High Energy Astrophysics at Southampton
Lead Research Organisation:
University of Southampton
Department Name: Sch of Physics and Astronomy
Abstract
On the smallest scales we are interested in why pulsars seem to favour the low neutral hydrogen environments in the SMC. We are also interested in the products of stellar collisions and near misses in the high density environment of globular clusters, and in studying the compact objects (ie black holes, neutron stars, or white dwarfs) in our Galaxy which are strong emitter of optical light from hydgrogen atoms. Some galactic X-ray binary sources, which consist of black hole of similar mass to our sun together with a more normal star have, as well as accretion discs, through which matter spirals onto the black hole, strong jets. We want to understand the relationship between the emission from jets and from the hot X-ray emitting coronae and to find out how the jet might emerge from the corona. In some cases the disappearance of the inner disc is followed by ejection of material along the jet and we shall determine whether such behaviour is typical in Active Galaxies, ie galaxies whose emission is powered material falling onto (ie being accreted) by a massive black hole. In the 20-100 keV band where absorption of photons by cold gas is unimportant, and so we obtain a very clear view, we are surveying the Galactic Plane with INTEGRAL to determine an unbiased census of compact objects. As time goes on, we will extend that survey to the extragalactic sky. We study the X-ray variability of Active Galaxies to determine how they relate to galactic X-ray binaries sources and whether characteristic timescales reflect only mass or another parameter such as accretion rate. We are interested in the binary populations of nearby galaxies and in the so-called `ultra luminous X-ray sources (ULXs)'. ULXs may be the long sought after black holes with masses intermediate between those of galactic binaries and Active Galaxies and so are very important for testing mass-based scaling relationships. We are interested in how the emission in different wavebands (Gamma-ray, X-ray, optical/IR, radio) in binaries and Active Galaxies is related and what is the dependence on mass. We are interested how the jet emission from Active Galaxies heats clusters of galaxies. On the largest scales, we are interested in whether the different faint source populations which we see in the radio, X-ray and IR bands are just different manifestations of the same underlying phenomenon and how massive black hole growth might be related to growth of the galaxy in which the black hole lives. We are also building detailed theoretical models, using computers, to explain the complicated variability which we see in the sky at high energies.
Organisations
Publications
Sguera V
(2007)
IGR J18483-0311: an accreting X-ray pulsar observed by INTEGRAL
in Astronomy & Astrophysics
Shahbaz T
(2008)
The First Polarimetric Signatures of Infrared Jets in X-Ray Binaries
in The Astrophysical Journal
Sion E
(2008)
Hubble Space Telescope STIS Spectroscopy of Long-Period Dwarf Novae in Quiescence
in The Astrophysical Journal
Sivakoff G
(2008)
A Transient Black Hole Low-Mass X-Ray Binary Candidate in Centaurus A
in The Astrophysical Journal
Soldi S
(2008)
The multiwavelength variability of 3C 273
in Astronomy & Astrophysics
Soria R
(2006)
An ultraluminous X-ray microquasar in NGC 5408?
in Monthly Notices of the Royal Astronomical Society
Steeghs D
(2007)
Dynamical Constraints on the Component Masses of the Cataclysmic Variable WZ Sagittae
in The Astrophysical Journal
Summons D
(2007)
Timing evidence in determining the accretion state of the Seyfert galaxy NGC 3783
in Monthly Notices of the Royal Astronomical Society
Tomsick J
(2008)
Broadband X-Ray Spectra of GX 339-4 and the Geometry of Accreting Black Holes in the Hard State
in The Astrophysical Journal
Tudose V
(2008)
A decade of radio imaging the relativistic outflow in the peculiar X-ray binary Circinus X-1
in Monthly Notices of the Royal Astronomical Society
Tudose V
(2006)
The large-scale jet-powered radio nebula of Circinus X-1
in Monthly Notices of the Royal Astronomical Society
Tudose V
(2007)
First e-VLBI observations of Cygnus X-3
in Monthly Notices of the Royal Astronomical Society: Letters
Türler M
(2006)
A historic jet-emission minimum reveals hidden spectral features in 3C 273
in Astronomy & Astrophysics
Villata M
(2006)
The unprecedented optical outburst of the quasar 3C 454.3 The WEBT campaign of 2004-2005
in Astronomy & Astrophysics
Walter R
(2006)
XMM-Newton and INTEGRAL observations of new absorbed supergiant high-mass X-ray binaries
in Astronomy & Astrophysics
Wang Y
(2008)
Cosmological evolution of the Fanaroff-Riley type II source population
in Monthly Notices of the Royal Astronomical Society
Wesson R
(2008)
A Planetary Nebula around Nova V458 Vulpeculae Undergoing Flash Ionization
in The Astrophysical Journal
Wijnands R
(2006)
The XMM-Newton / Chandra monitoring campaign of the Galactic center region Description of the program and preliminary results
in Astronomy & Astrophysics
Witham A
(2008)
The IPHAS catalogue of Ha emission-line sources in the northern Galactic plane
in Monthly Notices of the Royal Astronomical Society
Witham A
(2007)
Newly discovered cataclysmic variables from the INT/WFC photometric Ha survey of the northern Galactic plane Newly discovered CVs from IPHAS
in Monthly Notices of the Royal Astronomical Society
Witham A
(2006)
The properties of cataclysmic variables in photometric Ha surveys Properties of CVs in Ha surveys
in Monthly Notices of the Royal Astronomical Society
Worrall D
(2008)
Where Centaurus A Gets Its X-Ray Knottiness
in The Astrophysical Journal
Yu W
(2007)
Peak Luminosities of the Hard States of GX 339-4: Implications for the Accretion Geometry, Disk Mass, and Black Hole Mass
in The Astrophysical Journal