The possibility of detecting Sagittarius A* at 8.6 mum

Details The possibility of detecting Sagittarius A* at 8.6 mum The possibility of detecting Sagittarius A* at 8.6 mum

2006-11-15

arxiv.org/abs/astro-ph/0611472v1

Astronomy and Astrophysics

Astrophysics

accepted for publication as letter by Astronomy & Astrophysics

Scientific paper

The Galactic Center was observed at 8.6 mum in order to detect a mid-infrared (MIR) counterpart of Sgr A*, parallel to NIR observations. The goal was to set constraints on possible emission mechanisms.Imaging data were acquired with the adaptive optics assisted NIR instrument NACO and the MIR instrument VISIR at the ESO VLT. We present MIR imaging data of an unprecedented quality in terms of spatial resolution and sensitivity. An extended ridge of emission is found to be present in the immediate vicinity of Sgr A* and thus renders any detection of a point source difficult. No MIR point source related to Sgr A* was detected during the observations. We derive a tight upper limit of 22+-4 mJy (dereddened) on any possible point source present during the observations in the night of 4/5 June 2006. The absence of a flare in simultaneous observations at 2.2 mum and the low limits on any possible variability in the MIR suggest strongly that Sgr A* was in a quasi-quiescent state during this night. During the night from 5 to 6 June 2006, Sgr A* was found to be variable on a low level at 3.8 mum. No point source at 8.6 mum was detected during the simultaneous MIR observations. Due to the poorer atmospheric conditions a higher upper limit of 60+-30mJy was found for Sgr A* at 8.6 mum during the second night. The observations are consistent with theoretical predictions. If the published models are correct, the observations demonstrate successfully that a 8.6 mum counterpart of Sgr A* can be easily detected in its flaring state. Spectral indices derived from simultaneous observations of flaring emission from Sgr A* at NIR and MIR wavelengths will enable us to distinguish between different kinds of flare models.

Affiliated with

Also associated with

No associations

Rating

The possibility of detecting Sagittarius A* at 8.6 mum 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 The possibility of detecting Sagittarius A* at 8.6 mum, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The possibility of detecting Sagittarius A* at 8.6 mum will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-54374