Search Publications
The NGC 1614 interacting galaxy. Molecular gas feeding a "ring of fire"
Gallagher, J. S.; Aalto, S.; König, S. +2 more
Minor mergers frequently occur between giant and gas-rich low-mass galaxies and can provide significant amounts of interstellar matter to refuel star formation and power active galactic nuclei (AGN) in the giant systems. Major starbursts and/or AGN result when fresh gas is transported and compressed in the central regions of the giant galaxy. This…
How does star formation proceed in the circumnuclear starburst ring of NGC 6951?
Hunt, L. K.; Schinnerer, E.; Emsellem, E. +3 more
Gas inflowing along stellar bars is often stalled at the location of circumnuclear rings, which form an effective reservoir for massive star formation and thus shape the central regions of galaxies. However, how exactly star formation proceeds within these circumnuclear starburst rings is the subject of debate. Two main scenarios for this process …
The occulting galaxy pair UGC 3995. Dust properties from HST and CALIFA data
Holwerda, B. W.; Keel, W. C.
UGC 3995 is an interacting and occulting galaxy pair. UGC 3995B is a foreground face-on spiral and UGC 3995A a bright background spiral with an AGN. We present analysis of the dust in the disc of UGC 3995B based on archival Hubble Space Telescope (HST) WFPC2 and PPAK IFU data from the CALIFA survey's first data release. From the HST F606W image, w…
Modelling the asymmetric wind of the luminous blue variable binary MWC 314
Jorissen, A.; Frémat, Y.; Lobel, A. +12 more
Aims: We present a spectroscopic analysis of MWC 314, a luminous blue variable (LBV) candidate with an extended bipolar nebula. The detailed spectroscopic variability is investigated to determine if MWC 314 is a massive binary system with a supersonically accelerating wind or a low-mass B[e] star. We compare the spectrum and spectral energy d…
Planck intermediate results. II. Comparison of Sunyaev-Zeldovich measurements from Planck and from the Arcminute Microkelvin Imager for 11 galaxy clusters
Böhringer, H.; Kneissl, R.; Dahle, H. +204 more
A comparison is presented of Sunyaev-Zeldovich measurements for 11 galaxy clusters as obtained by Planck and by the ground-based interferometer, the Arcminute Microkelvin Imager. Assuming a universal spherically-symmetric Generalised Navarro, Frenk and White (GNFW) model for the cluster gas pressure profile, we jointly constrain the integrated Com…
CO rotational line emission from a dense knot in Cassiopeia A. Evidence for active post-reverse-shock chemistry
Rho, Jeonghee; Black, John H.; Berné, Olivier +6 more
We report a Herschel detection of high-J rotational CO lines from a dense knot in the supernova remnant Cas A. Based on a combined analysis of these rotational lines and previously observed ro-vibrational CO lines, we find the gas to be warm (two components at ~400 and 2000 K) and dense (106-7 cm-3), with a CO column density …
Fundamental parameters of bright Ap stars from wide-range energy distributions and advanced atmospheric models
Shulyak, D.; Ryabchikova, T.; Kochukhov, O.
Aims: As a well-established procedure for the vast majority of normal main-sequence stars, determination of atmospheric and stellar parameters turns to be a challenging process in case of magnetic chemically peculiar stars. Inhomogeneous distribution of chemical elements and strong magnetic fields make most of the standard photometric and spe…
X-ray source variability study of the M 31 central field using Chandra HRC-I
Della Valle, M.; Pietsch, W.; Haberl, F. +5 more
Context. The central field of the Andromeda galaxy (M 31) was monitored from 2006 to 2012 using the Chandra HRC-I detector (about 0.1-10 keV energy range) with the main aim of detecting X-rays from optical novae. We present a systematic analysis of all X-ray sources found in the 41 nova monitoring observations, along with 23 M 31 central field HRC…
X-ray activity cycle on the active ultra-fast rotator AB Doradus A?. Implication of correlated coronal and photometric variability
Schmitt, J. H. M. M.; Lalitha, S.
Context. Although chromospheric activity cycles have been studied in a larger number of late-type stars for quite some time, very little is known about coronal activity-cycles in other stars and their similarities or dissimilarities with the solar activity cycle.
Aims: While it is usually assumed that cyclic activity is present only in stars …
Observation of SN2011fe with INTEGRAL. I. Pre-maximum phase
Zhang, X.; Hernanz, M.; Jordi, C. +19 more
Context. SN2011fe was detected by the Palomar Transient Factory in M101 on August 24, 2011, a few hours after the explosion. From the early optical spectra it was immediately realized that it was a Type Ia supernova, thus making this event the brightest one discovered in the past twenty years.
Aims: The distance of the event offered the rare …