X-Ray Binaries as Flashlights to Map the Universe Through Stellar Wind Studies
Faculty Mentor Name
Pragati Pradhan
Format Preference
Poster
Abstract
Low Mass X-ray Binaries (LMXBs) comprise a low mass star and a compact object (neutron star/black hole) orbiting around a common center of mass. In such systems, X-rays are generated through the intense collision of star material on the surface of the compact object. Our study focuses on two LMXBs, GX 1+4 and 4U 1822- 37 using data from two X-ray detectors, NICER and NuSTAR. NICER takes short observations throughout the orbit collecting X-ray photons of energy ranging from 0.2 to 12 keV. NuSTAR takes one long observation of the target in X-rays ranging from 3 to 79 keV. Using X-ray data of GX 1+4 from NICER, we confirmed a strong presence of iron throughout the stellar wind accompanied with large absorption of X-rays. We plan to measure the size of clumps by measuring the X-ray extinction, through Spectro timing analysis. In addition, we have also analyzed the hard X-ray data from NuSTAR of the LMXB 4U 1822-37. We have confirmed the existence of cyclotron resonance scattering near 29 keV conveying magnetic field strength of 2-3 x 10^12 Gauss. The orbital period of ~21 kiloseconds is also seen clearly in the X-ray light curves. In the future, we are going to use time resolved spectroscopy to look at the cyclotron line variation with spin phase of the neutron star. Ultimately, continuous observation and analysis of these systems can be utilized to build a comprehensive picture of the complex physics at play in these X-ray binary systems.
X-Ray Binaries as Flashlights to Map the Universe Through Stellar Wind Studies
Low Mass X-ray Binaries (LMXBs) comprise a low mass star and a compact object (neutron star/black hole) orbiting around a common center of mass. In such systems, X-rays are generated through the intense collision of star material on the surface of the compact object. Our study focuses on two LMXBs, GX 1+4 and 4U 1822- 37 using data from two X-ray detectors, NICER and NuSTAR. NICER takes short observations throughout the orbit collecting X-ray photons of energy ranging from 0.2 to 12 keV. NuSTAR takes one long observation of the target in X-rays ranging from 3 to 79 keV. Using X-ray data of GX 1+4 from NICER, we confirmed a strong presence of iron throughout the stellar wind accompanied with large absorption of X-rays. We plan to measure the size of clumps by measuring the X-ray extinction, through Spectro timing analysis. In addition, we have also analyzed the hard X-ray data from NuSTAR of the LMXB 4U 1822-37. We have confirmed the existence of cyclotron resonance scattering near 29 keV conveying magnetic field strength of 2-3 x 10^12 Gauss. The orbital period of ~21 kiloseconds is also seen clearly in the X-ray light curves. In the future, we are going to use time resolved spectroscopy to look at the cyclotron line variation with spin phase of the neutron star. Ultimately, continuous observation and analysis of these systems can be utilized to build a comprehensive picture of the complex physics at play in these X-ray binary systems.