Rebecca B. Jervey
Lycoming College

REU program-Summer 2004
Univ. of Wisconsin - Madison
Madison, WI 53706

Research projects of other REU students
Useful links
My conclusions


Irregular Galaxies

Fig. 1 . Irregular Galaxies as seen by the Hubble Medium Deep Survey.

Irregular galaxies are dominant among star forming galaxies. Because of the lack of spiral density waves they are the ideal place to study alternate star formation processes. Namely in my research stellar feedback.

Fig. 1 . Various images of Irregular Blue Galaxies.

Give the history and motivation for your research. Use boldface if you want to say something important.

And of course, make sure to ask your advisors and other students to read over your work to make sure it makes sense.


Fig. 1 . Various images of supernovae.

At the end of a massive star's lifetime the star will explode. This supernova will release a shell of expanding gas sweeping up interstellar dust around where the star was. The energy of these winds is likely to be a major factor in star formation in these dwarf galaxies. The stellar winds are also very hot and will release some of their energy by radiating heat which should be detectable with x-rays.

Fig. 1 . Supernovae as seen through the Chandra telescope.


Fig. 1 . This is IC1613 seen through the B filter.

IC1613 is an irregular dwarf galaxy in the Local Group. It was discovered in 1906 by Wolf and was first resolved into stars, at 17-18 mag, by Baade in 1928. Bade identified it as a Magellanic Could-type galaxy. It is located about 730kpc away so it's distance modulus is about 24.27 according to Borrisova.

Fig. 1 . This is IC1613 seen through the V filter.

My Project

My project invoved calculating the energies of these winds, finding out how much energy is unaccounted for, and calculating what kind of x-ray luminosity that amount of energy will give us. I started by writing a program to calculate the energies of past supernova and current star formation but found the data on the ages of OB clusters in IC1613 not accurate enough. I used some data collected at Kitt Peak with U, B, and V filters and did photometry using IRAF to create a color magnetude diagram of the stars in IC1613. From this diagram we were able to make a more accurate determination of the ages of the OB clusters to plug into my original program. This information will be used in a proposal for collecting x-ray data on IC1613.

What I am doing right now

June 1-5:

We arrived this week and spent most of the week settling in. Madison is a lovely city and downtown is about a 10 minute walk from our dorms so we frequently go there to eat or just hang out. This week we also recieved tours of the campus and the department and met with our advisors. Eric is going to have me working on IC1613 so I've been doing a lot of reading on irregular dwarf galaxies and supernovas. Mostly this was a week for moving in and getting comfortable. Next week the real research starts.

June 6 - July 2:

I've spent the last few weeks programming. I've written programs in both C++ and JAVA that will find the number of stars in a galaxy based on its age and initial mass function (IMF). It will also find how many of those stars are O and B stars, the two types of stars most likely to produce supernovae. The program then calculates the total number of supernovas that have occured over the lifetime of the galaxy and then calculates the power of those supernovas and the mechanical energy of the wind in the supernova shell.

July 5 - now:

With my program written I found myself needing to know the ages of the OB clusters in IC1613. Eric had some data taken at Kitt Peak and he now has me using IRAF to analyze the data. Once we calibrate it we will be able to make a color magnitude diagram and find out the ages of the clusters. That information will then go back into last months program.

Fig. 1 . This is the first figure for my research.

Fig. 1 . This is the first figure for my research.

My research is encapsulated in the above figure.

The dramatic conclusions of my research project

There are billions and billions of stars.

Useful links

The following links are very useful for looking up info on UNIX, web page making, and astrophysical data and journals.

SIMBAD (Stellar database)

NED (Extragalactic database)

UNIX tutorial

Web page basics

NASA Astrophysics Data Service


Awful Waste of Space

My Presentation (draft 1)

My Movie (draft 1)