Search Publications
HZ Her: Stellar Radius from X-Ray Eclipse Observations, Evolutionary State, and a New Distance
Leahy, D. A.; Abdallah, M. H.
Observations of HZ Her/Her X-1 by the Rossi X-Ray Timing Explorer (RXTE) covering high state eclipses of the neutron star are analyzed here. Models of the eclipse are used to measure the radius and atmospheric scale height of HZ Her, the stellar companion to the neutron star. The radius is 2.58-3.01 × 1011 cm, depending on system inclin…
Valles Marineris dune fields as compared with other martian populations: Diversity of dune compositions, morphologies, and thermophysical properties
Chojnacki, Matthew; Moersch, Jeffrey E.; Burr, Devon M.
Planetary dune field properties and their bulk bedform morphologies relate to regional wind patterns, sediment supply, climate, and topography. On Mars, major occurrences of spatially contiguous low-albedo sand dunes are primarily found in three major topographic settings: impact craters, high-latitude basins, and linear troughs or valleys, the la…
Waves in high-speed plasmoids in the magnetosheath and at the magnetopause
Gunell, H.; Dandouras, I.; Nilsson, H. +9 more
Plasmoids, defined here as plasma entities with a higher anti-sunward velocity component than the surrounding plasma, have been observed in the magnetosheath in recent years. During the month of March 2007 the Cluster spacecraft crossed the magnetopause near the subsolar point 13 times. Plasmoids with larger velocities than the surrounding magneto…
Directly imaging damped Lyα galaxies at z > 2 - II. Imaging and spectroscopic observations of 32 quasar fields
Prochaska, J. Xavier; Fumagalli, Michele; Kanekar, Nissim +2 more
Damped Lyα absorbers (DLAs) are a well-studied class of absorption line systems, and yet the properties of their host galaxies remain largely unknown. To investigate the origin of these systems, we have conducted an imaging survey of 32 quasar fields with intervening DLAs between z ∼ 1.9 and 3.8, leveraging a technique that allows us to image gala…
Shockingly low water abundances in Herschel/PACS observations of low-mass protostars in Perseus
Fedele, D.; van Dishoeck, E. F.; Evans, N. J. +16 more
Context. Protostars interact with their surroundings through jets and winds impinging on the envelope and creating shocks, but the nature of these shocks is still poorly understood.
Aims: Our aim is to survey far-infrared molecular line emission from a uniform and significant sample of deeply-embedded low-mass young stellar objects (YSOs) in …
Temperature dependence of the sublimation rate of water ice: Influence of impurities
Kossacki, Konrad J.; Leliwa-Kopystynski, Jacek
The sublimation rate of ice is commonly calculated using the simple Hertz-Knudsen formula. This formula is derived from the kinetic theory of gases and ignores microphysical processes determining the actual sublimation rate. The microphysical processes can be accounted for by including the temperature dependent sublimation coefficient (Kossacki, K…
Properties of Submillimeter Galaxies in the CANDELS GOODS-South Field
Barro, Guillermo; Castellano, Marco; Ferguson, Henry C. +29 more
We derive physical properties of 10 submillimeter galaxies located in the CANDELS coverage of the GOODS-S field. The galaxies were first identified as submillimeter sources with the LABOCA bolometer and subsequently targeted for 870 µm continuum observation with ALMA. The high angular resolution of the ALMA imaging allows secure counterparts…
New Clues to the Cause of Extended Main-Sequence Turnoffs in Intermediate-age Star Clusters in the Magellanic Clouds
Goudfrooij, Paul; Puzia, Thomas H.; Correnti, Matteo +3 more
We use the Wide Field Camera 3 on board the Hubble Space Telescope (HST) to obtain deep, high-resolution images of two intermediate-age star clusters in the Large Magellanic Cloud of relatively low mass (≈104 M ⊙) and significantly different core radii, namely NGC 2209 and NGC 2249. For comparison purposes, we also reanalyzed…
Stellar tidal disruption candidates found by cross-correlating the ROSAT Bright Source Catalogue and XMM-Newton observations
Sazonov, S.; Khabibullin, I.
We performed a systematic search for stellar tidal disruption events (TDE) by looking for X-ray sources that were detected during the ROSAT All Sky Survey and faded by more than an order of magnitude over the next two decades according to XMM-Newton serendipitous observations. Besides a number of highly variable persistent X-ray sources (like acti…
Magnetopause reconnection and energy conversion as influenced by the dipole tilt and the IMF Bx
Palmroth, Minna; Hoilijoki, Sanni; Souza, Vitor M. +2 more
We study the effect of Earth's dipole tilt angle and interplanetary magnetic field (IMF) Bx and By components on the location of reconnection and the energy conversion at the magnetopause. We simulate southward IMF satisfying both inward- and outward-type Parker spiral conditions during three different dipole tilt angles usin…