Search Publications
Multiwavelength Imaging and Spectroscopy of Chromospheric Evaporation in an M-class Solar Flare
Temmer, M.; Veronig, A. M.; Vršnak, B. +6 more
We study spectroscopic observations of chromospheric evaporation mass flows in comparison with the energy input by electron beams derived from hard X-ray (HXR) data for the white-light M2.5 flare of 2006 July 6. The event was captured in high-cadence spectroscopic observing mode by SOHO/CDS combined with high-cadence imaging at various wavelengths…
Seasonal Changes in Titan's Polar Trace Gas Abundance Observed by Cassini
Irwin, P. G. J.; Teanby, N. A.; de Kok, R. +1 more
We use a six-year data set (2004-2010) of mid-infrared spectra measured by Cassini's Composite InfraRed Spectrometer to search for seasonal variations in Titan's atmospheric temperature and composition. During most of Cassini's mission Titan's northern hemisphere has been in winter, with an intense stratospheric polar vortex highly enriched in tra…
Detections of CO Molecular Gas in 24 µm Bright ULIRGs at z ~ 2 in the Spitzer First Look Survey
Lutz, D.; Tacconi, L. J.; Omont, A. +7 more
We present CO observations of nine ultra-luminous infrared galaxies (ULIRGs) at z ~ 2 with f ν(24 µm) gsim 1 mJy, previously confirmed with the mid-IR spectra in the Spitzer First Look Survey. All targets are required to have accurate redshifts from Keck/GEMINI near-IR spectra. Using the Plateau de Bure millimeter-wave Interferome…
Episodic Star Formation Coupled to Reignition of Radio Activity in 3C 236
Koekemoer, Anton M.; Baum, Stefi A.; O'Dea, Christopher P. +4 more
We present Hubble Space Telescope Advanced Camera for Surveys and STIS FUV/NUV/optical imaging of the radio galaxy 3C 236, whose relic ~4 Mpc radio jet lobes and inner 2 kpc compact steep spectrum (CSS) radio source are evidence of multiple epochs of active galactic nucleus (AGN) activity. Consistent with previous results, our data confirm the pre…
The Geometry and Ionization Structure of the Wind in the Eclipsing Nova-like Variables RW Tri and UX UMa
Long, Knox S.; Knigge, Christian; Noebauer, Ulrich M. +1 more
The UV spectra of nova-like variables are dominated by emission from the accretion disk, modified by scattering in a wind emanating from the disk. Here, we model the spectra of RW Tri and UX UMa, the only two eclipsing nova-like variables which have been observed with the Hubble Space Telescope in the far-ultraviolet, in an attempt to constrain th…
Detection of an X-ray Pulsation for the Gamma-Ray Pulsar Centered in CTA 1
Takata, J.; Kong, A. K. H.; Hui, C. Y. +3 more
We report the detection of X-ray pulsations with a period of ~315.87 ms from the 2009 XMM-Newton observation for the radio-quiet γ-ray pulsar, LAT PSR J0007+7303, centered in the supernova remnant CTA 1. The detected pulsed period is consistent with the γ-ray periodicity at the same epoch found with the Fermi Gamma-ray Space Telescope. The broader…
A Census of the Supersoft X-ray Sources in M31
Orio, Marina; Bianchini, Antonio; Harbeck, Daniel +2 more
We examined X-ray, ultraviolet, and optical archival data of 89 supersoft X-ray sources (SSS) in M31. We studied the timescales of X-ray variability and searched UV and optical counterparts. Almost a third of the SSS are known classical or recurrent novae, and at least half of the others exhibit the same temporal behavior as post-outburst novae. N…
Variability and Spectral Modeling of the Hard X-ray Emission of GX 339-4 in a Bright Low/Hard State
Malzac, J.; Belmont, R.; Jourdain, E. +1 more
We study the high-energy emission of the Galactic black hole candidate GX 339-4 using INTEGRAL/SPI and simultaneous RXTE/PCA data. By the end of 2007 January, when it reached its peak luminosity in hard X-rays, the source was in a bright hard state. The SPectrometer on INTEGRAL (SPI) data from this period show a good signal-to-noise ratio, allowin…
G-band and Hard X-ray Emissions of the 2006 December 14 Flare Observed by Hinode/SOT and Rhessi
Krucker, Säm; Masuda, Satoshi; Shimizu, Toshifumi +3 more
We report on G-band emission observed by the Solar Optical Telescope on board the Hinode satellite in association with the X1.5-class flare on 2006 December 14. The G-band enhancements originate from the footpoints of flaring coronal magnetic loops, coinciding with nonthermal hard X-ray bremsstrahlung sources observed by the Reuven Ramaty High Ene…
An Extended Grid of Nova Models. III. Very Luminous, Red Novae
Shara, Michael M.; Prialnik, Dina; Zurek, David +2 more
Extremely luminous, red eruptive variables like RV in M31 are being suggested as exemplars of a new class of astrophysical objects. Our greatly extended series of nova simulations shows that classical nova models can produce very red, luminous eruptions. In a poorly studied corner of three-dimensional nova parameter space (very cold, low-mass whit…