Search Publications
Heavy metals in intermediate He-rich hot subdwarfs: the chemical composition of HZ 44 and HD 127493
Heber, U.; Latour, M.; Dorsch, M.
Context. Hot subluminous stars can be spectroscopically classified as subdwarf B (sdB) and O (sdO) stars. While the latter are predominantly hydrogen deficient, the former are mostly helium deficient. The atmospheres of most sdOs are almost devoid of hydrogen, whereas a small group of hot subdwarf stars of mixed H/He composition exists, showing ex…
Weak and Compact Radio Emission in Early High-mass Star-forming Regions. II. The Nature of the Radio Sources
Menten, K. M.; Molinari, S.; Wyrowski, F. +9 more
In this study we analyze 70 radio continuum sources that are associated with dust clumps and which are considered to be candidates for the earliest stages of high-mass star formation. The detection of these sources was reported by Rosero et al., who found most of them to show weak (< 1 mJy) and compact (< 0.″6) radio emission. Herein, we use…
The XMM-Newton serendipitous survey. VIII. The first XMM-Newton serendipitous source catalogue from overlapping observations
Motch, C.; Page, M. J.; Carrera, F. +13 more
Context. XMM-Newton has observed the X-ray sky since early 2000. The XMM-Newton Survey Science Centre Consortium has published catalogues of X-ray and ultraviolet sources found serendipitously in the individual observations. This series is now augmented by a catalogue dedicated to X-ray sources detected in spatially overlapping XMM-Newton observat…
A progenitor candidate for the type II-P supernova SN 2018aoq in NGC 4151
Gromadzki, M.; Smartt, S. J.; Kotak, R. +9 more
We present our findings based on pre- and post-explosion data of the type II-Plateau SN 2018aoq that exploded in NGC 4151. As distance estimates to NGC 4151 vary by an order of magnitude, we utilised the well-known correlation between ejecta velocity and plateau brightness, i.e. the standard candle method, to obtain a distance of 18.2 ± 1.2 Mpc, w…
Merger induced clump formation in distant infrared luminous starburst galaxies
Calabrò, Antonello; Daddi, Emanuele; Jin, Shuowen +6 more
While the formation of stellar clumps in distant galaxies is usually attributed to gravitational violent disk instabilities, we show here that major mergers also represent a competitive mechanism to form bright clumps. Using ∼0.1″ resolution ACS F814W images in the entire COSMOS field, we measured the fraction of clumpy emission in 109 main sequen…
Constraining Mass-transfer Histories of Blue Straggler Stars with COS Spectroscopy of White Dwarf Companions
Sills, Alison; Knigge, Christian; Mathieu, Robert D. +4 more
Recent studies show that the majority of blue straggler stars (BSSs) in old open clusters are formed through mass transfer from an evolved star onto a main-sequence companion, resulting in a BSS and white dwarf (WD) in a binary system. We present constraints on the mass transfer histories of two BSS-WD binaries in the open cluster NGC 188, using W…
Rotating Halo Traced by the K-giant Stars from LAMOST and Gaia
Tian, Hao; Xu, Yan; Liu, Chao +1 more
With the help of Gaia DR2, we are able to obtain the full 6D phase space information for stars from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope DR5. With high precision of the position, velocity, and metallicity, the rotation of the local stellar halo is presented using the K-giant stars with [Fe/H] < -1 dex within 4 kpc from …
L1495 revisited: a PPMAP view of a star-forming filament
Griffin, M. J.; Smith, M. W. L.; Marsh, K. A. +4 more
We have analysed the Herschel and SCUBA-2 dust continuum observations of the main filament in the Taurus L1495 star-forming region, using the Bayesian fitting procedure PPMAP. (i) If we construct an average profile along the whole length of the filament, it has FWHM ∼eq 0.087± 0.003 pc; but the closeness to previous estimates is coincidental. (ii)…
Ripple Patterns in In-plane Velocities of OB Stars from LAMOST and Gaia
Cheng, Xinlun; Mao, Shude; Liu, Chao +1 more
With about 12,000 OB type stars selected from the LAMOST and Gaia survey, we study their three-dimensional velocity distribution over the range of galactocentric radius from 6 to 15 kpc in the Galactic disk plane. A clear ripple pattern in the radial velocity (V R ) map is shown. The median V R reaches -8 km s-1…
Through thick or thin: multiple components of the magneto-ionic medium towards the nearby H II region Sharpless 2-27 revealed by Faraday tomography
Federrath, Christoph; Gaensler, B. M.; McClure-Griffiths, N. M. +12 more
Sharpless 2-27 (Sh2-27) is a nearby H II region excited by ζOph. We present observations of polarized radio emission from 300 to 480 MHz towards Sh2-27, made with the Parkes 64 m Radio Telescope as part of the Global Magneto-Ionic Medium Survey. These observations have an angular resolution of 1.35°, and the data are uniquely sensitive to magneto-…