Star Formation Efficiency in the Barred Spiral Galaxy NGC 4303
Abstract
We present new ^(12)CO (J = 1 – 0) observations of the barred galaxy NGC 4303 using the Nobeyama 45 m telescope (NRO45) and the Combined Array for Research in Millimeter-wave Astronomy (CARMA). The Hα images of barred spiral galaxies often show active star formation in spiral arms, but less so in bars. We quantify the difference by measuring star formation rate (SFR) and star formation efficiency (SFE) at a scale where local star formation is spatially resolved. Our CO map covers the central 2.'3 region of the galaxy; the combination of NRO45 and CARMA provides a high fidelity image, enabling accurate measurements of molecular gas surface density. We find that SFR and SFE are twice as high in the spiral arms as in the bar. We discuss this difference in the context of the Kennicutt-Schmidt (KS) law, which indicates a constant SFR at a given gas surface density. The KS law breaks down at our native resolution (~250 pc), and substantial smoothing (to 500 pc) is necessary to reproduce the KS law, although with greater scatter.
Additional Information
© 2010 American Astronomical Society. Received 2010 March 28; accepted 2010 July 22; published 2010 August 27. We are very grateful to Yasutaka Kurono for helping us to combine our data, Takeshi Okuda for data analysis and discussions, Norio Ikeda for the three-dimensional FITS viewer package "FAZZ," and Jennifer Donovan Meyer and James Barrett for helpful comments on the English. We thank the NRO staff for NRO45 observations, the CARMA staff and CARMA summer school 2008 participants for CARMA observations and lectures, and helpful experience. This work made use of the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with the NASA, and the NASA/IPAC Extragalactic Database (NED). Support for CARMA construction was derived from the Gordon and Betty Moore Foundation, the Eileen and Kenneth Norris Foundation, the Caltech Associates, the states of California, Illinois, and Maryland, and the National Science Foundation. Ongoing CARMA development and operations are supported by the National Science Foundation under a cooperative agreement and by the CARMA partner universities. This research was partially supported by HST-AR-11261.01.Attached Files
Published - Momose2010p11584Astrophys_J.pdf
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Additional details
- Eprint ID
- 20558
- Resolver ID
- CaltechAUTHORS:20101027-094527032
- HST-AR-11261.01
- Hubble Space Telescope (HST)
- Created
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2010-10-27Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field