Browsing University of Hertfordshire by Title
Now showing items 24017-24036 of 24120
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The X-ray spectra of the luminous LMXBs in NGC 3379 : field and globular cluster sources
(2010-12)From a deep multi-epoch Chandra observation of the elliptical galaxy NGC 3379 we report the spectral properties of eight luminous LMXBs (L-X > 1.2 x 10(38) erg s(-1)). We also present a set of spectral simulations, produced ... -
X-Ray Studies of Radio-Loud AGN
(University of Hertfordshire, 2013-05-24)In this thesis I use X-ray observations to study the cores and extended structures of radio-loud AGN, to determine their structure, accretion properties and the impact they have on their surroundings. I use new Chandra ... -
An X-ray survey of the 2 Jy sample - II. X-ray emission from extended structures
(2017-09-21)The 2 Jy sample is a survey of radio galaxies with flux densities above 2 Jy at 2.7 GHz. As part of our ongoing work on the southern subset of 2 Jy sources, in paper I of this series we analysed the X-ray cores of the ... -
An X-ray survey of the 2 Jy sample-I : Is there an accretion mode dichotomy in radio-loud AGN?
(2014-05-01)We carry out a systematic study of the X-ray emission from the active nuclei of the 0.02 < z< 0.7 2 Jy sample, using Chandra and XMM-Newton observations.We combine our results with those from mid-infrared, optical emission-line ... -
X-ray Synchrotron Radiation and Particle Acceleration
(2004)I discuss X-ray synchrotron emission as a probe of particle acceleration, concentrating mainly on low-power (FRI) jets but also touching on the hotspots in FRII sources. Combining X-ray and radio data has allowed us to ... -
X-shooting Herbig Ae/Be stars : accretion probed by near-infrared He I emission
(2011)The Herbig Ae/Be stars are intermediate mass pre-main sequence stars that bridge the gap between the low mass T Tauri stars and the Massive Young Stellar Objects. In this mass range, the acting star forming mechanism ... -
XDR Chemistry in the Circumnuclear Disk of NGC 1068
(Astronomical Society of the Pacific, 2004)We have studied the feedback in°uence that the central engine of the Seyfert 2 galaxy NGC 1068 may have on the chemistry of the 200 pc circumnuclear gas disk (CND). With this purpose, we have conducted a multispecies/ ... -
xDSL Network Upgrade Employing FPGAs
(Institute of Electrical and Electronics Engineers (IEEE), 2008)This paper proposes an upgrade scenario for xDSL networks to provide broadband access for extendedlink lengths while demonstrating network grooming bymeans of more than one subscriber using a single network connection ... -
The XMM-Newton and Spitzer View of Galaxy/AGN Formation at z = 2-3
(European Space Agency (ESA), 2006-01-01)The genesis of spheroids is central to our understanding of galaxy formation. They contain half of the stellar mass of the Universe, and almost all of the black hole mass. According to galaxy formation models, cluster ... -
XMM-Newton Observations of the Nuclei of the Radio Galaxies 3C 305, DA 240, and 4C 73.08
(2008)We present new XMM-Newton EPIC observations of the nuclei of the nearby radio galaxies 3C 305, DA 240, and 4C 73.08, and investigate the origin of their nuclear X-ray emission. The nuclei of the three sources appear to ... -
XMM-Newton Observations of Three High Redshift Radio Galaxies
(2004)We present results on the physical states of three highredshift powerful radio galaxies (3C292 atz = 0.7, 3C184 at z= 1, and 3C322 atz = 1.7). They were obtained by combining radio measurements with X-ray measurements from ... -
XUE: Molecular Inventory in the Inner Region of an Extremely Irradiated Protoplanetary Disk
(2023-12-01)We present the first results of the eXtreme UV Environments (XUE) James Webb Space Telescope (JWST) program, which focuses on the characterization of planet-forming disks in massive star-forming regions. These regions are ... -
The XXL Survey: : XXIX. GMRT 610 MHz continuum observations
(2018-12-01)We present the 25 square-degree GMRT-XXL-N 610 MHz radio continuum survey, conducted at 50 cm wavelength with the Giant Metrewave Radio Telescope (GMRT) towards the XXL Northern field (XXL-N). We combined previously published ... -
The X–shooter/ALMA Sample of Quasars in the Epoch of Reionization. II. Black Hole Masses, Eddington Ratios, and the Formation of the First Quasars
(2022-12-20)We present measurements of black hole masses and Eddington ratios (λ Edd) for a sample of 38 bright (M 1450 < −24.4 mag) quasars at 5.8 ≲ z ≲ 7.5, derived from Very Large Telescope/X-shooter near-IR spectroscopy of their ...