Search Publications
Missions
Journals
Publication Years
Analysis of X-ray spectral variability and black hole mass determination of the NLS1 galaxy Mrk 766
Titarchuk, L.; Gilli, R.; Giacchè, S.
We present an XMM-Newton time-resolved spectral analysis of the narrow-line Seyfert 1 galaxy Mrk 766. We analysed eight available observations taken between May 2000 and June 2005 with the EPIC-pn camera in order to investigate the X-ray spectral variability produced by changes in the mass accretion rate. The 0.2 - 10 keV spectra are extracted in …
Searching for highly obscured AGNs in the XMM-Newton serendipitous source catalog
Ranalli, P.; Georgantopoulos, I.; Lanzuisi, G. +9 more
The majority of active galactic nuclei (AGNs) are obscured by large amounts of absorbing material that makes them invisible at many wavelengths. X-rays, given their penetrating power, provide the most secure way for finding these AGNs. The XMM-Newton serendipitous source catalog, of which 3XMM-DR4 is the latest version, is the largest catalog of X…
Spectral detection of multiple stellar populations in z ∼ 1 early-type galaxies
Longhetti, M.; Gargiulo, A.; Saracco, P. +2 more
We present a spectroscopic analysis based on measurements of two mainly age-dependent spectrophotometric indices in the 4000 Å rest-frame region, i.e. H+K(Ca II) and Δ4000, for a sample of 15 early-type galaxies (ETGs) at 0.7 < zspec < 1.1, morphologically selected in the GOODS-South field. Ages derived from the two different indi…
The ages of pedestal craters on Mars: Evidence for a late-Amazonian extended period of episodic emplacement of decameters-thick mid-latitude ice deposits
Head, James W.; Kadish, Seth J.
There is significant geomorphologic evidence for the past presence of longitudinally widespread, latitudinally zoned deposits composed of ice-rich material at the northern and southern mid latitudes on Mars (lobate debris aprons, lineated valley fill, concentric crater fill, pedestal craters, etc.). Among these features, pedestal craters (Pd) are …
Hot Topic, Warm Loops, Cooling Plasma? Multithermal Analysis of Active Region Loops
Schmelz, J. T.; Pathak, S.; Brooks, D. H. +2 more
We have found indications of a relationship between the differential emission measure (DEM) weighted temperature and the cross-field DEM width for coronal loops. The data come from the Hinode X-ray Telescope, the Hinode EUV Imaging Spectrometer, and the Solar Dynamics Observatory Atmospheric Imaging Assembly. These data show that cooler loops tend…
Swift J2218.4+1925: a new hard-X-ray-selected polar observed with XMM-Newton
Mukai, K.; de Martino, D.; Bernardini, F. +1 more
Swift J2218.4+1925, a hard-X-ray source detected by Swift Burst Alert Telescope (BAT), has been proposed as a candidate magnetic cataclysmic variable of the polar type from optical spectroscopy. Using XMM-Newton we perform detailed timing and spectral analysis with simultaneous X-ray (0.3-10 keV) and optical B-band data. We complement the spectral…
Observations of the Interplanetary Hydrogen during Solar Cycles 23 and 24. What can We Deduce about the Local Interstellar Medium?
Harris, Walter M.; Quémerais, Eric; Koutroumpa, Dimitra +5 more
Observations of interstellar helium atoms by the Interstellar Boundary Explorer (IBEX) spacecraft in 2009 reported a local interstellar medium (LISM) velocity vector different from the results of the Ulysses spacecraft between 1991 and 2002. The interplanetary hydrogen (IPH), a population of neutrals that fills the space between planets inside the…
Long-term X-Ray Stability and Ultraviolet Variability of the Ionized Absorption in NGC 3783
Brandt, W. N.; Behar, E.; Turner, T. J. +6 more
We present the results of recent Chandra High-Energy Transmission Grating Spectrometer and Hubble Space Telescope Cosmic Origins Spectrograph observations of the nearby Seyfert 1 galaxy NGC 3783, which show a strong, nonvarying X-ray warm absorber and physically related and kinematically varying UV absorption. We compare our new observations to hi…
The plasma depletion layer in Saturn's magnetosheath
Coates, A. J.; Russell, C. T.; Dougherty, M. K. +5 more
A plasma depletion layer (PDL) of reduced plasma density and enhanced magnetic field strength can form in the magnetosheath (shocked solar wind) adjacent to the magnetopause boundary of a planetary magnetosphere. The dominant factor controlling the level of plasma depletion and field enhancement in Earth's PDL is the magnetic shear across the magn…
Analytical Solution for Waves in Planets with Atmospheric Superrotation. II. Lamb, Surface, and Centrifugal Waves
López-Valverde, M. A.; Imamura, T.; Peralta, J. +3 more
This paper is the second in a two-part study devoted to developing tools for a systematic classification of the wide variety of atmospheric waves expected on slowly rotating planets with atmospheric superrotation. Starting with the primitive equations for a cyclostrophic regime, we have deduced the analytical solution for the possible waves, simul…