Search Publications
The Infrared Jet in 3C 31
Jones, Christine; Kraft, Ralph P.; Forman, William R. +5 more
We report the detection of infrared emission from the jet of the nearby Fanaroff-Riley type I radio galaxy 3C 31. The jet was detected with the IRAC instrument on Spitzer at 4.5 µm, 5.8 µm, and 8.0 µm out to 30'' (13 kpc) from the nucleus. We measure radio, infrared, optical, and X-ray fluxes in three regions along the jet determ…
Coronal Jets, Magnetic Topologies, and the Production of Interplanetary Electron Streams
van Driel-Gesztelyi, L.; Owen, C. J.; Li, C. +2 more
We investigate the acceleration source of the impulsive solar energetic particle (SEP) events on 2007 January 24. Combining the in situ electron measurements and remote-sensing solar observations, as well as the calculated magnetic fields obtained from a potential-field source-surface model, we demonstrate that the jets associated with the hard X-…
Fast Timing Analysis of Cygnus X-1 Using the SPectrometer on the International Gamma-Ray Astrophysics Laboratory
Jourdain, Elisabeth; Roques, Jean-Pierre; Cabanac, Clément
We report for the first time the high-frequency analysis of Cyg X-1 up to hard X-ray using the spectrometer on International Gamma-Ray Astrophysics Laboratory (INTEGRAL). After analyzing the possible contribution from the background, and using the INTEGRAL archive from 2005 March to 2008 May, power density spectra were obtained up to 130 keV. Firs…
The Suzaku View of the Disk-Jet Connection in the Low-excitation Radio Galaxy NGC 6251
Hardcastle, M. J.; Croston, J. H.; Gandhi, P. +4 more
We present results from an 87 ks Suzaku observation of the canonical low-excitation radio galaxy (LERG) NGC 6251. We have previously suggested that LERGs violate conventional active galactic nucleus unification schemes: they may lack an obscuring torus and are likely to accrete in a radiatively inefficient manner, with almost all of the energy rel…
On Asymmetry of Magnetic Helicity in Emerging Active Regions: High-resolution Observations
Alexander, David; Démoulin, Pascal; Zhu, Chunming +1 more
We employ the DAVE (differential affine velocity estimator) tracking technique on a time series of Michelson Doppler Imager (MDI)/1 minute high spatial resolution line-of-sight magnetograms to measure the photospheric flow velocity for three newly emerging bipolar active regions (ARs). We separately calculate the magnetic helicity injection rate o…
Pre-main-sequence Stellar Populations across Shapley Constellation III. I. Photometric Analysis and Identification
Henning, Thomas; Da Rio, Nicola; Gouliermis, Dimitrios A. +11 more
We present our investigation of pre-main-sequence (PMS) stellar populations in the Large Magellanic Cloud (LMC) from imaging with Hubble Space Telescope Wide-Field Planetary Camera 2. Our targets of interest are four star-forming regions located at the periphery of the super-giant shell LMC 4 (Shapley Constellation III). The PMS stellar content of…
Reinstating the M31 X-Ray System RX J0042.3+4115 as a Black Hole X-Ray Binary and Compelling Evidence for an Extended Corona
Murray, S. S.; Garcia, M. R.; Barnard, R.
The M31 X-ray source RX J0042.3+4115 was originally identified as a black hole (BH) binary because it displayed characteristic low-state variability at conspicuously high luminosities; unfortunately, this variability was later found to be artificial. However, analysis of 84 Chandra ACIS observations, a Hubble Space Telescope Advanced Camera for Su…
Two Types of Extreme-ultraviolet Brightenings In AR 10926 Observed by Hinode/EIS
Moon, Y. -J.; Choe, G. S.; Kim, Sujin +3 more
We have investigated seven extreme-ultraviolet (EUV) brightenings in the active region AR 10926 on 2006 December 2 observed by the EUV Imaging Spectrometer on board the Hinode spacecraft. We have determined their Doppler velocities and non-thermal velocities from 15 EUV spectral lines (log T = 4.7 - 6.4) by fitting each line profile to a Gaussian …
On the Anti-correlation between Spectral Line Broadening and Intensity in Coronal Structures Observed with EIS
Martens, P. C. H.; Scott, J. T.
The advance in spectral resolution of the Extreme Ultraviolet Imaging (EIS) spectrometer on board Hinode has allowed for more detailed analysis of coronal spectral lines. Large line broadening and blueshifted velocities have been found in the periphery of active region (AR) cores and near the footpoints of coronal loops. This line broadening is ye…
Vector Magnetic Fields and Current Helicities in Coronal Holes and Quiet Regions
Li, Ting; Yang, Shuhong; Zhang, Jun +1 more
In the solar photosphere, many properties of coronal holes (CHs) are not known, especially vector magnetic fields. Using observations from Hinode, we investigate vector magnetic fields, current densities, and current helicities in two CHs, and compare them with two normal quiet regions (QRs) for the first time. We find that the areas where large c…