Search Publications
Structure of magnetic separators and separator reconnection
Parnell, C. E.; Haynes, A. L.; Galsgaard, K.
Magnetic separators are important locations of three-dimensional magnetic reconnection. They are field lines that lie along the edges of four flux domains and represent the intersection of two separatrix surfaces. Since the intersection of two surfaces produces an X-type structure, when viewed along the line of intersection, the global three-dimen…
The solar-like CoRoT target HD 170987: spectroscopic and seismic observations
Auvergne, M.; García, R. A.; Chaplin, W. J. +22 more
Context. The CoRoT mission is in its third year of observation and the data from the second long run in the galactic centre direction are being analysed. The solar-like oscillating stars that have been observed up to now have given some interesting results, specially concerning the amplitudes that are lower than predicted. We present here the resu…
Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya. Constraining the disk gas mass
Pinte, C.; Ménard, F.; Duchêne, G. +49 more
Planets are formed in disks around young stars. With an age of ~10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study thei…
Discovery of a Second Transient Low-Mass X-ray Binary in the Globular Cluster Ngc 6440
Altamirano, D.; Wijnands, R.; Knigge, C. +11 more
We have discovered a new transient low-mass X-ray binary, NGC 6440 X-2, with Chandra/ACIS, RXTE/PCA, and Swift/XRT observations of the globular cluster NGC 6440. The discovery outburst (2009 July 28-31) peaked at LX ~ 1.5 × 1036 erg s-1 and lasted for <4 days above LX = 1035 erg s-1
Saturn's internal planetary magnetic field
Russell, C. T.; Dougherty, M. K.; Burton, M. E.
A model of Saturn's internal planetary magnetic field based on data from the Cassini prime mission has been derived. In the absence of a determination of the rotation rate, the model is constrained to be axisymmetric. Non-axisymmetric models for a range of plausible planetary rotation periods have also been derived and we evaluate upper limits on …
Detection of interstellar oxidaniumyl: Abundant H2O+ towards the star-forming regions DR21, Sgr B2, and NGC6334
Menten, K. M.; Boulanger, F.; Falgarone, E. +99 more
Aims: We identify a prominent absorption feature at 1115 GHz, detected in first HIFI spectra towards high-mass star-forming regions, and interpret its astrophysical origin.
Methods: The characteristic hyperfine pattern of the H2O+ ground-state rotational transition, and the lack of other known low-energy transitions…
Multiple Component Outflows in an Active Region Observed with the EUV Imaging Spectrometer on Hinode
Young, P. R.; Doschek, G. A.; Bryans, P.
We have used the Extreme Ultraviolet Imaging Spectrometer on the Hinode spacecraft to observe large areas of outflow near an active region. These outflows are seen to persist for at least 6 days. The emission line profiles suggest that the outflow region is composed of multiple outflowing components, Doppler-shifted with respect to each other. We …
Another look at the BL Lacertae flux and spectral variability. Observations by GASP-WEBT, XMM-Newton, and Swift in 2008-2009
Lähteenmäki, A.; Umana, G.; Capetti, A. +52 more
Aims: In a previous study we suggested that the broad-band emission and variability properties of BL Lacertae can be accounted for by a double synchrotron emission component with related inverse-Compton emission from the jet, plus thermal radiation from the accretion disc. Here we investigate the matter with further data extending over a wide…
The Cluster AgeS Experiment (CASE). IV. Analysis of the Eclipsing Binary V69 in the Globular Cluster 47 Tuc
Thompson, I. B.; Dotter, A.; Kaluzny, J. +4 more
We use photometric and spectroscopic observations of the eclipsing binary V69-47 Tuc to derive the masses, radii, and luminosities of the component stars. Based on measured systemic velocity, distance, and proper motion, the system is a member of the globular cluster 47 Tuc. The system has an orbital period of 29.5d and the orbit is slightly eccen…
Hot Gas Halos in Early-type Field Galaxies
Mulchaey, John S.; Jeltema, Tesla E.
We use Chandra and XMM-Newton to study the hot gas content in a sample of field early-type galaxies. We find that the L X-L K relationship is steeper for field galaxies than for comparable galaxies in groups and clusters. The low hot gas content of field galaxies with L K lap L sstarf suggests that inter…