IPAC 2MASS Science and Analysis Working Group Meeting #11 Minutes
IPAC 2MASS Science and Analysis Working Group Meeting #11 Minutes,
Attendees: C. Beichman, R. Cutri, L. Fullmer, T. Jarrett,
D. Kirkpatrick, G. Laughlin, B. Light, C. Lonsdale, S. Terebey,
- G. Laughlin: showed several sky plots from her comparisons of FOCAS results to
KAMPHOT and GALWORKS in Coma: the positions of FOCAS `stars',
`non-stars' and `galaxies' compared to the positions of
KAMPHOT and GALWORKS extractions. There is considerable agreement between
FOCAS and the 2MASS pipeline however detailed analysis of the differences
awaits a careful matching of magnitude limits between the two processors.
- S. Terebey: is building PSF models for bright stars to minimize the amount
of sky that is lost to the survey around bright stars. She
is characterizing the broadening due to the pixel size and to
- L. Fullmer: has generated the first 3-band coadd using all May 4 Coma scans.
As expected the coadd is J-band dominated, and no clear improvement
in SNR over the J-band image is apparent, to first order.
However, a proper test requires optimal weighting, as outlined in the
recent memo of T. Chester and T. Jarrett, which Linda will try next. Linda
will produce a red-green-blue image for the AAS poster.
- D. Kirkpatrick: has now accumulated 64 new high (0.1 to 1 arcsec/yr) proper
motion objects from his search through the 92-94 database;
roughly an increase of a factor of 2 in surface density over the
Luyten catalog. He has also found 19 sources with no optical counterpart at
all, many of them buried in the Plaiedes. He is limiting his search to
J=15 and Ks=14, which correspnds to SNR of about 10. Davy has also
serendipitously come across an unusual object with a small cone-shaped
nebulosity on the blue POSS I plate but no nebulosity at all at J, which
may be a high latitude reflection nebula.
- T. Jarrett: is modelling the effects of stellar confusion on galaxy photometry
by overlaying a simulated star field on top of a Coma coadd.
He has chosen a star density appropriate to b=25 degrees for his
first study. He finds a 0-2% brightening of the galaxy photometry in the
contaminated field, due to the effect of stars falling on top of galaxies. He
also finds that the adaptive aperture diameters become smaller because of
increased `noise' due to the contaminating stars in the outer regions of the
- S. Wheelock: having completed the C&R analysis for the good seeing test scan,
as reported previously in these minutes, has now automated the
procedures to run on any scan. She showed results for the high
source density scan FS28, which has greater than 10^4 sources per square
degree. The results are excellent, meeting the Level 1 requirements in
all three bands. Sherry will now study C&R as a function of seeing.