"Stellar Distributions in Dark Matter Halos: Looking Over the Edge" is an accepted Spitzer Science proposal that will investigate the outer structures of a large sample of nearby galaxies. Large IRAC 3.6 and 4.5 um maps of 92 galaxies will be taken at unprecedented depth in order to understand how outer and inner structures of galaxies interact. This website will provide details of the data processing for the IRAC imagery.
The Sample Summary Table
Surface Brightness Profiles
Tarball (Everything, last updated Dec. 20 2013)
Also available at arapaho:/arapaho4/shawns/EDGES/final/dec2013_release/
Surface Brightness Images
Astronomical Observation Requests (AORs) inform the Spitzer science staff when and where to point the telescope. We must be careful in making these in order to avoid bright stars and lineup edge-on galaxies so we can make the best use of the telescope's time. Below are links to two tables containing pointing maps for all the galaxies in our sample. (warning: the table with images may take a long time to load)
Table with ImagesTable without Images
Bright stars in our AORs can saturate and ruin an image. Also, IRAC has the nasty habit of leaving ghost images after viewing a very bright star so these stars should be avoided if possible. To determine if a star will be a problem we look at the star's K-band magnitude from the 2MASS catalog. Suspect stars are found by examining the AORs and comparing them to known problem stars. Also, from the LVL survey we have images of a K_m=7 mag (UGC07916) star and a K_m=7.6 mag (CGCG217018) star. LVL had a much shorter exposure time than EDGES so stars of this magnitude or brighter will be a problem. Also, from our pilot survey UGC1281 has a 6th and 4th magnitude star. The effect of these stars on the irac1 map is shown below.
In the EDGES sample, we know that there is a 6.1 mag star in the NGC4460 field and a 6.9 mag star in the NGC4203 field. Any star inside an AOR that looks brighter than those two stars could be a problem. Below is a table summarizing stars that have been found so far in the AORs.
|Galaxy||K_m (mag)||Distance (arcmin)||Cliff's Criterion||The Solution|
|NGC3507_01||6.69900||10.2934||Offset NoTiming IRAC1 IRAC2|
|NGC3726||6.83500||14.7452||Offset ExistingTiming IRAC1 IRAC2|
|NGC3893||3.85400||12.6747||Offset Timing IRAC1 IRAC2 MODIRAC1 MODIRAC2|
|UGC06112||5.81800||9.08095||FLAGGED!||Offset Timing IRAC1 IRAC2|
|NGC3917||6.46400||18.1011||Offset ExistingTiming IRAC1 IRAC2|
|NGC3922||6.90200||11.6625||Offset Timing IRAC1 IRAC2|
|NGC3938||6.84400||10.1343||Offset ExistingTiming IRAC1 IRAC2|
|UGC06917||6.63800||11.8048||Offset NoTiming IRAC1 IRAC2|
|UGC06983||3.62300||17.3295||NoOffset NoTiming N/A N/A|
|NGC4051||6.05200||16.6320||NoOffset NoTiming BetweenStars N/A|
|NGC4085_4088||6.30100||13.3117||Offset Timing IRAC1 IRAC2 GiveUpOnN4085?|
|UGC07089_7094_NGC4111||6.05700||13.9070||Two stars are right next to two of the galaxies...|
|NGC4096||6.67100||14.3587||Offset ExistingTiming IRAC1 IRAC2|
|NGC4143||6.90800||5.86466||FLAGGED!||Offset Timing IRAC1 IRAC2|
|NGC4151||4.14500||9.86687||FLAGGED!||Offset NoTiming IRAC1 IRAC2|
|UGC07577_7608||5.67100||25.0088||On the edge suggest delete TIMING2|
|NGC4460||6.49500||11.0601||Offset Timing IRAC1 IRAC2|
|NGC4861||5.35000||16.6892||NoOffset Timing IRAC1 IRAC2|
|NGC5523||6.79900||9.60591||FLAGGED!||Offset ExistingTiming IRAC1 IRAC2|
NOTE:'Cliff's Criterion' is a rule of thumb Cliff Johnson made for LVL. Any star with distance < 10' and k_mag < 7 or distance < 12' and k_mag < 6 is flagged for investigation (Cliff used 6.5 and 5 k_mag respectively but we have longer exposure times so I modified it slightly).
The UGC07089_7094_NGC4111 field looks like it may not be centered. That is because it is hard to see the third galaxy in the lower part of the image.
UGC08839 looks too dim for its coverage, but that is only because it is dim in the DSS image used to generate the AOR field.