Search Publications
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…
PACS and SPIRE spectroscopy of the red supergiant VY CMa
Ivison, R. J.; Blommaert, J. A. D. L.; Olofsson, G. +34 more
With a luminosity >105 L⊙ and a mass-loss rate of ~2 × 10-4 M⊙ yr-1, the red supergiant VY CMa truly is a spectacular object. Because of its extreme evolutionary state, it could explode as supernova any time. Studying its circumstellar material, into which the supernova blast will run, prov…
The photochemical products of benzene in Titan’s upper atmosphere
Delitsky, M. L.; McKay, C. P.
The Cassini spacecraft detected benzene high in Titan's atmosphere as well as the presence of large mass positive and negative ions. Previous work has suggested that these large mass ions could be composed of fused-ring polycyclic aromatic hydrocarbon compounds. These fused-ring PAHs, such as naphthalene and anthracene, are usually the result of h…
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…
The orbital period in the supergiant fast X-ray transient IGR J16465-4507
Hill, A. B.; Bird, A. J.; Scaringi, S. +6 more
Timing analysis of the INTEGRAL-IBIS and Swift-BAT light curves of the supergiant fast X-ray transient (SFXT) IGR J16465-4507 has identified a period of 30.32 +/- 0.02 d which we interpret as the orbital period of the binary system. In addition 11 outbursts (nine of which are previously unpublished) have been found between MJD 52652 and 54764, all…
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…
Water abundance variations around high-mass protostars: HIFI observations of the DR21 region
de Graauw, Th.; Liseau, R.; Braine, J. +56 more
Context. Water is a key molecule in the star formation process, but its spatial distribution in star-forming regions is not well known.
Aims: We study the distribution of dust continuum and H2O and 13CO line emission in DR21, a luminous star-forming region with a powerful outflow and a compact H ii region.
Methods: …
Evidence of Impulsive Heating in Active Region Core Loops
Tripathi, Durgesh; Mason, Helen E.; Klimchuk, James A.
Using a full spectral scan of an active region from the Extreme-Ultraviolet Imaging Spectrometer (EIS) we have obtained emission measure EM(T) distributions in two different moss regions within the same active region. We have compared these with theoretical transition region EMs derived for three limiting cases, namely, static equilibrium, strong …
The double-peaked 2008 outburst of the accreting milli-second X-ray pulsar, IGR J00291+5934
Bloom, J. S.; Wijnands, R.; Russell, D. M. +18 more
Context. In August 2008, the accreting milli-second X-ray pulsar (AMXP), IGR J00291+5934, underwent an outburst lasting ~100 days, the first since its discovery in 2004.
Aims: We present data from the 2008 double-peaked outburst of IGR J00291+5934 from Faulkes Telescope North, the Isaac Newton Telescope, the Keck Telescope, PAIRITEL, the West…