Search Publications
Interaction between an emerging flux region and a pre-existing fan-spine dome observed by IRIS and SDO
Yang, Shuhong; Zhang, Jun; Jiang, Fayu
We present multiwavelength observations of a fan-spine dome in the active region NOAA 11996 with the Interface Region Imaging Spectrograph (IRIS) and the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory (SDO) on 2014 March 9. The destruction of the fan-spine topology owing to the interaction between its magnetic fields and a ne…
Testing the tensor-vector-scalar theory with the latest cosmological observations
Wang, Bin; Zhang, Pengjie; Xu, Xiao-dong
The tensor-vector-scalar (TeVeS) model is considered a viable theory of gravity. It produces the Milgrom's modified Newtonian dynamics in the nonrelativistic weak field limit and is free from ghosts. This model has been tested against various cosmological observations. Here, we investigate whether new observations such as the galaxy velocity power…
Millimetre polarization of the protoplanetary nebula OH 231.8+4.2: a follow-up study with CARMA
Zijlstra, A. A.; Sabin, L.; Vázquez, R. +4 more
In order to investigate the characteristics and influence of the magnetic field in evolved stars, we performed a follow-up investigation of our previous submillimetre analysis of the protoplanetary nebula (PPN) OH 231.8+4.2, this time at 1.3 mm with the CARMA (Combined Array for Research in Millimeter-wave Astronomy) facility in polarization mode …
Does the Variation of Solar Intra-network Horizontal Field Follow Sunspot Cycle?
Wang, J. X.; Jin, C. L.
The ubiquitousness of the solar inter-network horizontal magnetic field has been revealed by space-borne observations with high spatial resolution and polarization sensitivity. However, no consensus has been achieved on the origin of the horizontal field among solar physicists. For a better understanding, in this study, we analyze the cyclic varia…
N2 state population in Titan's atmosphere
Galand, M.; Yelle, R. V.; Lavvas, P. +4 more
We present a detailed model for the vibrational population of all non pre-dissociating excited electronic states of N2, as well as for the ground and ionic states, in Titan's atmosphere. Our model includes the detailed energy deposition calculations presented in the past (Lavvas, P. et al. [2011]. Icarus 213(1), 233-251) as well as the …
Modeling the physical properties in the ISM of the low-metallicity galaxy NGC 4214
Madden, S. C.; Cormier, D.; Bigiel, F. +1 more
We present a model for the interstellar medium of NGC 4214 with the objective to probe the physical conditions in the two main star-forming regions and their connection with the star formation activity of the galaxy. We used the spectral synthesis code Cloudy to model an H ii region and the associated photodissociation region (PDR) to reproduce th…
Finding η Car Analogs in Nearby Galaxies Using Spitzer. II. Identification of An Emerging Class of Extragalactic Self-Obscured Stars
Kochanek, C. S.; Stanek, K. Z.; Khan, Rubab +1 more
Understanding the late-stage evolution of the most massive stars such as η Carinae is challenging because no true analogs of η Car have been clearly identified in the Milky Way or other galaxies. In Khan et al., we utilized Spitzer IRAC images of 7 nearby (lsim 4 Mpc) galaxies to search for such analogs, and found 34 candidates with flat or red mi…
Deriving plasma densities in tenuous plasma regions, with the spacecraft potential under active control
Andriopoulou, M.; Nakamura, R.; Baumjohann, W. +2 more
Variations of the floating potential on spacecraft are often used to derive plasma densities, complementing the plasma instrument measurements. All spacecraft of the Cluster mission are equipped with Active Spacecraft POtential Control (ASPOC) instruments that control the spacecraft potential. Although the ASPOC operation increases the accuracy of…
Asymmetric ionospheric outflow observed at the dayside magnetopause
Glassmeier, K. -H.; Zhang, H.; Zong, Q. -G. +4 more
An important source of the terrestrial magnetospheric plasma is the Earth's ionospheric outflows from the high-latitude regions of both hemispheres. The ionospheric ion outflows have rarely been observed at the dayside magnetopause. We report Cluster observations of the ionospheric ion outflows observed at the dayside magnetopause. The low-energy …
Groundwater seepage landscapes from distant and local sources in experiments and on Mars
Hauber, E.; Kleinhans, M. G.; Marra, W. A. +3 more
Valleys with theater-shaped heads can form due to the seepage of groundwater and as a result of knickpoint (waterfall) erosion generated by overland flow. This ambiguity in the mechanism of formation hampers the interpretation of such valleys on Mars, particularly since there is limited knowledge of material properties. Moreover, the hydrological …