论文标题
来自VLBI绝对星形标准在ICRF3框架中的射手座A*的位置和正确运动
Position and Proper Motion of Sagittarius A* in the ICRF3 Frame from VLBI Absolute Astrometry
论文作者
论文摘要
Sagittarius A*(Sgr A*)是一个强大的紧凑型无线电源,据信是由银河中心的超质量黑洞提供动力的。银河平面中的灰尘和气体灭绝可防止它光学观察,但是先前使用无线电干涉仪估计了其位置和适当的运动。我们介绍了其在国际天体参考框架第三次实现的框架中的精确位置和适当运动的新型VLBI绝对天体测量值。在2006年6月至2022年8月之间,在K -Band(24 GHz)的VLBA上进行了52个时期的观察结果。我们发现SGR A*的适当动议为-3.128 $ \ pm $ 0.042 MAS/yr,在正确的升天中,在-5.584 $ $ 0.075 Mas/yr/yr yr yr yr yr yr yr yr yr y yr yr yr y 0.0 $ 0.00 $ 0. 0.01。 209.26 $ \ pm $ 0.51度。我们还发现其J2000 ICRF3在2015.0适当的运动时期坐标为17 $^H $ 45 $^m $ 40.034047 $^S $ $ $ \ pm $ 0.000018 $^s $,-29 $^o $ $ 00'28.28.21601'$ 0.000444''。在银河坐标中,Sgr a*显示了-6.396 $ \ pm $ 0.071 mas/yr的银河经度和-0.239 $ \ pm $ 0.045 $ 0.045 MAS/YR银河纬度的MAS/YR,表明太阳能动作248.0 $ \ pm $ 2.8 $ $ $ $ pm pmm $ 1.19.3.3.3.3.3.3.3.3.3.3 $ 1.3.3.3.3杆。
Sagittarius A* (Sgr A*) is a strong, compact radio source believed to be powered by a super-massive black hole at the galactic center. Extinction by dust and gas in the galactic plane prevents observing it optically, but its position and proper motion have previously been estimated using radio interferometry. We present new VLBI absolute astrometry measurements of its precise position and proper motion in the frame of the third realization of the International Celestial Reference Frame, ICRF3. The observations used were made at 52 epochs on the VLBA at K-band (24 GHz) between June 2006 and August 2022. We find the proper motion of Sgr A* to be -3.128 $\pm$ 0.042 mas/yr in right ascension and -5.584 $\pm$ 0.075 mas/yr in declination, or 6.400 $\pm$ 0.073 mas/yr at a position angle of 209.26 $\pm$ 0.51 degrees. We also find its J2000 ICRF3 coordinates at the 2015.0 proper motion epoch to be 17$^h$45$^m$40.034047$^s$ $\pm$ 0.000018$^s$, -29$^o$00'28.21601'' $\pm$ 0.00044''. In galactic coordinates, Sgr A* shows proper motion of -6.396 $\pm$ 0.071 mas/yr in galactic longitude and -0.239 $\pm$ 0.045 mas/yr in galactic latitude, indicating solar motion of 248.0 $\pm$ 2.8 km/sec in the galactic plane and 9.3 $\pm$ 1.9 km/sec towards the north galactic pole.