Radial velocity measurements of an orbiting star around Sgr A*

• DOI: 10.1093/pasj/psy067
• Publication Date: 2018-05-24T11:09:29Z
• Authors: Shogo Nishiyama; Hiromi Saida; Yohsuke Takamori; Masaaki Takahashi; Rainer Schödel; Francisco Najarro; Satoshi Hamano; Masashi Omiya; Motohide Tamura; Mizuki Takahashi; Haruka Gorin; Schun Nagatomo; Tetsuya Nagata
• Keywords: Radial velocity

During the next closest approach of orbiting star S2/S0-2 to Galactic supermassive black hole (SMBH), it is estimated that RV uncertainties ~ 10 km/s allow us detect post-Newtonian effects throughout 2018. To evaluate an achievable uncertainty in and its stability, we have carried out near-infrared, high resolution (R 20,000) spectroscopic monitoring observations S2 using Subaru telescope near-infrared spectrograph IRCS from 2014 2016. The Br-gamma absorption lines are used determine RVs S2. obtained 497 km/s, 877 1108 2014, 2015, 2016, respectively. statistical derived jackknife analysis. wavelength calibrations our three-year stable: short-term (hours days) < 0.5 a long-term (three years) 1.2 km/s. different smoothing parameter, partial exclusion spectra, found be few final results line +- 17 (stat.) 3 (sys.) 15 4 12 When use two He I at 2.113\mum addition Br-gamma, mean 513 1114 for standard errors 16.2 (2014) 5.4 (2016), confirming reliability measurements. difference between by Newtonian mechanics general relativity will reach about 200 near pericenter passage Therefore 13 - with enable relativistic measurements more than sigma