ORCID Profile
0000-0002-3026-0562
Current Organisation
University of California, Irvine
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Astronomical Society
Date: 10-2020
Abstract: On Earth near sunset, the Sun may cast “crepuscular rays” such that clouds near the horizon obscure the origin of light scattered in bright rays. In principle, active galactic nuclei (AGN) should be able to produce similar effects. Using new Hubble Space Telescope (HST) near-infrared and optical observations, we show that the active galaxy IC 5063 contains broad radial rays extending to ≳11 kpc from the nucleus. We argue that the bright rays may arise from dusty scattering of continuum emission from the active nucleus, while the dark rays are due to shadowing near the nucleus, possibly by a warped torus. We also consider alternative AGN-related and stellar origins for the extended light.
Publisher: SPIE
Date: 26-07-2016
DOI: 10.1117/12.2233182
Publisher: SPIE
Date: 28-07-2014
DOI: 10.1117/12.2055599
Publisher: American Astronomical Society
Date: 03-06-2016
Publisher: American Astronomical Society
Date: 14-10-2020
Publisher: American Astronomical Society
Date: 18-01-2017
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.856521
Publisher: American Astronomical Society
Date: 11-09-2018
Publisher: American Astronomical Society
Date: 13-08-2015
Publisher: American Astronomical Society
Date: 18-03-2014
Publisher: American Astronomical Society
Date: 11-04-2016
Publisher: American Astronomical Society
Date: 02-2021
Abstract: In this contribution, we achieve the primary goal of the active galactic nucleus (AGN) STORM c aign by recovering velocity–delay maps for the prominent broad emission lines (Ly α , C iv , He ii , and H β ) 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 profile. The Ly α , C iv , and H β responses extend from inside 2 to outside 20 lt-day, with double peaks at ±2500 km s −1 in the 10–20 lt-day delay range. An incomplete ellipse in the velocity–delay plane is evident in H β . We interpret the maps in terms of a Keplerian disk with a well-defined outer rim at R = 20 lt-day. The far-side response is weaker than that from the near side. The line-center delay τ = ( R / c ) ( 1 − sin i ) ≈ 5 days gives the inclination i ≈ 45°. The inferred black hole mass is M BH ≈ 7 × 10 7 M ⊙ . In addition to reverberations, the fit residuals confirm that emission-line fluxes are depressed during the “BLR Holiday” identified in previous work. Moreover, a helical “Barber-Pole” pattern, with stripes moving from red to blue across the C iv and Ly α line profiles, suggests azimuthal structure rotating with a 2 yr period that may represent precession or orbital motion of inner-disk structures casting shadows on the emission-line region farther out.
Publisher: American Astronomical Society
Date: 20-08-2019
Location: United States of America
Location: United States of America
Location: United States of America
No related grants have been discovered for Aaron Barth.