29 results on '"Peterson, Bradley"'
Search Results
2. Scoping review of wearable and mobile devices used in the assessment and treatment of obsessive-compulsive disorder
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Frank, Adam, Li, Ruibei, Peterson, Bradley, and Narayanan, Shrikanth
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FOS: Computer and information sciences ,Obsessive-Compulsive Disorder ,OCD ,Bioinformatics ,digital ,Mental Disorders ,Scoping Review ,Life Sciences ,Psychiatry and Psychology ,mobile ,Social and Behavioral Sciences ,biosignal ,wearable ,Other Biomedical Engineering and Bioengineering ,Behavior and Behavior Mechanisms ,Engineering ,Medicine and Health Sciences ,biomarker ,smart phone ,Biomedical Engineering and Bioengineering - Abstract
This is a registration of a protocol for a scoping review on wearable and mobile device use in assessing and treating obsessive-compulsive disorder.
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- 2022
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3. Appendix 1: from The biogeography of community assembly: latitude and predation drive variation in community trait distribution in a guild of epifaunal crustaceans
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Gross, Collin P., Duffy, J. Emmett, Hovel, Kevin A., Kardish, Melissa R., Reynolds, Pamela L., Bostr��m, Christoffer, Boyer, Katharyn E., Cusson, Mathieu, Ekl��f, Johan, Engelen, Aschwin H., Eriksson, Britas Klemens, Fodrie, F. Joel, Griffin, John N., Hereu, Clara M., Hori, Masakazu, Hughes, A. Randall, Ivanov, Mikhail V., Jorgensen, Pablo, Kruschel, Claudia, Lee, Kun-Seop, Lefcheck, Jonathan, McGlathery, Karen, Moksnes, Per-Olav, Nakaoka, Masahiro, O'Connor, Mary I., O'Connor, Nessa E., Olsen, Jeanine L., Orth, Robert J., Peterson, Bradley J., Reiss, Henning, Rossi, Francesca, Ruesink, Jennifer, Sotka, Erik E., Thormar, Jonas, Tomas, Fiona, Unsworth, Richard, Voigt, Erin P., Whalen, Matthew A., Ziegler, Shelby L., and Stachowicz, John J.
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References for peracarid trait data used in analyses of trait dispersion
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- 2022
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4. Appendix 2: from The biogeography of community assembly: latitude and predation drive variation in community trait distribution in a guild of epifaunal crustaceans
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Gross, Collin P., Duffy, J. Emmett, Hovel, Kevin A., Kardish, Melissa R., Reynolds, Pamela L., Bostr��m, Christoffer, Boyer, Katharyn E., Cusson, Mathieu, Ekl��f, Johan, Engelen, Aschwin H., Eriksson, Britas Klemens, Fodrie, F. Joel, Griffin, John N., Hereu, Clara M., Hori, Masakazu, Hughes, A. Randall, Ivanov, Mikhail V., Jorgensen, Pablo, Kruschel, Claudia, Lee, Kun-Seop, Lefcheck, Jonathan, McGlathery, Karen, Moksnes, Per-Olav, Nakaoka, Masahiro, O'Connor, Mary I., O'Connor, Nessa E., Olsen, Jeanine L., Orth, Robert J., Peterson, Bradley J., Reiss, Henning, Rossi, Francesca, Ruesink, Jennifer, Sotka, Erik E., Thormar, Jonas, Tomas, Fiona, Unsworth, Richard, Voigt, Erin P., Whalen, Matthew A., Ziegler, Shelby L., and Stachowicz, John J.
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population characteristics ,social sciences - Abstract
Methods and Results �������� post-hoc modeling of individual trait dispersion (SES) against environmental predictors.
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- 2022
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5. sj-docx-1-jcn-10.1177_08830738221115982 - Supplemental material for Factor Analysis of the Einstein Neonatal Neurobehavioral Assessment Scale in Infants with Congenital Heart Disease and Healthy Controls
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Tran, Nhu N., Desai, Jay, Votava-Smith, Jodie K., Brecht, Mary-Lynn, Vanderbilt, Douglas L., Panigrahy, Ashok, Mackintosh, Liza, Brady, Kenneth M., and Peterson, Bradley S.
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FOS: Clinical medicine ,111403 Paediatrics ,110904 Neurology and Neuromuscular Diseases ,Neuroscience - Abstract
Supplemental material, sj-docx-1-jcn-10.1177_08830738221115982 for Factor Analysis of the Einstein Neonatal Neurobehavioral Assessment Scale in Infants with Congenital Heart Disease and Healthy Controls by Nhu N. Tran, Jay Desai, Jodie K. Votava-Smith, Mary-Lynn Brecht, Douglas L. Vanderbilt, Ashok Panigrahy, Liza Mackintosh, Kenneth M. Brady and Bradley S. Peterson in Journal of Child Neurology
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- 2022
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6. Supplemental tables and figures from The biogeography of community assembly: latitude and predation drive variation in community trait distribution in a guild of epifaunal crustaceans
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Gross, Collin P., Duffy, J. Emmett, Hovel, Kevin A., Kardish, Melissa R., Reynolds, Pamela L., Bostr��m, Christoffer, Boyer, Katharyn E., Cusson, Mathieu, Ekl��f, Johan, Engelen, Aschwin H., Eriksson, Britas Klemens, Fodrie, F. Joel, Griffin, John N., Hereu, Clara M., Hori, Masakazu, Hughes, A. Randall, Ivanov, Mikhail V., Jorgensen, Pablo, Kruschel, Claudia, Lee, Kun-Seop, Lefcheck, Jonathan, McGlathery, Karen, Moksnes, Per-Olav, Nakaoka, Masahiro, O'Connor, Mary I., O'Connor, Nessa E., Olsen, Jeanine L., Orth, Robert J., Peterson, Bradley J., Reiss, Henning, Rossi, Francesca, Ruesink, Jennifer, Sotka, Erik E., Thormar, Jonas, Tomas, Fiona, Unsworth, Richard, Voigt, Erin P., Whalen, Matthew A., Ziegler, Shelby L., and Stachowicz, John J.
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Table S1���Table S3; Figure S1���S8
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- 2022
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7. sj-docx-1-jcn-10.1177_08830738221115982 - Supplemental material for Factor Analysis of the Einstein Neonatal Neurobehavioral Assessment Scale in Infants with Congenital Heart Disease and Healthy Controls
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Tran, Nhu N., Desai, Jay, Votava-Smith, Jodie K., Brecht, Mary-Lynn, Vanderbilt, Douglas L., Panigrahy, Ashok, Mackintosh, Liza, Brady, Kenneth M., and Peterson, Bradley S.
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FOS: Clinical medicine ,111403 Paediatrics ,110904 Neurology and Neuromuscular Diseases ,Neuroscience - Abstract
Supplemental material, sj-docx-1-jcn-10.1177_08830738221115982 for Factor Analysis of the Einstein Neonatal Neurobehavioral Assessment Scale in Infants with Congenital Heart Disease and Healthy Controls by Nhu N. Tran, Jay Desai, Jodie K. Votava-Smith, Mary-Lynn Brecht, Douglas L. Vanderbilt, Ashok Panigrahy, Liza Mackintosh, Kenneth M. Brady and Bradley S. Peterson in Journal of Child Neurology
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- 2022
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8. Parsing the Heterogeneity of Brain Metabolic Disturbances in Autism Spectrum Disorder
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O'Neill, Joseph, Bansal, Ravi, Goh, Suzanne, Rodie, Martina, Sawardekar, Siddhant, and Peterson, Bradley S
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Adult ,Male ,Pediatric Research Initiative ,Magnetic Resonance Spectroscopy ,Autism Spectrum Disorder ,Autism ,Intellectual and Developmental Disabilities (IDD) ,Intelligence ,Medical and Health Sciences ,Choline ,Age ,Clinical Research ,Magnetic resonance spectroscopy ,Humans ,Child ,Symptom domains ,Pediatric ,Psychiatry ,Psychology and Cognitive Sciences ,Neurosciences ,Brain ,Biological Sciences ,Magnetic Resonance Imaging ,Brain Disorders ,Mental Health ,Female ,Sex ,Mental health - Abstract
BackgroundDespite rising prevalence of autism spectrum disorder (ASD), its brain bases remain uncertain. Abnormal levels of N-acetyl compounds, glutamate+glutamine, creatine+phosphocreatine, or choline compounds measured by proton magnetic resonance spectroscopy suggest that neuron or glial density, mitochondrial energetic metabolism, and/or inflammation contribute to ASD neuropathology. The neuroanatomic distribution of these metabolites could help evaluate leading theories of ASD. However, most prior magnetic resonance spectroscopy studies had small samples (all
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- 2020
9. A Great Successor to the Hubble Space Telescope
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Gaudi, B. Scott, Clarke, John C., Domagal-Goldman, Shawn, Fischer, Debra, Kiessling, Alina, Mennesson, Bertrand, Peterson, Bradley M., Roberge, Aki, Stern, Dan, and Warfield, Keith
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Earth and Planetary Astrophysics (astro-ph.EP) ,FOS: Physical sciences ,Astrophysics - Instrumentation and Methods for Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The Hubble Space Telescope (HST) has been the most impactful science-driven mission ever flown by NASA. However, when HST reaches the end of its life, there will be a void due to the loss of some of the science capabilities afforded by HST to astronomers world-wide. The previous 2010 Decadal Survey (DS) noted this void, arguing for the need for a successor to HST with UV capabilities in three separate places in the main report (pp. 190, 203, and 220). The large strategic missions that will follow HST, namely JWST and WFIRST, will continue to spark the interest of the public in space-based astronomy. In order to ensure continued US preeminence in the arena of large space-based astrophysics missions, and a seamless transition after WFIRST, a future flagship mission must be waiting in the wings. Anticipating this need, NASA initiated four large strategic mission concept studies (HabEx, LUVOIR, Lynx, and Origins), which have mature designs, including detailed technology assessments and development plans. Two of these concepts, HabEx and LUVOIR, are responsive to the recommendations of the previous DS regarding a UV-capable mission. Both are more powerful successors to HST, with UV-to-optical capabilities that range from significant enhancements to orders-of-magnitude improvement. At the same time, technological and scientific advances over the past decade only now make it feasible to marry such a mission with one that can search for life outside the solar system. Acknowledging that the constraints that the Astro2020 DS must consider may be difficult to anticipate, the HabEx and LUVOIR studies present eleven different variants, each of which enable groundbreaking science, including the direct imaging and characterization of exoplanets. The HabEx and LUVOIR mission studies offer a full suite of options to the Astro2020 DS, with corresponding flexibility in budgeting and phasing., Comment: 11 pages, 9 figures, Astro2020 APC White Paper. Corrected with the proper attribution of Figure 3 to Todd Tripp
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- 2019
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10. Black Hole Masses from Reverberation and Scaling Relationships
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Dalla Bontà, Elena and Peterson, Bradley M.
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quasars: emission lines ,General Relativity and Quantum Cosmology ,galaxies: quasars: general ,Astrophysics::High Energy Astrophysical Phenomena ,Active Galactic Nuclei ,AGN ,Computer Science::Databases ,galaxies: Seyfert - Abstract
Reverberation mapping and scaling relationships based on reverberation results provide the underpinning of all estimates of quasar black hole masses. When applying these scaling relationships, there are potential pitfalls that are widely unappreciated and can result in biases that can, in turn, lead to systematic errors in the black hole mass function and therefore conclusions about the evolution of black holes over time. Potential sources of biases are discussed and it is shown how they can be mitigated.
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- 2018
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11. Associations Between Brain Structure and Connectivity in Infants and Exposure to Selective Serotonin Reuptake Inhibitors During Pregnancy
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Lugo-Candelas, Claudia, Cha, Jiook, Hong, Susie, Bastidas, Vanessa, Weissman, Myrna M., Fifer, William P., Myers, Michael M., Talati, Ardesheer, Bansal, Ravi, Peterson, Bradley S., Monk, Catherine E., Gingrich, Jay A., and Posner, Jonathan Eric
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Psychiatry ,Pregnancy ,Developmental neurobiology ,Fetus--Development ,behavioral disciplines and activities ,Serotonin uptake inhibitors - Abstract
Importance Selective serotonin reuptake inhibitor (SSRI) use among pregnant women is increasing, yet the association between prenatal SSRI exposure and fetal neurodevelopment is poorly understood. Animal studies show that perinatal SSRI exposure alters limbic circuitry and produces anxiety and depressive-like behaviors after adolescence, but literature on prenatal SSRI exposure in humans is limited and mixed. Objective To examine associations between prenatal SSRI exposure and brain development using structural and diffusion magnetic resonance imaging (MRI). Design, Setting, and Participants A cohort study conducted at Columbia University Medical Center and New York State Psychiatric Institute included 98 infants: 16 with in utero SSRI exposure, 21 with in utero untreated maternal depression exposure, and 61 healthy controls. Data were collected between January 6, 2011, and October 25, 2016. Exposures Selective serotonin reuptake inhibitors and untreated maternal depression. Main Outcomes and Measures Gray matter volume estimates using structural MRI with voxel-based morphometry and white matter structural connectivity (connectome) using diffusion MRI with probabilistic tractography. Results The sample included 98 mother (31 [32%] white, 26 [27%] Hispanic/Latina, 26 [27%] black/African American, 15 [15%] other) and infant (46 [47%] boys, 52 [53%] girls) dyads. Mean (SD) age of the infants at the time of the scan was 3.43 (1.50) weeks. Voxel-based morphometry showed significant gray matter volume expansion in the right amygdala (Cohen d = 0.65; 95% CI, 0.06-1.23) and right insula (Cohen d = 0.86; 95% CI, 0.26-1.14) in SSRI-exposed infants compared with both healthy controls and infants exposed to untreated maternal depression (P
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- 2018
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12. Cortical interactions during the resolution of information processing demands in autism spectrum disorders
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Denisova, Kristina, Zhao, Guihu, Wang, Zhishun, Goh, Suzanne, Huo, Yuankai, and Peterson, Bradley S.
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Magnetic resonance imaging ,Human information processing ,Central nervous system ,Autism spectrum disorders ,behavioral disciplines and activities ,Psychophysiology - Abstract
Introduction Our flexible and adaptive interactions with the environment are guided by our individual representation of the physical world, estimated through sensation and evaluation of available information against prior knowledge. When linking sensory evidence with higher-level expectations for action, the central nervous system (CNS) in typically developing (TD) individuals relies in part on distributed and interacting cortical regions to communicate neuronal signals flexibly across the brain. Increasing evidence suggests that the balance between levels of signal and noise during information processing may be disrupted in individuals with Autism Spectrum Disorders (ASD). Methods Participants with and without ASD performed a visuospatial interference task while undergoing functional Magnetic Resonance Imaging (fMRI). We empirically estimated parameters characterizing participants’ latencies and their subtle fluctuations (noise accumulation) over the 16-min scan. We modeled hemodynamic activation and used seed-based analyses of neural coupling to study dysfunction in interference-specific connectivity in a subset of ASD participants who were nonparametrically matched to TD participants on age, male-to-female ratio, and magnitude of movement during the scan. Results Stochastic patterns of response fluctuations reveal significantly higher noise-to-signal levels and a more random and noisy structure in ASD versus TD participants, and in particular ASD adults who have the greatest clinical autistic deficits. While individuals with ASD show an overall weaker modulation of interference-specific functional connectivity relative to TD individuals, in particular between the seeds of Anterior Cingulate Cortex (ACC) and Inferior Parietal Sulcus (IPS) and the rest of the brain, we found that in ASD, higher uncertainty during the task is linked to increased interference-specific coupling between bilateral anterior insula and prefrontal cortex. Conclusions Subtle and informative differences in the structure of experiencing information exist between ASD and TD individuals. Our findings reveal in ASD an atypical capacity to apply previously perceived information in a manner optimal for adaptive functioning, plausibly revealing suboptimal message-passing across the CNS.
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- 2017
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13. Serotonin Signaling Modulates The Effects Of Familial Risk For Depression On Cortical Thickness
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Bansal, Ravi, Peterson, Bradley S., Gingrich, Jay, Hao, Xuejun, Odgerel, Zagaa, Warner, Virginia, Wickramaratne, Priya J., Talati, Ardesheer, Ansorge, Mark, Brown, Alan S., Sourander, Andre, and Weissman, Myrna M.
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- 2016
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14. Increased Default Mode Network Connectivity In Individuals At High Familial Risk For Depression
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Posner, Jonathan, Cha, Jiook, Wang, Zhishun, Talati, Ardesheer, Warner, Virginia, Gerber, Andrew, Peterson, Bradley S., and Weissman, Myrna
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- 2016
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15. The Sloan Digital Sky Survey Reverberation Mapping Project: First Broad-line Hbeta and MgII Lags at z>~0.3 from six-Month Spectroscopy
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Shen, Yue, Horne, Keith, Grier, C. J., Peterson, Bradley M., Denney, Kelly D., Trump, Jonathan R., Sun, Mouyuan, Brandt, W. N., Kochanek, Christopher S., Dawson, Kyle S., Green, Paul J., Greene, Jenny E., Hall, Patrick B., Ho, Luis C., Jiang, Linhua, Kinemuchi, Karen, McGreer, Ian D., Petitjean, Patrick, Richards, Gordon T., Schneider, Donald P., Strauss, Michael A., Tao, Charling, Wood-Vasey, W. M., Zu, Ying, Pan, Kaike, Bizyaev, Dmitry, Ge, Jian, Oravetz, Daniel, and Simmons, Audrey
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Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
Reverberation mapping (RM) measurements of broad-line region (BLR) lags in z>0.3 quasars are important for directly measuring black hole masses in these distant objects, but so far there have been limited attempts and success given the practical difficulties of RM in this regime. Here we report preliminary results of 15 BLR lag measurements from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project, a dedicated RM program with multi-object spectroscopy designed for RM over a wide redshift range. The lags are based on the 2014 spectroscopic light curves alone (32 epochs over 6 months) and focus on the Hbeta and MgII broad lines in the 100 lowest-redshift (z0.3 quasars., Replaced with the accepted version (ApJ); minor revisions in the presentation
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- 2015
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16. Neuroanatomical Correlates Of Religiosity And Spirituality: A Study In Adults At High And Low Familial Risk For Depression
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Miller, Lisa, Bansal, Ravi, Wickramaratne, Priya, Hao, Xuejun, Tenke, Craig E., Weissman, Myrna M., and Peterson, Bradley S.
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- 2014
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17. THE LOW-LUMINOSITY END OF THE RADIUS–LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI
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Bentz, Misty C, Denney, Kelly D, Grier, Catherine J, Barth, Aaron J, Peterson, Bradley M, Vestergaard, Marianne, Bennert, Vardha N, Canalizo, Gabriela, De Rosa, Gisella, Filippenko, Alexei V, Gates, Elinor L, Greene, Jenny E, Li, Weidong, Malkan, Matthew A, Pogge, Richard W, Stern, Daniel, Treu, Tommaso, and Woo, Jong-Hak
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Astrophysics::High Energy Astrophysical Phenomena ,nuclei [galaxies] ,Molecular ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astronomy & Astrophysics ,Atomic ,Particle and Plasma Physics ,Seyfert [galaxies] ,active [galaxies] ,photometry [galaxies] ,astro-ph.CO ,Nuclear ,Astrophysics::Galaxy Astrophysics ,Astronomical and Space Sciences ,Physical Chemistry (incl. Structural) - Abstract
We present an updated and revised analysis of the relationship between the Hβ broad-line region (BLR) radius and the luminosity of the active galactic nucleus (AGN). Specifically, we have carried out two-dimensional surface brightness decompositions of the host galaxies of nine new AGNs imaged with the Hubble Space Telescope Wide Field Camera 3. The surface brightness decompositions allow us to create "AGN-free" images of the galaxies, from which we measure the starlight contribution to the optical luminosity measured through the ground-based spectroscopic aperture. We also incorporate 20 new reverberation-mapping measurements of the Hβ time lag, which is assumed to yield the average Hβ BLR radius. The final sample includes 41 AGNs covering four orders of magnitude in luminosity. The additions and updates incorporated here primarily affect the low-luminosity end of the R BLR-L relationship. The best fit to the relationship using a Bayesian analysis finds a slope of , consistent with previous work and with simple photoionization arguments. Only two AGNs appear to be outliers from the relationship, but both of them have monitoring light curves that raise doubt regarding the accuracy of their reported time lags. The scatter around the relationship is found to be 0.19 ± 0.02 dex, but would be decreased to 0.13 dex by the removal of these two suspect measurements. A large fraction of the remaining scatter in the relationship is likely due to the inaccurate distances to the AGN host galaxies. Our results help support the possibility that the RBLR-L relationship could potentially be used to turn the BLRs of AGNs into standardizable candles. This would allow the cosmological expansion of the universe to be probed by a separate population of objects, and over a larger range of redshifts. © 2013. The American Astronomical Society. All rights reserved.
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- 2013
18. Masses of Black Holes in Active Galactic Nuclei: Implications for NLS1s
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Peterson, Bradley M.
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
I review how AGN black hole masses are calculated from emission-line reverberation-mapping data, with particular attention to both assumptions and caveats. I discuss the empirical relationship between AGN luminosity and broad-line region radius that underpins the indirect methods by which most AGN masses are estimated. I also discuss how line widths are characterized in this method and illustrate how different ways of measuring the line-widths can lead to systematic errors in the mass scale. I discuss specific implications for NLS1 galaxies and consider whether the NLS1 phenomenon is better explained by source inclination or by Eddington rate, and conclude that there is evidence that both of these effects are contributing factors and that at least the high-Eddington rate NLS1s are physically similar to some high-luminosity quasars., Comment: 19 pages, 5 figures. Based on an invited talk at the workshop "Narrow-Line Seyfert 1 Galaxies and Their Place in the Universe", Milan, 4-6 April 2011
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- 2011
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19. Star Cluster Dissolution in Arp 284
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Peterson, Bradley W., Struck, Curtis, Smith, Beverly J., and Hancock, Mark
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::Solar and Stellar Astrophysics ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present results from a study of proto-globular cluster candidates in the interacting galaxy system Arp 284 (NGC 7714/5). Studies of the Antennae and M51 have suggested that the majority of these star clusters dissolve within 20 Myr due to mass loss. We obtain cluster colors using archival \emph{HST} data, and estimate ages and extinctions for over 150 clusters using evolutionary synthesis models. We find that clusters in NGC 7714 are generally less than 20 Myr old, while the data in the bridge is too limited to allow good estimates for individual clusters. We also examine {H {\sc ii}} region complexes with lower-resolution \emph{GALEX} and ground-based H$\alpha$ images. Several of these regions appear to be much older than the detected clusters within them, which may indicate the presence of an older, unresolved population of low mass or dispersed clusters., Comment: To appear in the Proceedings of the Galaxy Wars: Stellar Populations and Star Formation in Interacting Galaxies Conference
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- 2009
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20. The Masses of Black Holes in Active Galactic Nuclei
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Peterson, Bradley M.
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General Relativity and Quantum Cosmology ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
Reverberation mapping methods have been used to measure masses in about three dozen AGNs. The consistency of the virial masses computed from line widths and time delays, the relationship between black hole mass and host-galaxy stellar bulge velocity dispersion, and the consistency with black hole masses estimated from stellar dynamics in the two cases in which such determinations are possible all indicate that reverberation mass measurements are robust and are accurate to typically a factor of a few. The reverberation-mapped AGNs are of particular importance because they anchor the scaling relationships that allow black hole mass estimation based on single spectra. We discuss potential sources of systematic error, particularly with regard to how the emission line widths are measured., Comment: 10 pages, 1 figure. To appear in "The Central Engine of Active Galactic Nuclei", ed. L.C. Ho and J.-M. Wang, ASP Conference Series
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- 2007
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21. Optical Variability of the Three Brightest Nearby Quasars
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Gaskell, C. Martin, Benker, Andrew J., Campbell, Jeffrey S., George, Thomas A., Hedrick, Cecelia H., Hiller, Mary E., Klimek, Elizabeth S., Leonard, Joseph P., Masatoshi, Shoji, Peterson, Bradley W., Peterson, Kelly C., and Sanders, Kelly M.
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Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
We report on the relative optical variability of the three brightest nearby quasars, 3C 273, PDS 456, and PHL 1811. All three have comparable absolute magnitudes, but PDS 456 and PHL 1811 are radio quiet. PDS 456 is a broad-line object, but PHL 1811 could be classified as a high-luminosity Narrow-Line Seyfert 1 (NLS1). Both of the radio-quiet quasars show significant variability on a timescale of a few days. The seasonal rms V-band variability amplitudes of 3C 273 and PDS 456 are indistinguishable, and the seasonal rms variability amplitude of PHL 1811 was only exceeded by 3C 273 once in 30 years of monitoring. We find no evidence that the optical variability of 3C 273 is greater than or more rapid than the variability of the comparably-bright, radio-quiet quasars. This suggests that not only do radio-loud and radio-quiet AGNs have similar spectral energy distributions, but that the variability mechanisms are also similar. The optical variability of 3C 273 is not dominated by a "blazer" component., Comment: 5 pages, 2 figures. In "AGN Variability from X-rays to Radio Waves", ed. C. M. Gaskell, I. M. McHardy, B. M. Peterson, and S. G. Sergeev
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- 2007
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22. Refining the Radius-Luminosity Relationship for Active Galactic Nuclei
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Bentz, Misty C., Denney, Kelly D., Peterson, Bradley M., and Pogge, Richard W.
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Astrophysics (astro-ph) ,FOS: Physical sciences ,Astrophysics - Abstract
We have measured the host-galaxy starlight contribution to four lower-luminosity AGNs (NGC 3516, NGC 4593, IC 4329A, and NGC 7469). We include these objects with new broad line region measurements for NGC 4151 and NGC 4593 to present a revised version of the radius-luminosity relationship for AGNs., Comment: 4 pages, 1 table, 1 figure, Conference proceedings to appear in "The Central Engine of Active Galactic Nuclei", ed. L. C. Ho and J.-M. Wang (San Francisco: ASP)
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- 2007
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23. The danger of sprawl
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Peterson, Bradley P.
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- 2004
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24. The Structure and Energetics of Active Galactic Nuclei
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Peterson, Bradley M.
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Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astrophysics::Solar and Stellar Astrophysics ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
The black-hole/accretion-disk paradigm for active galactic nuclei (AGNs) is now reasonably secure, but there are still important unresolved issues, some of which will require the capabilities of an 8 to 10-m class UV/optical space-based telescope. Imaging spectroscopy with a diffraction-limited large telescope will be required to measure AGN black-hole masses from stellar dynamics for direct comparison with reverberation mapping-based masses. High spectral resolution in the UV is required to determine the mass and kinetic energy of the outflows observed in the absorption spectra of AGNs and to understand the energetics of the accretion process. As with ground-based astronomy, however, effective use of a large UV/optical space telescope requires complementary smaller facility instruments; a meter-class UV spectroscopic telescope, for example, can fit into a Medium Explorer budget., Comment: 8 pages, including 1 figure. To be published in "Hubble's Science Legacy: Future Optical-Ultraviolet Astronomy from Space", eds. K.R. Sembach, J.C. Blades, G.D. Illingworth, & R.C. Kennicutt, ASP Conference Series
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- 2002
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25. A High Signal-to-Noise UV Spectrum of NGC 7469: New Support for Reprocessing of Continuum Radiation
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Kriss, Gerard A., Peterson, Bradley M., Crenshaw, D. Michael, and Zheng, Wei
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Astrophysics (astro-ph) ,FOS: Physical sciences ,Astrophysics - Abstract
From 1996 June 10 to 1996 July 29 the International AGN Watch monitored the Seyfert 1 galaxy NGC 7469 using IUE, RXTE, and a network of ground-based observatories. On 1996 June 18, in the midst of this intensive monitoring period, we obtained a high signal-to-noise snapshot of the UV spectrum from 1150-3300 A using the FOS on HST. This spectrum allows us to disentangle the UV continuum more accurately from the broad wings of the emission lines, to identify clean continuum windows free of contaminating emission and absorption, and to deblend line complexes such as Lya+NV, CIV+HeII+OIII], SiIII]+CIII], and MgII+FeII. Using the FOS spectrum as a template, we have fit and extracted line and continuum fluxes from the IUE monitoring data. The cleaner continuum extractions confirm the discovery of time delays between the different UV continuum bands by Wanders et al. Our new measurements show delays increasing with wavelength for continuum bands centered at 1485 A, 1740 A and 1825 A relative to 1315 A with delays of 0.09, 0.28 and 0.36 days, respectively. Like many other Seyfert 1 galaxies, the UV spectrum of NGC 7469 shows intrinsic, blue-shifted absorption in Lya, NV and C IV. Soft X-ray absorption is also visible in archival ASCA X-ray spectra. The strength of the UV absorption, however, is not compatible with a single-zone model in which the same material absorbs both the UV and X-ray light. Similar to other Seyfert galaxies such as NGC 3516, the UV-absorbing gas in NGC 7469 has a lower ionization parameter and column density than the X-ray absorbing material. While the UV and X-ray absorption does not arise in the same material, the frequent occurrence of both associated UV absorption and X-ray warm absorbers in the same galaxies suggests that the gas supply for each has a common origin., Comment: 18 pages, 16 PostScript figures, uses emulateapj.sty. To appear in the Astrophysical Journal
- Published
- 1999
- Full Text
- View/download PDF
26. Rejoinder
- Author
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Zhu, Hongtu, Zhang, Heping, Ibrahim, Joseph G., and Peterson, Bradley S.
- Published
- 2007
27. Synergistic Astrophysics in the Ultraviolet using Active Galactic Nuclei
- Author
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Kriss, Gerard, Arav, Nahum, Anton Koekemoer, Mathur, Smita, Peterson, Bradley M., and Scott, Jennifer E.
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Observing programs comprising multiple scientific objectives will enhance the productivity of NASA's next UV/Visible mission. Studying active galactic nuclei (AGN) is intrinsically important for understanding how black holes accrete matter, grow through cosmic time, and influence their host galaxies. At the same time, the bright UV continuum of AGN serves as an ideal background light source for studying foreground gas in the intergalactic medium (IGM), the circumgalactic medium (CGM) of individual galaxies, and the interstellar medium (ISM) and halo of the Milky Way. A well chosen sample of AGN can serve as the observational backbone for multiple spectroscopic investigations including quantitative measurements of outflows from AGN, the structure of their accretion disks, and the mass of the central black hole., Science white paper submitted to NASA Solicitation NNH12ZDA008L: Science Objectives and Requirements for the Next NASA UV/Visible Astrophysics Mission Concepts. 6 pages, 5 figures, PDF
28. Compact steep-spectrum sources as the parent population of flat-spectrum radio-loud NLS1s
- Author
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Alessandro Caccianiga, Peterson, Bradley M., Enrico Congiu, Giacomo Terreran, Giovanni La Mura, Luigi Foschini, Marco Berton, Michele Frezzato, Piero Rafanelli, Smita Mathur, Stefano Ciroi, and Valentina Cracco
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - Abstract
Narrow-line Seyfert 1 galaxies (NLS1s) are an interesting subclass of active galactic nuclei (AGN), which tipically does not exhibit any strong radio emission. Seven percent of them, though, are radio-loud and often show a flat radio-spectrum (F-NLS1s). This, along to the detection of $\gamma$-ray emission coming from them, is usually interpreted as a sign of a relativistic beamed jet oriented along the line of sight. An important aspect of these AGN that must be understood is the nature of their parent population, in other words how do they appear when observed under different angles. In the recent literature it has been proposed that a specific class of radio-galaxies, compact-steep sources (CSS) classified as high excitation radio galaxies (HERG), can represent the parent population of F-NLS1s. To test this hypothesis in a quantitative way,in this paper we analyzed the only two statistically complete samples of CSS/HERGs and F-NLS1s available in the literature. We derived the black hole mass and Eddington ratio distributions, and we built for the first time the radio luminosity function of F-NLS1s. Finally, we applied a relativistic beaming model to the luminosity function of CSS/HERGs, and compared the result with the observed function of F-NLS1s. We found that compact steep-spectrum sources are valid parent candidates and that F-NLS1s, when observed with a different inclination, might actually appear as CSS/HERGs., Comment: 9 pages, 5 figures, 4 tables. Accepted for publication in Astronomy & Astrophysics
29. Radio Continuum Variability and Molecular Gas Reservoirs in the Type-Transitioning Seyfert Galaxy Mrk 590
- Author
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Koay, Jun Yi, Marianne Vestergaard, Casasola, Viviana, and Peterson, Bradley M.
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