From: John M. Cannon Subject: Re: IRS SINGS dwarfs Date: Tue, 1 Mar 2005 20:42:24 +0100 (CET) Hi J.D. -- Thanks to you & Danny for your comments & suggestions on this. We have narrowed our recommendations for the IRS extranuclear pointings down to 9 pointings in 3 galaxies. Attached please find .eps file overlays of the proposed pointings in each system. More details follow below: IC 2574 ------- -3 recommended extranuclear pointings. 2 covering opposite sides of the supergiant shell, and 1 covering the luminous HII region in the east-central region of the galaxy. If the extranuclear maps can be made larger, the SGS region could be covered completely (which would be very interesting). HoII ---- -2 recommended extranuclear pointings. 1 covering the 24 micron emission peak in the east, and 1 covering the emission peak opposite in the west. NGC 6822 -------- -4 recommended extranuclear pointings, covering the major star formation regions in the center and easten sides of the galaxy. This system has the nice prospect of being essentially completely mapped (in the ir-luminous regions) with these extra pointings. M82 --- -Given the amount of attention that M82 is getting from various programs, we feel that it is better for the team to decide what to do here; perhaps a point for an upcoming telecon? HoI --- -We recommend that the nuclear pointing be moved to sample the (only) IR peak in the system. See attached figure. NGC 5408 -------- -This target has already been observed. However, that spectrum only sampled the major IR peak in the LL mode. If there is interest, a second pointing here in the high-res modules would be very interesting. Flux measures (without aperture corrections) for the recommended extranuclear pointings (in mJy; errors ~ 10% in IRAC and 20% in MIPS): Region S (8 micron) S (24 micron) ------------------ ------------ ------------- IC2574 SGS 1 2.8 9.7 IC2574 SGS 2 4.4 39.3 IC2574 HII 1.6 14.7 HoII East 3.7 4.1 HoII West 3.0 7.3 NGC6822 1 (central) 35.8 N/A NGC6822 2 (central) 33.1 N/A NGC6822 3 (south) 25.0 N/A NGC6822 4 (south) 37.7 N/A If you have availability for a telecon to discuss the finer details, please let us know. Thanks again, & best wishes -- John ------------------ John M. Cannon MPIA, Heidelberg cannon@mpia.de ------------------