In X-ray binary systems, either a neutron star or a black hole accretes matter from an orbiting companion star. This accretion process often powers the launch of powerful, relativistic, collimated outflows, called jets. While this connection between inflow and outflow is observed in systems ranging from forming stars to AGN, jet formation remains poorly understood. Neutron stars in X-ray binaries offer a unique avenue to understand this process: as accreted material accumulates on the neutron star surface, it can cause bursts of X-ray emission through runaway thermonuclear burning. The thermonuclear bursts can cool the surrounding structures, such as the base of the jet. While these effects have been predicted from simulations, such a response of the jet to thermonuclear bursts has never been observed directly.Our team have scheduled Australia Telescope Compact Array (ATCA) radio observations of an accreting neutron star to search for a response of the jet (brightness and morphology) to thermonuclear bursts. We have arranged with the INTEGRAL team to set up a simultaneous X-ray observation, in order to measure when thermonuclear bursts occur, for which we put in this official ToO. Comparing the INTEGRAL burst times with the radio light curve, we will be able to test whether the jet responds by, for instance, briefly decreasing in power, or by changing its spectrum. It will also reveal possible time delays between the X-ray and radio band, probing the physical structure and size scales of the jet. The ATCA observations are planned for April 3, 4, and 5, overlapping exactly with revolution 2350 of INTEGRAL. On April 3, they start at 12.30 GMT, allowing for calibration before the start of the INTEGRAL revolution (at 13.18 GMT). The selected target is 4U 1728-34.
Primordial black hole dark matter in the context of extra dimensions - Friedlander, Avi, Mack, Katherine J.,Schon, Sarah,Song, Ningqiang,Vincent, Aaron C. (2022-05-01) http://ui.adsabs.harvard.edu/#abs/2022PhRvD.105j3508F
Searching for orbital period modulation in X-ray observations of the symbiotic X-ray binary GX 1+4 - Klawin, Moritz, Ducci, Lorenzo,Mirac Serim, M.,Santangelo, Andrea,Ferrigno, Carlo,Bozzo, Enrico (2024-12-01) http://ui.adsabs.harvard.edu/#abs/2024A&A...692A..19K
Thermonuclear explosions on neutron stars reveal the speed of their jets - Russell, Thomas D., Degenaar, Nathalie,van den Eijnden, Jakob,Maccarone, Thomas,Tetarenko, Alexandra J.,Sanchez-Fernandez, Celia,Miller-Jones, James C. A.,Kuulkers, Erik,Del Santo, Melania (2024-03-01) http://ui.adsabs.harvard.edu/#abs/2024Natur.627..763R
Temporal Coverage
2021-04-03T14:27:07Z / 2021-04-05T23:27:16Z
Version
1.0
Mission Description
The INTEGRAL (International Gamma-Ray Astrophysics Laboratory) mission, launched by the European Space Agency (ESA) on October 17, 2002, was designed to study high-energy phenomena in the universe. INTEGRAL was operating until february 2025 and it was equipped with three high-energy instruments: the Imager on Board the INTEGRAL Satellite (IBIS), the Spectrometer on INTEGRAL (SPI), and the JEM-X (Joint European Monitor for X-rays). Its Optical Monitoring Camera (OMC) provided optical V-band magnitude measurements, complementing the high-energy observations.
European Space Agency, van den Eijnden, 2025, 'INTEGRAL TOO observations of 4U 1728-34', 1.0, European Space Agency, https://doi.org/10.57780/esa-14c9x5e
