The Experts below are selected from a list of 73722 Experts worldwide ranked by ideXlab platform
P Marziani - One of the best experts on this subject based on the ideXlab platform.
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new insights on the qso radio loud radio quiet dichotomy sdss spectra in the context of the 4d eigenvector1 parameter space
Monthly Notices of the Royal Astronomical Society, 2008Co-Authors: S Zamfir, Jack W Sulentic, P MarzianiAbstract:We search for a dichotomy/bimodality between radio-loud (RL) and radio-quiet (RQ) type 1 active galactic nuclei (AGN). We examine several samples of Slogan Digital Sky Survey (SDSS) quasi-stellar objects (QSOs) with high signal-to-noise ratio optical spectra and matching Faint Images of the Radio Sky at Twenty-cm/NRAO VLA Sky Survey (FIRST/NVSS) radio observations. We use the radio data to identify the weakest RL sources with a Fanaroff-Riley type II (FRII) structure to define a RL/RQ boundary which corresponds to log L 1.4 G Hz = 31.6 erg s -1 Hz -1 . We measure the properties of broad-line Hβ and Fe II emission to define the optical plane of a 4DE1 spectroscopic diagnostic space. The RL quasars occupy a much more Restricted Domain in this optical plane compared to the RQ sources, which a 2D Kolmogorov-Smimov test finds to be highly significant. This tells us that the range of broad-line region kinematics and structure for RL sources is more Restricted than for the RQ QSOs, which supports the notion of dichotomy. FR II and CD RL sources also show significant 4DE1 Domain differences that likely reflect differences in line-of-sight orientation (inclined versus face-on, respectively) for these two classes. The possibility of a distinct radio-intermediate (RI) population between RQ and RL source is disfavoured because a 4DE1 diagnostic space comparison shows no difference between RI and RQ sources. We show that searches for dichotomy in radio versus bolometric luminosity diagrams will yield ambiguous results mainly because in a reasonably complete sample, the radio brightest RQ sources will be numerous enough to blur the gap between RQ and RL sources. Within resolution constraints of NVSS and FIRST, we find no FR I sources among the broad-line quasar population.
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new insights on the qso radio loud radio quiet dichotomy sdss spectra in the context of the 4d eigenvector1 parameter space
arXiv: Astrophysics, 2008Co-Authors: S Zamfir, Jack W Sulentic, P MarzianiAbstract:We search fora dichotomy/bimodality between Radio Loud (RL) and Radio Quiet (RQ) Type 1 Active Galactic Nuclei (AGN). We examine several samples of SDSS QSOs with high S/N optical spectra and matching FIRST/NVSS radio observations. We use the radio data to identify the weakest RL sources with FRII structure to define a RL/RQ boundary which corresponds to log L$_{1.4GHz}$=31.6 ergs s$^{-1}$ Hz$^{-1}$. We measure properties of broad line H$\beta$ and FeII emission to define the optical plane of a 4DE1 spectroscopic diagnostic space. The RL quasars occupy a much more Restricted Domain in this optical plane compared to the RQ sources, which a 2D Kolmogorov-Smirnov test finds to be highly significant. This tells us that the range of BLR kinematics and structure for RL sources is more Restricted than for the RQ QSOs, which supports the notion of dichotomy. FRII and CD RL sources also show significant 4DE1 Domain differences that likely reflect differences in line of sight orientation (inclined vs. face-on respectively) for these two classes. The possibility of a distinct Radio Intermediate (RI) population between RQ and RL source is disfavored because a 4DE1 diagnostic space comparison shows no difference between RI and RQ sources. We show that searches for dichotomy in radio vs. bolometric luminosity diagrams will yield ambiguous results mainly because in a reasonably complete sample the radio brightest RQ sources will be numerous enough to blur the gap between RQ and RL sources. Within resolution constraints of NVSS and FIRST we find no FRI sources among the broad line quasar population.
S Zamfir - One of the best experts on this subject based on the ideXlab platform.
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new insights on the qso radio loud radio quiet dichotomy sdss spectra in the context of the 4d eigenvector1 parameter space
Monthly Notices of the Royal Astronomical Society, 2008Co-Authors: S Zamfir, Jack W Sulentic, P MarzianiAbstract:We search for a dichotomy/bimodality between radio-loud (RL) and radio-quiet (RQ) type 1 active galactic nuclei (AGN). We examine several samples of Slogan Digital Sky Survey (SDSS) quasi-stellar objects (QSOs) with high signal-to-noise ratio optical spectra and matching Faint Images of the Radio Sky at Twenty-cm/NRAO VLA Sky Survey (FIRST/NVSS) radio observations. We use the radio data to identify the weakest RL sources with a Fanaroff-Riley type II (FRII) structure to define a RL/RQ boundary which corresponds to log L 1.4 G Hz = 31.6 erg s -1 Hz -1 . We measure the properties of broad-line Hβ and Fe II emission to define the optical plane of a 4DE1 spectroscopic diagnostic space. The RL quasars occupy a much more Restricted Domain in this optical plane compared to the RQ sources, which a 2D Kolmogorov-Smimov test finds to be highly significant. This tells us that the range of broad-line region kinematics and structure for RL sources is more Restricted than for the RQ QSOs, which supports the notion of dichotomy. FR II and CD RL sources also show significant 4DE1 Domain differences that likely reflect differences in line-of-sight orientation (inclined versus face-on, respectively) for these two classes. The possibility of a distinct radio-intermediate (RI) population between RQ and RL source is disfavoured because a 4DE1 diagnostic space comparison shows no difference between RI and RQ sources. We show that searches for dichotomy in radio versus bolometric luminosity diagrams will yield ambiguous results mainly because in a reasonably complete sample, the radio brightest RQ sources will be numerous enough to blur the gap between RQ and RL sources. Within resolution constraints of NVSS and FIRST, we find no FR I sources among the broad-line quasar population.
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new insights on the qso radio loud radio quiet dichotomy sdss spectra in the context of the 4d eigenvector1 parameter space
arXiv: Astrophysics, 2008Co-Authors: S Zamfir, Jack W Sulentic, P MarzianiAbstract:We search fora dichotomy/bimodality between Radio Loud (RL) and Radio Quiet (RQ) Type 1 Active Galactic Nuclei (AGN). We examine several samples of SDSS QSOs with high S/N optical spectra and matching FIRST/NVSS radio observations. We use the radio data to identify the weakest RL sources with FRII structure to define a RL/RQ boundary which corresponds to log L$_{1.4GHz}$=31.6 ergs s$^{-1}$ Hz$^{-1}$. We measure properties of broad line H$\beta$ and FeII emission to define the optical plane of a 4DE1 spectroscopic diagnostic space. The RL quasars occupy a much more Restricted Domain in this optical plane compared to the RQ sources, which a 2D Kolmogorov-Smirnov test finds to be highly significant. This tells us that the range of BLR kinematics and structure for RL sources is more Restricted than for the RQ QSOs, which supports the notion of dichotomy. FRII and CD RL sources also show significant 4DE1 Domain differences that likely reflect differences in line of sight orientation (inclined vs. face-on respectively) for these two classes. The possibility of a distinct Radio Intermediate (RI) population between RQ and RL source is disfavored because a 4DE1 diagnostic space comparison shows no difference between RI and RQ sources. We show that searches for dichotomy in radio vs. bolometric luminosity diagrams will yield ambiguous results mainly because in a reasonably complete sample the radio brightest RQ sources will be numerous enough to blur the gap between RQ and RL sources. Within resolution constraints of NVSS and FIRST we find no FRI sources among the broad line quasar population.
Akaki Rusetsky - One of the best experts on this subject based on the ideXlab platform.
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kaon nucleon scattering lengths from kaonic deuterium experiments
European Physical Journal C, 2006Co-Authors: Ulfg Meisner, Udit Raha, Akaki RusetskyAbstract:The extraction of the S-wave kaon–nucleon scattering lengths a0 and a1 from a combined analysis of existing kaonic hydrogen and synthetic deuterium data has been carried out within the framework of a low-energy effective field theory. It turns out that with the present DEAR central values for the kaonic hydrogen ground-state energy and width, a solution for a0 and a1 exists only in a Restricted Domain of input values for the kaon–deuteron scattering length. Consequently, measuring this scattering length imposes stringent constraints on the theoretical description of the kaon–deuteron interactions at low energies, if supplemented with DEAR data on kaonic hydrogen.
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kaon nucleon scattering lengths from kaonic deuterium experiments
arXiv: Nuclear Theory, 2006Co-Authors: Ulfg Meisner, Udit Raha, Akaki RusetskyAbstract:The extraction of the S-wave kaon-nucleon scattering lengths a0 and a1 from a combined analysis of existing kaonic hydrogen and synthetic deuterium data has been carried out within the framework of a low-energy effective field theory. It turns out that with the present DEAR central values for the kaonic hydrogen ground-state energy and width, a solution for a0 and a1 exists only in a Restricted Domain of input values for the kaon-deuteron scattering length. Consequently, measuring this scattering length imposes stringent constraints on the theoretical description of the kaon-deuteron interactions at low energies.
Teresa P L Cheung - One of the best experts on this subject based on the ideXlab platform.
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multimodal characterization of the semantic n400 response within a rapid evaluation brain vital sign framework
Journal of Translational Medicine, 2018Co-Authors: Shaun D Fickling, Sujoy Ghosh Hajra, Careesa C Liu, Xiaowei Song, Teresa P L CheungAbstract:For nearly four decades, the N400 has been an important brainwave marker of semantic processing. It can be recorded non-invasively from the scalp using electrical and/or magnetic sensors, but largely within the Restricted Domain of research laboratories specialized to run specific N400 experiments. However, there is increasing evidence of significant clinical utility for the N400 in neurological evaluation, particularly at the individual level. To enable clinical applications, we recently reported a rapid evaluation framework known as “brain vital signs” that successfully incorporated the N400 response as one of the core components for cognitive function evaluation. The current study characterized the rapidly evoked N400 response to demonstrate that it shares consistent features with traditional N400 responses acquired in research laboratory settings—thereby enabling its translation into brain vital signs applications. Data were collected from 17 healthy individuals using magnetoencephalography (MEG) and electroencephalography (EEG), with analysis of sensor-level effects as well as evaluation of brain sources. Individual-level N400 responses were classified using machine learning to determine the percentage of participants in whom the response was successfully detected. The N400 response was observed in both M/EEG modalities showing significant differences to incongruent versus congruent condition in the expected time range (p < 0.05). Also as expected, N400-related brain activity was observed in the temporal and inferior frontal cortical regions, with typical left-hemispheric asymmetry. Classification robustly confirmed the N400 effect at the individual level with high accuracy (89%), sensitivity (0.88) and specificity (0.90). The brain vital sign N400 characteristics were highly consistent with features of the previously reported N400 responses acquired using traditional laboratory-based experiments. These results provide important evidence supporting clinical translation of the rapidly acquired N400 response as a potential tool for assessments of higher cognitive functions.
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Multimodal characterization of the semantic N400 response within a rapid evaluation brain vital sign framework
BMC, 2018Co-Authors: Sujoy Ghosh Hajra, Shaun D Fickling, Careesa C Liu, Xiaowei Song, Teresa P L Cheung, Ryan C. N. D’arcyAbstract:Abstract Background For nearly four decades, the N400 has been an important brainwave marker of semantic processing. It can be recorded non-invasively from the scalp using electrical and/or magnetic sensors, but largely within the Restricted Domain of research laboratories specialized to run specific N400 experiments. However, there is increasing evidence of significant clinical utility for the N400 in neurological evaluation, particularly at the individual level. To enable clinical applications, we recently reported a rapid evaluation framework known as “brain vital signs” that successfully incorporated the N400 response as one of the core components for cognitive function evaluation. The current study characterized the rapidly evoked N400 response to demonstrate that it shares consistent features with traditional N400 responses acquired in research laboratory settings—thereby enabling its translation into brain vital signs applications. Methods Data were collected from 17 healthy individuals using magnetoencephalography (MEG) and electroencephalography (EEG), with analysis of sensor-level effects as well as evaluation of brain sources. Individual-level N400 responses were classified using machine learning to determine the percentage of participants in whom the response was successfully detected. Results The N400 response was observed in both M/EEG modalities showing significant differences to incongruent versus congruent condition in the expected time range (p
Jack W Sulentic - One of the best experts on this subject based on the ideXlab platform.
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new insights on the qso radio loud radio quiet dichotomy sdss spectra in the context of the 4d eigenvector1 parameter space
Monthly Notices of the Royal Astronomical Society, 2008Co-Authors: S Zamfir, Jack W Sulentic, P MarzianiAbstract:We search for a dichotomy/bimodality between radio-loud (RL) and radio-quiet (RQ) type 1 active galactic nuclei (AGN). We examine several samples of Slogan Digital Sky Survey (SDSS) quasi-stellar objects (QSOs) with high signal-to-noise ratio optical spectra and matching Faint Images of the Radio Sky at Twenty-cm/NRAO VLA Sky Survey (FIRST/NVSS) radio observations. We use the radio data to identify the weakest RL sources with a Fanaroff-Riley type II (FRII) structure to define a RL/RQ boundary which corresponds to log L 1.4 G Hz = 31.6 erg s -1 Hz -1 . We measure the properties of broad-line Hβ and Fe II emission to define the optical plane of a 4DE1 spectroscopic diagnostic space. The RL quasars occupy a much more Restricted Domain in this optical plane compared to the RQ sources, which a 2D Kolmogorov-Smimov test finds to be highly significant. This tells us that the range of broad-line region kinematics and structure for RL sources is more Restricted than for the RQ QSOs, which supports the notion of dichotomy. FR II and CD RL sources also show significant 4DE1 Domain differences that likely reflect differences in line-of-sight orientation (inclined versus face-on, respectively) for these two classes. The possibility of a distinct radio-intermediate (RI) population between RQ and RL source is disfavoured because a 4DE1 diagnostic space comparison shows no difference between RI and RQ sources. We show that searches for dichotomy in radio versus bolometric luminosity diagrams will yield ambiguous results mainly because in a reasonably complete sample, the radio brightest RQ sources will be numerous enough to blur the gap between RQ and RL sources. Within resolution constraints of NVSS and FIRST, we find no FR I sources among the broad-line quasar population.
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new insights on the qso radio loud radio quiet dichotomy sdss spectra in the context of the 4d eigenvector1 parameter space
arXiv: Astrophysics, 2008Co-Authors: S Zamfir, Jack W Sulentic, P MarzianiAbstract:We search fora dichotomy/bimodality between Radio Loud (RL) and Radio Quiet (RQ) Type 1 Active Galactic Nuclei (AGN). We examine several samples of SDSS QSOs with high S/N optical spectra and matching FIRST/NVSS radio observations. We use the radio data to identify the weakest RL sources with FRII structure to define a RL/RQ boundary which corresponds to log L$_{1.4GHz}$=31.6 ergs s$^{-1}$ Hz$^{-1}$. We measure properties of broad line H$\beta$ and FeII emission to define the optical plane of a 4DE1 spectroscopic diagnostic space. The RL quasars occupy a much more Restricted Domain in this optical plane compared to the RQ sources, which a 2D Kolmogorov-Smirnov test finds to be highly significant. This tells us that the range of BLR kinematics and structure for RL sources is more Restricted than for the RQ QSOs, which supports the notion of dichotomy. FRII and CD RL sources also show significant 4DE1 Domain differences that likely reflect differences in line of sight orientation (inclined vs. face-on respectively) for these two classes. The possibility of a distinct Radio Intermediate (RI) population between RQ and RL source is disfavored because a 4DE1 diagnostic space comparison shows no difference between RI and RQ sources. We show that searches for dichotomy in radio vs. bolometric luminosity diagrams will yield ambiguous results mainly because in a reasonably complete sample the radio brightest RQ sources will be numerous enough to blur the gap between RQ and RL sources. Within resolution constraints of NVSS and FIRST we find no FRI sources among the broad line quasar population.
