Low-redshift IGM measured to be extremely hot (T0 ≈ 28,000 K) and nearly isothermal at z=0.1, with Gamma_HI lower than UV-background models, possibly due to 15 km/s turbulence.
Luminosity function from dedicated SDSS-III and MMT data of quasars in 0.7<z < 4.0 selected with a new approach
4 Pith papers cite this work, alongside 102 external citations. Polarity classification is still indexing.
abstract
We present a measurement of the quasar luminosity function in the range 0.68<z<4 down to extinction corrected magnitude g_dered=22.5, using a simple and well understood target selection technique based on the time-variability of quasars. The completeness of our sample was derived directly from a control sample of quasars, without requiring complex simulations of quasar light-curves or colors. A total of 1877 quasar spectra were obtained from dedicated programs on the Sloan telescope (as part of the SDSS-III/BOSS survey) and on the Multiple Mirror Telescope. They allowed us to derive the quasar luminosity function. It agrees well with previously published results in the redshift range 0.68<z<2.6. Our deeper data allow us to extend the measurement to z=4. We measured quasar densities to g_dered<22.5, obtaining 30 QSO per deg^2 at z<1, 99 QSO per deg^2 for 1<z<2.15, and 47 QSO per deg^2 at z>2.15. Using pure luminosity evolution models, we fitted our LF measurements, and predicted quasar number counts as a function of redshift and observed magnitude. These predictions are useful inputs for future cosmology surveys such as those relying on the observation of quasars to measure baryon acoustic oscillations.
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Fisher forecasts indicate that Lyα-21cm cross-spectra with PUMA and CMB data can improve constraints on neutrino self-interaction strength G_eff by 1-2 orders of magnitude over CMB alone.
Forecasts show DESI-like and SKA1-Mid observations could constrain primordial magnetic field amplitude and spectral index to roughly 10% precision via 21cm auto-spectrum and Lyα-21cm cross-spectrum.
DESI will target luminous red galaxies to z=1, emission-line galaxies to z=1.7, quasars for tracers and Ly-alpha forest at 2.1<z<3.5, plus a bright galaxy survey, to obtain more than 30 million redshifts for BAO and matter power spectrum measurements.
citing papers explorer
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A Measurement of the Thermal and Ionization State of the IGM at $z < 0.5$
Low-redshift IGM measured to be extremely hot (T0 ≈ 28,000 K) and nearly isothermal at z=0.1, with Gamma_HI lower than UV-background models, possibly due to 15 km/s turbulence.
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Neutrino self-interactions in post-reionization era: Lyman-$\alpha$, 21-cm and cross-spectra
Fisher forecasts indicate that Lyα-21cm cross-spectra with PUMA and CMB data can improve constraints on neutrino self-interaction strength G_eff by 1-2 orders of magnitude over CMB alone.
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Primordial magnetic fields in the light of upcoming post-EoR Lyman-$\alpha$ and 21-cm observations
Forecasts show DESI-like and SKA1-Mid observations could constrain primordial magnetic field amplitude and spectral index to roughly 10% precision via 21cm auto-spectrum and Lyα-21cm cross-spectrum.
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The DESI Experiment Part I: Science,Targeting, and Survey Design
DESI will target luminous red galaxies to z=1, emission-line galaxies to z=1.7, quasars for tracers and Ly-alpha forest at 2.1<z<3.5, plus a bright galaxy survey, to obtain more than 30 million redshifts for BAO and matter power spectrum measurements.