interest in Europa plumes and the implications they might hold has regained momentum.</p><p>In 2014, Roth et al. presented first evidence for Europa plume activity based on Hubble Space Telescope (HST) Space Telescope Imaging Spectograph (STIS) Lyman-alpha and OI 1304 Å line emission observations. The observed line emissions imply two underlying plumic sources, located ~20° apart, exhibiting radial expansions of ~200 km and latitudinal expansions of ~20°, and containing ~2,000 kg of H2O (~1.5 ∙ 10<sup>16</sup> H<sub>2</sub>O/cm<sup>2</sup>). Since then, several more Europa plume observation attempts were undertaken, though only a hand full proved successful. </p><p>Most importantly, the true nature of the observed plume signature still remains to be determined. Plumes can either originate from the topmost surface layer, from within the ice layer, or from the sub-surface ocean. Depending on the location of origin, the plumes contain information about vastly different zones: If they are surficial, they will contain information about the highly irradiated and highly processed surface, if they originate from the sub-surface ocean, they might hold information on Europa’s potentially life-bearing region.</p><p>In this presentation, we present 3D Monte-Carlo model results of three different plume scenarios, two of which originate in Europa’s surface ice layer (near-surface liquid inclusion and diapir) whereas the third originates in the sub-surface ocean (oceanic plume). In this model we trace not only the H<sub>2</sub>O molecules, but also its dissociation products, i.e., OH, H and O. To compare the plume structures obtained from the Monte-Carlo model to the HST-STIS observations, we include all known relevant Lyman-alpha and OI 1304 Å emission excitation mechanisms in our model. Such a comparison does not only shed more light on the plumes that have already been observed, but will also help targeting plume measurements in the near future, as well as interpreting in situ measurements once such become available.</p>

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