Analysis of Ultracompact X-Ray Binary Source 4U-1916
Faculty Mentor Name
Pragati Pradhan
Format Preference
Poster
Abstract
Ultracompact X-ray binary systems are a rare type of low mass X-ray binary system consisting of a low mass donor star and an accretor, which is typically a neutron star or black hole. The donor star transfers mass to the accretor, forming an accretion disk that contains the heated gases of the donor star. These heated gases are responsible for emitting the X-rays as they become accelerated through the accretion disk. Ultracompact X-ray binary systems are characterized as having relatively short orbital periods, usually less than an hour. The goal of this project is to examine the mass transfer between donor and accretor for several UCXB systems. The overarching drive behind this project questions how mass transfer varies with orbital period and mass ratio between the compact objects, and how accurate are current models for UCXB mass transfer parameters. Thus far 4U-1916, which is an ultracompact X-ray binary system that has been shown to experience noticeable periodic dips in X-ray emission, has been analyzed thoroughly. These dips are aligned with the orbital period of the system, which is about 50 minutes and are caused by the obstruction of the central source of the X-rays via an object that is located within the accretion disk of the neutron star. This system has been observed using both the Chandra and NuSTAR X-ray telescopes. Using data from the observations of the NuSTAR telescope, the lightcurve and spectral curve of the system have been extracted and analyzed. Moving forward, additional sources will be examined with data collected by the NuStar telescope. Ultimately, this data from several sources will be compiled to evaluate the validity of current models for mass transfer within UCXBs.
Analysis of Ultracompact X-Ray Binary Source 4U-1916
Ultracompact X-ray binary systems are a rare type of low mass X-ray binary system consisting of a low mass donor star and an accretor, which is typically a neutron star or black hole. The donor star transfers mass to the accretor, forming an accretion disk that contains the heated gases of the donor star. These heated gases are responsible for emitting the X-rays as they become accelerated through the accretion disk. Ultracompact X-ray binary systems are characterized as having relatively short orbital periods, usually less than an hour. The goal of this project is to examine the mass transfer between donor and accretor for several UCXB systems. The overarching drive behind this project questions how mass transfer varies with orbital period and mass ratio between the compact objects, and how accurate are current models for UCXB mass transfer parameters. Thus far 4U-1916, which is an ultracompact X-ray binary system that has been shown to experience noticeable periodic dips in X-ray emission, has been analyzed thoroughly. These dips are aligned with the orbital period of the system, which is about 50 minutes and are caused by the obstruction of the central source of the X-rays via an object that is located within the accretion disk of the neutron star. This system has been observed using both the Chandra and NuSTAR X-ray telescopes. Using data from the observations of the NuSTAR telescope, the lightcurve and spectral curve of the system have been extracted and analyzed. Moving forward, additional sources will be examined with data collected by the NuStar telescope. Ultimately, this data from several sources will be compiled to evaluate the validity of current models for mass transfer within UCXBs.