Search Publications
Masses and age of the chemically peculiar double-lined binary χ Lupi
Ménard, F.; Beust, H.; Le Bouquin, J. -B. +3 more
Aims: We aim at measuring the stellar parameters of the two chemically peculiar components of the B9.5Vp HgMn + A2 Vm double-lined spectroscopic binary HD 141556 (χ Lup), whose period is 15.25 days.
Methods: We combined historical radial velocity measurements with new spatially resolved astrometric observations from PIONIER/VLTI to recon…
Characteristic Length of Energy-containing Structures at the Base of a Coronal Hole
Goode, P. R.; Zank, G. P.; Abramenko, V. I. +4 more
An essential parameter for models of coronal heating and fast solar wind acceleration that rely on the dissipation of MHD turbulence is the characteristic energy-containing length λ of the squared velocity and magnetic field fluctuations (u 2 and b 2) transverse to the mean magnetic field inside a coronal hole (CH)…
Spectral Energy Distributions of Low-luminosity Radio Galaxies at z ~1-3: A High-z View of the Host/AGN Connection
Sparks, William B.; Chiaberge, Marco; Capetti, Alessandro +3 more
We study the spectral energy distributions, SEDs (from FUV to MIR bands), of the first sizeable sample of 34 low-luminosity radio galaxies at high redshifts, selected in the COSMOS field. To model the SEDs, we use two different template-fitting techniques: (1) the Hyperz code that only considers single stellar templates and (2) our own developed t…
PSR J1840-1419: A Very Cool Neutron Star
Kramer, M.; McLaughlin, M. A.; Bassa, C. G. +4 more
We present upper limits on the X-ray emission for three neutron stars. For PSR J1840-1419, with a characteristic age of 16.5 Myr, we calculate a blackbody temperature upper limit (at 99% confidence) of kT ∞ bb < 24+17 -10 eV, making this one of the coolest neutron stars known. PSRs J1814-1744 and J184…
Discovery of a 168.8 s X-ray pulsar transiting in front of its Be companion star in the Large Magellanic Cloud
Pietsch, W.; Haberl, F.; Greiner, J. +5 more
Aims: We report the discovery of LXP 169, a new high-mass X-ray binary in the Large Magellanic Cloud. The optical counterpart has been identified and appears to exhibit an eclipsing light curve. We performed follow-up observations to clarify the eclipsing nature of the system.
Methods: Energy spectra and time series were extracted from t…
Distribution of Si, Fe, and Ni in the Intracluster Medium of the Coma Cluster
Sato, Kosuke; Matsushita, Kyoko; Sato, Takuya +1 more
We studied the distributions of Si, Fe, and Ni in the intracluster medium (ICM) of the Coma cluster, one of the largest clusters in the nearby universe, using XMM-Newton data up to 0.5 r180 and Suzaku data of the central region up to 0.16 r180. Using the flux ratios of the Lyα line of H-like Si and the 7.8 keV line blend to t…
A Generalized Power-law Diagnostic for Infrared Galaxies at z > 1: Active Galactic Nuclei and Hot Interstellar Dust
Caputi, K. I.
I present a generalized power-law (PL) diagnostic which allows one to identify the presence of active galactic nuclei (AGNs) in infrared (IR) galaxies at z > 1, down to flux densities at which the extragalactic IR background is mostly resolved. I derive this diagnostic from the analysis of 174 galaxies with S ν(24 µm)>80 &mi…
Verification of the GUMICS-4 global MHD code using empirical relationships
Janhunen, P.; Gordeev, E.; Sergeev, V. +4 more
Global magnetohydrodynamic (MHD) modeling is a powerful tool in space physics research. There are several advanced and still developing global MHD codes that are widely used to simulate plasma processes in solar wind magnetosphere-ionosphere system. The verification of global simulation codes is an important but a difficult problem. We present an …
A multiwavelength view of star-disk interaction in NGC 2264
Baglin, A.; Micela, G.; Stauffer, J. R. +2 more
Variability is a signature property of cool young stars, particularly for those surrounded by disks. Traditional single-band time series display complex features associated with accretion, disk structure, and accompanying stellar activity, but these processes are challenging to model. To make progress in connecting observed time domain properties …
Spin and spectral variations of a peculiar high-mass X-ray binary 4U 2206+54
Wang, Wei
Spin properties and spectral variations of a high-mass X-ray binary 4U 2206+54 are studied with long-term hard X-ray monitoring observations by INTEGRAL. A long-period X-ray pulsar of Pspin ∼ 5558 s has been identified in 4U 2206+54. The spin evolution of the neutron star in 4U 2206+54 is detected with the INTEGRAL/IBIS data. From 2005 …