5 papers
Low-Frequency Recombination Lines from Galaxies and AGN over Cosmic Time
Kimberly L. Emig, Sergei Balashev, Francoise Combes +10
Radio recombination lines (RRLs) at low frequencies (<10 GHz) can provide a multi-phase view of interstellar gas in nearby galaxies, absorption-line-systems, and AGN. Hydrogen RRLs…
Tracing Cold Gas in Absorption Across Cosmic Time with the SKA
Elizabeth K. Mahony, Neeraj Gupta, Sergei A. Balashev +12
Observing the 21-cm HI line in absorption provides a powerful means of tracing the cold neutral gas in normal and active galaxies across cosmic time. The frequency coverage and sen…
H I Properties of Field Galaxies at -0.6: Insights into Declining Cosmic Star Formation
David DePalma, Neeraj Gupta, Hsiao-Wen Chen +18
We report statistically significant detection of H I 21-cm emission from intermediate-redshift (-0.6) galaxies. By leveraging multi-sightline galaxy survey data from t…
New constraints on the values of the fundamental constants at a look-back time of 7.3 Gyr
Renzhi Su, Stephen J. Curran, Francoise Combes +4
The study of redshifted spectral lines can provide a measure of the fundamental constants over large look-back times. Current grand unified theories predict an evolution in these c…
Quasar radiation transforms the gas in a merging companion galaxy
Sergei Balashev, Pasquier Noterdaeme, Neeraj Gupta +7
Quasars, powered by gas accretion onto supermassive black holes, rank among the most energetic objects of the Universe. While they are thought to be ignited by galaxy mergers and a…