Search Publications
Cluster observations of simultaneous resonant interactions of ULF waves with energetic electrons and thermal ion species in the inner magnetosphere
Zong, Q. -G.; Reme, H.; Korth, A. +6 more
In this study, we report in situ observations on the simultaneous periodic modulations in the drifting energetic electrons (∼100 keV) and in the bouncing thermal ion species (O+ at ∼4.5 keV and H+ at ∼280 eV) with the same frequency of 3.3 mHz during the storm recovery phase on 21 October 2001. The Cluster fleet was traveling…
X-QUEST: A Comprehensive X-ray Study of Local ULIRGS and QSOs
Veilleux, Sylvain; Teng, Stacy H.
We present results from the X-ray portion of a multi-wavelength study of local ULIRGs and QSOs called QUEST (Quasar-ULIRG Evolution STudy). The data consist of new and archival X-ray data on 40 ULIRGs and 26 Palomar Green (PG) QSOs taken with Chandra and XMM-Newton. A combination of traditional and hardness ratio spectral fitting methods is used t…
Continued Cooling of the Crust in the Neutron Star Low-mass X-ray Binary KS 1731-260
Miller, Jon M.; Cackett, Edward M.; Wijnands, Rudy +3 more
Some neutron star low-mass X-ray binaries have very long outbursts (lasting several years) which can generate a significant amount of heat in the neutron star crust. After the system has returned to quiescence, the crust then thermally relaxes. This provides a rare opportunity to study the thermal properties of neutron star crusts, putting constra…
The linear rms-flux relation in an ultraluminous X-ray source
Vaughan, S.; Heil, L. M.
We report the first detection of a linear correlation between rms variability amplitude and flux in the ultraluminous X-ray source (ULX) NGC 5408 X-1. The rms-flux relation has previously been observed in several galactic black hole X-ray binaries (BHBs), several active galactic nuclei (AGN) and at least one neutron star X-ray binary. This result …
Cluster observations of bidirectional beams caused by electron trapping during antiparallel reconnection
Fazakerley, A.; Egedal, J.; Lê, A. +4 more
So-called bidirectional electron beams have been observed by a number of spacecraft missions mainly in the inflow of reconnection regions. Here we show that these beam-like features in the electron distribution function are explained by electron trapping. The trapping is mainly controlled by a positive acceleration potential, Φ$\parallel$
The number density of superdense early-type galaxies at 1 < z < 2 and the local cluster galaxies
Longhetti, M.; Gargiulo, A.; Saracco, P.
Many of the early-type galaxies (ETGs) observed so far at z > 1 turned out to have smaller radii with respect to that of a typical present day ETG with comparable mass. This has generated the conviction that in the past ETGs were more compact, hence denser, and that as a consequence, they should have increased their radius across the time to re…
On the Progenitor and Supernova of the SN 2002cx-like Supernova 2008ge
Foley, Ryan J.; Rest, Armin; Phillips, Mark M. +6 more
We present observations of supernova (SN) 2008ge, which is spectroscopically similar to the peculiar SN 2002cx, and its pre-explosion site indicating that its progenitor was probably a white dwarf. NGC 1527, the host galaxy of SN 2008ge, is an S0 galaxy with no evidence of star formation or massive stars. Astrometrically matching late-time imaging…
First results from HerMES on the evolution of the submillimetre luminosity function
Altieri, B.; Aussel, H.; Elbaz, D. +81 more
We have carried out two extremely deep surveys with SPIRE, one of the two cameras on Herschel, at 250 µm, close to the peak of the far-infrared background. We have used the results to investigate the evolution of the rest-frame 250-µm luminosity function out to z = 2. We find evidence for strong evolution out to z ≃ 1 but evidence for …
Thermo-dynamic and chemical properties of the intra-cluster medium
Rossetti, M.; Molendi, S.; Leccardi, A.
Aims: We aim to provide constraints on evolutionary scenarios in clusters. One of our main goals is to understand whether, as claimed by some, the cool core/non-cool core division is established once and for all during the early history of a cluster.
Methods: We employ a sample of ≃60 objects to classify clusters according to different p…
The 2009 December Gamma-ray Flare of 3C 454.3: The Multifrequency Campaign
Sakamoto, T.; Pian, E.; Fugazza, D. +81 more
During the month of 2009 December, the blazar 3C 454.3 became the brightest gamma-ray source in the sky, reaching a peak flux F ~ 2000 × 10-8 photons cm-2 s-1 for E > 100 MeV. Starting in 2009 November intensive multifrequency campaigns monitored the 3C 454 gamma-ray outburst. Here, we report on the results of a…