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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 …
Composite Inflation in the light of 2015 Planck data
Channuie, Phongpichit
In this work, we examine cosmological constraints on models of composite inflation based on the slow-roll approximation by using the recent Planck measurement. We compare the spectral index of curvature perturbation (and its running) and the tensor-to-scalar ratio predicted by such models with Planck 2015 data. We find that the predictions of tech…
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…
The prolonged southward IMF-Bz event of 2-4 May 1998: Solar, interplanetary causes and geomagnetic consequences
Janardhan, P.; Yan, Y.; Tokumaru, M. +5 more
A detailed investigation is carried out to understand the prolonged (∼44 h) weakly southward interplanetary magnetic field (IMF-Bz) condition during 2-4 May 1998. In situ observations, during the period, show the passage of an expanding magnetic cloud embedded in an interplanetary coronal mass ejection (ICME), followed up by a shock and…
Flight model measurements of the porous plug and film flow suppression system for the ASTRO-H Soft X-ray Spectrometer dewar
Ezoe, Yuichiro; Ishikawa, Kumi; Ohashi, Takaya +9 more
Flight model measurements of a porous plug phase separator and a film flow suppression system for the ASTRO-H Soft X-ray Spectrometer dewar are described. ASTRO-H is the sixth Japanese astronomy satellite and will be launched in 2016. It carries the Soft X-ray Spectrometer consisting of an X-ray optic and an X-ray microcalorimeter system operated …
New temperature and pressure retrieval algorithm for high-resolution infrared solar occultation spectroscopy: analysis and validation against ACE-FTS and COSMIC
Olsen, Kevin S.; Strong, Kimberly; Toon, Geoffrey C. +1 more
Motivated by the initial selection of a high-resolution solar occultation Fourier transform spectrometer (FTS) to fly to Mars on the ExoMars Trace Gas Orbiter, we have been developing algorithms for retrieving volume mixing ratio vertical profiles of trace gases, the primary component of which is a new algorithm and software for retrieving vertica…
High-energy monitoring of Seyfert galaxies: The case of NGC 4593
Bianchi, S.; Cappi, M.; Ponti, G. +6 more
We discuss preliminary results from a joint XMM-Newton and NuSTAR monitoring program on the active galactic nucleus NGC 4593, consisting of 5 × 20 ks observations, spaced by two days, performed in January 2015. The source is found to be variable, both in flux and spectral shape, on time scales as short as a few ks. The spectrum clearly softens whe…