Search Publications
Planetary nebula IC 5148 and its ionized halo
Kimeswenger, S.; Barría, D.; Kausch, W. +1 more
Context. Many round or roundish planetary nebulae (PNe) show multiple shells and halo structures during their evolutionary stage near the maximum temperature of their central star. Controversial debate is ongoing if these structures are recombination halos, as suggested by hydrodynamic modeling efforts, or ionized material. Recently, we discovered…
A statistical study towards high-mass BGPS clumps with the MALT90 survey
Zhang, Chuan-Peng; Xu, Jin-Long; Liu, Xiao-Lan +2 more
In this work, we perform a statistical investigation towards 50 high-mass clumps using data from the Bolocam Galactic Plane Survey (BGPS) and Millimetre Astronomy Legacy Team 90-GHz survey (MALT90). Eleven dense molecular lines (N2H+(1-0), HNC(1-0), HCO+(1-0), HCN(1-0), HN13C(1-0), H13CO+…
Massive star population of the Virgo Cluster galaxy NGC4535. Discovery of new massive variable candidates with the Hubble Space Telescope
Hatzidimitriou, D.; Nota, A.; Gavras, P. +10 more
We analyzed the massive star population of the Virgo Cluster galaxy NGC 4535 using archival Hubble Space Telescope Wide Field Planetary Camera 2 images in filters F555W and F814W, equivalent to Johnson V and Kron-Cousins I. We performed high precision point spread function fitting photometry of 24353 sources including 3762 candidate blue supergian…
Oxygen Ion Reflection at Earthward Propagating Dipolarization Fronts in the Magnetotail
Parks, G. K.; Sun, W. J.; Fu, S. Y. +7 more
A dipolarization front (DF) is known as the leading edge of an earthward high-speed flow with a sharp enhancement in the northward magnetic field (Bz). Analysis of an event observed by Cluster shows that the behavior of oxygen ions (O+) around the DF is very different from protons (H+). After the crossing of the DF…
Hall Effect in Laboratory and Space Current Sheets
Petrukovich, A. A.; Nakamura, R.; Artemyev, A. V. +2 more
The role of the Hall effect in the formation of thin current sheets (CSs) is analyzed by comparing results of laboratory and satellite experiments. In spite of the strong difference in the plasma parameters, both laboratory and space CSs are characterized by the hot ion component and cold isotropic electron component. Such a relation between the i…
Multiwavelength Ground and Space Observations of the Variable White Dwarf BOKS 53856: Nonuniform Metal Absorption in Dark Spots
Debes, John H.; Howell, Steve B.; Hoard, D. W. +3 more
We analyze extensive ground- and space-based ultraviolet-infrared observations of the variable white dwarf BOKS 53856. Photometry and spectroscopy were obtained from the Hubble Space Telescope, Spitzer Space Telescope, Kepler and Swift satellites, Palomar Observatory, and Kitt Peak National Observatory. Time series data spanning the entire four-ye…
OMEGA - OSIRIS mapping of emission-line galaxies in A901/2 - IV. Extinction of star formation estimators with inclination
Chies-Santos, Ana L.; Wolf, Christian; Aragón-Salamanca, Alfonso +6 more
We study the effect of inclination on the apparent brightness of star-forming galaxies in spectral passbands that are commonly used as star formation indicators. As diagnostics we use mass-to-light ratios in three passbands: the UV continuum at 280 nm, the Hα emission line, and the FIR 24µ band. We include a study of inclination trends in th…
Compositional and chronological characterization of mare crisium using Chandrayaan-1 and LROC-WAC data
Karthi, A.; Arivazhagan, S.
The surface of the Moon has been observed by human being since time immemorial and it appears distinctly different from that of the earth. Moon is geologically inactive for quite long time and therefore it's an ideal place to study the early solar system history. The lunar surface is dominated by various morphological features such as craters, ril…
New limits on coupled dark energy model after Planck 2015
Yang, Weiqiang; Wu, Yabo; Li, Hang +1 more
We used the Planck 2015 cosmic microwave background anisotropy, baryon acoustic oscillation, type-Ia supernovae, redshift-space distortions, and weak gravitational lensing to test the model parameter space of coupled dark energy. We assumed the constant and time-varying equation of state parameter for dark energy, and treated dark matter and dark …
Probing the rotational velocity of Galactic WO stars with spectropolarimetry
Crowther, P. A.; Maund, J. R.; Ignace, R. +3 more
Oxygen sequence Wolf-Rayet stars (WO) are thought to be the final evolution phase of some high-mass stars, as such they may be the progenitors of Type Ic SNe as well as potential progenitors of broad-lined Ic and long gamma-ray bursts. We present the first spectropolarimetric observations of the Galactic WO stars WR93b and WR102 obtained with FORS…