Related papers: An Expanding Neutral Hydrogen Supershell Evacuated…
We use a new, improved version of the HI Parkes All-Sky Survey to search for HI emission from nine new, ultra-faint Milky Way satellite galaxy candidates recently discovered in data from the Dark Energy Survey. None of the candidates is…
We present a multiwavelength study of star formation within the nearby M101 Group, including new deep H$\alpha$ imaging of M101 and its two companions. We perform a statistical analysis of the H$\alpha$ to FUV flux ratios in HII regions…
Based on an ultra deep (230 ks) ROSAT HRI imaging of M101, we have detected 5 X-ray sources that coincide spatially with optical emission line features previously classified as supernova remnants in this nearby galaxy. Two of these…
We present a new face-on map of dense neutral atomic hydrogen (HI) gas in the outer Galaxy. Our map has been produced from the Leiden/Argentine/Bonn (LAB) HI 21-cm line all-sky survey by finding intensity maxima along every line of sight…
We combine several surveys at different wavelengths with intermediate-band $ uvby\beta$ photometry to examine the correlation between the location of the OB-stars in the Centaurus star-forming field and the neutral and ionized material in…
Hypervelocity stars have been recently discovered in the outskirts of galaxies, such as the unbound star in the Milky Way halo, or the three anomalously fast intracluster planetary nebulae (ICPNe) in the Virgo Cluster. These may have been…
Superbubbles are crucial for stellar feedback, with supposedly high (of the order of 10 per cent) thermalization rates. We combined multiband radio continuum observations from the Very Large Array (VLA) with Effelsberg data to study the…
The Type Ib/c supernova SN 2001em was observed to have strong radio, X-ray, and Halpha emission at an age of about 2.5 yr. Although the radio and X-ray emission have been attributed to an off-axis gamma-ray burst, we model the emission as…
Hydrogen-poor superluminous supernovae (SLSN-I) are a class of rare and energetic explosions discovered in untargeted transient surveys in the past decade. The progenitor stars and the physical mechanism behind their large radiated energies…
We present optical observations of supernova SN 2014C, which underwent an unprecedented slow metamorphosis from H-poor type Ib to H-rich type IIn over the course of one year. The observed spectroscopic evolution is consistent with the…
We mapped the ultra-high-velocity feature (the "Bullet") detected in the expanding molecular shell associated with the W44 supernova remnant using the Nobeyama Radio Observatory 45-m telescope and the ASTE 10-m telescope. The Bullet clearly…
We present deep, narrowband imaging of the nearby spiral galaxy M101 and its group environment to search for star-forming dwarf galaxies and outlying HII regions. Using the Burrell Schmidt telescope, we target the brightest emission lines…
Two mysterious unresolved HI structures at velocities of +12 and -6 km/s were discovered in high resolution 21-cm survey data in the direction of a faint white dwarf star. Examination of the HI morphology in this area of sky shows that the…
As a major interstellar medium, the atomic neutral hydrogen (HI) plays an important role in the galaxy evolution. It provides the ingredient for star formation, and sensitively traces the internal processes and external perturbations…
We present Herschel/HIFI observations (WISH KP) of 14 water lines in a small sample of galactic massive protostellar objects: NGC6334I(N), DR21(OH), IRAS16272-4837, and IRAS05358+3543. We analyze the gas dynamics from the line profiles.…
The young, compact, very high surface brightness but low excitation planetary nebula (PN) BD+303639 is one of the very few PNe that have been reported to exhibit the 21cm HI emission line. As part of a long-term programme to search for…
Roughly ten per cent of OB stars are kicked out of their natal clusters before ending their life as supernovae. These so-called runaway stars can travel hundreds of parsecs into the low-density interstellar medium, where momentum and energy…
In the hierarchical structure formation scenario, galaxies enlarge through multiple merging events with less massive galaxies. In addition, the Magorrian relation indicates that almost all galaxies are occupied by a central supermassive…
We have obtained resolved stellar photometry from Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) observations of a field in the outer disk of M81 as part of the ACS Nearby Galaxy Survey Treasury (ANGST). Motivated by the…
We present new J=1-0 12-CO observations along the northern spiral arm of the grand-design spiral galaxy M100 (NGC 4321), and study the distribution of molecular hydrogen as derived from these observations, comparing the new data with a set…