Article - GCNEWS, Vol. 23, March 2006
A Newsletter for Galactic Center Research
This Volume was edited by Sera Markoff, Loránt Sjouwerman,
Joseph Lazio, Cornelia Lang, Rainer Schödel & Robin Herrnstein
Volume 23, March 2006
The Spitzer View of the Galactic Center
Courtesy of Susan Stolovy
On the cover of this issue is one of the first Spitzer images
of the GC, unveiled by Stolovy et al. at the recent American
Astronomical Society meeting. Using the IRAC instrument, they
conducted a survey of the central 2o * 1.5o (280
* 210 pc) of the Galaxy at 3.6, 4.5, 5.8, and 8.0 micron .
These images have an angular resolution of 2'',
corresponding to 0.08 pc at the GC, making them the highest
spatial resolution and sensitivity large-scale map made to date of the
GC at mid-infrared wavelengths.
While analysis of these images is on-going, several aspects are
already clear. Much of the dust and the absorption is in highly
filamentary structure in the interstellar medium. At the longer
wavelengths, much of the interstellar emission is dominated by PAH
emission from small grains in star-forming regions. Comparisons with
other wavelengths may provide indications of the relative locations of
many of these features.
Stay tuned for many additional results from these fascinating images.
Figure 2: :
These three images show the same field of view at
wavelengths ranging from 1.25 micron (2MASS) to 8.0 micron (IRAC).
dramatically the need for longer IR wavelength studies to
penetrate the severe interstellar extinction toward the GC. The
IRAC 3.6 micron image is dominated by red giants and AGB stars. The
diffuse ISM structures in the IRAC 8.0 micron image are dominated by emission
from small dust grains (PAHs) in star forming regions.
(Click here for PostScript (top,middle,bottom) versions.)
The GCNEWS Logo
at the top of this page shows a 20cm radio map of the GC (Sgr A) made by Yusef-Zadeh & Morris.
The GCNEWS newsletters, newsflashes and web pages are based on scripts originally developed by
Internet access for GCNEWS is currently sponsored by the
National Radio Astronomy Observatory in Socorro NM/USA.
Page currently maintained by
L. O. Sjouwerman.
File last modified on Friday 03 March 2006 [09:30 MST].