Speaker
Description
In this talk, I will discuss our current understanding of the formation efficiency of high-mass X-ray binaries (HMXBs) by focusing on results derived from young accreting binary populations in the Magellanic Clouds. Using data from our Chandra X-ray Visionary program, extensive shallow Chandra and XMM-Newton surveys and the literature for the Small and Large Magellanic Cloud (SMC and LMC), respectively, I will present the formation efficiency of HMXBs based on three different indicators: the number ratio of the HMXBs to the (a) total number of OB stars in the same area, (b) the local star-formation rate, and (c) the stellar mass produced during the specific star-formation burst, all as a function of the age of their parent stellar populations. Each of these indicators serves a different role, but in all cases, we find that the HMXB formation efficiency increases as a function of time (following a burst of star formation) up to ∼40-60 Myr, and then gradually decreases. The formation efficiency peaks at ∼30-40 Myr with average rates of ${\rm N(HMXBs)/SFR=339^{+78}_{-83}(M_{\odot}/yr)^{-1}}$, and ${\rm N(HMXB)/M_{\star}=8.74^{+1.0}_{-0.92}M_{\odot}^{-1}}$, in good agreement with previous estimates of the average formation efficiency in the broad ∼20-60 Myr age range. Furthermore, I will compare the formation efficiency of HMXBs in the SMC and the LMC. We have found that the formation efficiency of HMXBs in the LMC is ∼17 times lower than that in the SMC, primarily due to the different ages and metallicity of these X-ray binary populations in the two galaxies (Antoniou et al. 2016, 2019). Finally, I will discuss questions raised by both X-ray binary population studies and studies of individual objects of interest, and prospects for yet further progress from future observations performed by eROSITA.
| Presenter status | late abstract submission allowed by Andrea Merloni |
|---|
