Possible Fluctuation of the Position of Sagittarius A* Relative to Extragalactic Radio Sources

Details Possible Fluctuation of the Position of Sagittarius A* Relative to Extragalactic Radio Sources Possible Fluctuation of the Position of Sagittarius A* Relative to Extragalactic Radio Sources

Nov 2002

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002apj...580l..43h&link_type=abstract

The Astrophysical Journal, Volume 580, Issue 1, pp. L43-L46.

Astronomy and Astrophysics

Astronomy

2

Astrometry, Galaxy: Center, Galaxy: Fundamental Parameters, Cosmology: Gravitational Lensing, Radio Continuum: Galaxies

Scientific paper

When we measure the position of an extragalactic radio source through the Galaxy, apparent position wander will be induced because of the gravitational deflection by intervening stars in the Galaxy. When measuring the annual parallax of a radio source with respect to the nearby extragalactic radio sources, such position wander should be taken into account. This effect is especially serious in the case of the trigonometric measurement of Sgr A*, located in the Galactic center. We estimated the optical depth and the event rate of the position wander of the extragalactic radio sources near Sgr A* and found that such position wander degrades the measurement of trigonometric parallax of Sgr A* significantly. For observations with an accuracy of 10 μas, the probability of degradation is a few tens of percent. Several years of continuous observation are needed for the separation of this gravitational position wander from the annual parallactic motion. Even for observations with an accuracy of 25 μas, a few years of continuous observation are needed to eliminate the effect of position wander.

Affiliated with

Also associated with

No associations

Rating

Possible Fluctuation of the Position of Sagittarius A* Relative to Extragalactic Radio Sources does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Possible Fluctuation of the Position of Sagittarius A* Relative to Extragalactic Radio Sources, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Possible Fluctuation of the Position of Sagittarius A* Relative to Extragalactic Radio Sources will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-735534