Search Publications
Hot Plasma from Solar Active-Region Cores: Constraints from the Hinode X-Ray Telescope
Schmelz, J. T.; Christian, G. M.; Matheny, P. O.
Mechanisms invoked to heat the solar corona to millions of degrees kelvin involve either magnetic waves or magnetic reconnections. Turbulence in the convection zone produces MHD waves, which travel upward and dissipate. Photospheric motions continuously build up magnetic energy, which is released through magnetic reconnection. In this paper, we co…
Assessment of Models of Galactic Thermal Dust Emission Using COBE/FIRAS and COBE/DIRBE Observations
Kogut, A.; Odegard, N.; Chuss, D. T. +1 more
Accurate modeling of the spectrum of thermal dust emission at millimeter wavelengths is important for improving the accuracy of foreground subtraction for cosmic microwave background (CMB) measurements, for improving the accuracy with which the contributions of different foreground emission components can be determined, and for improving our under…
Spectroscopy from the Hubble Space Telescope Cosmic Origins Spectrograph of the Southern Nova-like BB Doradus in an Intermediate State
Szkody, Paula; Sion, Edward M.; Godon, Patrick +6 more
We present a spectral analysis of the spectrum from the Hubble Space Telescope Cosmic Origins Spectrograph (HST/COS) of the southern VY Scl nova-like variable BB Doradus, obtained as part of a Cycle 20 HST/COS survey of accreting white dwarfs (WDs) in cataclysmic variables. BB Dor was observed with COS during an intermediate state with a low mass …
Analysis of Co-spatial UV-optical HST/STIS Spectra of Planetary Nebula NGC 3242
Corradi, Romano L. M.; Balick, Bruce; Shaw, Richard A. +4 more
This project sought to consider two important aspects of the planetary nebula NGC 3242 using new long-slit HST/STIS spectra. First, we investigated whether this object is chemically homogeneous by spatially dividing the slit into different regions and calculating the abundances of each region. The major result is that the elements of He, C, O, and…
Long-term Study of the Double Pulsar J0737-3039 with XMM-Newton: Pulsar Timing
Tiengo, A.; Iacolina, M. N.; Pellizzoni, A. +8 more
The relativistic double neutron star binary PSR J0737-3039 shows clear evidence of orbital phase-dependent wind-companion interaction, both in radio and X-rays. In this paper, we present the results of timing analysis of PSR J0737-3039 performed during 2006 and 2011 XMM-Newton Large Programs that collected ∼20,000 X-ray counts from the system. We …
Dry Merger Rate and Post-merger Fraction in the Coma Cluster Core
De Propris, Roberto; Jogee, Shardha; Weinzirl, Tim +3 more
We evaluate the dry merger activity in the Coma cluster, using a spectroscopically complete sample of 70 red-sequence (RS) galaxies, most of which (∼75%) are located within 0.2R200 (∼0.5 Mpc) from the cluster center, with data from the Coma Treasury Survey obtained with the Hubble Space Telescope. The fraction of close galaxy pairs in t…
Spectral Variations of the Sky: Constraints on Alternate Universes
Chary, R.
The fine tuning of parameters required to reproduce our present day universe suggests that our universe may simply be a region within an eternally inflating super-region. Many other regions beyond our observable universe would exist with each such region governed by a different set of physical parameters. Collision between these regions, if they o…
Searching for the HR 8799 Debris Disk with HST/STIS
Venn, K.; Matthews, B.; Lawler, S. +3 more
We present a new algorithm for space telescope high contrast imaging of close-to-face-on planetary disks called Optimized Spatially Filtered (OSFi) normalization. This algorithm is used on HR 8799 Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) coronagraphic archival data, showing an over-luminosity after reference star po…
Transport of Solar Wind H+ and He++ Ions across Earth’s Bow Shock
Liu, Y.; Dandouras, I.; Rème, H. +10 more
We have investigated the dependence of mass, energy, and charge of solar wind (SW) transport across Earth’s bow shock. An examination of 111 crossings during quiet SW in both quasi-perpendicular and quasi-parallel shock regions shows that 64 crossings had various degrees of heating and thermalization of SW. We found 22 crossings where the SW speed…
Ocular Shock Front in the Colliding Galaxy IC 2163
Brinks, Elias; Struck, Curtis; Elmegreen, Bruce G. +5 more
ALMA observations in the 12CO J=1\to 0 line of the interacting galaxy pair IC 2163 and NGC 2207 at 2″ × 1.″5 resolution reveal how the encounter drives gas to pile up in narrow, ∼1 kpc wide, “eyelids” in IC 2163. IC 2163 and NGC 2207 are involved in a grazing encounter, which has led to the development in IC 2163 of an eye-shaped (ocula…