a novel approach to measure the dust attenuation law at z~1 · highest-sfr galaxies, which always...
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Construction of attenuation curves
To obtain the attenuation curve slope and the UV bump strength we fit a linear combination of the 2nd order polynomial and the Drude profile. The UV bump strength is defined as the amplitude of the Drude profile normalised by the polynomial value at 2175Å. We define the slope of the attenuation curve as the A(4500Å)/E(3000Å-4500Å).
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A novel approach to measure the dust attenuation law at z~1
Ivana Barisic MPIA, Heidelberg [email protected]
face-on
edge-on
slope
shall
owste
epshallower slope
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er s
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weaker bump
With deep, high-resolution optical spectra of z~1 galaxies from LEGA-C survey (van der Wel et al. 2016) we infer the intrinsic stellar spectrum. A comparison with photometry results in attenuation information. Here we present the initial results on the bump strength and slope of the attenuation curve as a function of various galaxy parameters with unprecedented precision for galaxies at large lookback time.
A3000Å
A4500Å
• High-mass galaxies have weaker UV bump strength than lower-mass galaxies (Left)
•High star formation rate galaxies and high-mass galaxies have shallow dust attenuation (Right)
shall
owste
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• Edge-on galaxies have shallow dust attenuation, with the exception of the highest-SFR galaxies, which always have shallow dust attenuation (Left)
Take-away message: the powerful combination of deep optical spectra and broad-band photometry allows us to constrain the relative importance of diffuse and star-forming region attenuation at z~1 as a function of a variety of galaxy properties.
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