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Borguet B.C.J.,Virginia Polytechnic Institute and State University | Edmonds D.,Virginia Polytechnic Institute and State University | Arav N.,Virginia Polytechnic Institute and State University | Benn C.,Isaac Newton Group | Chamberlain C.,Virginia Polytechnic Institute and State University
Astrophysical Journal | Year: 2012

We present spectroscopic analysis of the broad absorption line (BAL) outflow in quasar SDSS J1512+1119. In particular, we focus our attention on a kinematic component in which we identify P V and S IV/S IV* absorption troughs. The shape of the unblended phosphorus doublet troughs and the three S IV/S IV* troughs allow us to obtain reliable column density measurements for these two ions. Photoionization modeling using these column densities and those of He I* constrain the abundance of phosphorus to the range of 0.5-4times the solar value. The total column density, ionization parameter, and metallicity inferred from the P V and S IV column densities lead to large optical depth values for the common transition observed in BAL outflows. We show that the true C IV optical depth is 1000times greater in the core of the absorption profile than the value deduced from its apparent optical depth. © 2012. The American Astronomical Society. All rights reserved. Source


Farhang A.,Institute for Research in Fundamental Sciences | Farhang A.,Sharif University of Technology | Khosroshahi H.G.,Institute for Research in Fundamental Sciences | Javadi A.,Institute for Research in Fundamental Sciences | And 10 more authors.
Astrophysical Journal | Year: 2015

We present a new high signal-to-noise ratio spectroscopic survey of the Northern hemisphere to probe the Local Bubble and its surroundings using the λ5780Å and λ5797Å diffuse interstellar bands (DIBs). We observed 432 sightlines to a distance of 200 pc over a duration of three years. In this study, we establish the λ5780 and λ5797 correlations with Na I, Ca II and EB-V, for both inside and outside the Local Bubble. The correlations show that among all neutral and ionized atoms, the correlation between Ca ii and λ5780 is stronger than its correlation with λ5797, suggesting that λ5780 is more associated with regions where Ca+ is more abundant. We study the λ5780 correlation with λ5797, which shows a tight correlation within and outside the Local Bubble. In addition, we investigate the DIB properties in UV irradiated and UV shielded regions. We find that, within and beyond the Local Bubble, λ5797 is located in denser parts of clouds, protected from UV irradiation, while λ5780 is located in the low-density regions of clouds. © 2015. The American Astronomical Society. All rights reserved. Source


Bruni G.,Max Planck Institute for Radio Astronomy | Bruni G.,National institute for astrophysics | Gonzalez-Serrano J.I.,University of Cantabria | Pedani M.,National institute for astrophysics | And 6 more authors.
Astronomy and Astrophysics | Year: 2014

Context. Broad absorption lines (BALs) are present in the spectra of ~20% of quasars (QSOs); this indicates fast outflows (up to 0.2c) that intercept the observer's line of sight. These QSOs can be distinguished again into radio-loud (RL) BAL QSOs and radio-quiet (RQ) BAL QSOs. The first are very rare, even four times less common than RQ BAL QSOs. The reason for this is still unclear and leaves open questions about the nature of the BAL-producing outflows and their connection with the radio jet. Aims. We explored the spectroscopic characteristics of RL and RQ BAL QSOs with the aim to find a possible explanation for the rarity of RL BAL QSOs. Methods. We identified two samples of genuine BAL QSOs from SDSS optical spectra, one RL and one RQ, in a suitable redshift interval (2.5 < z < 3.5) that allowed us to observe the Mg ii and Hβ emission lines in the adjacent near-infrared (NIR) band. We collected NIR spectra of the two samples using the Telescopio Nazionale Galileo (TNG, Canary Islands). By using relations known in the literature, we estimated the black-hole mass, the broad-line region radius, and the Eddington ratio of our objects and compared the two samples. Results. We found no statistically significant differences from comparing the distributions of the cited physical quantities. This indicates that they have similar geometries, accretion rates, and central black-hole masses, regardless of whether the radio-emitting jet is present or not. Conclusions. These results show that the central engine of BAL QSOs has the same physical properties with and without a radio jet. The reasons for the rarity of RL BAL QSOs must reside in different environmental or evolutionary variables. © 2014 ESO. Source


Borguet B.C.J.,Virginia Polytechnic Institute and State University | Arav N.,Virginia Polytechnic Institute and State University | Edmonds D.,Virginia Polytechnic Institute and State University | Chamberlain C.,Virginia Polytechnic Institute and State University | Benn C.,Isaac Newton Group
Astrophysical Journal | Year: 2013

We present the most energetic BALQSO outflow measured to date, with a kinetic luminosity of at least 1046 erg s-1, which is 5% of the bolometric luminosity of this high Eddington ratio quasar. The associated mass-flow rate is 400 solar masses per year. Such kinetic luminosity and mass-flow rate should provide strong active galactic nucleus feedback effects. The outflow is located at about 300 pc from the quasar and has a velocity of roughly 8000 km s-1. Our distance and energetic measurements are based in large part on the identification and measurement of S IV and S IV* broad absorption lines (BALs). The use of this high-ionization species allows us to generalize the result to the majority of high-ionization BALQSOs that are identified by their C IV absorption. We also report the energetics of two other outflows seen in another object using the same technique. The distances of all three outflows from the central source (100-2000 pc) suggest that we observe BAL troughs much farther away from the central source than the assumed acceleration region of these outflows (0.01-0.1 pc). © 2013. The American Astronomical Society. All rights reserved. Source


Bautista M.A.,University of Virginia | Bautista M.A.,Western Michigan University | Dunn J.P.,University of Virginia | Arav N.,University of Virginia | And 3 more authors.
Astrophysical Journal | Year: 2010

Using high-resolution Very Large Telescope spectra, we study the multi-component outflow systems of two quasars exhibiting intrinsic Fe II absorption (QSO 2359-1241 and SDSS J0318-0600). From the extracted ionic column densities and using photoionization modeling, we determine the gas density, total column density, and ionization parameter for several of the components. For each object, the largest column density component is also the densest, and all other components have densities of roughly 1/4 of that of the main component. We demonstrate that all the absorbers lie roughly at the same distance from the source. Further, we calculate the total kinetic luminosities and mass outflow rates of all components and show that these quantities are dominated by the main absorption component. © 2010. The American Astronomical Society. All rights reserved. Source

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