Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Active galactic nuclei (3)
- Supermassive black holes (2)
- AGN host galaxies (1)
- Active galaxies (1)
- Aquifer (1)
-
- Aquitard (1)
- Astrophysical black holes (1)
- BOEM (1)
- Black hole physics (1)
- California (1)
- Call areas (1)
- Central California (1)
- Connectivity (1)
- Deepwater floating offshore wind energy (1)
- Environmental impacts analysis (1)
- Galaxy evolution (1)
- Habitat loss (1)
- Hydraulic conductivity (1)
- Impact assessment (1)
- Leakage (1)
- Mitigation (1)
- Morro bay (1)
- Ocean energy (1)
- Offshore wind power (1)
- Renewable energy (1)
- Resistivity (1)
- Reverberation mapping (1)
- Scaling relations (1)
- Seyfert galaxies (1)
- Species composition (1)
Articles 1 - 8 of 8
Full-Text Articles in Physics
Hα Reverberation Mapping Of The Intermediate-Mass Active Galactic Nucleus In Ngc 4395, Hojin Cho, Jong-Hak Woo, Tommaso Treu, Peter R. Williams, Stephen F. Armen, Aaron J. Barth, Vardha N. Bennert, Wanjin Cho, Alexei V. Filippenko, Elena Gallo, Jaehyuk Geum, Diego González-Buitrago, Kayhan Gültekin, Edmund Hodges-Kluck, John C. Horst, Seong Hyeon Hwang, Wonseok Kang, Minjin Kim, Taewoo Kim, Douglas C. Leonard, Matthew A. Malkan, Raymond P. Remigio, David J. Sand, Jaejin Shin, Donghoon Son, Hyun-Il Sung, Vivian U
Hα Reverberation Mapping Of The Intermediate-Mass Active Galactic Nucleus In Ngc 4395, Hojin Cho, Jong-Hak Woo, Tommaso Treu, Peter R. Williams, Stephen F. Armen, Aaron J. Barth, Vardha N. Bennert, Wanjin Cho, Alexei V. Filippenko, Elena Gallo, Jaehyuk Geum, Diego González-Buitrago, Kayhan Gültekin, Edmund Hodges-Kluck, John C. Horst, Seong Hyeon Hwang, Wonseok Kang, Minjin Kim, Taewoo Kim, Douglas C. Leonard, Matthew A. Malkan, Raymond P. Remigio, David J. Sand, Jaejin Shin, Donghoon Son, Hyun-Il Sung, Vivian U
Physics
We present the results of a high-cadence spectroscopic and imaging monitoring campaign of the active galactic nucleus (AGN) of NGC 4395. High signal-to-noise-ratio spectra were obtained at the Gemini-N 8 m telescope using the GMOS integral field spectrograph (IFS) on 2019 March 7 and at the Keck I 10 m telescope using the Low-Resolution Imaging Spectrometer with slit masks on 2019 March 3 and April 2. Photometric data were obtained with a number of 1 m-class telescopes during the same nights. The narrow-line region (NLR) is spatially resolved; therefore, its variable contributions to the slit spectra make the standard procedure …
A Local Baseline Of The Black Hole Mass Scaling Relations For Active Galaxies. Iv. Correlations Between MBh And Host Galaxy Σ, Stellar Mass, And Luminosity, Vardha N. Bennert, Tommaso Treu, Xuheng Ding, Isak Stomberg, Simon Birrer, Tomas Snyder, Matthew A. Malkan, Andrew W. Stephens, Matthew W. Auger
A Local Baseline Of The Black Hole Mass Scaling Relations For Active Galaxies. Iv. Correlations Between MBh And Host Galaxy Σ, Stellar Mass, And Luminosity, Vardha N. Bennert, Tommaso Treu, Xuheng Ding, Isak Stomberg, Simon Birrer, Tomas Snyder, Matthew A. Malkan, Andrew W. Stephens, Matthew W. Auger
Physics
The tight correlations between the mass of supermassive black holes (MBH) and their host-galaxy properties have been of great interest to the astrophysical community, but a clear understanding of their origin and fundamental drivers still eludes us. The local relations for active galaxies are interesting in their own right and form the foundation for any evolutionary study over cosmic time. We present Hubble Space Telescope optical imaging of a sample of 66 local active galactic nuclei (AGNs); for 14 objects, we also obtained Gemini near-infrared images. We use state-of-the-art methods to perform surface photometry of the AGN host …
Scenarios For Offshore Wind Power Production For Central California Call Areas, Yi-Hui Wang, Ryan K. Walter, Crow White, Matthew D. Kehrli, Benjamin Ruttenberg
Scenarios For Offshore Wind Power Production For Central California Call Areas, Yi-Hui Wang, Ryan K. Walter, Crow White, Matthew D. Kehrli, Benjamin Ruttenberg
Physics
In response to the growing interest in offshore wind energy development in California, the U.S. Bureau of Ocean Energy Management delineated three Call Areas for potential leasing. This study provides a comprehensive characterization and comparison of offshore wind power potential within the two Central California Call Areas (Diablo Canyon and Morro Bay) using 12-and 15-MW turbines under different inter-turbine spacing and wind farm size scenarios. Our analysis shows similar daily and seasonal patterns of wind power produced within the Call Areas, which peak in spring and during evening hours. Per-turbine power production is higher in the Morro Bay Call Area …
Potential Environmental Effects Of Deepwater Floating Offshore Wind Energy Facilities, Hayley Farr, Benjamin Ruttenberg, Ryan K. Walter, Yi-Hui Wang, Crow White
Potential Environmental Effects Of Deepwater Floating Offshore Wind Energy Facilities, Hayley Farr, Benjamin Ruttenberg, Ryan K. Walter, Yi-Hui Wang, Crow White
Physics
Over the last few decades, the offshore wind energy industry has expanded its scope from turbines mounted on foundations driven into the seafloor and standing in less than 60 m of water, to floating turbines moored in 120 m of water, to prospecting the development of floating turbines moored in ~1,000 m of water. Since there are few prototype turbines and mooring systems of these deepwater, floating offshore wind energy facilities (OWFs) currently deployed, their effects on the marine environment are speculative. Using the available scientific literature concerning appropriate analogs, including fixed-bottom OWFs, land-based wind energy facilities, wave and tidal …
Ultrafast Investigation And Control Of Dirac And Weyl Semimetals, Christopher P. Weber
Ultrafast Investigation And Control Of Dirac And Weyl Semimetals, Christopher P. Weber
Physics
Ultrafast experiments using sub-picosecond pulses of light are poised to play an important role in the study and use of topological materials and, particularly, of the three-dimensional Dirac and Weyl semimetals. Many of these materials’ characteristic properties—their linear band dispersion, Berry curvature, near-vanishing density of states at the Fermi energy, and sensitivity to crystalline and time-reversal symmetries—are closely related to their sub- and few-picosecond response to light. Ultrafast measurements offer the opportunity to explore excitonic instabilities and transient photocurrents, the latter depending on the Berry curvature and possibly quantized by fundamental constants. Optical pulses may, through Floquet effects, controllably and …
Assessing Stream-Aquifer Connectivity In A Coastal California Watershed, Bwalya Malama, Devin Pritchard-Peterson, John J. Jasbinsek, Christopher Surfleet
Assessing Stream-Aquifer Connectivity In A Coastal California Watershed, Bwalya Malama, Devin Pritchard-Peterson, John J. Jasbinsek, Christopher Surfleet
Physics
We report the results of field and laboratory investigations of stream-aquifer interactions in a watershed along the California coast to assess the impact of groundwater pumping for irrigation on stream flows. The methods used include subsurface sediment sampling using direct-push drilling, laboratory permeability and particle size analyses of sediment, piezometer installation and instrumentation, stream discharge and stage monitoring, pumping tests for aquifer characterization, resistivity surveys, and long-term passive monitoring of stream stage and groundwater levels. Spectral analysis of long-term water level data was used to assess correlation between stream and groundwater level time series data. The investigations revealed the presence …
Space Telescope And Optical Reverberation Mapping Project. Ix. Velocity–Delay Maps For Broad Emission Lines In Ngc 5548, Keith Horne, G. De Rosa, B. M. Peterson, A. J. Barth, Vardha N. Bennert, Y. Zu
Space Telescope And Optical Reverberation Mapping Project. Ix. Velocity–Delay Maps For Broad Emission Lines In Ngc 5548, Keith Horne, G. De Rosa, B. M. Peterson, A. J. Barth, Vardha N. Bennert, Y. Zu
Physics
In this contribution, we achieve the primary goal of the active galactic nucleus (AGN) STORM campaign by recovering velocity–delay maps for the prominent broad emission lines (Lyα, C IV, He II, and Hβ) in the spectrum of NGC 5548. These are the most detailed velocity–delay maps ever obtained for an AGN, providing unprecedented information on the geometry, ionization structure, and kinematics of the broad-line region. Virial envelopes enclosing the emission-line responses show that the reverberating gas is bound to the black hole. A stratified ionization structure is evident. The He II response inside 5–10 lt-day has a broad single-peaked velocity …
Effects Of Estuary-Wide Seagrass Loss On Fish Populations, Jennifer K. O'Leary, Maurice C. Goodman, Ryan K. Walter, Kariss Willits, Daniel J. Pondella
Effects Of Estuary-Wide Seagrass Loss On Fish Populations, Jennifer K. O'Leary, Maurice C. Goodman, Ryan K. Walter, Kariss Willits, Daniel J. Pondella
Physics
Globally, habitat loss in coastal marine systems is a major driver of species decline, and estuaries are particularly susceptible to loss. Along the United States Pacific coast, monospecific eelgrass (Zostera marina) beds form the major estuarine vegetated habitat. In Morro Bay, California, eelgrass experienced an unprecedented decline of > 95%, from 139 ha in 2007 to < 6 ha by 2017. Fish populations were compared before and after the eelgrass decline using trawl surveys. Beach seines surveys were also conducted during the post-decline period to characterize species within and outside of remnant eelgrass beds.While the estuary-wide loss of eelgrass did not result in fewer fish or less biomass, it led to changes in species composition. The post-eelgrass decline period was characterized by increases in flatfish (mainly Citharichthys stigmaeus) and staghorn sculpin (Leptocottus armatus), and decreases in habitat specialists including bay pipefish (Syngnathus leptorhynchus) and shiner perch (Cymatogaster aggregata). There were similar trends inside and outside of remnant eelgrass patches. These findings support evidence across multiple ecosystems suggesting that the predominance of habitat-specialists predicts whether or not habitat loss leads to an overall decline in fish abundance. In addition, loss of critical habitats across seascapes can restrict population connectivity and lead to range contraction. For bay pipefish, the loss of eelgrass in Morro Bay is likely to create a population biogeographic divide. Currently, Morro Bay is dominated by flatfish and sculpins, and the longevity of this new ecosystem state will depend on future eelgrass recovery dynamics supported by ecosystem-based management approaches.