Observations of the high-redshift Universe with the 21cm hyperfine line of neutral hydrogen
promise to open an entirely new window onto the early phases of cosmic structure formation …

Abstract We present a Radio Recombination Line (RRL) survey of the Galactic plane from
the H i Parkes All-sky Survey and associated Zone of Avoidance survey, which mapped the …

In the first paper of this series, we study the level population problem of recombining carbon
ions. We focus our study on high quantum numbers, anticipating observations of carbon …

In the second paper of the series, we have modeled low-frequency carbon radio
recombination lines (CRRLs) from the interstellar medium. Anticipating the Low Frequency …

Diffuse radio recombination lines (RRLs) in the Galaxy are possible foregrounds for
redshifted 21 cm experiments. We use EDGES drift scans centered at− 26 fdg 7 decl. to …

ABSTRACT H ii regions are the ionized spheres surrounding high-mass stars. They are
ideal targets for tracing Galactic structure because they are predominantly found in spiral …

Quantitative understanding of the interstellar medium requires knowledge of its physical
conditions. Low-frequency carbon radio recombination lines (CRRLs) trace cold interstellar …

Cassiopeia A was observed using the low-band antennas of the LOw Frequency ARray
(LOFAR) with high spectral resolution. This allowed a search for radio recombination lines …

Context. The Herschel HIFI GOT C+ Galactic plane [C ii] spectral survey has detected strong
emission at the spiral arm tangencies. Aims. We use the unique viewing geometry of the …

Abstract Using Green Bank Telescope radio recombination line (RRL) data, we analyze the
role of leaking radiation from H ii regions in maintaining the ionization of the interstellar …