Search Publications
Suzaku Observation of IRAS 00521-7054, a Peculiar Type-II AGN with a Very Broad Feature at 6 keV
Paltani, S.; Ricci, C.; Terashima, Y. +3 more
IRAS 00521-7054 is the first Seyfert 2 in which the presence of an extremely large Fe Kα line has been claimed. We report here on the analysis of a 100 ks Suzaku observation of the source. We confirm the existence of a very strong excess over the power-law X-ray continuum at E ~ 6 keV (EW ~= 800 eV), extending down to ~4.5 keV, and found that the …
The Extreme Ultraviolet Deficit and Magnetically Arrested Accretion in Radio-loud Quasars
Punsly, Brian
The Hubble Space Telescope composite quasar spectra presented in Telfer et al. show a significant deficit of emission in the extreme ultraviolet for the radio-loud component of the quasar population (RLQs) compared to the radio-quiet component of the quasar population. The composite quasar continuum emission between 1100 Å and ~580 Å is generally …
First Extragalactic Detection of Submillimeter CH Rotational Lines from the Herschel Space Observatory
Wilson, Christine D.; Glenn, Jason; Spinoglio, Luigi +5 more
We present the first extragalactic detections of several CH rotational transitions in the far-infrared in four nearby galaxies, NGC 1068, Arp 220, M82, and NGC 253, using the Herschel Space Observatory. The CH lines in all four galaxies are a factor of 2-4 brighter than the adjacent HCN and HCO+ J = 6-5 lines (also detected in the same …
Super-Eddington Accretion in the Ultraluminous X-Ray Source NGC 1313 X-2: An Ephemeral Feast
Weng, Shan-Shan; Zhao, Hai-Hui; Zhang, Shuang-Nan
We investigate the X-ray spectrum, variability, and the surrounding ionized bubble of NGC 1313 X-2 to explore the physics of super-Eddington accretion. Beyond the Eddington luminosity, the accretion disk of NGC 1313 X-2 is truncated at a large radius (~50 times the innermost stable circular orbit), and displays the similar evolution track with bot…
Hubble Space Telescope Observations of the Nucleus of Comet C/2012 S1 (ISON)
Weaver, Harold A.; Toth, Imre; Lamy, Philippe L.
We report on the analysis of several sequences of broadband visible images of comet C/2012 S1 (ISON) taken with the Wide Field Camera 3 of the Hubble Space Telescope on 2013 April 10, May 8, October 9, and November 1 in an attempt to detect and characterize its nucleus. Whereas the overwhelming coma precluded the detection of the nucleus in the fi…
Solar Energetic Particle Events in Different Types of Solar Wind
Vourlidas, A.; Kahler, S. W.
We examine statistically some properties of 96 20 MeV gradual solar energetic proton (SEP) events as a function of three different types of solar wind (SW) as classified by Richardson and Cane. Gradual SEP (E > 10 MeV) events are produced in shocks driven by fast (V >~ 900 km s-1) and wide (W > 60°) coronal mass ejections (CMEs…
XMM-Newton and Chandra Observations of the Ejecta-dominated Mixed-morphology Galactic Supernova Remnant G352.7-0.1
Kargaltsev, Oleg; Pannuti, Thomas G.; Napier, Jared P. +1 more
We present a spatial and spectral X-ray analysis of the Galactic supernova remnant (SNR) G352.7-0.1 using archival data from observations made with the XMM-Newton X-ray Observatory and the Chandra X-ray Observatory. Prior X-ray observations of this SNR had revealed a thermal center-filled morphology that contrasts with a shell-like radio morpholog…
Suzaku Monitoring of Hard X-Ray Emission from η Carinae over a Single Binary Orbital Cycle
Hamaguchi, Kenji; Corcoran, Michael F.; Ishida, Manabu +6 more
The Suzaku X-ray observatory monitored the supermassive binary system η Carinae 10 times during the whole 5.5 yr orbital cycle between 2005 and 2011. This series of observations presents the first long-term monitoring of this enigmatic system in the extremely hard X-ray band between 15 and 40 keV. During most of the orbit, the 15-25 keV emission v…
Bulgeless Galaxies at Intermediate Redshift: Sample Selection, Color Properties, and the Existence of Powerful Active Galactic Nuclei
Bell, Eric F.; Brinchmann, Jarle; Bizzocchi, Luca +11 more
We present a catalog of bulgeless galaxies, which includes 19,225 objects selected in four of the deepest, largest multi-wavelength data sets available—COSMOS, AEGIS, GEMS, and GOODS—at intermediate redshift (0.4 <= z <= 1.0). The morphological classification was provided by the Advanced Camera for Surveys General Catalog (ACS-GC), which use…
On the Dust Environment of Comet C/2012 S1 (ISON) from 12 AU Pre-perihelion to the End of its Activity around Perihelion
López-Moreno, J. J.; Moreno, F.; García, F. +48 more
A Monte Carlo dust tail model has been applied to extract the dust environment parameters of the comet C/2012 S1 (ISON) from both Earth-based and SOHO LASCO C3 observations, performed from about six astronomical units (AU) inbound, to just after perihelion passage, when only a small portion of the original comet nucleus has survived in the form of…