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A SINFONI view of the nuclear activity and circumnuclear star formation in NGC 4303
Colina, L.; Storchi-Bergmann, T.; Riffel, Rogemar A. +8 more
We present new maps of emission-line flux distributions and kinematics in both ionized (traced by H I and [Fe II] lines) and molecular (H2) gas of the inner 0.7 × 0.7 kpc2 of the galaxy NGC 4303, with a spatial resolution 40-80 pc and velocity resolution 90-150 km s- 1 obtained from near-IR integral field spectrosc…
The fossil wind structures of Eta Carinae: changes across one 5.54-yr cycle
Hamaguchi, Kenji; Corcoran, Michael; Moffat, Anthony F. J. +11 more
Eta Carinae, the closest, active, massive binary containing a highly unstable Luminous Blue Variable, exhibits expanding, compressed wind shells, seen in emission, that are spatially and spectrally resolved by Hubble Space Telescope/Space Telescope Imaging Spectrograph. Starting in 2009 June, these structures were mapped across its 5.54-yr, highly…
The spectroscopic imprint of the pre-eruptive configuration resulting into two major coronal mass ejections
Gontikakis, C.; Patsourakos, S.; Tsinganos, K. +1 more
Aims: We present a spectroscopic analysis of the pre-eruptive configuration of active region NOAA 11429, prior to two very fast coronal mass ejections (CMEs) on March 7, 2012 that are associated with this active region. We study the thermal components and the dynamics associated with the ejected flux ropes.
Methods: Using differential em…
Interaction of ULF waves with different ion species: Pitch angle and phase space density implications
Zong, Q. G.; Rankin, R.; Wang, Y. F. +2 more
ULF waves can accelerate/decelerate the charged particles including the ring current ions via drift-bounce resonance, which play an important role in the dynamics of ring current during storm times. This study compares the different behaviors of oxygen ions (10.5-35.1 keV) and protons (0.3-12.3 keV) which simultaneously interact with Pc5 ULF waves…
A Comprehensive Investigation on the Slowing Down of Cosmic Acceleration
Li, Nan; Li, Miao; Wang, Shuang +1 more
Shafieloo et al. first proposed the possibility that the current cosmic acceleration (CA) is slowing down. However, this is rather counterintuitive because a slowing down CA cannot be accommodated in most mainstream cosmological models. In this work, by exploring the evolutionary trajectories of the dark energy equation of state w(z) and decelerat…
Rotational modulation of Saturn's radio emissions after equinox
Gurnett, D. A.; Kurth, W. S.; Ye, S. -Y. +2 more
Saturn kilometric radiation (SKR), narrowband emission, and auroral hiss are periodically modulated due to Saturn's rotation, and the periods were found to vary with time. We analyze Cassini observations of Saturn's radio emissions with the main focus on the four years 2012-2015. It is shown that the rotation rates of SKR north and south were diff…
Empirically Constrained Predictions for Metal-line Emission from the Circumgalactic Medium
Schiminovich, David; Corlies, Lauren
The circumgalactic medium (CGM) is one of the remaining least constrained components of galaxies and as such has significant potential for advancing galaxy formation theories. In this work, we vary the extragalactic ultraviolet background for a high-resolution cosmological simulation of a Milky-Way-like galaxy and examine the effect on the absorpt…
An HST Proper-motion Study of the Large-scale Jet of 3C273
Anderson, Jay; Sparks, William B.; Georganopoulos, Markos +7 more
The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly rela…
Detail studies of the physical properties in the outer regions of galaxy clusters using Suzaku observations
Babyk, Iu. V.
A detailed physical analysis of five nearby galaxy clusters using Suzaku observationsis presented. The low and stable level of the instrumental background at large radii facilitate the determination of the main physical characteristics in clusters at the virial radius. The temperatures, metal abundances, and entropy profiles have been constructed …
H I-deficient galaxies in intermediate-density environments
Koribalski, B. S.; Dénes, H.; Wong, O. I. +1 more
Observations show that spiral galaxies in galaxy clusters tend to have on average less neutral hydrogen (H I) than galaxies of the same type and size in the field. There is accumulating evidence that such H I-deficient galaxies are also relatively frequent in galaxy groups. An important question is that which mechanisms are responsible for the gas…