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An Alternative Interpretation of the Relationship between the Inferred Open Solar Flux and the Interplanetary Magnetic Field
Riley, Pete
Photospheric observations at the Wilcox Solar Observatory (WSO) represent an uninterrupted data set of 32 years and are therefore unique for modeling variations in the magnetic structure of the corona and inner heliosphere over three solar cycles. For many years, modelers have applied a latitudinal correction factor to these data, believing that i…
Global Coronal Seismology
Ballai, I.
Following the observation and analysis of large-scale coronal-wave-like disturbances, we discuss the theoretical progress made in the field of global coronal seismology. Using simple mathematical techniques we determine average values for the magnetic field together with a magnetic map of the quiet Sun. The interaction between global coronal waves…
Titan's surface from Cassini RADAR SAR and high resolution radiometry data of the first five flybys
Lorenz, R. D.; Janssen, M. A.; Stiles, B. +12 more
The first five Titan flybys with Cassini's Synthetic Aperture RADAR (SAR) and radiometer are examined with emphasis on the calibration and interpretation of the high-resolution radiometry data acquired during the SAR mode (SAR-radiometry). Maps of the 2-cm wavelength brightness temperature are obtained coincident with the SAR swath imaging, with s…
Observation of similar radio signatures at Saturn and Jupiter: Implications for the magnetospheric dynamics
Gurnett, D. A.; Persoon, A. M.; Hospodarsky, G. B. +13 more
We report on radio signatures observed at Saturn by the Cassini RPWS experiment which are strikingly similar to the Jovian ``energetic events'' observed by Galileo. They consist of sudden intensifications of the auroral radio emission (SKR) followed by the detection of a periodic narrowband radiation which most likely originates from Saturn's plas…
ConvPhot: A profile-matching algorithm for precision photometry
Santini, P.; Fontana, A.; Grazian, A. +1 more
We describe in this paper a new, public software for accurate "PSF-matched" multiband photometry for images of different resolution and depth, that we have named ConvPhot, of which we analyse performances and limitations. It is designed to work when a high resolution image is available to identify and extract the objects, and colours or variations…
Differences in the AGN Populations of Groups and Clusters: Clues to AGN Evolution
Shen, Yue; Raychaudhury, Somak; Mulchaey, John S. +2 more
We combine optical and X-ray data for eight low-redshift (z~0.06) poor groups of galaxies from the XI (XMM-IMACS) Groups Project to study the AGN population in the group environment. Among ~140 group members, we identify five AGNs based on their optical emission lines. None of these optically selected AGNs are detected by XMM-Newton. One additiona…
XMM-Newton observation of the persistent Be/neutron star system X Persei at a high-luminosity level
Mereghetti, S.; La Palombara, N.
We report on the XMM-Newton observation of the HMXRB X Persei, the prototype of the persistent and low-luminosity Be/neutron star pulsars, which was performed in February 2003. The source was detected at a luminosity level of ~1.4×1035 erg s-1, which is the highest level of the latest three decades. The pulsation period has i…
Obscured and unobscured AGN populations in a hard-X-ray selected sample of the XMDS survey
Maccagni, D.; Maraschi, L.; Chiappetti, L. +16 more
Aims:Our goal is to probe the populations of obscured and unobscured AGN investigating their optical-IR and X-ray properties as a function of X-ray flux, luminosity and redshift within a hard X-ray selected sample with wide multiwavelength coverage.
Methods: We selected a sample of 136 X-ray sources detected at a significance of ≥3 σ in the 2{…
A Spitzer IRAC Census of the Asymptotic Giant Branch Populations in Local Group Dwarfs. I. WLM
Skillman, Evan D.; Gehrz, Robert D.; Woodward, Charles E. +2 more
We present Spitzer IRAC observations at 3.6 and 4.5 µm along with optical data from the Local Group Galaxies Survey to investigate the evolved stellar population of the Local Group dwarf irregular galaxy WLM. These observations provide a nearly complete census of the AGB stars. We find that 39% of the infrared-detected AGB stars are not dete…
Dressing a Naked Quasar: Star Formation and Active Galactic Nucleus Feedback in HE 0450-2958
Feain, Ilana J.; Ekers, Ronald D.; Papadopoulos, Padelis P. +1 more
We present Australia Telescope Compact Array radio continuum observations of the quasar/galaxy system HE 0450-2958. An asymmetric triple linear morphology is observed, with the central radio component coincident with the quasar core and a second radio component associated with a companion galaxy at a projected distance of 7 kpc from the quasar. Th…