Related papers: Head-tail molecular clouds falling onto the Milky …
The Milky Way is surrounded by a hot diffuse circumgalactic medium (CGM) with temperatures of millions of degrees. Recent X-ray observations with the eROSITA satellite discovered a significant temperature asymmetry of this hot CGM, with the…
We present a wide-field $(60\arcmin \times 30\arcmin)$ study of a dense region within the Polaris Flare, hereafter referred to as the `Polaris molecular cloud', using $^{12}$CO, $^{13}$CO, and C$^{18}$O ($J=1-0$) observations at $20\arcsec$…
We report the discovery of very high latitude molecular gas in the edge-on spiral galaxy, NGC 5775. Emission from both the J=1-0 and 2-1 lines of 12CO is detected up to 4.8 kpc away from the mid-plane of the galaxy. NGC 5775 is known to…
We report the first detection of a hot molecular core outside our Galaxy based on radio observations with ALMA toward a high-mass young stellar object (YSO) in a nearby low metallicity galaxy, the Large Magellanic Cloud (LMC). Molecular…
Recent observations in the 21cm line with the Green Bank Telescope have changed our view of the neutral interstellar medium (ISM) in several ways. The new data show that in the inner parts of the Milky Way the disk-halo interface is…
The morphology of molecular clouds is crucial for understanding their origin and evolution. In this work, we investigate the morphology of the filamentary molecular clouds (filaments for short) using a portion of the $^{12}\text{CO}…
We present the results of a high angular resolution, multi-transition analysis of the molecular gas in M82. The analysis is based on the two lowest transitions of 12CO and the ground transition of the rare isotopes 13CO and C18O measured…
We present J=2-1, J=3-2, J=4-3 12CO maps as well as J=2-1, J=3-2 13CO and 492 GHz [CI] measurements of the central region in M51. The distribution of CO is strongly concentrated towards the spiral arms. The center itself is poor in, though…
We observed a 10x20 pc region of the molecular cloud M17 in the 12CO and 13CO J=3-2 and J=2-1 transitions to determine their global behavior and to assess the reliability of using ratios of CO line intensities integrated over an entire…
Understanding mass, size, and surface mass density of giant molecular clouds (GMCs) in galaxies is key to insights into star formation processes. We analyze these in M33 using Herschel dust and archival IRAM 30m telescope data, compared to…
(Abridged) Axisymmetric models of the Milky Way exhibit strong interrelations between the Galactic constants (R_0 and T_0), the stellar columndensity (S_*) and the shape of the dark matter (DM) halo. Here we present analytical relations…
We have detected over 400 HI clouds in the lower halo of the Galaxy within the pilot region of the Galactic All-Sky Survey (GASS), a region of the fourth quadrant that spans 18 degrees in longitude, 40 degrees in latitude and is centered on…
The Large Magellanic Cloud is the most massive satellite galaxy of the Milky Way, with an estimated mass exceeding a tenth of the mass of the Milky Way. Just past its closest approach of about 50 kpc, and flying by the Milky Way at an…
Neither HI nor CO emission can reveal a significant quantity of so-called dark gas in the interstellar medium (ISM). It is considered that CO-dark molecular gas (DMG), the molecular gas with no or weak CO emission, dominates dark gas. We…
The Milky Way is acquiring gas from infalling high-velocity clouds. The material enters a disk-halo interface that in many places is populated with HI clouds that have been ejected from the disk through processes linked to star formation.…
The Magellanic Stream (MS) is a nearby laboratory for studying the fate of cool gas streams injected into a gaseous galactic halo. We investigate properties of the boundary layer between the cool MS gas and the hot Milky Way halo with 21 cm…
Molecular hydrogen (H$_2$) is by far the most abundant molecule in the Universe. However, due to the low emissivity of H$_2$, carbon monoxide (CO) is widely used instead to trace molecular gas in galaxies. The relative abundances of these…
We use spectroscopic data from HST and FUSE to study the wide range of ionization states of the "highly ionized high-velocity clouds". Studied extensively in OVI absorption, these clouds are usually assumed to be infalling gas in the…
We present results on gas flows in the halo of a Milky Way-like galaxy at z=0.413 based on high-resolution spectroscopy of a background galaxy. This is the first study of circumgalactic gas at high spectral resolution towards an extended…
Relating the observed CO emission from giant molecular clouds (GMCs) to the underlying H2 column density is a long-standing problem in astrophysics. While the Galactic CO-H2 conversion factor (Xco) appears to be reasonably constant,…