Table 1.
Properties of X8 between 2006 and 2016.
| Date | Distance to Sgr A* | Position angle | Spatial extension | On-source exp. | Total exp. time | |||
|---|---|---|---|---|---|---|---|---|
| Total | ΔRA | ΔDec | x-direction | y-direction | ||||
| (YYYY) | (mas) | (mas) | (mas) | (°) | (mas) | (mas) | (min) | |
| 2006 | 380 | 210 | 310 | 45.5 | 130 | 230 | 24 | 240 |
| 2007 | – | – | – | – | – | – | 17 | 170 |
| 2008 | – | – | – | – | – | – | 21 | 210 |
| 2009 | 390 | 210 | 330 | 67.5 | 120 | 170 | 27 | 270 |
| 2010 | 430 | 230 | 360 | 41.7 | 140 | 200 | 64 | 640 |
| 2011 | 440 | 250 | 360 | 47.3 | 110 | 180 | 43 | 430 |
| 2012 | 440 | 230 | 370 | 59.7 | 120 | 170 | 61 | 610 |
| 2013 | 450 | 250 | 370 | 48.0 | 080 | 190 | 176 | 1760 |
| 2014 | 480 | 260 | 410 | 52.3 | 110 | 170 | 218 | 1454 |
| 2015 | 470 | 260 | 380 | 54.2 | 080 | 140 | 49 | 327 |
| 2016 | 500 | 300 | 400 | 54.8 | 130 | 190 | 54 | 360 |
Notes. The position error can be determined to ±1.5 pixel, which translates into ±20 mas for every position value given for ΔRA and ΔDec. The error of the total distance of X8 to Sgr A* results with error propagation in ±20 mas. In every year, an 8 pixel Gaussian is fit to the blueshifted Brγ line maps of X8. In the data cubes that cover 2007 and 2008, X8 is located at the border of the FOV. Parts of the emission are not covered by these data cubes. The spatial extension refers to the long (y-direction) and short axis (x-direction) of X8. The PA is measured east of north.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.