相关论文: A High Resolution Study of Carbon Radio Recombinat…
Quantitative understanding of the interstellar medium requires knowledge of its physical conditions. Low frequency carbon radio recombination lines (CRRLs) trace cold interstellar gas, and can be used to determine its physical conditions…
We use the Low Frequency Array to perform a systematic high spectral resolution investigation of the low-frequency 33-78 MHz spectrum along the line of sight to Cassiopeia A. We complement this with a 304-386 MHz Westerbork Synthesis Radio…
In this paper, we report the detection of a series of radio recombination lines (RRLs) in absorption near 26 MHz arising from the largest bound carbon atoms detected in space. These atoms, which are more than a million times larger than the…
Context. The combined use of carbon radio recombination lines (CRRLs) and the 158 $\mu$m-[CII] line is a powerful tool for the study of the energetics and physical conditions (e.g., temperature and density) of photodissociation regions…
Carbon Radio Recombination Lines (CRRLs) at decametre wavelengths trace the diffuse phase of the interstellar medium (ISM) of the Galaxy. Their observation allows to measure physical parameters of this phase. We observed CRRLs with the…
We present results from a search for radio recombination lines in three HI self-absorbing (HISA) clouds at 750 MHz and 321 MHz with the Robert C. Byrd Green Bank Telescope (GBT), and in three Galactic Plane positions at 327 MHz with the…
In earlier papers (Roshi & Anantharamaiah 2000, 2001a), we presented extensive surveys (angular resolution -- 2\deg $\times$ 2\deg & 2\deg $\times$ 6\arcmin) of radio recombination lines (RRLs) near 327 MHz in the longitude range $l = $…
We present a study of carbon radio recombination lines towards Cassiopeia A using LOFAR observations in the frequency range 10-33 MHz. Individual carbon $\alpha$ lines are detected in absorption against the continuum at frequencies as low…
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 (RRLs) along the line-of-sight to this source. Five carbon-alpha…
A survey of radio recombination lines (RLs) in the Galactic plane ($l = $ 332\deg $\to$ 89\deg) near 327 MHz made using the Ooty Radio Telescope (ORT) has detected carbon RLs from all the positions in the longitude range 0\deg $< l < $…
We present the first detection of carbon radio recombination line absorption along the line of sight to Cygnus A. The observations were carried out with the LOw Frequency ARray in the 33 to 57 MHz range. These low frequency radio…
We present a study of hydrogen, helium, and carbon millimeter-wave radio-recombination lines (RRLs) toward ten representative positions throughout the Orion Nebula complex, using the Yebes 40m telescope in the Q band (31.3 GHz to 50.6 GHz)…
We model Carbon Recombination Line (CRL) emission from the Photo Dissociation Region (PDR) surrounding the Ultra-Compact (UC) HII region W48A. Our modelling shows that the inner regions ($A_V \sim 1$) of the CII layer in the PDR contribute…
A significant fraction of the molecular gas in star-forming regions is irradiated by stellar UV photons. In these environments, the electron density (n_e) plays a critical role in the gas dynamics, chemistry, and collisional excitation of…
We have mapped the [C I] emission at 492 GHz toward the supernova remnant Cas A. We detect [C I] emission from the periphery of the diffuse Photon Dominated Region (PDR) covering the disk of Cas A, as traced by the carbon recombination…
We present results of a search for carbon recombination lines in the Galaxy at 34.5 MHz (C$575\alpha$) made using the dipole array at Gauribidanur near Bangalore. Observations made towards 32 directions, led to detections of lines in…
We report here on a survey of carbon recombination lines (RLs) near 8.5 GHz toward 17 ultra-compact \HII regions (\UCHII s). Carbon RLs are detected in 11 directions, indicating the presence of dense photodissociation regions (PDRs)…
We present a Radio Recombination Line (RRL) survey of the Galactic Plane from the HI Parkes All-sky Survey and associated Zone of Avoidance survey, which mapped the region l=196degr -- 0degr --52degr and |b| < 5degr at 1.4 GHz and 14.4…
Understanding the transition from atomic gas to molecular gas is critical to explain the formation and evolution of molecular clouds. However, the gas phases involved, cold HI and CO-dark molecular gas, are challenging to directly observe…
Recombination lines involving high principal quantum numbers populate the radio spectrum in large numbers. Low-frequency (<1 GHz) observations of radio recombination lines (RRLs) primarily from carbon and hydrogen offer a new, if not…