Search Publications
Inferring the Galactic Potential with GAIA and Friends: Synergies with Other Surveys
Sanderson, Robyn E.
In the coming decade, the Gaia satellite will precisely measure the positions and velocities of millions of stars in the Galactic halo, including stars in many tidal streams. These streams, the products of hierarchical accretion of satellite galaxies by the Milky Way (MW), can be used to infer the Galactic gravitational potential thanks to their i…
Dependence of Occurrence Rates of Solar Flares and Coronal Mass Ejections on the Solar Cycle Phase and the Importance of Large-scale Connectivity
Moon, Y. -J.; Nakariakov, V. M.; Lee, Kangjin
We investigate the dependence of the occurrence rates of major solar flares (M- and X-class) and front-side halo coronal mass ejections (FHCMEs), observed from 1996 to 2013, on the solar cycle (SC) phase for six active McIntosh sunspot group classes: Fkc, Ekc, Dkc, Fki, Eki, and Dki. We classify SC phases as follows: (1) ascending phase of SC 23 (…
Star-formation Activity in the Neighborhood of W-R 1503-160L Star in the Mid-infrared Bubble N46
Dewangan, L. K.; Ojha, D. K.; Zinchenko, I. +4 more
In order to investigate star-formation (SF) processes in extreme environments, we have carried out a multi-wavelength analysis of the mid-infrared bubble N46, which hosts a WN7 Wolf-Rayet (W-R) star. We have used 13CO line data to trace an expanding shell surrounding the W-R star containing about five condensations within the molecular …
Studying the Interstellar Medium and the Inner Region of NPS/LOOP 1 with Shadow Observations toward MBM36
Liu, W.; Galeazzi, M.; Ursino, E.
We analyzed data from a shadow observation of the high density molecular cloud MBM36 (l ∼ 4°, b ∼ 35°) with Suzaku. MBM36 is located in a region that emits relatively weakly in the 3/4 keV band compared to the surrounding North Polar Spur (NPS)/Loop 1 structure and the Galactic Bulge (GB). The contrast between high and low density targets in the M…
A Multi-instrument Analysis of a C4.1 Flare Occurring in a δ Sunspot
Guglielmino, S. L.; Romano, P.; Zuccarello, F. P. +5 more
We present an analysis of multi-instrument space- and ground-based observations relevant to a C4.1 solar flare that occurred in the active region (AR) NOAA 11267 on 2011 August 6. Solar Dynamics Observatory observations indicate that at the flare’s beginning, it was localized in the preceding sunspot of the AR, which exhibits a δ configuration. Al…
Solar Energetic Particle Event Associated with the 2012 July 23 Extreme Solar Storm
Wang, Rui; Yang, Zhongwei; Liu, Ying D. +3 more
We study the solar energetic particle (SEP) event associated with the 2012 July 23 extreme solar storm, for which Solar Terrestrial Relations Observatory (STEREO) and the spacecraft at L1 provide multi-point remote sensing and in situ observations. The extreme solar storm, with a superfast shock and extremely enhanced ejecta magnetic fields observ…
Multi-wavelength Study of a Delta-spot. I. A Region of Very Strong, Horizontal Magnetic Field
Jaeggli, S. A.
Active region NOAA 11035 appeared in 2009 December, early in the new solar activity cycle. This region achieved a delta sunspot (δ spot) configuration when parasitic flux emerged near the rotationally leading magnetic polarity and traveled through the penumbra of the largest sunspot in the group. Both visible and infrared imaging spectropolarimetr…
Investigating the Origin of Hot Gas Lines in Herbig Ae/Be Stars
Johns-Krull, Christopher M.; Cauley, P. Wilson
We analyze high-resolution UV spectra of a small sample of Herbig Ae/Be stars (HAEBESs) in order to explore the origin of the T ∼ 105 K gas in these stars. The C IV λ λ1548, 1550 line luminosities are compared to nonsimultaneous accretion rate estimates for the objects showing C IV emission. We show that the correlation between L C…
The Gini Coefficient as a Morphological Measurement of Strongly Lensed Galaxies in the Image Plane
Florian, Michael K.; Gladders, Michael D.; Li, Nan
Characterization of the morphology of strongly lensed galaxies is challenging because images of such galaxies are typically highly distorted. Lens modeling and source plane reconstruction is one approach that can provide reasonably undistorted images from which morphological measurements can be made, though at the expense of a highly spatially var…
Subsurface Characterization of 67P/Churyumov-Gerasimenko’s Abydos Site
Jorda, L.; Lamy, P.; Mousis, O. +12 more
On 2014 November 12, the ESA/Rosetta descent module Philae landed on the Abydos site of comet 67P/Churyumov-Gerasimenko. Aboard this module, the Ptolemy mass spectrometer measured a CO/CO2 ratio of 0.07 ± 0.04, which differs substantially from the value obtained in the coma by the Rosetta/ROSINA instrument, suggesting a heterogeneity in…