A5070618431- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Scientific Research and Discoveries
- Adaptive optics and wavefront sensing
- Radio Astronomy Observations and Technology
- Computational Physics and Python Applications
- Calibration and Measurement Techniques
- Stellar, planetary, and galactic studies
Heidelberg Institute for Theoretical Studies
2024
Heidelberg University
2024
Recent quasar absorption line observations suggest that reionization may end as late $z \approx 5.3$. As a means to search for large neutral hydrogen islands at $z<6$, we revisit long dark gaps in the Ly$\beta$ forest VLT/X-Shooter and Keck/ESI spectra. We stack Ly$\alpha$ corresponding both edges of these identify damping wing-like extended profile. The average redshift stacked is $z=5.8$. By comparing with simulations, infer such feature can be naturally explained if are least partially...
Context. Recent observations have positioned the end point of Epoch Reionization (EoR) at a redshift z ∼ 5.3. However, Lyman- α forest not yet been able to discern whether reionization occurred slowly and late, with substantial neutral hydrogen persisting ∼6, or rapidly earlier, apparent late driven by fluctuating ultraviolet background. Gunn-Peterson (GP) absorption troughs are solid indicators that is complete until = 5.3, but they contain significantly gas has proven. Aims. We aim answer...
ABSTRACT Cosmological simulations serve as invaluable tools for understanding the Universe. However, technical complexity and substantial computational resources required to generate such often limit their accessibility within broader research community. Notable exceptions exist, but most are not suited simultaneously studying physics of galaxy formation cosmic reionization during first billion years history. This is especially relevant now that a fleet advanced observatories (e.g. James...
The mean and the scatter of HI content a dark-matter halo as function mass are useful statistics that can be used to test models structure galaxy formation. We investigate possibility constraining this HI-halo relation (HIHMR) from intensity maps redshifted 21 cm line. In particular, we use geometry topology brightness-temperature isocontours in single frequency channel quantified by Minkowski functionals. First, generate mock large N-body simulation considering impact thermal noise...
Cosmological simulations serve as invaluable tools for understanding the Universe. However, technical complexity and substantial computational resources required to generate such often limit their accessibility within broader research community. Notable exceptions exist, but most are not suited simultaneously studying physics of galaxy formation cosmic reionization during first billion years history. This is especially relevant now that a fleet advanced observatories (e.g. James Webb Space...
Recent observations have positioned the endpoint of Epoch Reionisation (EoR) at redshift $z \sim 5.3$. However, Lyman-$\alpha$ forest not yet been able to discern whether reionisation occurred slowly and late, with substantial neutral hydrogen persisting $\sim 6$, or rapidly earlier, apparent late end driven by fluctuating UV background. Gunn-Peterson (GP) absorption troughs are solid indicators that is complete until $z=5.3$, but they contain significantly gas has proven. We aim answer this...
ABSTRACT Recent quasar absorption line observations suggest that reionization may end as late $z \approx 5.3$. As a means to search for large neutral hydrogen islands at $z\ \lt\ 6$, we revisit long dark gaps in the Ly $\beta$ forest Very Large Telescope/X-Shooter and Keck/Echellette Spectrograph Imager spectra. We stack $\alpha$ corresponding both edges of these identify damping wing-like extended profile. The average redshift stacked is $z=5.8$. By comparing with simulations, infer such...
We aim to construct a machine-learning approach that allows for pixel-by-pixel reconstruction of the intergalactic medium (IGM) density field various warm dark matter (WDM) models using Lyman-alpha forest. With this regression machinery, we constrain mass potential WDM particle from observed sightlines directly field. design and train Bayesian neural network on supervised task recovering optical depth-weighted $\Delta_\tau$ as well its uncertainty forest flux utilise Sherwood-Relics...