Ok, so… what was I saying?

25 11 2008

Well, I guess it is better start from the beginning… or no…in the end, my thesis covered 3 different subjects and it was not easy at all to put everything in a single coherent picture.

The first work was related to the discovery of new visual binaries in the Orion Nebula Cluster. We used 26 images, which together create a beautiful mosaic, produced by the Advanced Camera for Surveys (ACS), on board the Hubble Space Telescope. The filter used was a narrow one (F658) centered in the H-alpha plus N[II] lines. It all means that we can detect young stars more easily given they have H-alpha emission lines. However, the background is a major concern because it also emits in the H-alpha line. The advantage given by the ACS is its high angular resolution, 0.05 arcseconds per pixel. With such resolution we can discover visual binaries previously unknown.

In fact, we discovered 50 new visual binaries in the Orion Nebula Cluster. Some of these new multiple systems are very interesting because they can be formed by substellar objects. One system, named COUP 1061, was previously reported to be a brown dwarf and we discovered it as a multiple system! Thus, COUP 1061 is a binary system composed of two brown dwarf objects, separated by approximately 100 AU.

We also used our results to study the dynamics of the multiple systems inside the cluster. We have found an interesting gradient meaning that the system with wide separations (more than 225 AU) are more common in the outer parts of the clusters. The explanation is that the wide system close to the center were already destroyed by their interaction with the gravitational potential well of the cluster.

This fact helps us understand why the Orion Nebula Cluster has a deficit in binaries when compared to young T associations and also with the Galactic field.

Well, this was chapter 2 in my PhD thesis… chapter one was obviously the introduction. I tell about the other ones in the future…





PhD, at last…

20 11 2008

Eons without posting…

I defended my PhD last September. In the end the thesis looked like a Frankenstein, made of different subjects. However, the commitee like it very much and I enjoyed it also.

You may wonder… what is it about? Well, it is about a lot of things. I promise I will write about it later.

The title, well, I can tell you about the title, it is: Survey of Young Stars: Variability and Binarity.

Ok, so, see you later…





Some news

20 06 2008

In the end, the thesis will have 6 chapters, an introduction (of course), a chapter about the visual binaries in the Orion Nebula Cluster, then a chapter about variability and statistical indices used to check for variability in stars, one chapter about the variability in the Orion Nebula, another chapter about the Cygnus OB2 association and finally the conclusions.

I’m working on the chapter about the Cygnus OB2 region right now. I have found interesting things there, like proplyds and new infrared clusters. It is going to be a great work I guess. It looks like these proplyds are actually unknown in the region. They were not observed by anybody else so far. That’s great, I think I’ll put them in a separate paper as soon as possible.





Work, as far as the eye can see…

17 06 2008

Yes, I know it has been a long time since the last post.

I can explain, I must defend my PhD thesis in August, meaning I have to finish writing it by July. I have tons of work to do and I’m not in the exact mood to do it. But I guess we are not always in the mood to do boring things and writing a thesis is extremely boring and painful.

I’ll say more things about the thesis during this week. For now what I can say is that I have very interesting results about Cygnus OB2. I’d like to have more time to work on it but unfortunately this is not the case.

Oh! by the way, I got a postdoc fellowship here at UFMG, starting September, that’s one good reason to finish the PhD.





Cygnus OB2

3 04 2008

OK, ok, I know it’s been a long time since I posted the last post… but recently I’ve been using all my time to read papers about Cygnus OB2.

Also I’m using my free time (the time not used to work) to stay with my girlfriend and love of my live. It’s been a good time.

Some weeks ago I went to the observatory (LNA – Laboratório Nacional de Astrofísica – something like Astrophysics National Laboratory). I stayed 3 nights there, together with my girlfriend who is also an astrophysicist. The first night was awesome, it rained! We stayed in bedroom watching movies. The other nights were ok, we observed our targets (NGC2264, PDS078, ESO442-04). LNA is known for its bad and raining weather.

I was also busy with post-doc forms. I don’t know for sure what I wanna do after PhD. I’ll maybe go out of Brazil, but there is nothing formal yet. Pauline (that’s my girlfriend’s name) will spend 5 months in Germany, starting in October… that will be hard for me, but I’m thinking in going to France in the end of the year, for the post-doc. Well, who knows?

But first, I’ve got finish the PhD… more papers to read.





IDL

27 02 2008

Lately I’m having problems with one IDLASTRO routine: headfits.pro

I need to read the headers from some FITS files and later use the header information in other routine… but I don’t know why the routine is incapable of opening the file… strange…

Any hint? Anyone? I guess not…





Iraf 2.14 warning

15 01 2008

Bugs on Iraf 2.14! If you have it installed on your machine better install it again. I have a very good script to install it on Ubuntu and Suse.





Mosaic

14 01 2008

I created the mosaic of my observational fields, observed with the WFCAM, using Starlink and its routines, extremely easy. Unfortunately they so big (around 500Mb) that I cannot out them here or anywhere else… anyway I have to work more on them.

I finally downloaded the nights released for CygOB2 (43 nights), 35Gb of data. When I unpack them the size of each one of the files increases 4 times… yeah … lots of data. Today I wrote some routines to read the fits headers, display the images based on the catalogs, etc.  It was a productive day I would say.

Soon I’ll have light curves … well, I better have them anytime soon…





Starlink and other stuff

10 01 2008

So far I have more than 50Gb of data stored in the machine… about time to start thinking in how am I going to work with this stuff.

I decided to install the Starlink package to deal with the WFCAM observations. Starlink is sort of similar to IRAF and MIDAS (I guess). It is a set of routines and programs to deal with astronomical data. The advantage of using Starlink in this case is that the routines to work qith the WFCAM data are ready and they seem to be easy to use. I don’t know if I’m right but it seems to me that IRAF was developed by the North American (and others and is the most used), MIDAS was developed by the ESO guys (the Europeans love it) and STARLINK was developed by the English guys.

Actually there is one reason to me to use Starlink, build the mosaic images with the WFCAM data. All my programs and important stuff is written in IDL.

I also started to think about my thesis, I started to prepare my Latex macro to write it and I decided to write it in english … bad idea? good idea? Wait and see…





Lots of data

8 01 2008

Things were calm here until yesterday…

But then tons of data just showed up!!! Now I have lots of Gigabytes to work with…insane.

Let me explain; part of my thesis consists in observations made with the UKIRT (United Kingdom Infrared Telescope) and the WFCAM (Wide Field Camera). UKIRT is based on top of the Maune Kea Vulcano in Hawaii. We are observing M42 and Cygnus OB2, which are star forming regions, in a long run program. I have 101 nights of observations for M42 and more than that for CygOB2, the observations consist of short exposures (usually 5 seconds)  every night (or almost every night).

So it happened that the guys from the pipeline reduction released the data and now I have all the M42 observations and 43 nights for CygOB2. Now I’m downloading the data… so far I got 8.6Gb of catalogs (just the tables with the results from the pipeline) and well until now  13Gb of images … only for CygOB2. I’ll start the M42 download today… I’m happy I have 2 HD with 500Gb each… but I’m worried with so much data!!!