Search Publications
HST Imaging of the Local Volume Dwarf Galaxies Pisces A and B: Prototypes for Local Group Dwarfs
Dolphin, Andrew E.; Weisz, Daniel R.; Putman, Mary E. +3 more
We present observations of the Pisces A and B galaxies with the Advanced Camera for Surveys on the Hubble Space Telescope. Photometry from these images clearly resolves a red giant branch (RGB) for both objects, demonstrating that they are nearby dwarf galaxies. We describe a Bayesian inferential approach to determining the distance to these galax…
Mapping Seyfert and LINER Excitation Modes in the Inner kpc of NGC 3393
Elvis, Martin; Raymond, John; Storchi-Bergmann, Thaisa +5 more
We mapped the extended narrowline region (ENLR) of NGC 3393 on scales of r≲ 4\prime\prime (∼ 1 kpc) from the nucleus using emission line images of Hα λ6563, [O III]λ 5007, and [S II]λ λ 6717,6731, taken with the Hubble Space Telescope as part of the CHandra survey of Extended Emission line Regions in nearby Seyfert galaxies (CHEERS). By…
A statistical study on the shape and position of the magnetotail neutral sheet
Zhang, Tielong; Nakamura, Rumi; Ge, Yasong +3 more
We study the average shape and position of the magnetotail neutral sheet based on magnetic field data obtained by Cluster, Geotail, TC-1, and THEMIS from the years 1995 to 2013. All data in the aberrated GSM (geocentric solar magnetospheric) coordinate system are normalized to the same solar wind pressure 2 nPa and downtail distance X ∼ -20RE…
Parallax of a Mira variable R Ursae Majoris studied with astrometric VLBI
Kurayama, Tomoharu; Honma, Mareki; Nakagawa, Akiharu +5 more
We have measured an annual parallax of the Mira variable R Ursae Majoris (R UMa) with the VLBI Exploration for Radio Astronomy (VERA). From the monitoring VLBI observations over a span of about two years, we detected H2O maser spots in the LSR velocity range from 37 to 42 km s-1. We derived an annual parallax of 1.97 ± 0.05 m…
Themis Regio, Venus: Evidence for recent (?) volcanism from VIRTIS data
Helbert, Joern; Stofan, Ellen R.; Smrekar, Suzanne E. +1 more
Themis Regio is interpreted to be a hotspot rise underlain by one or more mantle plumes. Many volcanic features in the Themis region have high emissivity anomalies in Venus Express Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) data. Other high emissivity anomalies have been found to correspond to volcanic flows interpreted to be relat…
ALMA Imaging of the CO (6-5) Line Emission in NGC 7130*
Inami, Hanae; Murphy, Eric; van der Werf, Paul +11 more
In this paper, we report our high-resolution (0.″20 × 0.″14 or ∼70 × 49 pc) observations of the CO(6-5) line emission, which probes warm and dense molecular gas, and the 434 µm dust continuum in the nuclear region of NGC 7130, obtained with the Atacama Large Millimeter Array (ALMA). The CO line and dust continuum fluxes detected in our ALMA …
Magnetic Doppler imaging of the chemically peculiar star HD 125248
Ilyin, I.; Ryabchikova, T.; Kochukhov, O. +1 more
Context. Intermediate-mass, chemically peculiar stars with strong magnetic fields provide an excellent opportunity to study the topology of their surface magnetic fields and the interplay between magnetic geometries and abundance inhomogeneities in the atmospheres of these stars.
Aims: We reconstruct detailed maps of the surface magnetic fiel…
Coronal mass ejection-related particle acceleration regions during a simple eruptive event
Rouillard, Alexis P.; Klein, Karl-Ludwig; Salas-Matamoros, Carolina
An intriguing feature of many solar energetic particle (SEP) events is the detection of particles over a very extended range of longitudes in the heliosphere. This may be due to peculiarities of the magnetic field in the corona, to a broad accelerator, to cross-field transport of the particles, or to a combination of these processes. The eruptive …
Constraining the physical properties of Titan's empty lake basins using nadir and off-nadir Cassini RADAR backscatter
Zebker, H. A.; Hayes, A. G.; Malaska, M. J. +5 more
We use repeat synthetic aperture radar (SAR) observations and complementary altimetry passes acquired by the Cassini spacecraft to study the scattering properties of Titan's empty lake basins. The best-fit coefficients from fitting SAR data to a quasi-specular plus diffuse backscatter model suggest that the bright basin floors have a higher dielec…
The NuSTAR view of the non-thermal emission from PSR J0437-4715
Harrison, F. A.; Boggs, S.; Stern, D. +11 more
We present a hard X-ray Nuclear Spectroscopic Telescope Array (NuSTAR) observation of PSR J0437-4715, the nearest millisecond pulsar. The known pulsations at the apparent pulse period {∼ }5.76{ ms} are observed with a significance of 3.7σ, at energies up to 20 keV above which the NuSTAR background dominates. We measure a photon index Γ = 1.50 ± 0.…