Search Publications
X-Ray Studies of the Extended TeV Gamma-Ray Source VER J2019+368
Mizuno, T.; Takahashi, H.; Katsuta, J. +3 more
This article reports the results of X-ray studies of the extended TeV γ-ray source VER J2019+368. Suzaku observations conducted to examine properties of the X-ray pulsar wind nebula (PWN) around PSR J2021+3651 revealed that the western region of the X-ray PWN has a source extent of 15\prime × 10\prime with the major axis orie…
Cosmological models with running cosmological term and decaying dark matter
Szydłowski, Marek; Stachowski, Aleksander
We investigate the dynamics of the generalized ΛCDM model, which the Λ term is running with the cosmological time. On the example of the model Λ(t) =Λbare + α2/t2 we show the existence of a mechanism of the modification of the scaling law for energy density of dark matter: ρdm ∝a - 3 + λ(t). W…
Near-infrared variability study of the central 2.3 arcmin × 2.3 arcmin of the Galactic Centre - I. Catalogue of variable sources
Morris, Mark R.; Williams, Benjamin F.; Do, Tuan +7 more
We used 4-yr baseline Hubble Space Telescope/Wide Field Camera 3 IR observations of the Galactic Centre in the F153M band (1.53 µm) to identify variable stars in the central ∼2.3 arcmin × 2.3 arcmin field. We classified 3845 long-term (periods from months to years) and 76 short-term (periods of a few days or less) variables among a total sam…
Variations between Dust and Gas in the Diffuse Interstellar Medium. II. Search for Cold Gas
Heiles, Carl; Reach, William T.; Bernard, Jean-Philippe
The content of interstellar clouds, in particular the inventory of diffuse molecular gas, remains uncertain. We identified a sample of isolated clouds, approximately 100 M⊙ in size, and used the dust content to estimate the total amount of gas. In Paper I, the total inferred gas content was found significantly larger than that seen in 2…
Optical and ultraviolet spectroscopic analysis of SN 2011fe at late times
Filippenko, Alexei V.; Foley, Ryan J.; Pan, Yen-Chen +16 more
We present optical spectra of the nearby Type Ia supernova SN 2011fe at 100, 205, 311, 349 and 578 d post-maximum light, as well as an ultraviolet (UV) spectrum obtained with the Hubble Space Telescope at 360 d post-maximum light. We compare these observations with synthetic spectra produced with the radiative transfer code phoenix. The day +100 s…
Magnetically controlled density structures in the topside layer of the Martian ionosphere
Venkateswara Rao, N.; Mohanamanasa, P.; Rao, S. V. B.
Magnetically controlled density structures in the main layer of the Martian ionosphere are regularly detected by the Mars Advance Radar for Subsurface and Ionospheric Sounder (MARSIS) on board the Mars Express spacecraft when it passes over the regions of strong crustal magnetic fields. These structures appear as oblique echoes in an ionogram and …
Investigating target versus impactor influences on Martian crater morphology at the simple-complex transition
Hynek, Brian M.; Herrick, Robert R.
Comparing craters of identical diameter on a planet is an empirical method of studying the effects of different target and impactor properties while holding total impact energy nearly constant. We have analyzed the Martian crater population within a narrow diameter range (7 km < crater diameter < 9 km) at the simple-complex crater transition…
Machine learning techniques to select Be star candidates. An application in the OGLE-IV Gaia south ecliptic pole field
Hernández, J.; Pérez-Ortiz, M. F.; García-Varela, A. +2 more
Context. Optical and infrared variability surveys produce a large number of high quality light curves. Statistical pattern recognition methods have provided competitive solutions for variable star classification at a relatively low computational cost. In order to perform supervised classification, a set of features is proposed and used to train an…
Toward Understanding The B[e] Phenomenon. VI. Nature and Spectral Variations of HD 85567.
Reichart, D. E.; Miroshnichenko, A. S.; Haislip, J. B. +7 more
We report the results of high-resolution (R ∼ 80,000) spectroscopic observations of the emission-line object HD 85567, which has been classified as an FS CMa type object or a pre-main-sequence star. The main goal is to put more constraints on the object’s fundamental parameters, as well as on its nature and evolutionary state. Absorption lines in …
Testing physical models for dipolar asymmetry with CMB polarization
Banday, A. J.; Górski, K. M.; Scott, D. +2 more
The cosmic microwave background (CMB) temperature anisotropies exhibit a large-scale dipolar power asymmetry. To determine whether this is due to a real, physical modulation or is simply a large statistical fluctuation requires the measurement of new modes. Here we forecast how well CMB polarization data from Planck and future experiments will be …