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Low-mass Group Environments Have No Substantial Impact on the Circumgalactic Medium Metallicity
Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +4 more
We explore how environment affects the metallicity of the circumgalactic medium (CGM) using 13 low-mass galaxy groups (two to five galaxies) at $\langle {z}_{\mathrm{abs}}\rangle =0.25 identified near background quasars. Using quasar spectra from the Hubble Space Telescope/COS and from Keck/HIRES or the Very Large Telescope/UVES, we measure column…
In the Quest for Cosmic Rotation
Korotky, Vladimir A.; Masár, Eduard; Obukhov, Yuri N.
This paper analyzes the problem of global rotation in general relativity (GR) theory. Simple cosmological models with rotation and expansion are presented, which give a natural explanation of the modern values of the acceleration parameter at different red shifts without involving the concepts of "dark energy" and "dark matter". It is shown that d…
Onthe changes in the physical properties of the ionized region around the Weigelt structures in η Carinae over the 5.54-yr spectroscopic cycle
Gull, T. R.; Corcoran, M. F.; Hillier, D. J. +3 more
We present HST/STIS observations and analysis of two prominent nebular structures around the central source of η Carinae, the knots C and D. The former is brighter than the latter for emission lines from intermediate- or high-ionization potential ions. The brightness of lines from intermediate- and high-ionization potential ions significantly decr…
Pulsation in the white dwarf HE 1017-1352: confirmation of the class of hot DAV stars
Kepler, S. O.; Romero, Alejandra D.; Antunes Amaral, L. +3 more
We report the detection of periodic variations on the $T_\mathrm{eff}\simeq 32\, 000$ K DA white dwarf star HE 1017-1352. We obtained time series photometry using the 4.1-m Southern Astrophysical Research telescope on three separate nights for a total of 16.8 h. From the frequency analysis, we found four periods of 605, 556, 508, and 869 s with si…
X-Ray Constraints on the Spectral Energy Distribution of the z = 5.18 Blazar SDSS J013127.34-032100.1
An, Hongjun; Romani, Roger W.
We report on X-ray measurements constraining the spectral energy distribution (SED) of the high-redshift z = 5.18 blazar SDSS J013127.34-032100.1 with new XMM-Newton and NuSTAR exposures. The blazar's X-ray spectrum is well fit by a power law with Γ = 1.9 and ${N}_{{\rm{H}}}=1.1\times {10}^{21}\,{\mathrm{cm}}^{-2}$ , or a broken power law with ${{…
A low-mass stellar companion to the young variable star RZ Psc
Henning, Thomas; Ménard, François; Kral, Quentin +10 more
RZ Psc is a young Sun-like star with a bright and warm infrared excess that is occasionally dimmed significantly by circumstellar dust structures. Optical depth arguments suggest that the dimming events do not probe a typical sightline through the circumstellar dust, and are instead caused by structures that appear above an optically thick mid-pla…
Dipolar and Kelvin-Stuart's cat's eyes vortices in magnetoplasmas with non-Maxwellian electron distribution
Masood, W.; Naeem, Ismat; Mirza, Arshad M.
Linear and nonlinear propagation characteristics of drift ion acoustic waves are analyzed in an inhomogeneous plasma comprising of warm ions having shear flow parallel to the magnetic field and electrons that are followed by a distribution which is dictated by spectral indices,
Structural insights into the mechanism of rhodopsin phosphodiesterase
Ikuta, Tatsuya; Shihoya, Wataru; Sugiura, Masahiro +9 more
Rhodopsin phosphodiesterase (Rh-PDE) is an enzyme rhodopsin belonging to a recently discovered class of microbial rhodopsins with light-dependent enzymatic activity. Rh-PDE consists of the N-terminal rhodopsin domain and C-terminal phosphodiesterase (PDE) domain, connected by 76-residue linker, and hydrolyzes both cAMP and cGMP in a light-dependen…
Infrared Color Separation between Thin-shelled Oxygen-rich and Carbon-rich AGB Stars
Sjouwerman, Loránt O.; Pihlström, Ylva M.; Lewis, Megan O. +1 more
We present 43 GHz VLA spectra for 51 AGB sources with the goal of verifying an infrared (IR) color cut intended to separate carbon-rich (C) and oxygen-rich (O) AGB sources throughout the Galaxy. The color cut is a simple line in the [Ks] - [A] versus [A] - [E] color-color diagram based on 2MASS and MSX photometry, and was originally der…
Luminous blue variable candidates in M31
Vinokurov, A.; Solovyeva, Y.; Bizyaev, D. +7 more
We study five luminous blue variable (LBV) candidates in the Andromeda galaxy and one more (MN112) in the Milky Way. We obtain the same-epoch near-infrared (NIR) and optical spectra on the 3.5-m telescope at the Apache Point Observatory and on the 6-m telescope of the SAO RAS. The candidates show typical LBV features in their spectra: broad and st…