1. sptool is a quick way to compare standards to stellar spectra. Nice, I'd been looking for a tool like that. 2. GNU screen captions are useful especially when working in a screen-within-a-screen environment (who does that, really?) 3. finally got SPLAT to work... turns out I just hadn't reduced my damned data 4. kill -STOP and kill -CONT are really useful ways to pause programs that are sucking up resources if you want to resume them later. Haven't tried this on "real" code yet.
New python software
Next Generation Astronomy
A brief commentary on a recent article Next Generation Astronomy: I'm probably one of the folks who will be working on making that future happen, in the sense of being the intermediary between the end-user and the instrumentalist. Scientists are still needed to build instruments, but those who build the instruments don't necessarily have the time or expertise to build the software pipelines that generate high-quality data. At the same time, the STARLINK folks do a much better job than I do, and I already spend about half of my time comparing different archival data sets... so I think his crystal ball is overall very accurate.
Observing 10/20
I don't have a better place to post this one, so here it is:
My automated fitter (Gaussfitting Cube Collapser) has come a long way. I now adaptively choose to fit 1, 2, or 3 Gaussian components to output to a data cube. The purpose of that code is primarily to find a two-dimensional way to display information about the 3D structure, specifically about the presence/absence of outflows. Outflows will inevitably be confused with multiple velocity components, but they are also likely to be convolved with them.
Observing @ GBT: Signs of good & bad data
So far, all of the observations for the H2CO densitometry project have been performed at the Green Bank Telescope. During a 10-day long observing trip here, I've learned a lot about diagnosing bad data.
This first image shows TSYS vs Airmass for good data. The high outliers are just sources with continuum in them - the continuum is the source of the extra signal, not atmosphere. The receiver temperature is a nice 20.6 K, and you get about 5 K extra per airmass, suggesting a zenith optical depth of 0.018 assuming a round atmospheric temperature of 300K.
In the same style plot, there is a set of observations with low system temperatures: that stuff is good. There is also a set with clearly rising system temperatures, even at constant elevation. These data are bad. During this observation, the "blowers" that are meant to keep dew off of the receivers failed. Dew buildup on the receiver covers lead to higher optical depths and therefore system temperatures.
Finally, this data set was totally useless. Ku-band is not particularly sensitive to water in the atmosphere... but it's still not a good idea to observe during a rain storm. Note that the fitted receiver temperature TREC is nonsensical.
Observing run summary
3 nights of worse than grade 4 weather (tau ~.4, i.e. the atmosphere is nearly opaque) have given me a few interesting results. 1. Non-detections of CS 5-4 in a few bright BGPS cores. My best guess is that the pointing was off, though, because I definitely got down to a noise level around 50mK. 2. Lots of CO 2-1 mapping, 13CO/C18O too. That means I can now use this plot: http://dustem.astro.umd.edu/pdrt/co3221web.html to try to measure the incident flux. 3. I can't do homework at the summit. Maybe it's just that I can't do stellar structures homework, but I really am not processing this stuff well. Damn. 4. Running at altitude uphill is really, really hard. All the running I've been doing the past N months has not even come close to preparing me. Need to correct that... 5. "I am inappropriate." I probably violate a bunch of those rules... the important ones... 6. gotta get back to the mountains. Really. Seriously. OMFG. 7. ARGH those papers need writing! Lots of it! For the next observing run, need the following: 1. Pre-prepared A3 rasters 2. Larger selection of summit music 3. Better sleep schedule preparation 4. More caffeinated drinks per night 5. Cloud cannons.
Observing this weekend
whoops, never made this post. Turns out I got rained out - 3 inches of rain on my night. Sad, no DIS time for P Cyg.
Offset symbols?
Orion in the Infrared and Millimeter
This composite image of the Orion A Giant Molecular Cloud star-forming complex shows infrared emission from the WISE and MSX missions in 4 micron (red), 12 micron (blue), and 22 micron (green) emission with Bolocam Galactic Plane Survey 1.1mm emission overlaid in yellow/orange. The Orion A region is frequently featured in astronomical images:
but its tail tends to be ignored. This quiescent region is the source of the next generation of stars, although the relatively small mass concentrations imply that no massive stars like the bright Theta 1C that powers the Orion Nebula will form. The infrared colors show all sorts of stars including protostars. The infrared can pierce through the dust and find young stars still forming. The green and blue bands also see diffuse clouds of dust being illuminated by the central stars of the Orion nebula. The yellow 1.1 mm dust emission shows the coldest dust that is shielded from external radiation. These cold clumps contain enough mass to form new stars...
Outreach Observing
Some notes for this Friday... the ISS will rise at about 10:55 on Friday, July 18th, and 9:43 on Saturday, July 19th. Jupiter will be in the sky, but Venus and Mercury will not. Jupiter will rise in the Southeast
Denver, CO 2008/07/16 10:15 pm Sunrise/set: 05:46 am / 08:26 pmPredicted passes for: ISS daylight-saving time enabled Local Duration Date Time (min) Approach Max. elevation Departure------------------------------------------------------------------------2008/07/17 02:57 am <1 10° above N 10° above N 10° above NNE2008/07/17 04:30 am 5 12° above NNW 31° above NE 10° above E 2008/07/17 10:30 pm <1 13° above WSW 15° above WSW 15° above WSW2008/07/18 03:19 am 4 10° above NNW 16° above NNE 10° above ENE2008/07/18 04:54 am 5 15° above NW 78° above W 10° above SE 2008/07/18 09:19 pm 5 13° above SSW 29° above SE 11° above ENE2008/07/18 10:55 pm 4 17° above WNW 25° above NNW 10° above NNE2008/07/19 03:42 am 5 13° above NNW 32° above NNE 12° above E 2008/07/19 05:18 am 4 16° above W 22° above SW 11° above S 2008/07/19 09:43 pm 5 19° above WSW 71° above N 10° above NE
