Nahum Arav

About

Nahum Arav is a faculty member at the Fralin Biomedical Research Institute at Virginia Tech, where his research involves the use of functional magnetic resonance imaging (fMRI) to study various aspects of neuroscience, psychology, political science, law, and economics. His laboratory contains research-dedicated Siemens fMRI devices in Roanoke and Blacksburg, enabling the simultaneous scanning of multiple participants during negotiation or game-based experiments using a novel technique called hyperscanning. Faculty across the institute collaborate with the Human Neuroimaging Laboratory to utilize fMRI technology in human research studies, particularly within the Addiction Recovery Research Center, the Center for Transformative Health Behaviors, and the Computational Psychiatry Unit. His work focuses on understanding brain function through advanced imaging techniques, with a particular emphasis on how brain activity correlates with decision-making and behavior. The laboratory's research includes detailed anatomical imaging of the brain using conventional MRI, as well as functional imaging to observe brain activation in response to various stimuli. The fMRI technology employed detects small changes in blood flow related to neural activity, allowing researchers to identify specific brain regions involved in different cognitive and behavioral processes. The Roanoke Brain Study, part of a large-scale research initiative, combines neuroimaging, genetics, and computational…

Research topics

• Astronomy
• Astrophysics
• Physics
• Optics

Selected publications

• AGN STORM 2. I. First results: A Change in the Weather of Mrk 817

  The Astrophysical Journal · 2021 · 112 citations

  <jats:title>Abstract</jats:title>
\n <jats:p>We present the first results from the ongoing, intensive, multiwavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part, selected for its historically unobscured nature, we discovered that the X-ray spectrum is highly absorbed, and there are new blueshifted, broad, and narrow UV absorption lines, which suggest that a dust-free, ionized obscurer located at the inner br…

  DOI

• Suppression of black-hole growth by strong outflows at redshifts 5.8–6.6

  Nature · 2022 · 73 citations

  DOI

• AGN STORM 2. VII. A Frequency-resolved Map of the Accretion Disk in Mrk 817: Simultaneous X-Ray Reverberation and UVOIR Disk Reprocessing Time Lags

  The Astrophysical Journal · 2024-10-01 · 18 citations

  articleOpen access

  Abstract X-ray reverberation mapping is a powerful technique for probing the innermost accretion disk, whereas continuum reverberation mapping in the UV, optical, and infrared (UVOIR) reveals reprocessing by the rest of the accretion disk and broad-line region (BLR). We present the time lags of Mrk 817 as a function of temporal frequency measured from 14 months of high-cadence monitoring from Swift and ground-based telescopes, in addition to an XMM-Newton observation, as part of the AGN STORM 2…

  PublisherDOI

• AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817*

  The Astrophysical Journal · 2024-11-01 · 11 citations

  articleOpen access

  Abstract The local ( z = 0.0315) active galactic nucleus (AGN) Mrk 817 was monitored over more than 500 days with space-borne and ground-based instruments as part of a large international campaign, AGN STORM 2. Here, we present a comprehensive analysis of the broadband continuum variations using detailed modeling of the broad line region (BLR), several types of disk winds classified by their optical depth, and new numerical simulations. We find that diffuse continuum (DC) emission, with addition…

  PublisherDOI

• AGN STORM 2. IX. Studying the Dynamics of the Ionized Obscurer in Mrk 817 with High-resolution X-Ray Spectroscopy

  The Astrophysical Journal · 2024-10-01 · 9 citations

  articleOpen access

  Abstract We present the results of the XMM-Newton and NuSTAR observations taken as part of the ongoing, intensive multiwavelength monitoring program of the Seyfert 1 galaxy Mrk 817 by the AGN Space Telescope and Optical Reverberation Mapping 2 (AGN STORM 2) Project. The campaign revealed an unexpected and transient obscuring outflow, never before seen in this source. Of our four XMM-Newton/NuSTAR epochs, one fortuitously taken during a bright X-ray state has strong narrow absorption lines in the…

  PublisherDOI

Recent grants

• The Impact of Observed Quasar Outflows on Cosmological Structure Formation

  NSF · $342k · 2008–2011

• Where are the Broad Absorption Line Outflows Situated and How Important are they to Active Galactic Nuclei Feedback?

  NSF · $497k · 2014–2018

• QUASAR ABSORPTION OUTFLOWS, THE MAIN AGENT OF AGN FEEDBACK

  NSF · $500k · 2021–2026

Frequent coauthors

• J. S. Kaastra

  SRON Netherlands Institute for Space Research

  203 shared

• G. A. Kriss

  Space Telescope Science Institute

  186 shared

• P.‐O. Petrucci

  Institut de Planétologie et d'Astrophysique de Grenoble

  167 shared

• M. Mehdipour

  Space Telescope Science Institute

  110 shared

• E. Costantini

  The Netherlands Cancer Institute

  108 shared

• K. C. Steenbrugge

  Centre National de la Recherche Scientifique

  102 shared

• J. Ebrero

  European Space Agency

  86 shared

• G. Ponti

  85 shared

Similar researchers at Virginia Tech

• Charles Caoh-35
• Edwin Barnesh-32
• Lara Andersonh-30