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تسجيل مستخدم جديدScaling Relations of Star-Forming Regions: from kpc-size clumps to HII regions
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We present the properties of 8 star-forming regions, or clumps, in 3 galaxies at z~1.3 from the WiggleZ Dark Energy Survey, which are resolved with the OSIRIS integral field spectrograph. Within turbulent discs, sigma~90 km/s, clumps are measured with average sizes of 1.5 kpc and average Jeans masses of 4.2 x 10^9 Msolar, in total accounting for 20-30 per cent of the stellar mass of the discs. These findings lend observational support to models that predict larger clumps will form as a result of higher disc velocity dispersions driven-up by cosmological gas accretion. As a consequence of the changes in global environment, it may be predicted that star-forming regions at high redshift should not resemble star-forming regions locally. Yet despite the increased sizes and dispersions, clumps and HII regions are found to follow tight scaling relations over the range z=0-2 for size, velocity dispersion, luminosity, and mass when comparing >2000 HII regions locally and 30 clumps at z>1 (sigma propto r^{0.42+/-0.03}, L(Halpha) propto r^{2.72+/-0.04}, L(Halpha) propto sigma^{4.18+/-0.21}, and L(Halpha) propto M_{Jeans}^{1.24+/-0.05}). We discuss these results in the context of the existing simulations of clump formation and evolution, with an emphasis on the processes that drive-up the turbulent motions in the interstellar medium. Our results indicate that while the turbulence of discs may have important implications for the size and luminosity of regions which form within them, the same processes govern their formation from high redshift to the current epoch.
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We investigate star forming scaling relations using Bayesian inference on a comprehensive data sample of low- (z<0.1) and high-redshift (1<z<5) star forming regions. This full data set spans a wide range of host galaxy stellar mass ($M_{*} sim10^6-10
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The determination of accurate distances to star-forming regions are discussed in the broader historical context of astronomical distance measurements. We summarize recent results for regions within 1 kpc and present perspectives for the near and more distance future.
Context. The derived physical parameters for young HII regions are normally determined assuming the emission region to be optically thin. However, this assumption is unlikely to hold for young HII regions such as hyper-compact HII(HCHII) and ultra-co
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