Publications (96)
The star-forming environment of a ULX in NGC 4559: an optical study
Roberto Soria, Mark Cropper, Manfred Pakull +2
We have studied the candidate optical counterparts and the stellar population in the star-forming complex around a bright ULX in NGC4559, using HST/WFPC2, XMM-Newton/OM, and ground…
Galactic Bar Resonances Inferred from Kinematically Hot Stars in Gaia EDR3
Daisuke Kawata, Junichi Baba, Jason A. S. Hunt +5
Using a numerical simulation of an isolated barred disc galaxy, we first demonstrate that the resonances of the inner bar structure induce more prominent features in the action spa…
Twisted accretion curtains in the intermediate polar FO Aquarii
P. A. Evans, Coel Hellier, Gavin Ramsay +1
We report on a ~37-ks XMM-Newton observation of the intermediate polar FO Aquarii, presenting X-ray and UV data from the EPIC and OM cameras. We find that the system has changed fr…
The optical counterpart of the double degenerate polar RX J1914+24
Gavin Ramsay, Mark Cropper, Keith Mason +1
Cropper et al 1998 presented X-ray observations of RX J1914+24 and claimed that the most likely interpretation of their data was that of a double degenerate Polar. Here we show the…
On the shear estimation bias induced by the spatial variation of colour across galaxy profiles
Elisabetta Semboloni, Henk Hoekstra, Zhuoyi Huang +13
The spatial variation of the colour of a galaxy may introduce a bias in the measurement of its shape if the PSF profile depends on wavelength. We study how this bias depends on the…
Classifying the zoo of ultraluminous X-ray sources
Roberto Soria, Mark Cropper, Christian Motch
Ultraluminous X-ray sources (ULXs) are likely to include different physical types of objects. We discuss some possible subclasses, reviewing the properties of a sample of ULXs rece…
XMM-Newton observations of the ultra-compact binary RX J1914+24
Gavin Ramsay, Pasi Hakala, Kinwah Wu +4
We present XMM-Newton observations of the 569 sec period system RX J1914+24 (V407 Vul). This period is believed to represent the binary orbital period making it an ultra-compact bi…
Optical and Infrared Signatures of ULX's
Christopher Copperwheat, Mark Cropper, Roberto Soria +1
We have constructed a model to describe the optical emission from ultra-luminous X-ray sources (ULXs). We assume a binary model with a black hole accreting matter from a Roche lobe…
First XMM-Newton observations of strongly magnetic cataclysmic variables - II. Timing studies of DP Leo and WW Hor
Dirk Pandel, France A. Cordova, Robert E. Shirey +5
XMM-Newton was used to observe two eclipsing, magnetic cataclysmic variables, DP Leo and WW Hor, continuously for three orbital cycles each. Both systems were in an intermediate st…
Ionisation Structure in Accretion Shocks with a Composite Cooling Function
Kinwah Wu, Mark Cropper, Gavin Ramsay
We have investigated the ionisation structure of the post-shock regions of magnetic cataclysmic variables using an analytic density and temperature structure model in which effects…
Spiral and bar driven peculiar velocities in Milky Way sized galaxy simulations
Robert J. J. Grand, Jo Bovy, Daisuke Kawata +5
We investigate the kinematic signatures induced by spiral and bar structure in a set of simulations of Milky Way-sized spiral disc galaxies. The set includes test particle simulati…
An electrically powered binary star?
Kinwah Wu, Mark Cropper, Gavin Ramsay +1
We propose a model for stellar binary systems consisting of a magnetic and a non-magnetic white-dwarf pair which is powered principally by electrical energy. In our model the lumin…
The vertical metallicity gradients of mono-age stellar populations in the Milky Way with the RAVE and Gaia data
Ioana CiucÄ, Daisuke Kawata, Jane Lin +3
We investigate the vertical metallicity gradients of five mono-age stellar populations between 0 and 11 Gyr for a sample of 18 435 dwarf stars selected from the cross-matched Tycho…
The Milky Way's halo in 6D: Gaia's Radial Velocity Spectrometer performance
George Seabroke, Mark Cropper, David Katz +9
Gaia's Radial Velocity Spectrometer (RVS) has been operating in routine phase for over one year since initial commissioning. RVS continues to work well but the higher than expected…
How well can Charge Transfer Inefficiency be corrected? A parameter sensitivity study for iterative correction
Holger Israel, Richard Massey, Thibaut Prod'homme +9
Radiation damage to space-based Charge-Coupled Device (CCD) detectors creates defects which result in an increasing Charge Transfer Inefficiency (CTI) that causes spurious image tr…
First X-ray observations of the polar CE Gru
Gavin Ramsay, Mark Cropper
We report the detection of the polar CE Gru in X-rays for the first time. We find evidence for a dip seen in the hard X-ray light curve which we attribute to the accretion stream o…
A ULX in NGC 4559: a "mini-cartwheel" scenario?
Roberto Soria, Mark Cropper, Manfred Pakull
We have studied an ultraluminous X-ray source (ULX) in NGC 4559 with XMM-Newton, and its peculiar star-forming environment with HST/WFPC2. The X-ray source is one of the brightest…
RVS Spectra of Gaia Photometric Science Alerts
George Seabroke, Mark Cropper, Steven Baker +8
Gaia Photometric Science Alerts (GPSA) publishes Gaia G magnitudes and Blue Photometer (BP) and Red Photometer (RP) low-resolution epoch spectra of transient events. 27 high-resolu…
VIS: the visible imager for Euclid
Mark Cropper, R. Cole, A. James +25
Euclid-VIS is a large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled for launch in 2019. Together with the near infrared imaging w…
Accretion in dipole magnetic fields: flow structure and X-ray emission of accreting white dwarfs
Joao B. G. Canalle, Curtis J. Saxton, Kinwah Wu +2
Field-channelled accretion flows occur in a variety of astrophysical objects, including T Tauri stars,magnetic cataclysmic variables and X-ray pulsars. We consider a curvilinear co…
Could the Galactic disk heating be due to Globular Cluster impacts?
D. Vande Putte, Mark Cropper, Ignacio Ferreras
So far, six mechanisms have been proposed to account for the Galactic disk heating. Of these, the most important appear to be a combination of scattering of stars by molecular clou…
Modelling the spin pulse profile of the isolated neutron star RX J0720.4--3125 observed with XMM-Newton
Mark Cropper, Silvia Zane, Gavin Ramsay +2
We model the spin pulse intensity and hardness ratio profiles of the isolated neutron star RXJ0720.4--3125 using XMM-Newton data. The observed variation is approximately sinusoidal…
Timing analysis of the isolated neutron star RX J0720.4-3125
Silvia Zane, Frank Haberl, Mark Cropper +4
We present a combined analysis of XMM-Newton, Chandra and Rosat observations of the isolated neutron star RXJ0720.4-3125, spanning a total period of \sim 7 years. We develop a maxi…
Probable intermediate mass black holes in NGC4559: XMM-Newton spectral and timing constraints
Mark Cropper, Roberto Soria, Richard F. Mushotzky +3
We have examined X-ray and optical observations of two ultra-luminous X-ray sources, X7 and X10 in NGC4559, using XMM-Newton, Chandra and HST. The UV/X-ray luminosity of X7 exceeds…
Impact of radial migration on stellar and gas radial metallicity distribution
Robert J. J. Grand, Daisuke Kawata, Mark Cropper
Radial migration is defined as the change in guiding centre radius of stars and gas caused by gains or losses of angular momentum that result from gravitational interaction with no…
Orbits of radial migrators and non-migrators around a spiral arm in N-body simulations
Robert J. J. Grand, Daisuke Kawata, Mark Cropper
Recent numerical N-body simulations of spiral galaxies have shown that spiral arms in N-body simulations seem to rotate at a similar speed to the local rotation speed of the stella…
Stellar dynamics around transient co-rotating spiral arms
Daisuke Kawata, Robert J. J. Grand, Mark Cropper
Spiral density wave theory attempts to describe the spiral pattern in spiral galaxies in terms of a long-lived wave structure with a constant pattern speed in order to avoid the wi…
Effects of Gravity on the Structure of Postshock Accretion Flows in Magnetic Cataclysmic Variables
Mark Cropper, Kinwah Wu, Gavin Ramsay +1
We have calculated the temperature and density structure of the hot postshock plasma in magnetically confined accretion flows, including the gravitational potential. This avoids th…
The Emission from Post-Shock Flows in mCVs
Mark Cropper, Kinwah Wu, Gavin Ramsay
We re-examine the vertical structure of the post-shock flow in the accretion region of mCVs, and the X-ray emission as a function of height. We then predict X-ray light curves and…
RX J2115--5840: confirmation of a new near-synchronous polar
Gavin Ramsay, David A. H. Buckley, Mark Cropper +1
Following the suggestion of Schwope et al that the magnetic cataclysmic variable RX J2115-5840 maybe a near-synchronous polar, we obtained optical polarimetry of this system over a…
Measuring a Charge-Coupled Device Point Spread Function: Euclid Visible Instrument CCD273-84 PSF Performance
Sami-Matias Niemi, Mark Cropper, Magdalena Szafraniec +1
In this paper we present the testing of a back-illuminated development Euclid Visible Instrument (VIS) Charge-Coupled Device (CCD) to measure the intrinsic CCD Point Spread Functio…
XMM-Newton observations of the polars EV UMa, RX J1002-19 and RX J1007-20
Gavin Ramsay, Mark Cropper
We present XMM-Newton data of three strongly magnetic cataclysmic variables (polars) EV UMa, RX J1002-19 and RX J1007-20. These include the polar with the shortest orbital period (…
The focal plane instrumentation for the DUNE mission
Jeff Booth, Mark Cropper, Frank Eisenhauer +2
DUNE (Dark Universe Explorer) is a proposed mission to measure parameters of dark energy using weak gravitational lensing The particular challenges of both optical and infrared foc…
Accretion Flow Along a Dipolar Field: Application to Intermediate Polars
J. B. G. Canalle, Kinwah Wu, Mark Cropper +2
A hydrodynamic formulation for accretion flow channeled by a dipolar magnetic field is constructed using a curvi-linear coordinate system natural to the field structure. We solve t…
A Concept for an STJ-based Spectrograph
Mark Cropper, M. Barlow, M. A. C. Perryman +8
We describe a multi-order spectrograph concept suitable for 8m-class telescopes, using the intrinsic spectral resolution of Superconducting Tunneling Junction detectors to sort the…
XMM-Newton observations of the eclipsing polar V2301 Oph
Gavin Ramsay, Mark Cropper
We present XMM-Newton observations of the eclipsing polar V2301 Oph which cover nearly 2.5 binary orbital cycles and 2 eclipses. This polar is believed to have the lowest magnetic…
The energy balance in polars revisited
Gavin Ramsay, Mark Cropper
In the EXOSAT and ROSAT eras a significant number of polars were found to show a soft/hard X-ray ratio much greater than that expected from the standard accretion shock model. This…
Timing Analysis of the Isolated Neutron Star RX J0720.4-3125 Revisited
Mark Cropper, Frank Haberl, Silvia Zane +1
We present a reanalysis of the X-ray data for RX J0720.4-3125 presented in Zane et al. (2002), using more data recently available from XMM-Newton and Chandra. This analysis also co…
Radial Distribution of Stellar Motions in Gaia DR2
Daisuke Kawata, Junichi Baba, Ioana CiucÄ +4
By taking advantage of the superb measurements of position and velocity for an unprecedented large number of stars provided in Gaia DR2, we have generated the first maps of the rot…
Accretion stream mapping with genetically modified "fire-flies"
C. M. Bridge, Pasi Hakala, Mark Cropper +1
We apply an eclipse mapping technique using `genetically modified fire-flies' to the eclipse light curves of HU Aqr and EP Dra. The technique makes as few assumptions as possible a…
XMM-Newton observations of polars in low accretion states
Gavin Ramsay, Mark Cropper, Kinwah Wu +3
We have made a series of snap-shot observations of 37 polars using XMM-Newton. We found that 16 of these systems were in a low, or much reduced, accretion state. Of those, 6 were n…
First XMM-Newton observations of an isolated neutron star: RXJ0720.4-3125
Frits Paerels, Christian Motch, Frank Haberl +5
We present the high resolution spectrum of the isolated neutron star RXJ0720.4-3125, obtained with the Reflection Grating Spectrometer on XMM-Newton, complemented with the broad ba…
XMM-Newton observations of the eclipsing polar EP Dra
Gavin Ramsay, C. M. Bridge, Mark Cropper +3
We present XMM-Newton observations of the eclipsing polar EP Dra which cover nearly 3 binary orbital cycles. The X-ray and UV data show evidence for a prominent dip before the ecli…
Continuum and line emission from post-shockc flows
Mark Cropper, Kinwah Wu, Gavin Ramsay
The post-shock flow in the accretion region of MCVs is considered to be a magnetically confined cooling flow. The X-ray spectrum from this hot plasma is emitted from a range of tem…
XMM-Newton observations of three short period polars: V347 Pav, GG Leo and EU UMa
Gavin Ramsay, Mark Cropper, K. O. Mason +2
We present phase-resolved XMM_Newton data of three short period polars: V347 Pav, GG Leo and EU UMa. All three systems show one dominant accretion region which is seen for approxim…
Detection of Pulsed X-ray Emission from XMM-Newton Observations of PSR J0538+2817
Katherine E. McGowan, Jamie A. Kennea, Silvia Zane +5
We report on the XMM-Newton observations of the 143 ms pulsar PSR J0538+2817. We present evidence for the first detections of pulsed X-rays from the source at a frequency which is…
Indirect imaging of the accretion stream in HU Aquarii
M K Harrop-Allin, Mark Cropper, P Hakala +2
We apply our technique for indirect imaging of the accretion stream to UBVR eclipse profiles of HU Aqr obtained when the system was in a high state. We perform model fits to the ec…
Timing study of the isolated neutron star RX J0720.4-3125
Silvia Zane, Frank Haberl, Mark Cropper +4
We present a combined analysis of XMM-Newton, Chandra and Rosat observations of the isolated neutron star RX J0720.4-3125, spanning a total period of \sim 7 years. We develop a max…
XMM-Newton observations of AM CVn binaries
Gavin Ramsay, Pasi Hakala, Tom Marsh +3
We present the results of XMM-Newton observations of four AM CVn systems -- AM CVn, CR Boo, HP Lib and GP Com. Their light curves show very different characteristics. The X-ray lig…
Tracking radiation damage of Euclid VIS detectors after 1 year in space
Jesper Skottfelt, Matt Wander, Mark Cropper +13
Due to the space radiation environment at L2, ESA's Euclid mission will be subject to a large amount of highly energetic particles over its lifetime. These particles can cause dama…
New short period stellar pulsators at large Galactocentric distances
Gavin Ramsay, Ralf Napiwotzki, Thomas Barclay +3
We report the discovery of 31 blue, short period, pulsators made using data taken as part of the Rapid Temporal Survey (RATS). We find they have periods between 51-83 mins and full…
Astro2020 Activity, Project of State of the Profession Consideration (APC) White Paper: All-Sky Near Infrared Space Astrometry. State of the Profession Considerations: Development of Scanning NIR Detectors for Astronomy
David Hobbs, Christopher Leitz, Jo Bartlett +11
Gaia is a revolutionary space mission developed by ESA and is delivering 5 parameter astrometry, photometry and radial velocities over the whole sky with astrometric accuracies dow…
Indirect imaging of the accretion stream in eclipsing polars IV: V895 Cen
Nikita Salvi, Gavin Ramsay, Mark Cropper +2
We present spectroscopic and high speed photometric data of the eclipsing polar V895 Cen. We find that the eclipsed component is consistent with it being the accretion regions on t…
The GOSSIP on the MCV V347 Pav
S. B. Potter, Mark Cropper, Pasi Hakala
Modelling of the polarized cyclotron emission from magnetic cataclysmic variables (MCVs) has been a powerful technique for determining the structure of the accretion zones on the w…
Probing the Pulsar Wind Nebula of PSR B0355+54
Katherine E. McGowan, W. Tom Vestrand, Jamie A. Kennea +3
We present XMM-Newton and Chandra X-ray observations of the middle-aged radio pulsar PSR B0355+54. Our X-ray observations reveal emission not only from the pulsar itself, but also…
Origins of weak lensing systematics, and requirements on future instrumentation (or knowledge of instrumentation)
Richard Massey, Henk Hoekstra, Thomas Kitching +11
The first half of this paper explores the origin of systematic biases in the measurement of weak gravitational lensing. Compared to previous work, we expand the investigation of PS…
Detection of the optical counterpart of the proposed double degenerate polar RX J1914+24
Gavin Ramsay, Mark Cropper, Kinwah Wu +2
We have detected the optical counterpart of the proposed double degenerate polar RX J1914+24. The I band light curve is modulated on the 9.5 min period seen in X-rays. There is no…
Spin up in RX J0806+15 - the shortest period binary
Pasi Hakala, Gavin Ramsay, Kinwah Wu +4
RX J0806+15 has recently been identified as the binary system with the shortest known orbital period. We present a series of observations of RX J0806+15 including new optical obser…
XMM-Newton observations of the asynchronous polar BY Cam
Gavin Ramsay, Mark Cropper
We report observations of the asynchronous polar BY Cam made using XMM-Newton. We find evidence for two accretion regions which have significantly different spectra. In both region…
The Rotation-Metallicity Relation for the Galactic Disk as Measured in the Gaia DR1 TGAS and APOGEE Data
Carlos Allende Prieto, Daisuke Kawata, Mark Cropper
Previous studies have found that the Galactic rotation velocity-metallicity (V-[Fe/H]) relations for the thin and thick disk populations show negative and positive slopes, respecti…
Gas and Stellar Motions and Observational Signatures of Co-Rotating Spiral Arms
Daisuke Kawata, Jason A. S. Hunt, Robert J. J. Grand +2
We have observed a snapshot of our N-body/Smoothed Particle Hydrodynamics simulation of a Milky Way-sized barred spiral galaxy in a similar way to how we can observe the Milky Way.…
Stream eclipse mapping with 'fire-flies'
C. M. Bridge, Pasi Hakala, Mark Cropper +1
We apply a new method of eclipse mapping to the light curves of eclipsing polars. The technique aims to locate the bright emission associated with the accretion stream, using a tec…
The stellar kinematics of co-rotating spiral arms in Gaia mock observations
Jason A. S. Hunt, Daisuke Kawata, Robert J. J. Grand +3
We have observed an N-body/Smoothed Particle Hydrodynamics simulation of a Milky Way like barred spiral galaxy. We present a simple method that samples N-body model particles into…
An improved model of Charge Transfer Inefficiency and correction algorithm for the Hubble Space Telescope
Richard Massey, Tim Schrabback, Oliver Cordes +7
Charge-Coupled Device (CCD) detectors, widely used to obtain digital imaging, can be damaged by high energy radiation. Degraded images appear blurred, because of an effect known as…
Evidence for surface cooling emission in the XMM-Newton spectrum of the X-ray pulsar PSR B2334+61
Katherine E. McGowan, Silvia Zane, Mark Cropper +2
We report on the first XMM-Newton observation of the Vela-like pulsar PSR B2334+61. Spectral analysis reveals soft X-ray emission, with the bulk of the photons emitted at energies…
The dynamics of stars around spiral arms
Robert J. J. Grand, Daisuke Kawata, Mark Cropper
Spiral density wave theory attempts to describe the spiral pattern in spiral galaxies in terms of a long-lived wave structure with a constant pattern speed in order to avoid the wi…
Cosmology and Fundamental Physics with the Euclid Satellite
Luca Amendola, Stephen Appleby, Anastasios Avgoustidis +69
Euclid is a European Space Agency medium class mission selected for launch in 2020 within the Cosmic Vision 2015 2025 program. The main goal of Euclid is to understand the origin o…
On Weak Lensing Shape Noise
Sami-Matias Niemi, Thomas Kitching, Mark Cropper
One of the most powerful techniques to study the dark sector of the Universe is weak gravitational lensing. In practice, to infer the reduced shear, weak lensing measures galaxy sh…
The XMM-Newton-MSSL survey of Polars
Gavin Ramsay, Mark Cropper
The XMM-Newton-MSSL survey of polars is a snapshot survey of nearly 40 polars. We present the initial results, with an emphasis on the energy balance in these systems and the numbe…
XMM-Newton Observations of PSR B1706-44
Katherine E. McGowan, Silvia Zane, Mark Cropper +5
We report on the XMM-Newton observations of the young, 102 ms pulsar PSR B1706-44. We have found that both a blackbody plus power-law and a magnetized atmospheric model plus power-…
RX J2115-5840: confirmation of a new near-synchronous polar
Gavin Ramsay, David Buckley, Mark Cropper +1
Schwope et al (1997) suggested that the newly discovered Polar RX J2115-5840 is a near-synchronous system. We have obtained circular polarisation observations of RX J2115-5840 whic…
Dynamics of stars around spiral arms in an N-body/SPH simulated barred-spiral galaxy
Robert J. J. Grand, Daisuke Kawata, Mark Cropper
We run N-body smoothed particle hydrodynamics (SPH) simulations of a Milky Way sized galaxy. The code takes into account hydrodynamics, self-gravity, star formation, supernova and…
On the Nature of Ultra-Luminous X-ray Sources from Optical/IR Measurements
Mark Cropper, Christopher Copperwheat, Kinwah Wu +1
We present a model for the prediction of the optical/infra-red emission from ULXs. In the model, ULXs are binary systems with accretion taking place through Roche lobe overflow. We…
X-ray Spectroscopy of the IP PQ Gem
Cynthia H. James, Gavin Ramsay, Mark Cropper +1
Using RXTE and ASCA data, we investigate the roles played by occultation and absorption in the X-ray spin pulse profile of the Intermediate Polar PQ Gem. From the X-ray light curve…
XMM-Newton and Chandra observations of the ultra-compact binary RX J1914+24
Gavin Ramsay, Mark Cropper, Pasi Hakala
The nature of the X-ray source RX J1914+24 has been the subject of much debate. It shows a prominent period of 569 sec in X-rays and the optical/infra-red: in most models this has…
Variability of the Accretion Stream in the Eclipsing Polar EP Dra
C. M. Bridge, Mark Cropper, Gavin Ramsay +3
We present the first high time resolution light curves for six eclipses of the magnetic cataclysmic variable EP Dra, taken using the superconducting tunnel junction imager S-Cam2.…
The Swift/UVOT catalogue of NGC4321 star forming sources: A case against density wave theory
Ignacio Ferreras, Mark Cropper, Daisuke Kawata +2
We study the star forming regions in the spiral galaxy NGC4321, taking advantage of the spatial resolution (2.5 arcsec FWHM) of the Swift/UVOT camera and the availability of three…
The Gaia Spectroscopic Instrument (RVS): A Technical Challenge
Mark Cropper, David Katz
The lack of radial velocity data in the Hipparcos catalogue was considered a significant deficiency, so when Gaia was conceived, a spectrometer was a core constituent of its payloa…
Quasi-Periodic Variability in NGC 5408 X-1
Tod E. Strohmayer, Richard F. Mushotzky, Lisa Winter +3
We report the discovery with XMM-Newton of quasiperiodic variability in the 0.2 - 10 keV X-ray flux from the ultraluminous X-ray source NGC 5408 X-1. The average power spectrum of…
Projected XMM Vision for MCVs
Cynthia H. James, Graziella Branduardi-Raymont, Mark Cropper
The XMM satellite has a scientific payload of 3 EPIC and 2 RGS instruments which provide for both imaging and non-dispersive spectroscopy as well as medium-to-high resolution dispe…
Transformational astrophysics and exoplanet science with Habitable Worlds Observatory's High Resolution Imager
Vincent Van Eylen, Richard Massey, Saeeda Awan +167
Habitable Worlds Observatory (HWO) will be NASA's flagship space telescope of the 2040s, designed to search for life on other planets and to transform broad areas of astrophysics.…
Multi-epoch spectroscopy and XMM-Newton observations of RX J2115-58
Mark Cropper, Gavin Ramsay, Tom Marsh
We present phase resolved optical spectroscopy and X-ray light curves of the asynchronous polar RX J2115-58 as they change on the beat period.
STJ Observations of the Eclipsing Polar HU Aqr
C. M. Bridge, Mark Cropper, Gavin Ramsay +6
We apply an eclipse mapping technique to observations of the eclipsing magnetic cataclysmic variable HU Aqr. The observations were made with the S-Cam2 Superconducting Tunnel Junct…
On the pressure equilibrium and timescales in the scale free convection theory
Stefano Pasetto, Cesare Chiosi, Mark Cropper +2
Convection is one of the fundamental energy transport processes in physics and astrophysics, and its description is central to allstellar models. In the context of stellar astrophy…
Cosmology and fundamental physics with the Euclid satellite
Luca Amendola, Stephen Appleby, David Bacon +60
Euclid is a European Space Agency medium class mission selected for launch in 2019 within the Cosmic Vision 2015-2025 programme. The main goal of Euclid is to understand the origin…
Two-temperature accretion flows in magnetic cataclysmic variables: Structures of post-shock emission regions and X-ray spectroscopy
Curtis Saxton, Kinwah Wu, Mark Cropper +1
We use a two-temperature hydrodynamical formulation to determine the temperature and density structures of the post-shock accretion flows in magnetic cataclysmic variables (mCVs) a…
Defining a weak lensing experiment in space
Mark Cropper, Henk Hoekstra, Thomas Kitching +9
This paper describes the definition of a typical next-generation space-based weak gravitational lensing experiment. We first adopt a set of top-level science requirements from the…
The lower boundary of the accretion column in magnetic cataclysmic variables
Kinwah Wu, Mark Cropper
Using a parameterised function for the mass loss at the base of the post-shock region, we have constructed a formulation for magnetically confined accretion flows which avoids sing…
Detecting the effect of Globular Cluster impacts on the disk of the Milky Way
D. Vande Putte, Mark Cropper
The crossing of the Galactic disk by a Globular Cluster could produce star formation due to gravitational focussing or compression of disk material. We report on simulations of the…
The Euclid mission design
Giuseppe D Racca, Rene Laureijs, Luca Stagnaro +39
Euclid is a space-based optical/near-infrared survey mission of the European Space Agency (ESA) to investigate the nature of dark energy, dark matter and gravity by observing the g…
Spiral arm pitch angle and galactic shear rate in N-body simulations of disc galaxies
Robert J. J. Grand, Daisuke Kawata, Mark Cropper
Spiral galaxies are observed to exhibit a range of morphologies, in particular in the shape of spiral arms. A key diagnostic parameter is the pitch angle, which describes how tight…
X-ray emissions from two-temperature accretion flows within a dipole magnetic funnel
Curtis J. Saxton, Kinwah Wu, Joao. B. G. Canalle +2
We investigate the hydrodynamics of accretion channelled by a dipolar magnetic field (funnel flows). We consider situations in which the electrons and ions in the flow cannot maint…
Ultra-Short Period Double-Degenerate Binaries
Mark Cropper, Gavin Ramsay, Kinwah Wu +1
We review the current observational status of the ROSAT sources RX J1914.4+2456 and RX J0806.3+1527, and the evidence that these are ultra-short period (<10min) binary systems. We…
A kinematic study of Open Clusters: implications for their origin
D. Vande Putte, T. P. Garnier, Ignacio Ferreras +2
The Galactic population of open clusters provides an insight into star formation in the Galaxy. The open cluster catalogue by Dias et al.(2002b) is a rich source of data, including…
Simultaneous optical polarimetry and X-ray data of the near synchronous polar RX J2115-5840
Gavin Ramsay, Stephen Potter, Mark Cropper +2
We present simultaneous optical polarimetry and X-ray data of the near synchronous polar RX J2115-5840. We model the polarisation data using the Stokes imaging technique of Potter…
VIS: the visible imager for Euclid
Mark Cropper, S. Pottinger, S. Niemi +33
Euclid-VIS is the large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled for launch in 2020. Together with the near infrared imaging…