Search Publications
Microwave observations of a large-scale coronal wave with the Nobeyama radioheliograph
Mann, G.; Shibasaki, K.; Warmuth, A. +1 more
Context. Large-scale globally propagating waves in the solar corona have been studied extensively, mainly using extreme ultraviolet (EUV) observations. In a few events, corresponding wave signatures have been detected in microwave radioheliograms provided by the Nobeyama radioheliograph (NoRH). Several aspects of these observations seem to contrad…
Quasi-continuous reconnection accompanied by FTEs during IMF Bz ≈ 0 nT observed by Double Star TC-1 at the dawnside magnetopause
Shen, Chao; Chen, Tao; Phan, Tai +6 more
During a one-hour interval of interplanetary magnetic field (IMF) Bz ≈ 0 nT, the equatorial spacecraft Double Star TC-1 encountered the dawn flank magnetopause many times at the magnetic local time (MLT) of about 08:00 and the latitude of about -27°. During each encounter, reconnection jets were observed with their velocities up to more…
Variability of the emission line fluxes and ratios of HH 1/2
Raga, A. C.; Reipurth, B.; Castellanos-Ramírez, Bally, J.
We compare spectrophotometric data of HH 1 and 2 obtained in 1978 (by Brugel et al. 1981a) with the emission line fluxes from calibrated Hubble Space Telescope (HST) images obtained in 1994 and 2014. This comparison shows that the emission line ratios of these objects have remained surprisingly invariant during the past 36 years. On the other hand…
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…
Ptolemy operations at the surface of a comet, from planning to reality
Andrews, D. J.; Sheridan, S.; Wright, I. P. +3 more
Ptolemy is a Gas Chromatograph-Isotope Ratio-Mass Spectrometer (GC-IR-MS) aboard the Philae lander element of the Rosetta mission to comet 67P/Churyumov-Gerasimenko. Developed to determine the chemical and stable light isotopic composition of cometary material, Ptolemy was conceived as a highly flexible instrument able to accommodate changes in op…
First performance of the GeMS + GMOS system - 1. Imaging
Hibon, Pascale; Rigaut, Francois; Carrasco, Eleazar R. +6 more
During the commissioning of the Gemini MCAO System (GeMS), we had the opportunity to obtain data with the Gemini Multi-Object Spectrograph (GMOS), the most utilized instrument at Gemini South Observatory, in 2012 March and May. Several globular clusters were observed in imaging mode that allowed us to study the performance of this new and untested…
A vertical rift in Saturn's inner C ring
Nicholson, Philip D.; Hedman, Matthew M.
In 1988 Rosen and Lissauer identified an unusual wavelike feature in Saturn's inner C ring as a bending wave driven by a nodal resonance with Titan (Science 241, 690). This is sometimes referred to as the - 1 : 0 resonance since it occurs where the local nodal regression rate is approximately equal to -nT , where nT = 22 .577…
Broadband short term X-ray variability of the quasar PDS 456
Tombesi, F.; Reeves, J. N.; Braito, V. +4 more
We present a detailed analysis of a recent 500 ks net exposure Suzaku observation, carried out in 2013, of the nearby (z=0.184) luminous (L_bol∼1047 erg s-1) quasar PDS 456 in which the X-ray flux was unusually low. The short term X-ray spectral variability has been interpreted in terms of variable absorption and/or intrinsic…
Absorption from a multi-layer circumnuclear medium and reflection from the accretion disc in NGC 1365
Risaliti, G.
NGC 1365 hosts an X-ray obscured AGN known for both its variable absorption and its relativistic features in the reflection component. Recent simultaneous observations performed by XMM-Newton and NuSTAR caught the source in a rare, nearly unobscured state, revealing the presence of a warm absorber and a neutral, but low column density (∼ 1022…
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 …