Search Publications
Steepened inner density profiles of group galaxies via interactions: an N-body analysis
King, Lindsay J.; Fellhauer, Michael; Dobke, Benjamin M.
We continue to see a range of values for the Hubble constant obtained from gravitationally lensed multiple image time-delays when assuming an isothermal lens despite a robust value from the Hubble Space Telescope (HST) key project (72 +/- 8 kms-1 Mpc-1). One explanation is that there is a variation in Hubble constant values d…
Microwave Type III-Like Bursts as Possible Signatures of Magnetic Reconnection
Yan, Y.; Grechnev, V. V.; Altyntsev, A. T. +1 more
Magnetic reconnection is commonly accepted to play a key role in flare energy release, but only poor information about the main characteristics of this process is available so far. An intrinsic feature of reconnection is plasma density enhancement in current sheets. A unique method to detect this effect is provided by analysis of drifting bursts, …
XMM-Newton Observations of the Cataclysmic Variable GW Librae
Hellier, Coel; Szkody, Paula; Mukai, Koji +4 more
XMM-Newton observations of the accreting, pulsating white dwarf in the quiescent dwarf nova GW Librae were conducted to determine whether the nonradial pulsations present in previous UV and optical data affect the X-ray emission. The nonradial pulsations are evident in the simultaneous Optical Monitor data but are not detected in the X-ray with an…
The mass function of ω Centauri down to 0.15 Msolar
Bellazzini, M.; Ferraro, F. R.; Sollima, A.
By means of deep FORS1/VLT and ACS/Hubble Space Telescope observations of a wide area in the stellar system ω Cen we measured the luminosity function of main-sequence stars down to R = 22.6 and IF814W = 24.5. The luminosity functions obtained have been converted into mass functions and compared with analytical initial mass functions (IM…
Near-infrared photometry of carbon stars in the Sagittarius dwarf irregular galaxy and DDO 210
Rejkuba, M.; Gullieuszik, M.; Held, E. V. +2 more
Aims:We investigate the intermediate-age asymptotic giant branch stellar population of two Local Group dwarf irregular galaxies to characterize their carbon star population in near-infrared (IR).
Methods: Our work is based on near-IR photometry complemented with optical ground based and Hubble Space Telescope (HST) photometry. Near-IR photomet…
A Far-Ultraviolet Study of the Nova-like V794 Aquilae
Szkody, Paula; Sion, Edward M.; Godon, Patrick +1 more
V794 Aql was observed in a high state with the Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS) on 2003 August 28, and with the Far Ultraviolet Spectroscopic Explorer (FUSE) on 2004 May 13. We present here a spectral analysis of the FUSE and HST STIS spectra. For a 0.9 Msolar, the best fit is an accretion disk with…
Simultaneous XMM-Newton and VLT/UVES observations of the flare star CN Leonis
Liefke, C.; Schmitt, J. H. M. M.; Fuhrmeister, B.
Aims:We present simultaneous observations with VLT/UVES and XMM-Newton of the active M5.5 dwarf CN Leo (Gl 406). The data were gathered during three half nights in May 2004 and December 2005, and they cover quiescent states, as well as flaring activity. Our main aim is to derive coronal properties from X-ray data and to compare these to results fr…
The SCUBA HAlf Degree Extragalactic Survey (SHADES) - V. Submillimetre properties of near-infrared-selected galaxies in the Subaru/XMM -Newton deep field
Smail, I.; Ivison, R. J.; Clements, D. L. +21 more
We have studied the submillimetre (submm) properties of the following classes of near-infrared-selected (NIR-selected) massive galaxies at high redshifts: BzK-selected star-forming galaxies (BzKs); distant red galaxies (DRGs); and extremely red objects (EROs). We used the SCUBA HAlf Degree Extragalactic Survey (SHADES), the largest uniform submm s…
Our distorted view of magnetars: application of the resonant cyclotron scattering model
Turolla, Roberto; Rea, Nanda; Lyutikov, Maxim +1 more
The X-ray spectra of the magnetar candidates are customarily fitted with an empirical, two component model: an absorbed blackbody and a power-law. However, the physical interpretation of these two spectral components is rarely discussed. It has been recently proposed that the presence of a hot plasma in the magnetosphere of highly magnetized neutr…
New approach for determining the normal of the bow shock based on Cluster four-point magnetic field measurements
Balogh, A.; Zhang, T. L.; Dunlop, M. +6 more
We introduce a new approach to determine the normal of Earth's bow shock, based on four-point magnetic field measurements. The method obtains the local bow shock normal, based on the assumption that the normal is in the opposite direction to the gradient of the magnetic pressure or magnetic strength (within the shock front). This gradient can be d…