Search Publications
AGN-driven perturbations in the intracluster medium of the cool-core cluster ZwCl 2701
Naik, Sachindra; Vagshette, Nilkanth D.; Sonkamble, Satish S. +1 more
We present the results obtained from a total of 123 ks X-ray (Chandra) and 8 h of 1.4 GHz radio (Giant Metrewave Radio Telescope - GMRT) observations of the cool-core cluster ZwCl 2701 (z = 0.214). These observations of ZwCl 2701 showed the presence of an extensive pair of ellipsoidal cavities along the east and west directions within the central …
A Nanoflare-based Cellular Automaton Model and the Observed Properties of the Coronal Plasma
Klimchuk, James A.; López Fuentes, Marcelo
We use the cellular automaton model described in López Fuentes & Klimchuk to study the evolution of coronal loop plasmas. The model, based on the idea of a critical misalignment angle in tangled magnetic fields, produces nanoflares of varying frequency with respect to the plasma cooling time. We compare the results of the model with active reg…
Revised wavelength and spectral response calibrations for AKARI near-infrared grism spectroscopy: Cryogenic phase
Nakagawa, Takao; Baba, Shunsuke; Isobe, Naoki +6 more
We perform revised spectral calibrations for the AKARI near-infrared grism to correct quantitatively for the effect of the wavelength-dependent refractive index. The near-infrared grism covering the wavelength range of 2.5-5.0 µm, with a spectral resolving power of 120 at 3.6 µm, is found to be contaminated by second-order light at wav…
Attitude reconstruction of ROSETTA's Lander PHILAE using two-point magnetic field observations by ROMAP and RPC-MAG
Richter, Ingo; Auster, Hans-Ulrich; Heinisch, Philip +5 more
As part of the European Space Agency's ROSETTA Mission the Lander PHILAE touched down on comet 67P/Churyumov-Gerasimenko on November 12, 2014. The magnetic field has been measured onboard the orbiter and the lander. The orbiter's tri-axial fluxgate magnetometer RPC-MAG is one of five sensors of the ROSETTA Plasma Consortium. The lander is also equ…
Correlation of Coronal Plasma Properties and Solar Magnetic Field in a Decaying Active Region
Warren, Harry P.; Ugarte-Urra, Ignacio; Young, Peter R. +2 more
We present the analysis of a decaying active region observed by the EUV Imaging Spectrometer on Hinode during 2009 December 7-11. We investigated the temporal evolution of its structure exhibited by plasma at temperatures from 300,000 to 2.8 million degrees, and derived the electron density, differential emission measure, effective electron temper…
Eight-color maps of Titan's surface from spectroscopy with Huygens' DISR
Karkoschka, Erich; Schröder, Stefan E.
During the descent of the Huygens probe in Titan's atmosphere, the Descent Imager/Spectral Radiometer (DISR) acquired spectra of 3660 locations within 250 km of the landing site. Each spectrum consisted of 200 resolution elements between 480 and 960 nm wavelength. With the help of radiative transfer models, contributions from the atmosphere and su…
Breaking Be: a sterile neutrino solution to the cosmological lithium problem
Lattanzi, M.; Melchiorri, A.; Pagano, L. +2 more
The possibility that the so-called ``lithium problem'', i.e., the disagreement between the theoretical abundance predicted for primordial 7Li assuming standard nucleosynthesis and the value inferred from astrophysical measurements, can be solved through a non-thermal Big Bang Nucleosynthesis (BBN) mechanism has been investigated by seve…
The Extreme Ultraviolet Variability of Quasars
O'Dea, Christopher P.; Zhang, Shaohua; Muzahid, Sowgat +2 more
We study the extreme ultraviolet (EUV) variability (rest frame wavelengths 500-920 Å) of high-luminosity quasars using Hubble Space Telescope (HST) (low to intermediate redshift sample) and Sloan Digital sky Survey (SDSS) (high redshift sample) archives. The combined HST and SDSS data indicates a much more pronounced variability when the sampling …
The apparent synchronization of V1500 Cygni
Harrison, Thomas E.; Campbell, Ryan K.
We have used XMM-Newton and ground-based optical/near-infrared photometry to explore the old classical nova, and asynchronous polar V1500 Cyg. The X-ray light curve shows a single bright phase once per orbit, associated with the main accretion region. Analysis of the X-ray light curve indicates that the white dwarf spin period is now similar to th…
Variation of Jupiter's aurora observed by Hisaki/EXCEED: 1. Observed characteristics of the auroral electron energies compared with observations performed using HST/STIS
Tsuchiya, Fuminori; André, Nicolas; Fujimoto, Masaki +9 more
Temporal variation of Jupiter's northern aurora is detected using the Extreme Ultraviolet Spectroscope for Exospheric Dynamics (EXCEED) on board JAXA's Earth-orbiting planetary space telescope Hisaki. The wavelength coverage of EXCEED includes the H2 Lyman and Werner bands at 80-148 nm from the entire northern polar region. The prominen…