Related papers: Low-Frequency Carbon Recombination Lines in the Or…

The results of a submillimetre wavelength spectral line survey between 455.1 -- 507.4 GHz of the Orion-KL hot cloud core are reported. A total of 254 lines were detected to a main beam brightness temperature sensitivity ~ 1 - 3 K. The…

In galaxies, the flattening of the spectrum at low radio frequencies below 300 MHz has been the subject of some debate. A turnover at low frequencies could be caused by multiple physical processes, which can yield new insights into the…

We report the results obtained from a multi-wavelength study of the HII region, G18.148$-$0.283, using the upgraded Giant Metre-wave Radio Telescope (uGMRT) at 1350 MHz along with other archival data. In addition to the radio continuum…

Hydrogen recombination lines (HRLs) are valuable diagnostics of the physical conditions in ionized regions around high-mass stars. Understanding their broadening mechanisms and intensity trends can provide insights into the densities,…

We present the results of a wide-area mapping of the far-infrared continuum emission toward the Orion complex by using a Japanese balloon-borne telescope. The 155-um continuum emission was detected over a region of 1.5 deg^2 around the KL…

Carbon Radio Recombination Lines trace the interface between molecular and atomic gas. We present GMRT observations of Carbon Radio Recombination Lines (CRRL), C$\alpha$244-C$\alpha$250 towards Cassiopeia A. We use a novel technique of…

HII regions made of gas ionized by radiations from young massive stars, are widely distributed in the Milky Way. They are tracers for star formation, and their distributions are correlated with the Galactic spiral structure. Radio…

Absorption lines from the molecules OH+, H2O+, and H3+ have been observed in a diffuse molecular cloud along a line of sight near W51 IRS2. We present the first chemical analysis that combines the information provided by all three of these…

Diffuse radio recombination lines (RRLs) in the Galaxy are possible foregrounds for redshifted 21~cm experiments. We use EDGES drift scans centered at $-26.7^o$~declination to characterize diffuse RRLs across the southern sky. We find RRLs…

We present a near-IR survey for the visual multiples in the Orion molecular clouds region at separations between 100 and 1000 AU. These data were acquired at 1.6~$\mu$m with the NICMOS and WFC3 cameras on the Hubble Space Telescope.…

We report the first extragalactic detection of the higher-order millimeter hydrogen recombination lines ($\Delta n>2$). The $\gamma$-, $\epsilon$-, and $\eta$-transitions have been detected toward the millimeter continuum source N105-1A in…

The power mechanism and accretion geometry for low-power FR1 radio galaxies is poorly understood in comparison to Seyfert galaxies and QSOs. In this paper we use the diagnostic power of the Lya recombination line observed using the Cosmic…

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…

The OH molecule, found abundantly in the Milky Way, has four transitions at the ground state rotational level(J = 3/2) at cm wavelengths. These are E1 transitions between the F+ and F- hyperfine levels of the Lambda doublet of the J=3/2…

We have surveyed molecular line emission from Orion BN/KL from 42.3 to 43.6 GHz with the Green Bank Telescope. Sixty-seven lines were identified and ascribed to 13 different molecular species. The spectrum at 7 mm is dominated by SiO, SO2,…

We present highly sensitive measurements taken with MeerKAT at 1280 MHz as well as archival GBT, MWA and VLA images at 333, 88 and 74 MHz. We report the detection of synchrotron radio emission from the infrared dark cloud (IRDC) associated…

We report a 0.2" resolution, 15 GHz survey of a sample of 48 low-luminosity active galactic nuclei with the Very Large Array. Compact radio emission has been detected in 57% (17 of 30) of LINERs and low-luminosity Seyferts, at least 15 of…

Examination of emission lines in high-velocity resolution optical spectra of the Orion Nebula confirms that the velocity component on the red wing of the main ionization front emission line is due to backscattering in the Photon Dominated…

We critically analyze the Bell et al. findings on "anomalous" widths of high-order Hydrogen radio recombination lines in the Orion Nebula at 6 GHz. We review their method of modified frequency switching and show that the way this method is…

We conducted a Ka-band (26.1--35 GHz) line survey towards Orion KL using the TianMa 65-m Radio Telescope (TMRT). It is the first blind line survey in the Ka band, and achieves a sensitivity of mK level (1--3 mK at a spectral resolution of…