Search Publications
Polar and Equatorial Coronal Hole Winds at Solar Minima: From the Heliosphere to the Inner Corona
Zhao, L.; Landi, E.
Fast solar wind can be accelerated from at least two different sources: polar coronal holes and equatorial coronal holes. Little is known about the relationship between the wind coming from these two different latitudes and whether these two subcategories of fast wind evolve in the same way during the solar cycle. Nineteen years of Ulysses observa…
Another Short-burst Host Galaxy with an Optically Obscured High Star Formation Rate: The Case of GRB 071227
Palazzi, E.; Greiner, J.; Hunt, L. K. +9 more
We report on radio continuum observations of the host galaxy of the short gamma-ray burst 071227 (z = 0.381) with the Australia Telescope Compact Array. We detect the galaxy in the 5.5 GHz band with an integrated flux density of F ν = 43 ± 11 µJy, corresponding to an unobscured star-formation rate of about 24 M ⊙ yr
XMM-Newton Observations of Young and Energetic Pulsar J2022+3842
Pavlov, G. G.; Kargaltsev, O.; Arumugasamy, P.
We report on XMM-Newton EPIC observations of the young pulsar J2022+3842, with a characteristic age of 8.9 kyr. We detected X-ray pulsations and found the pulsation period P ≈ 48.6 ms, and its derivative \dot{P}\approx 8.6\times 10^{-14}, which is two times larger than previously reported values. The pulsar exhibits two very narrow (FWHM ~1.2 ms) …
Star Formation Rate and Extinction in Faint z ~ 4 Lyman Break Galaxies
Owen, Frazer N.; Wang, Wei-Hao; To, Chun-Hao
We present a statistical detection of 1.5 GHz radio continuum emission from a sample of faint z ~ 4 Lyman break galaxies (LBGs). To constrain their extinction and intrinsic star formation rate (SFR), we combine the latest ultradeep Very Large Array 1.5 GHz radio image and the Hubble Space Telescope Advanced Camera for Surveys (ACS) optical images …
Short-term Variability of X-Rays from Accreting Neutron Star Vela X-1. II. Monte Carlo Modeling
Makishima, Kazuo; Takahashi, Tadayuki; Odaka, Hirokazu +3 more
We develop a Monte Carlo Comptonization model for the X-ray spectrum of accretion-powered pulsars. Simple, spherical, thermal Comptonization models give harder spectra for higher optical depth, while the observational data from Vela X-1 show that the spectra are harder at higher luminosity. This suggests a physical interpretation where the optical…
PdBI Cold Dust Imaging of Two Extremely Red H - [4.5] > 4 Galaxies Discovered with SEDS and CANDELS
Dunlop, J. S.; Castellano, M.; Krips, M. +11 more
We report Plateau de Bure Interferometer (PdBI) 1.1 mm continuum imaging toward two extremely red H - [4.5] > 4 (AB) galaxies at z > 3, which we have previously discovered making use of Spitzer SEDS and Hubble Space Telescope CANDELS ultra-deep images of the Ultra Deep Survey field. One of our objects is detected on the PdBI map with a 4.3σ …
Investigating CXOU J163802.6-471358: A New Pulsar Wind Nebula in the Norma Region?
Kaspi, Victoria M.; Tomsick, John A.; Gotthelf, Eric V. +2 more
We present the first analysis of the extended source CXOU J163802.6-471358, which was discovered serendipitously during the Chandra X-ray survey of the Norma region of the Galactic spiral arms. The X-ray source exhibits a cometary appearance with a point source and an extended tail region. The complete source spectrum is fitted well with an absorb…
Three-dimensional Stereoscopic Analysis of a Coronal Mass Ejection and Comparison with UV Spectroscopic Data
Susino, Roberto; Bemporad, Alessandro; Dolei, Sergio
A three-dimensional (3D) reconstruction of the 2007 May 20 partial-halo coronal mass ejection (CME) has been made using STEREO/EUVI and STEREO/COR1 coronagraphic images. The trajectory and kinematics of the erupting filament have been derived from Extreme Ultraviolet Imager (EUVI) image pairs with the "tie-pointing" triangulation technique, while …
Herschel Extreme Lensing Line Observations: Dynamics of Two Strongly Lensed Star-forming Galaxies near Redshift z = 2
Carilli, Chris; Strauss, Michael A.; Frye, Brenda +11 more
We report on two regularly rotating galaxies at redshift z ≈ 2, using high-resolution spectra of the bright [C II] 158 µm emission line from the HIFI instrument on the Herschel Space Observatory. Both SDSS090122.37+181432.3 ("S0901") and SDSSJ120602.09+514229.5 ("the Clone") are strongly lensed and show the double-horned line profile that is…
On the Area Expansion of Magnetic Flux Tubes in Solar Active Regions
Cirtain, Jonathan W.; Dudík, Jaroslav; Dzifčáková, Elena
We calculated the three-dimensional (3D) distribution of the area expansion factors in a potential magnetic field, extrapolated from the high-resolution Hinode/SOT magnetogram of the quiescent active region NOAA 11482. Retaining only closed loops within the computational box, we show that the distribution of area expansion factors show significant…