196 citations · 696 across the 13 of their papers we have counts for
13 papers
Strong 21-cm fluctuations and anisotropy due to the line-of-sight effect of radio galaxies at cosmic dawn
Sudipta Sikder, Rennan Barkana, Anastasia Fialkov +1
The reported detection of the global 21-cm signal by the EDGES collaboration is significantly stronger than standard astrophysical predictions. One possible explanation is an early…
Emulation of the Cosmic Dawn 21-cm Power Spectrum and Classification of Excess Radio Models Using an Artificial Neural Network
Sudipta Sikder, Rennan Barkana, Itamar Reis +1
The cosmic 21-cm line of hydrogen is expected to be measured in detail by the next generation of radio telescopes. The enormous dataset from future 21-cm surveys will revolutionize…
Effect of the cosmological transition to metal-enriched star-formation on the hydrogen 21-cm signal
Mattis Magg, Itamar Reis, Anastasia Fialkov +6
Mapping Cosmic Dawn with 21-cm tomography offers an exciting new window into the era of primordial star formation. However, self-consistent implementation of both the process of st…
HERA Phase I Limits on the Cosmic 21-cm Signal: Constraints on Astrophysics and Cosmology During the Epoch of Reionization
The HERA Collaboration, Zara Abdurashidova, James E. Aguirre +81
Recently, the Hydrogen Epoch of Reionization Array (HERA) collaboration has produced the experiment's first upper limits on the power spectrum of 21-cm fluctuations at z~8 and 10.…
Shot noise and scatter in the star formation efficiency as a source of 21-cm fluctuations
Itamar Reis, Rennan Barkana, Anastasia Fialkov
The 21-cm signal from cosmic dawn and the epoch of reionization (EoR) probes the characteristics of the high redshift galaxy population. Many of the astrophysical properties of gal…
The subtlety of Ly-a photons: changing the expected range of the 21-cm signal
Itamar Reis, Anastasia Fialkov, Rennan Barkana
We present the evolution of the 21-cm signal from cosmic dawn and the epoch of reionization (EoR) in an upgraded model including three subtle effects of Ly-a radiation: Ly-a heatin…
Mapping discrete galaxies at cosmic dawn with 21-centimeter observations
Itamar Reis, Rennan Barkana, Anastasia Fialkov
At cosmic dawn, the 21-centimeter signal from intergalactic hydrogen was driven by Lyman- photons from some of the earliest stars, producing a spatial pattern that reflected the…
High-redshift radio galaxies: a potential new source of 21-cm fluctuations
Itamar Reis, Anastasia Fialkov, Rennan Barkana
Radio sources are expected to have formed at high redshifts, producing an excess radiation background above the cosmic microwave background (CMB) at low frequencies. Their effect o…
Effectively using unsupervised machine learning in next generation astronomical surveys
Itamar Reis, Michael Rotman, Dovi Poznanski +2
In recent years many works have shown that unsupervised Machine Learning (ML) can help detect unusual objects and uncover trends in large astronomical datasets, but a few challenge…
Probabilistic Random Forest: A machine learning algorithm for noisy datasets
Itamar Reis, Dalya Baron, Sahar Shahaf
Machine learning (ML) algorithms become increasingly important in the analysis of astronomical data. However, since most ML algorithms are not designed to take data uncertainties i…
Redshifted broad absorption line quasars found via machine-learned spectral similarity
Itamar Reis, Dovi Poznanski, Patrick B. Hall
We report the discovery of 31 new redshifted broad absorption line quasars (RSBALs) from the Sloan Digital Sky Survey (SDSS). The number of previously known such objects is 19. The…
Detecting outliers and learning complex structures with large spectroscopic surveys - a case study with APOGEE stars
Itamar Reis, Dovi Poznanski, Dalya Baron +2
In this work we apply and expand on a recently introduced outlier detection algorithm that is based on an unsupervised random forest. We use the algorithm to calculate a similarity…
Self-organized topological state in the magnetic chain on the surface of a superconductor
I. Reis, D. J. J. Marchand, M. Franz
Electronic states associated with a chain of magnetic adatoms on the surface of an ordinary s- wave superconductor have been shown theoretically to form a one dimensional topologic…