Lynds Target Selection

I haven't done this legwork yet because I thought you might want to be involved - finding a good target for observation is a substantial part of doing science! :)

Ideally, we'd pick a target for our observation using a combination of

• searching ADS and/or SIMBAD for existing literature .... we want something that doesn't have a LOT of other references, but some references are fine - if someone else has already assembled data on an object, we might be able to use those data and/or results - we just don't want something that has already been "done to death." (page from the wiki on literature searching)
• checking POSS and other existing multi-wavelength data to see what the object looks like in those bands .... does it look thick and dark in the optical? bright in the infrared? Both of those things suggest that it will be interesting with Spitzer. Something that looks diaphanous in the optical will likely turn out to be completely transparent with Spitzer. (page from the wiki on introduction to data at other wavelengths; you can also do this with Leopard -- see next item.)
• and, checking to see if it is or is not in the Spitzer archive .... you need to use Leopard to do this. (page from the wiki on searching the archive using Leopard-- NB: "searching the archive to see what is there" is the same thing as "downloading data" except that when you search to see what is there, you don't actually download the data, you just see that there is something there.) Also, note that just because there is data already in the Archive on a given cloud doesn't mean it's a BAD thing, just that it's not a good thing for a new proposal. You should make a note of the "nice" ones you find, because you can go grab the data as soon as the data are public.

My original thoughts on good targets were the following three:

• LDN 470
• LDN 1225
• LDN 880 (but maybe too diaphanous)

And, at the AAS, you guys also came up with

• LDN 1340

The master list of objects that I worked from is here, courtesy of Babar Ali. Note that these are all opacity class 5 objects. Opacity class 5 or higher is what we probably want for Spitzer observations. None of these have many references in ADS. This is not meant to be a comprehensive list by any means, just a place to start. If you want to instead start with the complete Lynds Dark Nebulae catalog, it's here (the data are linked as "online data" or something similar).

Please post your thoughts and reactions to each of these targets, and any new ones you think are viable candidates for observation. For example, you might post a gif or jpeg of the POSS image you found, or a summary list of references (e.g., "3 papers besides Lynds, one radio, others submm" or whatever). Note the syntax I'm using to post comments on LDN 1340 below -- this is a method suggested by the Oil City folks, and I think it works really well to follow the conversation. See the help page linked from the left (above the search box) for hints on how do this.

LDN 1340

--Rebull 20:14, 8 January 2008 (PST) Here's a summary of the latest developments on this object:

One of you (Peter?) suggested this object - and it was a fabulous suggestion. Beautiful in the optical, with IRAS sources, a handful of existing literature, and no Spitzer. Perfect! The icing on the cake was that it's visible in the Spring.

One of you (Peter again?) noticed that there was another AAS poster from 2005 on this object. I mentioned that I knew 2 of the authors (JoAnn O'Linger and Grace Wolf-Chase). Not 2 hours after leaving you, I ran into them. One thing I didn't mention in the context of searching the archive is that there is an open call for proposals out now, eg., there are ~700 proposals for objects that are currently being reviewed, and 20% of them will get their targets approved by March. To some extent, since you're putting in a proposal more or less now, you kind of trump them. On the other hand, it's never good to make enemies.... So, it turns out that JoAnn and collaborators have submitted a proposal to map this region over 1 square degree. There's no guarantee that their data will actually be taken this cycle (before we run out of cryogen in Spring 2009), but at the same time, we probably won't be able to ask for a full square degree (it would take too much time). We could pick a subregion to focus on, or we could find another target entirely.

I'll continue to talk to JoAnn (we had just a brief conversation today), and if I can get her posters (one from before, one from this meeting!), I'll post them here.

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