Barred Magellanic Spirals in Ursa Major and Canes Venatici: Global Properties

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Barred Magellanic Spirals in Ursa Major and Canes
Venatici Global Properties

• Kwayera Davis
• (College of Charleston)
• Advisor Eric Wilcots
• (University of Wisconsin-Madison)
• University of Wisconsin-Madison REU 2003

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Motivation

• Some galaxy types are not well studied
• We want to better understand their
• formation
• evolution
• interaction with neighbours
• structure
• dark matter distribution

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Barred Magellanic Spirals (SBms)

• SBms are a transitional class
• Some spiral structure
• Some irregular structure
• Barred
• The LMC is a SBm

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H I emission

• Neutral(atomic) hydrogen atom
• 1 proton and 1 electron
• Electron changes spin
• Light emitted
• 21 cm wavelength
• 1.4 GHz frequency
• This is in the radio part of the e.m. Spectrum

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Observing H I with the VLA

• The Very Large Array is an interferometer
• 30'' resolution
• Observations in C configuration
• Compact array gives increased sensitivity
• H I line allows velocity determination
• We know the radial velocity of the hydrogen gas
  we are seeing

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NGC 3264
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NGC 4288
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NGC 4861
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Conclusions

• rotation curves are fairly typical
• also have interesting differences
• further analysis should be possible

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Further Work

• Compare H I to optical image from WIYN
• Calculate dark matter distribution
• Compare with predictions of dark matter models

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Acknowledgments

• I would like to thank
• University of Wisconsin-Madison REU Program
• My advisor Dr. Eric Wilcots
• My research partner Stephanie Bush
• The scientists working in the department
• My fellow students

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This Experience
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Some Optical Images