Radio Frequency Timing Analysis of the Compact Jet in the Black Hole X-ray Binary Cygnus X-1
Abstract
Black holes drive the most powerful jets in the universe, from the kiloparsec-scale jets launched by the most massive black holes in Active Galactic Nuclei (AGN), to the smaller-scale jets launched by their stellar mass analogues in black hole X-ray binaries (BHXBs). BHXBs are typically transient in nature, evolving from periods of inactivity into a bright out-bursting state lasting days to months. During an outburst, BHXBs emit across the electromagnetic spectrum, where jet emission dominates in the lower frequency bands (radio, sub-mm) and emission from the accretion flow dominates in the higher frequency bands (optical, X-ray). Time domain observations now offer a promising new way to address the key open questions in jet research (e.g., size scales, geometry, speeds, a sequence of events leading to jet launching), contrary to previous works, which have focused primarily on the spectra or morphology of these outflows. However, while time-resolved observations are a staple for BHXB studies at X-ray/optical frequencies, there are many challenges that accompany such studies at radio frequencies (e.g., distinguishing intrinsic source variations from atmospheric variations, having to routinely cycle between a target and calibrator source, limits on the number of frequency bands that can be sampled at once). In this talk, I will present new results from our simultaneous multi-band VLA radio and NuSTAR X-ray observations of the BHXB Cygnus X-1. With this data, we have developed observational techniques and computational tools designed to overcome the challenges of radio timing analysis, and ultimately connect jet variability properties to internal jet physics. The combination of these techniques and the improved capabilities of planned next-generation instruments (such as the ngVLA and ALMA-2030), will make more of these radio time domain studies possible, not just in BHXBs, but in other jet-producing sources as well.
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1711225T