On the enhancement of the Ly equivalent width by a multiphase - - PowerPoint PPT Presentation
On the enhancement of the Ly equivalent width by a multiphase interstellar medium or: debunking the Neufeld scenario Peter Laursen With Florent Duval & Gran stlin (OKC) Dark Cosmology Centre | Niels Bohr Institutet | Kbenhavns
www.dark-cosmology.dk/~pela
– or: debunking the Neufeld scenario
Dark Cosmology Centre | Niels Bohr Institutet | Københavns Universitet
Peter Laursen With Florent Duval & Göran Östlin (OKC)
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Lyman α emitting galaxies (LAEs) are important probes of the high-redshift Universe:
These are statistical properties. Individual observations are hampered by insufficient knowledge about radiative transfer
looking at the equivalent width of Lyα.
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Equivalent width:
“But… but…”, say Kudritzki et al. (2000), Malhotra & Rhoads (2002), Rhoads et al. (2003), Dawson et al. (2004), Hu et al. (2004), Shimasaku et al. (2006), Ouchi et al. (2008), Nilsson et al. (2009), Kashikawa et al. (2011), etc.
Boost:
“Max 240 Å!”, say Charlot & Fall (1993), and Schaerer (2003). “Clumpiness!”, say Chapman et al. (2005), Finkelstein et al. (2007, 2008, 2009a,b,c, 2011a,b), Dayal et al. (2008, 2009, 2010, 2011), Niino et al. (2009), Yuma et al. (2010), Kobayashi et al. (2010), Blanc et al. (2011), Nakajima et al. (2012), etc.
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Gas density and temperature Dust density and cross-section
T = 104 K, NHI = 1019 cm-2, E(B–V) = 0.1
Neufeld (1990)
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Neufeld (1991); Hansen & Oh (2006)
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Enter Hansen & Oh (2006)
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(Laursen et al. 2009)
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3 1 cm-3 Z 0 km s-1 0 km s-1 0 cm-3 Central 104 K; 106 K 100 pc “Fiducial” model:
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(on at a time)
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(varying in unison)
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(each dot is the result of a model)
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Average spectrum of boost-yielding (extreme) models — not realistic (too narrow)
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(even in a homogeneous medium, without dust, a “boost” can be measured)
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