Exploring the spatial correlation between the kinematics of neutral hydrogen and diffuse x-ray emission in IC5332

or  . . .

searching for really big bubbles

REU UW-Madison

Eric Wilcots' Homepage

WWU Physics


Why IC5332?

    IC5332 is a late type spiral galaxy with obvious spiral arms. This is important because it means that star formation is still taking place. HI shells are created by massive stars and because massive stars are short lived it is important that star formation be present in the galaxy in question.

    Also, IC5332 is viewed nearly face on. This is important because it means that the photons being used for detection, notably the x-rays, will not have to travel through a bunch of "stuff" before leaving the galaxy and heading to our detectors. If this were not so all of the photons between us and the source could have been absorbed without ever leaving the galaxy.


What did we find out?

Well, here are the statistics:

    Calculated mass of HI: 1.28 x 10^10 Msun or 544Jykm/s

    Previously published value: 3.89 x 10^9 Msun or 165 Jykm/s

    Calculated noise column density: 5.1 x 10^18 /cm^2


And here are some of the finished images:

By overlaying the optical or Hα, HI, X-ray, and continuum images we were able to examine whether or not the warm x-ray emission originated inside of an HI shell.

            Optical Overlay                                    Hα Overlay


    HI                    X-ray               Continuum


The boxed area appears most promising.


Velocity-intensity graphs were created for this area. If the intensity were to peak at more than one velocity we would have evidence that the bubble were expanding. However, our graphs showed no evidence of this.


Altogether three possible HI shells were identified in IC5332. There was no evidence of expanding HI shells.

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