Related papers: Study of Interstellar Molecular Clouds using Forma…
Revealing the 3D dynamics of HII regions and their associated molecular clouds is important for understanding the longstanding problem as to how stellar feedback affects the density structure and kinematics of the interstellar medium. We…
The outer Galaxy presents an optimal setting for investigating molecular clouds and star formation in environments with low metallicity. A total of 72 Galactic edge clouds were surveyed using the CO\,(2--1) line with the IRAM\,30\,m…
This paper reports dual-epoch, Very Long Baseline Array observations of H I absorption toward 3C 147. One of these epochs (2005) represents new observations while one (1998) represents the reprocessing of previous observations to obtain…
High-Velocity Clouds (HVCs) have radial velocities that cannot be explained by the global Galactic rotation; their distances remain mostly unknown, and their true nature and origin are still a mystery. Some of them could be of galactic…
We explore the possibility of detecting the excess of the cosmic radio background (CRB) toward galaxy clusters due to its Compton scattering by electrons of the hot intergalactic gas. When mapping the background fluctuations at frequencies…
High spectral resolution ISO-LWS observations of the [OI] 63.2 and 145.5 microns and [CII] 157.7 microns fine structure lines are presented for the center of the Sagittarius B2 complex (SgrB2). Both the [OI] 63.2 microns and the [CII] 157.7…
Spectral features absorbed against some radio quasars exhibit ~50mJy variations, with the lines varying both relative to the continuum and, when several lines are present, even relative to one another. We point out that such variability can…
A 12 year-long monitoring of the absorption caused by a z=0.89 spiral galaxy on the line of sight to the radio-loud gravitationally lensed quasar PKS 1830-211 reveals spectacular changes in the HCO+ and HCN (2-1) line profiles. The depth of…
Significant progress has been made over the last few years to explore the gaseous halo of the Milky Way by way of absorption spectroscopy. I review recent results on absorption line studies in the halo using various instruments, such as the…
We present CARMA observations in 3.3 mm continuum and several molecular lines of the surroundings of N14, N22, and N74, three infrared bubbles from the GLIMPSE catalog. We have discovered 28 compact continuum sources and confirmed their…
ALMA HCO+ observations of the infrared dark cloud G0.253+0.016 located in the Central Molecular Zone of the Galaxy are presented. The 89 GHz emission is area-filling, optically thick, and sub-thermally excited. Two types of filaments are…
In the time domain, the radio sky in particular along the Galactic plane direction may vary significantly because of various energetic activities associated with stars, stellar and supermassive black holes. Using multi-epoch Very Large…
We performed high-sensitivity mapping observations of several complex organic molecules around Sagittarius B2 with ARO 12m telescope at 3-mm wavelength. Based on their spatial distribution, molecules can be classified as either "extended"…
Nearby interstellar clouds with high (|v| >/= 10 km/s) random velocities although easily detected in NaI and CaII lines have hitherto not been detected (in emission or absorption) in the HI 21cm line. We describe here deep Giant Metrewave…
We report on one of the highest sensitivity surveys for molecular lines in the frequency range 6.0 to 7.4 GHz conducted to date. The observations were done with the 305m Arecibo Telescope toward a sample of twelve intermediate/high-mass…
Within the last 10 years, strong, narrow Na I absorption has appeared at v_sun ~ -38 km/s toward the halo star HD 219188; that absorption has continued to strengthen, by a factor 2-3, over the past three years. The line of sight appears to…
We describe a moderate-resolution FUSE mini-survey of H2 in the Milky Way and Magellanic Clouds, using four hot stars and four AGN as background sources. FUSE spectra of nearly every stellar and extragalactic source exhibit numerous…
We have observed 6 clouds along the line-of-sight toward W49A using the Submillimeter Wave Astronomy Satellite (SWAS) and several ground-based observatories. The ortho-H2O 1-0 and OH (1665 and 1667 MHz) transitions are observed in…
Context. Recent studies of the optical depth comparing [12CII] and [13CII] line profiles in Galactic star-forming regions revealed strong self-absorption in [12CII] by low excitation foreground material, implying a large column density of…
To provide constraints on the chemical processes responsible for the observed columns of organic species, we used NOEMA to observe the sight line toward NRAO150 in the 2mm spectral window. We targeted the low excitation lines of o-H2CO…