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
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
Knigge C
(2006)
A Blue Straggler Binary with Three Progenitors in the Core of a Globular Cluster?
in The Astrophysical Journal
Capitanio F
(2006)
Spectral States of the X-Ray Binary IGR J17091-3624 Observed by INTEGRAL and RXTE
in The Astrophysical Journal
Chatterjee R
(2008)
Correlated Multi-Wave Band Variability in the Blazar 3C 279 from 1996 to 2007
in The Astrophysical Journal
Boutloukos S
(2006)
Discovery of Twin kHz QPOs in the Peculiar X-Ray Binary Circinus X-1
in The Astrophysical Journal
Worrall D
(2008)
Where Centaurus A Gets Its X-Ray Knottiness
in The Astrophysical Journal
Bazzano A
(2006)
INTEGRAL IBIS Census of the Sky Beyond 100 keV
in The Astrophysical Journal
Evans D
(2008)
XMM-Newton Observations of the Nuclei of the Radio Galaxies 3C 305, DA 240, and 4C 73.08
in The Astrophysical Journal
Hardcastle M
(2007)
The Interaction between Radio Lobes and Hot Gas in the Nearby Radio Galaxies 3C 285 and 3C 442A
in The Astrophysical Journal
Miller J
(2006)
Simultaneous Chandra and RXTE Spectroscopy of the Microquasar H1743-322: Clues to Disk Wind and Jet Formation from a Variable Ionized Outflow
in The Astrophysical Journal
Knigge C
(2008)
Stellar Exotica in 47 Tucanae
in The Astrophysical Journal
Dieball A
(2007)
Unveiling the Core of the Globular Cluster M15 in the Ultraviolet
in The Astrophysical Journal
Marshall K
(2009)
MULTIWAVELENGTH VARIABILITY OF THE BROAD LINE RADIO GALAXY 3C 120
in The Astrophysical Journal
Sion E
(2008)
Hubble Space Telescope STIS Spectroscopy of Long-Period Dwarf Novae in Quiescence
in The Astrophysical Journal
Homan J
(2007)
Rossi X-Ray Timing Explorer Observations of the First Transient Z Source XTE J1701-462: Shedding New Light on Mass Accretion in Luminous Neutron Star X-Ray Binaries
in The Astrophysical Journal
Aharonian F
(2009)
DISCOVERY OF VERY HIGH ENERGY ?-RAY EMISSION FROM CENTAURUS A WITH H.E.S.S.
in The Astrophysical Journal
Kraft R
(2007)
A Radio through X-Ray Study of the Hot Spots, Active Nucleus, and Environment of the Nearby FR II Radio Galaxy 3C 33
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
Malizia A
(2007)
Swift XRT Observation of 34 New INTEGRAL IBIS AGNs: Discovery of Compton-Thick and Other Peculiar Sources
in The Astrophysical Journal
Sivakoff G
(2008)
A Transient Black Hole Low-Mass X-Ray Binary Candidate in Centaurus A
in The Astrophysical Journal
Hardcastle M
(2007)
New Results on Particle Acceleration in the Centaurus A Jet and Counterjet from a Deep Chandra Observation
in The Astrophysical Journal
Leigh N
(2008)
Erratum: "Where the Blue Stragglers Roam: Searching for a Link between Formation and Environment" ( ApJ, 661, 210 [2007] )
in The Astrophysical Journal
Hardcastle M
(2007)
A Chandra Study of Particle Acceleration in the Multiple Hot Spots of Nearby Radio Galaxies
in The Astrophysical Journal
Croston J
(2007)
Shock Heating in the Nearby Radio Galaxy NGC 3801
in The Astrophysical Journal
Leigh N
(2007)
Where the Blue Stragglers Roam: Searching for a Link between Formation and Environment
in The Astrophysical Journal