Search Publications
Two-plasma Model for Low Charge State Interplanetary Coronal Mass Ejection Observations
Zurbuchen, Thomas H.; Gruesbeck, Jacob R.; Lepri, Susan T.
Recent ACE/SWICS observations have revealed that ~5% of all in situ observed interplanetary coronal mass ejections include time periods with very low charge state ions found to be associated with prominence eruptions. It was also shown that these low charge state ions are often observed concurrently with very high charge state ions. But, the physi…
The Penn State-Toruń Centre for Astronomy Planet Search stars. I. Spectroscopic analysis of 348 red giants
Nowak, G.; Zieliński, P.; Adamów, M. +2 more
Aims: We present basic atmospheric parameters (Teff, log g, vt, and [Fe/H]) as well as luminosities, masses, radii, and absolute radial velocities for 348 stars, presumably giants, from the ~1000 star sample observed within the Penn State-Toruń Centre for Astronomy Planet Search with the High Resolution Spectrograph of t…
Quenched Cold Accretion of a Large-scale Metal-poor Filament due to Virial Shocking in the Halo of a Massive z = 0.7 Galaxy
Kacprzak, Glenn G.; Spitler, Lee R.; Steidel, Charles C. +4 more
Using HST/COS/STIS and HIRES/Keck high-resolution spectra, we have studied a remarkable H I absorbing complex at z = 0.672 toward the quasar Q1317+277. The H I absorption has a velocity spread of Δv = 1600 km s-1, comprises 21 Voigt profile components, and resides at an impact parameter of D = 58 kpc from a bright, high-mass (log M
Near- and mid-infrared colors of evolved stars in the Galactic plane. The Q1 and Q2 parameters
Menten, K. M.; Habing, H.; Churchwell, E. +1 more
Context. Mass-loss from evolved stars chemically enriches the interstellar medium (ISM). Stellar winds from massive stars and their explosions as supernovae shape the ISM and trigger star formation. Studying evolved stars is fundamental for understanding galaxy formation and evolution at any redshift.
Aims: We aim to establish a photometric c…
Resolved Measurements of X CO in NGC 6946
Momose, Rieko; Scoville, Nick; Kuno, Nario +9 more
We present the largest sample to date of giant molecular clouds (GMCs) in a substantial spiral galaxy other than the Milky Way. We map the distribution of molecular gas with high resolution and image fidelity within the central 5 kpc of the spiral galaxy NGC 6946 in the 12CO (J = 1-0) transition. By combining observations from the Nobey…
Hall magnetohydrodynamic effects for three-dimensional magnetic reconnection with finite width along the direction of the current
Nakamura, R.; Kubota, Y.; Nakamura, T. K. M. +2 more
We performed three-dimensional Hall magnetohydrodynamic (MHD) simulations of magnetic reconnection with finite width along the direction perpendicular to the antiparallel magnetic field (i.e., the direction of the electric current). Previous similar simulations including the Hall term have shown that the localized reconnection region itself can br…
New Solar Wind Diagnostic Using Both in Situ and Spectroscopic Measurements
Lepri, S. T.; Zurbuchen, T. H.; Landi, E. +1 more
We develop a new diagnostic technique that utilizes, at the same time, two completely different types of observations—in situ determinations of solar wind charge states and high-resolution spectroscopy of the inner solar corona—in order to study the temperature, density, and velocity of the solar wind as a function of height in the inner corona be…
Geological map and stratigraphy of asteroid 21 Lutetia
Massironi, Matteo; Pajola, Maurizio; Tubiana, Cecilia +15 more
The OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) images acquired during the recent Rosetta fly-by of Lutetia (10th of July 2010), enabled us to unravel the long geological history of the asteroid. This is recorded on its highly varied surface which displays geological units of disparate ages. In particular, using images of t…
A Statistical Study on the Morphology of Rays and Dynamics of Blobs in the Wake of Coronal Mass Ejections
Feng, S. W.; Chen, Y.; Li, B. +4 more
In this paper, with a survey through the Large Angle and Spectrometric Coronagraph (LASCO) data from 1996 to 2009, we present 11 events with plasma blobs flowing outwards sequentially along a bright coronal ray in the wake of a coronal mass ejection. The ray is believed to be associated with the current-sheet structure that formed as a result of s…
Adiabatic electron heating in the magnetotail current sheet: Cluster observations and analytical models
Petrukovich, A. A.; Zelenyi, L. M.; Nakamura, R. +1 more
We consider the electron distribution in current sheets observed by Cluster mission in the Earth magnetotail. We use the statistics of 70 fast (less than 20 minutes) and 12 slow (more than one hour) crossings of horizontal current sheets. We demonstrate that for both types electron temperature decreases with increase of magnetic field ∣Bx