Related papers: HI ``Tails'' from Cometary Globules in IC1396

We present numerical radiation-hydrodynamic simulations of the evolution of HII regions formed in an inhomogeneous medium resulting from turbulence simulations. We find that the filamentary structure of the underlying density distribution…

We report the discovery of three proplyd-like structures in the giant HII region NGC 3603. The emission nebulae are clearly resolved in narrow-band and broad-band HST/WFPC2 observations in the optical and broad-band VLT/ISAAC observations…

Our view of the high velocity cloud (HVC) system is changing dramatically with new observations from the Far Ultraviolet Spectroscopic Explorer mission and the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. In…

The structure of the high galactic latitude Cometary Globule 12 (CG 12) has been investigated by means of radio molecular line observations. Detailed, high signal to noise ratio maps in C18O (1-0), C18O (2-1) and molecules tracing high…

We have recently identified several high velocity (V < -100 km/s) clouds in the directions of Mrk 509 and PKS 2155-304 that have unusual ionization properties. The clouds exhibit strong C IV absorption with little or no detectable low ion…

We present narrow-band near-infrared images of a sample of 11 Galactic planetary nebulae (PNe) obtained in the molecular hydrogen (H$_{2}$) 2.122 $\mu$m and Br$\gamma$ 2.166 $\mu$m emission lines and the $K_{\rm c}$ 2.218 $\mu$m continuum.…

We present new observational results on high-velocity clouds (HVCs) based on an analysis of the Leiden/Dwingeloo HI survey. We cataloged all HVCs with NHI > 1 10^19 cm^-2 and found 252 clouds that form a representative flux limited sample.…

Cometary ultracompact HII regions have been modelled as the interaction of the hypersonic wind from a moving star with the molecular cloud which surrounds the star. We here show that a similar morphology can ensue even if the star is…

We report observations of ionized and warm molecular gas in the extended regions of the central galaxies in several cooling flow clusters. These show that both gas phases are present in these clusters to large radii. We trace both Pa alpha…

CRL 618 is an object that exhibits characteristics of both AGB and post-AGB star. It also displays a spectacular array of bipolar lobes with a dense equatorial region, which makes it an excellent object to study the development of…

Context: The past decade has witnessed a large number of Galactic plane surveys at angular resolutions below 20". However, no comparable high-resolution survey exists at long radio wavelengths around 21cm in line and continuum emission.…

Photodissociation regions (PDRs), where the (far-)ultraviolet light from hot young stars interact with the gas in surrounding molecular clouds, provide laboratories for understanding the nature and role of feedback by star formation on the…

We present VLA 21-cm observations of the spiral galaxy ESO 481-G017 to determine the nature of remote star formation traced by an HII region found 43 kpc and ~800 km s^-1 from the galaxy center (in projection). ESO 481-G017 is found to have…

High-resolution (0."03 - 0."09) (9 - 26 pc)) ALMA (100 - 350 GHz (3 - 0.8 mm)) and VLA 45 GHz measurements have been used to image continuum and spectral line emission from the inner region of the nearby infrared luminous galaxy IC 860. We…

The HII region IC 1848 harbors a lot of intricate elephant trunk-like structures that look morphologically different from usual bright-rimmed clouds (BRCs). Of particular interest is a concentration of thin and long elephant trunk-like…

We present deep Halpha+[NII], [SII] (6716,6731A) and [OII] (3726,3729A) images of the highly inclined, actively star--forming SBm galaxy NGC 55, located in the nearby Sculptor Group. Due to its proximity, NGC 55 provides a unique…

We have recently used the Hubble Space Telescope to study a pair of high velocity clouds in the direction of Mrk 509 that have unusual ionization properties. They exhibit strong CIV absorption with little or no low ion absorption or HI 21cm…

The Green Bank Telescope HII Region Discovery Survey has doubled the number of known HII regions in the Galactic zone 343deg.\leql\leq67deg. with |b|\leq1deg. We detected 603 discrete hydrogen radio recombination line (RRL) components at…

This work presents the magnetic field geometry in a complex of three cometary (with head-tail morphology) globules, namely LDN 323, LDN 328, and LDN 331, using R-band polarization measurements of background stars. These observations were…

Based on MUSE data from the GASP survey, we study the Halpha-emitting extraplanar tails of 16 cluster galaxies at z~0.05 undergoing ram pressure stripping. We demonstrate that the dominating ionization mechanism of this gas (between 64% and…