440 citations · 1.1k across the 19 of their papers we have counts for
19 papers
Observational Tests of Sgr A*'s State of the Accretion Flow
F. Yusef-Zadeh, R. G. Arendt, H. Bushouse +4
General relativistic magneto-hydrodynamic (GRMHD) simulations of the possibly magnetically arrested disk (MAD) of the accretion flow of Sgr A* predict short and long time variabili…
Simultaneous JWST, NuSTAR, and VLA Monitoring of Sgr A*: A Unified Picture of the Variable IR, X-ray and Radio Emission
F. Yusef-Zadeh, M. Wardle, R. G. Arendt +5
Flux variability is a fundamental channel of information from Sgr A* because of its direct probe of processes occurring within an accretion disk under strong gravity. We present si…
Non-stop Variability of Sgr A* using JWST at 2.1 and 4.8 micron Wavelengths: Evidence for Distinct Populations of Faint and Bright Variable Emission
F. Yusef-Zadeh, H. Bushouse, R. G. Arendt +3
We present first results of JWST Cycle 1 and 2 observations of Sgr A* using NIRCam taken simultaneously at 2.1 and 4.8 micron for a total of ~48 hours over seven different epochs i…
Multiwavelength Observations of Sgr A*. II. 2019 July 21 and 26
Joseph M. Michail, Farhad Yusef-Zadeh, Mark Wardle +6
We report on the final two days of a multiwavelength campaign of Sgr A* observing in the radio, submillimeter, infrared, and X-ray bands in July 2019. Sgr A* was remarkably active,…
An Algorithm to Mitigate Charge Migration Effects in Data from the Near Infrared Imager and Slitless Spectrograph on the James Webb Space Telescope
Paul Goudfrooij, David Grumm, Kevin Volk +1
We present an algorithm that mitigates the effects of charge migration due to the "brighter-fatter effect'' (BFE) that occurs for highly illuminated stars in the Teledyne HAWAII-2R…
JWST/NIRCam Coronagraphy: Commissioning and First On-Sky Results
Julien H. Girard, Jarron Leisenring, Jens Kammerer +53
In a cold and stable space environment, the James Webb Space Telescope (JWST or "Webb") reaches unprecedented sensitivities at wavelengths beyond 2 microns, serving most fields of…
The Science Performance of JWST as Characterized in Commissioning
Jane Rigby, Marshall Perrin, Michael McElwain +623
This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performanc…
ALMA and VLA observations of emission from the environment of Sgr A*
F. Yusef-Zadeh, R. Schödel, M. Wardle +6
We present 44 and 226 GHz observations of the Galactic center within 20 of Sgr A*. Millimeter continuum emission at 226 GHz is detected from eight stars that have previously bee…
Sgr A* and its Environment: Low Mass Star Formation, the Origin of X-ray Gas and Collimated Outflow
F. Yusef-Zadeh, M. Wardle, R. Schödel +5
We present high-resolution multiwavelength radio continuum images of the region within 150 of Sgr A*, revealing a number of new extended features and stellar sources in this reg…
Compact Radio Sources within 30" of Sgr A*: Proper Motions, Stellar Winds and the Accretion Rate onto Sgr A*
F. Yusef-Zadeh, H. Bushouse, R. Schödel +5
Recent broad-band 34 and 44 GHz radio continuum observations of the Galactic center have revealed 41 massive stars identified with near-IR counterparts, as well as 44 proplyd candi…
The Discovery of Radio Stars within 10 arcseconds of Sgr A* at 7mm
F. Yusef-Zadeh, D. A. Roberts, H. Bushouse +4
Very Large Array observations of the Galactic Center at 7 mm have produced an image of the 30 arcseconds surrounding Sgr A* with a resolution of 82x42 milliarcseconds (mas). A comp…
ALMA Observations of the Galactic Center: SiO Outflows and High Mass Star Formation near Sgr A*
F. Yusef-Zadeh, M. Royster, M. Wardle +7
ALMA observations of the Galactic center with spatial resolution resulted in the detection of 11 SiO (5-4) clumps of molecular gas within 0.6pc (15) of Sgr A*…
A Three Parsec-Scale Jet-Driven Outflow from Sgr A*
F. Yusef-Zadeh, R. Arendt, H. Bushouse +6
The compact radio source Sgr A* is coincident with a 4 million solar mass black hole at the dynamical center of the Galaxy and is surrounded by dense orbiting ionized and molecular…
An Inverse Compton Scattering Origin of X-ray Flares from Sgr A*
F. Yusef-Zadeh, M. Wardle, K. Dodds-Eden +6
The X-ray and near-IR emission from Sgr A* is dominated by flaring, while a quiescent component dominates the emission at radio and sub-mm wavelengths. The spectral energy distribu…
Massive Star Formation of the Sgr A East HII Regions Near the Galactic Center
F. Yusef-Zadeh, J. H. Lacy, M. Wardle +4
A group of four compact HII regions associated with the well-known 50 km/s molecular cloud is the closest site of on-going star formation to the dynamical center of the Galaxy, at…
The Size Evolution of Passive Galaxies: Observations from the Wide Field Camera 3 Early Release Science Program
R. E. Ryan, P. J. McCarthy, S. H. Cohen +28
We present results on the size evolution of passively evolving galaxies at 1<z<2 drawn from the Wide Field Camera 3 Early Release Science program. Our sample was constructed using…
Simultaneous Multi-Wavelength Observations of Sgr A* during 2007 April 1-11
F. Yusef-Zadeh, H. Bushouse, M. Wardle +18
We report the detection of variable emission from Sgr A* in almost all wavelength bands (i.e. centimeter, millimeter, submillimeter, near-IR and X-rays) during a multi-wavelength o…
A Multi-Wavelength Study of Sgr A*: The Role of Near-IR Flares in Production of X-ray, Soft -ray and Sub-millimeter Emission
F. Yusef-Zadeh, H. Bushouse, C. D. Dowell +8
(abridged) We describe highlights of the results of two observing campaigns in 2004 to investigate the correlation of flare activity in Sgr A* in different wavelength regimes, usin…
Ultraluminous Infrared Galaxies: Atlas of Near-Infrared Images
H. Bushouse, K. Borne, L. Colina +6
A sample of 27 ultraluminous infrared galaxy (ULIRG) systems has been imaged at 1.6 microns using the HST Near Infrared Camera and Multi-Object Spectrometer (NICMOS). These ULIRGs…