Search Publications
Interstellar Flow and Temperature Determination with IBEX: Robustness and Sensitivity to Systematic Effects
Wurz, P.; McComas, D. J.; Fuselier, S. A. +11 more
The Interstellar Boundary Explorer (IBEX) samples the interstellar neutral (ISN) gas flow of several species every year from December through late March when the Earth moves into the incoming flow. The first quantitative analyses of these data resulted in a narrow tube in four-dimensional interstellar parameter space, which couples speed, flow lat…
Constraints on cosmological parameters in power-law cosmology
Rani, Sarita; Altaibayeva, A.; Shahalam, M. +2 more
In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters H0 (Hubble constant) and q (deceleration parameter). We investigate the constraints on these parameters using the latest 28 points of H(z) data and 580 points of Union2.1 compilation data and, compare the results with …
Testing the dark energy consistency with geometry and growth
Huterer, Dragan; Ruiz, Eduardo J.
We perform parametric tests of the consistency of the standard w CDM model in the framework of general relativity by carefully separating information between the geometry and growth of structure. We replace each late-Universe parameter that describes the behavior of dark energy with two parameters: one describing geometrical information in cosmolo…
The post-common envelope central stars of the planetary nebulae Henize 2-155 and Henize 2-161
Corradi, R. L. M.; Boffin, H. M. J.; Jones, D. +4 more
We present a study of Hen 2-155 and Hen 2-161, two planetary nebulae which bear striking morphological similarities to other planetary nebulae known to host close-binary central stars. Both central stars are revealed to be photometric variables while spectroscopic observations confirm that Hen 2-155 is host to a double-eclipsing, post-common-envel…
Molecular and atomic gas in dust lane early-type galaxies - I. Low star formation efficiencies in minor merger remnants
Ting, Yuan-Sen; Smith, Matthew W. L.; Shabala, Stanislav S. +12 more
In this work we present IRAM 30-m telescope observations of a sample of bulge-dominated galaxies with large dust lanes, which have had a recent minor merger. We find these galaxies are very gas rich, with H2 masses between 4 × 108 and 2 × 1010 M⊙. We use these molecular gas masses, combined with atomic g…
Wave energy budget analysis in the Earth's radiation belts uncovers a missing energy
Artemyev, A. V.; Agapitov, O. V.; Mozer, F. S. +2 more
Whistler-mode emissions are important electromagnetic waves pervasive in the Earth's magnetosphere, where they continuously remove or energize electrons trapped by the geomagnetic field, controlling radiation hazards to satellites and astronauts and the upper-atmosphere ionization or chemical composition. Here, we report an analysis of 10-year Clu…
Positive correlation between the cyclotron line energy and luminosity in sub-critical X-ray pulsars: Doppler effect in the accretion channel
Tsygankov, Sergey S.; Mushtukov, Alexander A.; Suleimanov, Valery F. +2 more
Cyclotron resonance scattering features observed in the spectra of some X-ray pulsars show significant changes of the line centroid energy with the pulsar luminosity. Whereas for bright sources above the so-called critical luminosity, these variations are established to be connected with the appearance of the high-accretion column above the neutro…
NuSTAR, XMM-Newton, and Suzaku Observations of the Ultraluminous X-Ray Source Holmberg II X-1
Harrison, F. A.; Stern, D.; Fabian, A. C. +14 more
We present the first broadband 0.3-25.0 keV X-ray observations of the bright ultraluminous X-ray source (ULX) Holmberg II X-1, performed by NuSTAR, XMM-Newton, and Suzaku in 2013 September. The NuSTAR data provide the first observations of Holmberg II X-1 above 10 keV and reveal a very steep high-energy spectrum, similar to other ULXs observed by …
Spectroscopic Study of Star-forming Galaxies in Filaments and the Field at z ~ 0.5: Evidence for Environmental Dependence of Electron Density
Sobral, David; Shivaei, Irene; Mobasher, Bahram +3 more
We study the physical properties of a spectroscopic sample of 28 star-forming galaxies in a large filamentary structure in the COSMOS field at z ∼ 0.53, with spectroscopic data taken with the Keck/DEIMOS spectrograph, and compare them with a control sample of 30 field galaxies. We spectroscopically confirm the presence of a large galaxy filament (…
500 days of SN 2013dy: spectra and photometry from the ultraviolet to the infrared
Fox, O. D.; Lee, W. H.; Zheng, W. +23 more
SN 2013dy is a Type Ia supernova (SN Ia) for which we have compiled an extraordinary data set spanning from 0.1 to ∼ 500 d after explosion. We present 10 epochs of ultraviolet (UV) through near-infrared (NIR) spectra with Hubble Space Telescope/Space Telescope Imaging Spectrograph, 47 epochs of optical spectra (15 of them having high resolution), …