Hu, Haili, Nelemans, Gijs, Aerts, Conny, Dupret, Marc-Antoine
Realistic stellar models are essential to the forward modelling approach in asteroseismology. For practicality however, certain model assumptions are also required. For example, in the case of...
A census of AM CVn stars: three new candidates and one confirmed 48.3-minute binary (2009)
Rau, Arne, Roelofs, Gijs H. A., Groot, Paul J., Marsh, Tom R., Nelemans, Gijs, Steeghs, Danny, ...
We present three new candidate AM CVn binaries, plus one confirmed new system, from a spectroscopic survey of color-selected objects from the Sloan Digital Sky Survey. All four systems were found...
The influence of short term variations in AM CVn systems on LISA measurements (2009)
Stroeer, Alexander, Nelemans, Gijs
We study the effect of short term variations of the evolution of AM CVn systems on their gravitational wave emissions and in particular LISA observations. We model the systems according to their...
RAT J1953+1859: a dwarf nova discovered through high amplitude QPOs in quiescence (2009)
Ramsay, Gavin, Hakala, Pasi, Barclay, Thomas, Wheatley, Peter, Marshall, George, Lehto, Harry, ...
We report the discovery of an accreting binary, RAT J1953+1859, made during the RApid Temporal Survey (RATS) on the Isaac Newton Telescope. It showed high amplitude (0.3 mag) quasi-periodic...
Nelemans, Gijs, Voss, Rasmus, Roelofs, Gijs, Bassa, Cees
We present HST/WFPC2, GALEX and Chandra observations of the position of the type Ia supernova SN2007sr in the Antennae galaxies, taken before the explosion. No source is found in any of the...
Discovery of the progenitor of the type Ia supernova 2007on (2008)
Type Ia supernovae are exploding stars that are used to measure the accelerated expansion of the Universe and are responsible for most of the iron ever produced. Although there is general agreement...
On the detection of the progenitor of the type Ia supernova 2007on (2008)
Roelofs, Gijs, Bassa, Cees, Voss, Rasmus, Nelemans, Gijs
We present new Chandra X-ray observations and detailed astrometry of the field of the type Ia supernova 2007on, for which the detection of a likely progenitor in archival Chandra data was recently...
Hydrogen deficient donors in low-mass X-ray binaries (2007)
A number of X-ray binaries (neutron stars or black holes accreting from a companion star) have such short orbital periods that ordinary, hydrogen rich, stars do not fit in. Instead the mass-losing...
Faint Thermonuclear Supernovae from AM Canum Venaticorum Binaries (2007)
Bildsten, Lars, Shen, Ken J., Weinberg, Nevin N., Nelemans, Gijs
Helium that accretes onto a Carbon/Oxygen white dwarf in the double white dwarf AM Canum Venaticorum (AM CVn) binaries undergoes unstable thermonuclear flashes when the orbital period is in the...
XMM-Newton observations of AM CVn binaries: V396 Hya & SDSS J1240-01 (2006)
Ramsay, Gavin, Groot, Paul J., Marsh, Tom, Nelemans, Gijs, Steeghs, Danny, Hakala, Pasi
We present the results of XMM-Newton observations of two AM CVn systems - V396 Hya and SDSS J1240-01. Both systems are detected in X-rays and in the UV: neither shows coherent variability in their...
The Thermal State of the Accreting White Dwarf in AM Canum Venaticorum Binaries (2005)
Bildsten, Lars, Townsley, Dean M., Deloye, Christopher J., Nelemans, Gijs
We calculate the heating and cooling of the accreting white dwarf (WD) in the ultracompact AM Canum Venaticorum (AM CVn) binaries and show that the WD can contribute significantly to their optical...
Cygnus X-3 and the problem of the missing Wolf-Rayet X-ray binaries (2005)
Lommen, Dave, Yungelson, Lev, Heuvel, Ed Van Den, Nelemans, Gijs, Zwart, Simon Portegies
Cygnus X-3 is a strong X-ray source (L_X about 10^38 erg/s) which is thought to consist of a compact object, accreting matter from a helium star. We find analytically that the estimated ranges of...
XMM-Newton observations of AM CVn binaries (2005)
Ramsay, Gavin, Hakala, Pasi, Marsh, Tom, Nelemans, Gijs, Steeghs, Danny, Cropper, Mark
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 light curves show no...
The White Dwarf -- White Dwarf galactic background in the LISA data (2005)
Edlund, Jeffrey A., Tinto, Massimo, Krolak, Andrzej, Nelemans, Gijs
LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic...
Simulation of the White Dwarf -- White Dwarf galactic background in the LISA data (2005)
Edlund, Jeffrey A., Tinto, Massimo, Królak, Andrzej, Nelemans, Gijs
LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic...
Arbitrarily Degenerate Helium White Dwarfs as Donors in AM CVn Binaries (2005)
Deloye, Christopher J., Bildsten, Lars, Nelemans, Gijs
We apply the Deloye & Bildsten (2003) isentropic models for donors in ultracompact low-mass X-ray binaries to the AM CVn population of ultracompact, interacting binaries. The mass-radius relations of...
Optical spectroscopy of (candidate) ultra-compact X-ray binaries (2004)
We present (preliminary) results of our systematic spectroscopic study of (candidate) ultra-compact X-ray binaries. Most candidates are confirmed and we found the first optical spectra of (pure)...
I review our observational and theoretical knowledge of AM CVn stars, focusing on recent developments. These include newly discovered systems, the possibility that two recently discovered extremely...
The Quiescent Spectrum of the AM CVn star CP Eri (2001)
Groot, Paul J., Nelemans, Gijs, Steeghs, Danny, Marsh, Tom
We used the 6.5m MMT to obtain a spectrum of the AM CVn star CP Eri in quiescence. The spectrum is dominated by He I emission lines, which are clearly double peaked with a peak-to-peak separation of...
The population of close double white dwarfs in the Galaxy (2000)
Yungelson, Lev, Nelemans, Gijs, Zwart, Simon. F. Portegies, Verbunt, Frank
We present a new model for the Galactic population of close double white dwarfs. The model accounts for the suggestion of the avoidance of a substantial spiral-in during mass transfer between a giant...
Population synthesis for double white dwarfs I.Close detached systems (2000)
Nelemans, Gijs, Yungelson, Lev R., Zwart, Simon F. Portegies, Verbunt, Frank
We model the population of double white dwarfs in the Galaxy and find a better agreement with observations compared to earlier studies, due to two modifications. The first is the treatment of the...
Reconstructing the evolution of double helium white dwarfs: envelope loss without spiral-in (2000)
Nelemans, Gijs, Verbunt, Frank, Yungelson, Lev R., Zwart, Simon F. Portegies
The unique core-mass - radius relation for giants with degenerate helium cores enables us to reconstruct the evolution of three observed double helium white dwarfs with known masses of both...