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Old 20-May-2004, 11:08 PM
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Andromeda321 Andromeda321 is offline
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Default My Quasar Project

Hello all. Lately I've been doing my first ever bit of "real" astronomical research and I figured some of you guys might be interested in it.
At my school the seniors are kicked out after AP exams are done to work on their senior projects, which are essentially anything you want to do provided you do 40 hours of it. For my project I called up the one astronomer I know down at the University of Pittsburgh and asked if I could do a project down there. She was nice and said yes.
My first day was Tuesday, I spent the time trying to figure out how UNIX and IRAF works, or at least making a noble attempt (I'd worked a little with the stuff before but nothing really). This all in all culminated yesterday when, after trying to play around with an image and failing spectacularly, it took two grad students a half hour to figure out what I had done and undo it.
Apparently if you are capable of disabling a computer to that extent you are capable of analyzing spectra. So I was given a spectrum of some quasar observed the previous week and given the lovely task of analyzing it. This was, for the record, along with the words "no one's really looked at this quasar before so you'll be the first human being to ever examine it." I just kind of gave a blank look and said "ok" because I couldn't think of much else to say to that!
So today I spent my time working on that trying to figure out the redshift of the quasar and the dust in front of the quasar causing absorption lines. It's rather interesting that I didn't have any major computer code malfunctions today- a minor miracle because I think I was starting to irritate a few grad students working around me. Based on the redshift I calculated (and I calculated right apparently, yay!) the quasar is about 9 billion light years away which REALLY blows my mind.
I started working through the elements seen in the spectra earlier today as well. So far there's been some Aluminum, Zinc, Iron, and a touch of Chromium. There's also a rare Fe II line that shouldn't really be there (some lines appear more often then others, this particular one is a few hundred or so times rarer then the others observed) so that was rather interesting.
So up to date that is my senior project, which is utterly nothing like most people's senior projects but I happen to think is the coolest thing ever. If anyone is at all interested I'm still working there next week so I can post my thoughts on that.
And with that I'd like to say working in the "Dupartmint of Fizzix and Astrolugy" is really fun and anyone who gets the chance should not pass it up!
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Old 20-May-2004, 11:52 PM
siriusastronomer siriusastronomer is offline
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Default Re: My Quasar Project

Quote:
Originally Posted by Andromeda321
And with that I'd like to say working in the "Dupartmint of Fizzix and Astrolugy" is really fun and anyone who gets the chance should not pass it up!
Well DUH! I think anyone on this board could have told you THAT!! :-p
Yea, i remember last year before astronomy camp i was planning to try to get spectra of the blazar that i was observing. that would have been really fun and interesting, unfortunatly, due to cirucumstances beyond our control that didn't happen. thankfully i never had to deal with UNIX or IRAF becuase i probably wouldn't have gotten much done and my advisor REALLY would have killed me! mmm...DOS...fun.... Hey, how bout in June we see if Don or Eric or someone show us a bit more UNIX (or, if you've figured it out by then, you could show me )
anyways, have fun!
I want to know what happens!!
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Old 21-May-2004, 12:58 AM
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My first day was Tuesday, I spent the time trying to figure out how UNIX and IRAF works
Wait, you mean IRAF works?!? I'm still unconvinced that it's not simply some sort of sadistic prank that UNIX users and astro grads play on unsuspecting undergrads who grew up in a Windows environment...
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Old 21-May-2004, 01:39 AM
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Originally Posted by Ut
Quote:
My first day was Tuesday, I spent the time trying to figure out how UNIX and IRAF works
Wait, you mean IRAF works?!? I'm still unconvinced that it's not simply some sort of sadistic prank that UNIX users and astro grads play on unsuspecting undergrads who grew up in a Windows environment...
Does it make you feel any better to contemplate how those of us who grew up with IRAF in Unix and are fairly proficient at them feel when confronted with the, umm, different way everything works (sort of) under Windows? I always feel as if I'm not really talking to the computer. And my brian is completely wrong for dealing with a Mac. Now, SGIs are the way things should have gone...
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Old 21-May-2004, 02:40 AM
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Just curious...is it an SDSS quasar? U of Pittsburgh is a participating institution in the SDSS.

I worked at Fermilab on the SDSS in the 2001-2002 school year (teacher fellowship) so I know full well the frustrations of that type of research. I can't count the numbers of times I gummed up the works by putting stuff on the wrong disk and filling it up while I was there...they were very patient with me

I spent last summer at the National Radio Astronomy Observatory in Green Bank. I think that AIPS++ has to be competetive with IRAF in terms of jokes played on Windows users! Boy, what a pain that one is!

Rob
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Old 21-May-2004, 07:52 PM
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Hale_Bopp and Andromeda,
out of curiousity, do either of you guys know Julia Thompson? she's at the unviersity of pitts. astro and physics dept, i do believe. Last summer she did a Research Experience for Teachers where I was working (quite obviously i wasn't one of the teachers but we all worked in the same room). I remember hearing the teachers mention Fermilab a few times, just wondering if you'd done the same thing they were doing?
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Old 21-May-2004, 09:25 PM
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Well, I don't know about the others, Andromeda, but I"M impressed! Rather beats my son's project, determining the periods of the Galilean moons.

But then, he's still a freshman.
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Old 21-May-2004, 10:24 PM
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Oh, I'm thuroughly impressed. Don't get me wrong. I have the utmost respect for anyone willing to learn IRAF on their own. Or with help. In fact, if you know how to use IRAF, you're practically my god. All I've ever been able to manage is to launch ds9, and getting the urge to stab random strangers.
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Old 21-May-2004, 11:28 PM
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There's a reason I call it IRALF, or IBARF. :-) I prefer IDL.

Analyzing quasar spectrum is a major pain due to the zillions of absorption lines, so that's pretty good work. Even with software, getting the redshift can be hard. We did it with active galaxies in the STIS spectra, but it wasn't hard-- if you saw two lines, you assumed one was H-alpha and the other was OII. It worked out pretty well.

So, some of you have observed blazars, eh? I have some involvement with that now! I'll be giving a talk on that project at a Society for Astronomical Sciences meeting next week!

Anyway, good for you! You done good.
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Old 22-May-2004, 02:09 AM
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I am major league impressed. I didn't do anything within a lightyear of that cool in high school. Heck, I didn't start on research projects till my junior year in college. I hope you have a blast.
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Old 22-May-2004, 04:27 AM
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Quote:
Originally Posted by siriusastronomer
Hale_Bopp and Andromeda,
out of curiousity, do either of you guys know Julia Thompson? she's at the unviersity of pitts. astro and physics dept, i do believe. Last summer she did a Research Experience for Teachers where I was working (quite obviously i wasn't one of the teachers but we all worked in the same room). I remember hearing the teachers mention Fermilab a few times, just wondering if you'd done the same thing they were doing?
No, I haven't met her. Dan VanDenBerk, now at U of Pittsburgh, was at Fermilab while I was there. The Fermilab gig was a year long teacher fellowship as opposed to a summer RET.

The NRAO position last summer was an RET.

Sounds like you are doing some great work, Andromeda. When you get to college, be sure to keep tabs on opportunities in the Research Experience for Undergraduates program. It provides summer research at various sites and in various disciplines for undergrad students. Check it out at http://www.nsf.gov/home/crssprgm/reu/start.htm

Rob
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Old 22-May-2004, 02:55 PM
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Default Re: My Quasar Project

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Originally Posted by Andromeda321
So up to date that is my senior project, which is utterly nothing like most people's senior projects but I happen to think is the coolest thing ever.
I agree. I was just re-reading a year-old article in Nature (May 1, 2003) about a quasar at z=2.701 that was in line with a damped Lyman alpha galaxy at z=2.62, so the absorption lines caused by the galaxy showed what elements were present in that galaxy. I guess this was publishable because they found approximately 25 elements, including a number of heavy elements such as zinc and germanium. The presence of these elements, particularly those heavier than iron, in such a young galaxy was termed "striking." John Cowan of the U. of Oklahoma, who summarized the paper, said "Their work opens a new window on the early formation of elements and stars in the Universe." Very cool stuff.
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Old 22-May-2004, 08:05 PM
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Quote:
Originally Posted by siriusastronomer
Hale_Bopp and Andromeda,
out of curiousity, do either of you guys know Julia Thompson? she's at the unviersity of pitts. astro and physics dept, i do believe. Last summer she did a Research Experience for Teachers where I was working (quite obviously i wasn't one of the teachers but we all worked in the same room). I remember hearing the teachers mention Fermilab a few times, just wondering if you'd done the same thing they were doing?
Maybe. The thing is a lot of people come through the astro computing lab looking for someone and start up conversations I end up getting drawn into. They all seem to know who I am and assume I know who they are (why I've no idea) and I've gotta admit most of the time I'm too shy to ask. ops:
Quote:
Originally Posted by Hale_Bopp
Just curious...is it an SDSS quasar? U of Pittsburgh is a participating institution in the SDSS.
Yes it is an SDSS quasar. It was supposedly observed last week by a grad student at the MMT. I don't know the official name of it, however, because I might be tempted to look into what's known about it and such. So I only find that out at the end.

As for what happened yesterday- I finished up the spectrum, the only really new stuff worth mentioning is some Fe I and Mangenese. Then I cleaned up the bad pixels and such and tried to print only to discover it wouldn't. So another one of those "grad students figuring out what the high school kid" moments happened, this time only to find that it wasn't my fault (yay!) because the printers were all off line due to renovation. This led to the evolution of my new theory that every institution in the known universe is perpetually plagued by printer problems and if I was actually smart I would find work as a printer-fixer person.
The day ended early because my boyfriend's prom was later that day and I had to get my hair done. A lot of people ended up doing a double take on this news because we were sitting in the grad student lounge at the time and I don't think that's something you normally hear there! :wink:
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Old 23-May-2004, 06:52 PM
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Originally Posted by The Bad Astronomer
There's a reason I call it IRALF, or IBARF. :-) I prefer IDL.
Ah, even the Bad One sounds like a young grasshopper. If y'all had ever worked with IPPS, which is what IRAF replaced in 1985, we wouldn't hear so much grousing. The I stood for interactive - as in every command and parameter had to be entered when prompted, no scripting. Ran in one room with three graphics terminals and a single image display, located directly below the CDC 7600 machine so they could put a custom "high-speed" link. Didn't like the order of steps the programmer had imposed on reduction? Tough.

Still, it had one very cool feature - the IIS image display had three image planes which could be mapped to RGB, and each plane had actual physical knobs you could turn to change the brightness and contrast on the fly. Getting decent 3-color composites for me still hasn't gotten quite as fast.

And one thing I still haven't seen competition for IRAF in is in reduction of two-dimensional spectra, long slit or multi-object. Now once it's extracted to one dimension or rectified to pure wavelength/position/intensity, I often bolt to IDL as fast as the next grumpy astronomer... And for a lot of routine imaging tasks, I've stared using Axiom Research's (i.e. Mike Newberry's) Mira package running on my laptop (the one I bought with proceeds from playing trombone in a ballroom dance band - does that jeopardize my professional status?). Image alignment, combination, and aperture photometry are a lot more convenient than in other things I've tried. Well, except that I seem to have an uncanny ability to find data sets which uncover hitherto invisible bugs, but Mike has been stunningly fast in finding the problem and updating the software.

Mind you, I need IRAF, STSDAS, IDL, and (gasp) FORTRAN on a pretty much daily basis... and spend a fair amount of time trying to help grad students and summer research folks over the vertical part of the learning curve. If anybody needs it, I can make a PDF of my instructions for reducing a 2D galaxy spectrum in IRAF (great, now he tells us!).
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Old 23-May-2004, 07:31 PM
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Is this going to turn into one of these "Well, when I was a grad student, I had to walk twenty miles uphill to the computer lab barefoot, enter the data by beating on the side of the computer with a two-by-four, get the output by having it tattooed on my stomach with red-hot needles - and I was grateful!" threads?
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Old 23-May-2004, 08:36 PM
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Originally Posted by ToSeek
Is this going to turn into one of these "Well, when I was a grad student, I had to walk twenty miles uphill to the computer lab barefoot, enter the data by beating on the side of the computer with a two-by-four, get the output by having it tattooed on my stomach with red-hot needles - and I was grateful!" threads?
Well, not if I can help it. I won't post any scans of that old roll of printed grocery tape with photon counts from prime-focus scanner operated from the platform riding up and down the dome slit opening at the Crossley telescope. (but the trasformation [i]has[/] been remarkable considering that some of us aren't all that old)

On the other hand, anyone who has a viable idea on how to bring data-reduction software into the 21st century is much more than welcome to present a plan here...
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Old 23-May-2004, 08:39 PM
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On the other hand, anyone who has a viable idea on how to bring data-reduction software into the 21st century is much more than welcome to present a plan here...
What do you mean by data reduction software?
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Old 23-May-2004, 09:07 PM
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Software that reduces raw data down to something comprehendable?
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Old 23-May-2004, 11:00 PM
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Quote:
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Quote:
Originally Posted by ngc3314
On the other hand, anyone who has a viable idea on how to bring data-reduction software into the 21st century is much more than welcome to present a plan here...
What do you mean by data reduction software?
Basically, at least to remove the instrumental and atmospheric signature, and present results in as nearly physical units as possible. For example, beginning with a set of CCD frames containing a possib ly distorted registration of a galaxy spectrum in counts per exposure, yield a corrected array of intensity in energy units per wavelength as a function of position in arcseconds, with foreground night-sky emission removed as well as defects of the CCD. Optionally, measuring a velocity and linewidth profile along the slit tracking statistical errors. Another example would be taking a set of CCD images, normalizing from the median of stars to remove atmospheric changes, and doing time-series photometry of stars within the series. As another poster said - any of the processes going from raw data to physically interpretable results.

This is what most of the time of many practicing astronomers gets taken up with, which the practically religious obsession in discussions of particular platforms or approaches.
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