Date: Fri, 25 Sep 1998 11:36:09 -0700 (PDT) To: 2mass Subject: IPAC 2MASS WG Meeting #166 Minutes Cc: chas, stiening, bgreen Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Content-MD5: MnIS547jGtk0US01L2Z+Cw== IPAC 2MASS Working Group Meeting #166 Minutes 9/22/98 Attendees: R.Cutri, G. Kopan, S. Van Dyk, R. Beck, T. Evans, R. Hurt, J. White, J. Fowler, H. McCallon, S. Wheelock, R. Tam, D. Kirkpatrick, D. Engler, W. Wheaton, J. Mazzarella, T. Jarrett, L. Fullmer, B. Nelson AGENDA 1.) Project Update 2.) Sampler and Spring Release 3.) Palomar Run 4.) Outreach Update 5.) New Action Items DISCUSSION A big turnout, undoubtedly related to the candy brought back from Hawaii. 1.) Project Update Northern OPS are back up again. The problem of image elongation has been greatly improved. The polar axis alignment has also been improved. However, the pole scans still need to be analyzed. The backup electronics may be tested again. The K-band jump problem in the south was discussed via a telecon. R. Hurt provided a report. The speculation was that the dome was partially eclipsing the aperture. Every other scan was being affected (the north scans, not the south). What the actual cause may be is stray light spilling over from the secondary when the dome moves. It is hoped that the stray illumination is uniform across the array. Before the dome drive broke, the effect was about 30 DN; after the dome broke, the effect was substantially more, about 600 DN; and, after the repair, the counts dropped to about 10 DN. R. Beck and D. Engler will rerun some individual frame reductions, to see if the effect is uniform across the frames before coaddition. In the worst cases seen so far, obvious structure is apparent in the images, including vignetting; these fields clearly will need to be rescanned. Hopefully, the whole problem will just come down to flagging in QA, since a uniform illumination will not affect source photometry. G. Kopan gave an update on the cross-scan photometric bias problem. A proposal has been made to the Calibration Working Group for establishment of the photometric zero point to be done based on the aperture photometry on the cal scans. These are low stellar density fields and therefore difficult to correct with DMAGCOR. His tests seem to indicate that the routine corrects well for larger-area, higher-density sci scans. The corrections to cal scans could be set as interpolations between adjacent sci scans; this is another possibility. On Sept 3 a 15-micron shift was made in the focus set point. The focus had been originally set to optimize image quality. The small shift may actually help the cross-scan photometric bias problem; the focus curve has a fairly flat bottom at minimum, so shifting slightly from the point of optimal image quality does not change the configuration by very much. Jupiter was actually scanned recently in the south, but fears were allayed by a realization by M. Skrutskie that the planet has a m_K ~ -1 (a bright red star, such as Arcturus, is significantly brighter at K!) and also appears extended. So, its effect on adjoining scans should be not as dire as originally thought. The QA scan-by-scan webpage has been modified by R. Hurt to work well, and it is linked to the nightly QA page. The QA pages will remain on the irsatest server, rather than the irsa server. One last point discussed by R. Hurt is the "H-band worm" artifact in the southern data. This may be either a persistence artifact or due to electronics. It occurs infrequently, but it will be analyzed further. 2.) Sampler and Spring Release The Sampler has been delayed some more. The plan is know to allow the External Review Board, Science Team, and selected external scientists to "beta-test" the Sampler before the ERB meeting on Oct 30. The Sampler will then be released within a few days after the ERB meeting, most likely on or about Nov 3. The catalogs need to be readied for this date. The 1999 Spring release was to include all data processed by Oct 1, with about 3500 tiles, >~38 million point sources, and ~6 million extended sources. Now, it will more likely consist of ~20 million point sources in the +12 to +18 dec bands with quality scores >~ 7. This will be a somewhat patchy distribution of sky within this range. The pipeline is currently in good shape, including the southern pipeline using 2MAPPS 2.1. (Southern nights that have been processed are to be QA'ed imminently.) This means that there will be no more deliveries until v2.2. The shift now must be to analysis of the Spring release data. To that end, J. Mazzarella provided an IRSA update. The docs have been revised, and the catalogs are hidden behind passwords at the moment. An artifact overlay is being worked on. The extended source catalog is ready for the Sampler, with the point source catalog to be added soon. R. Hurt had a comment on the Survey Visualizer, on the difficulty of properly accessing regions that are near the edge of the Aitoff projection. He suggested possibly being provided with a choice of projections, one of them being a flat projection. J. Mazz would consider this suggestion further. 3.) Palomar Run D. Kirkpatrick and B. Nelson recently had 2 nights at the Palomar 200-in. Only the first night was usable. D. Kirkpatrick reported that out of 10 candidates, half the stars were late M dwarfs and half were brand-new L dwarfs. The total count of known L dwarfs is now in the mid-30's. One of the new L dwarfs was, in fact, one of B. Nelson's candidates. Another of the new L dwarfs (of L3 type) is the nearest case so far, with a K~11 and a proper motion of 1" per annum. It appears to have a faint companion, too faint for follow-up with the Keck LRIS instrument. B. Nelson had 16 candidates, 12 of which are new AGNs/QSOs, continuing his ~75% success rate. Of the other candidates, one is an L dwarf (as pointed out above); one, a carbon star; one, a galaxy without emission lines; and one, a M giant. His count is now 50 red AGNs, found above b=30 degrees. 4.) Outreach Update S. Van Dyk is analyzing data taken on 1998 Jul 4 in the south, which corresponds to the anti-radiant during the peak of the Leonid meteor shower on 1998 Nov 17. The Hubble Space Telescope will be pointed within 1 degree of this point for ten hours (about 6 orbits). He will consult with B. Nelson, T. Jarrett, D. Kirkpatrick, and R. Hurt to see if there are 2MASS objects of interest for which we can take advantage of this free time. Observing plans are due in the HST Director's office by Sep 30. The Austin AAS Meeting in January is looming. 2MASS will once again have an exhibit there, but this time, with one workstation set-up, in conjunction with IRSA, which will ideally have a contiguous exhibit. The object is to have the workstation to demonstrate the Sampler data interface to meeting participants. 5.) New Action Items %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % & ACTION ITEMS % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% No new action items were issued by R. Cutri.