Presentation Title

Constraining the Star Formation Rate in the SMC through a Rate-limiting Timescale Parameterization

Faculty Mentor

Barry Madore

Start Date

23-11-2019 10:45 AM

End Date

23-11-2019 11:30 AM

Location

238

Session

poster 4

Type of Presentation

Poster

Subject Area

physical_mathematical_sciences

Abstract

The Schmidt Law describes a power law relationship between the gas density and the rate of star formation in a galaxy. We present an approach to this relationship which invokes two rate-limiting timescales corresponding to the stellar lifetime and the cloud collapse time. We probe the nearby Small Magellanic Cloud using publicly available MCPS photometry, ATCA neutral hydrogen maps, and Herschel-derived molecular hydrogen maps, obtaining a population of massive main sequence (MS) stars and a map of the total gas density. While the MS lifetime ts is well determined by stellar evolution models, the cloud collapse timescale tc is poorly constrained. We can determine the ratio of the two timescales by correlating the relative areal frequencies of regions with and without stars in regions of similar gas densities. We can then derive an absolute timescale by knowing the longest main sequence lifetime in the stellar sample. Our preliminary results indicate a normalized timescale to gas column density (N) dependence of (tc+ts)/ts = 10-12.1N + 4.2 for 0.05c+ts)/ts = 10-2.5N + 1.4 for 0.3

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Nov 23rd, 10:45 AM Nov 23rd, 11:30 AM

Constraining the Star Formation Rate in the SMC through a Rate-limiting Timescale Parameterization

238

The Schmidt Law describes a power law relationship between the gas density and the rate of star formation in a galaxy. We present an approach to this relationship which invokes two rate-limiting timescales corresponding to the stellar lifetime and the cloud collapse time. We probe the nearby Small Magellanic Cloud using publicly available MCPS photometry, ATCA neutral hydrogen maps, and Herschel-derived molecular hydrogen maps, obtaining a population of massive main sequence (MS) stars and a map of the total gas density. While the MS lifetime ts is well determined by stellar evolution models, the cloud collapse timescale tc is poorly constrained. We can determine the ratio of the two timescales by correlating the relative areal frequencies of regions with and without stars in regions of similar gas densities. We can then derive an absolute timescale by knowing the longest main sequence lifetime in the stellar sample. Our preliminary results indicate a normalized timescale to gas column density (N) dependence of (tc+ts)/ts = 10-12.1N + 4.2 for 0.05c+ts)/ts = 10-2.5N + 1.4 for 0.3